FLOORING WORK - 1



FLOORING WORK

14.1. Brick flooring

14.1.1. SPECIFICATIONS FOR BRICK ON EDGE FLOORING

Bricks - Bricks of Specified dimensions and designations shall be used. These shall conform to the specifications described in Section 6 of KBS.  Broken bricks shall not be used in flooring except for closing the line. The bricks shall be laid on edge.

14.1.1.2. Mortar - The mortar used shall be as specified (in case of dry bricks flooring fine sand shall be filled in the joints).

14.1.1.3. Base concrete

Flooring shall be laid on base concrete where so provided.  The base concrete shall be provided with the slope required for the flooring.  Floors in verandah, courtyard kitchens, and baths shall have slope ranging from 1 in 36 to 1 in 48 depending upon locations as decided by the engineer.  Floors in water closet portion shall have slope of 1 in 30 or as decided by the engineer to drain off washing water. Plinth masonry off-set shall be depressed so as to allow the base concrete to rest on it. If the base consists of lime concrete, it shall be allowed to set for seven days and the flooring shall be laid in the next three days. If the base is of lean cement concrete, the flooring shall commence within 48 hours of the laying of base, failing which, the surface of base shall be roughened with steel wire brushes without disturbing the concrete. Before laying the flooring the base shall be wetted and smeared with a coat of cement slurry at 2 kg of cement spread over an area of one sqm so as to get a good bond between sub grade and flooring.

Where base concrete is not provided, the earth flow shall be properly sloped, watered, rammed and consolidated. Before laying the flooring, it shall be moistened.

14.1.1.4. Soaking of bricks - Bricks required for flooring shall be adequately soaked in stacks before use, by profusely spraying with clean water at regular intervals for a period of not less than six hours as to keep them wet to the satisfaction of the engineer.  (In case the joints are to be filled with sand, the bricks need not be soaked).

14.1.1.5. Laying

The bricks shall be laid on the edge in plain, diagonal herring bone bond or other pattern as specified or directed by the engineer.

Bricks shall be laid on edge on 12 mm thick mortar bed and each brick shall be properly bedded and set home by gentle tapping and trowel handle or wooden mallet. Its inside face shall be buttered with mortar, before the next brick is laid and pressed against it.

On completion of a portion of flooring, the vertical joints shall be fully filled from the top with mortar. The surface of the flooring during lying, shall be frequently checked with a straight edge at least 2 m long, so as to obtain a true plain surface with the required slope.

14.1.1.6. Joints - Bricks shall be so laid that all joints are full of mortar. The thickness of joints shall not exceed 1.0 cm for brick work with bricks of any class designation. All face joints shall be raked to a minimum depth of 15 mm by raking tool during the progress of work when the mortar is still green so as to provide proper key for the plaster or pointing to be done. Where plastering or pointing is not required to be done, the joints shall be struck flush and finished at the time of laying. The face of brick work shall be cleaned on the same day on which brick work is laid and all mortar droppings removed promptly.

14.1.1.7. Curing - Brick work shall be protected from rain by suitable covering when the mortar is green. Masonry work in cement mortar, composite lime mortar, lime mortar shall be kept constantly moist on all faces for a minimum period of seven days. Brick work carried out during the day shall be suitably marked indicating the date on which the work is done so as to keep a watch on the curing period. In case of masonry with fat lime mortar, curing shall commence two days after lying of masonry and shall continue for at least seven days thereafter.

14.1.1.8. Measurements - Length and breadth shall be measured correct to a cm and area as laid shall be calculated in square meters correct to two places of decimal. Length and breadth shall be measured before laying skirting, dado or wall plaster. No deduction shall be made nor extra paid for voids not exceeding 0.20 sqm. Deduction for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 sqm.

Brick flooring when laid in diagonal herring bone bond or other pattern as specified or directed by the engineer shall be measured separately.

14.1.1.9. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above, including application of cement slurry on base concrete of RCC slab and cleaning of base. Base concrete shall be paid for separately.

14.1.2. SPECIFICATIONS FOR DRY BRICK FLOORING

All provisions in 14.1.1 to 14.1.8 will be applicable subject to following modifications. Bricks need not be soaked. Bricks will be laid on a bed of 12 mm thick mud mortar laid to required slope. The joints shall be as fine as possible and not exceeding 5 mm which will be filled with fine sand. No curing is to be done.

14.1.2.1. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

14.2. SPECIFICATIONS FOR CEMENT CONCRETE FLOORING

14.2.1. Cement concrete - Cement concrete of specified mix shall be used and it shall generally conform to the specifications described in Section 4.

14.2.2. Base concrete

Flooring shall be laid on base concrete where so provided. The base concrete shall be provided with the slopes required for the flooring. Flooring in verandah courtyard kitchens & baths shall have slope ranging from 1 48 to 1 60 depending upon location and as decided by the engineer.  Floors in water closet portion shall have slope of 130 or as decided by the engineer to drain off washing water. Plinth masonry off set shall be depressed so as to allow the base concrete to rest on it. If the base consists of lime concrete, it shall be allowed to set for seven days and the flooring shall be laid within the next three days.

If the base is of lean cement concrete, the flooring shall be commenced preferably within 48 hours of the laying of base concrete. The surface of the base shall be roughened with steel wire brushes without disturbing the concrete. Immediately before laying the flooring, the base shall be wetted and a coat of cement slurry at 2 kg of cement spread over an area of one sqm so as to get a good bond between the base and concrete floor.

If the cement concrete flooring is to be laid directly on the RCC slab, the top surface of RCC slab shall be cleaned and the laitance shall be removed and a coat of cement slurry at 2 kg of cement spread over an area of one sqm so as to get a good bond between the base and concrete floor.

14.2.3. Thickness - The thickness of floor shall be as specified in the description of the item.

14.2.4. Laying

14.2.4.1. Panels - Flooring of specified thickness shall be laid in the pattern including the border/ or as given in the drawings or as directed by the engineer.  The border panels shall not exceed 450 mm in width and the joints in the border in line with panel joints.  The panels shall be of uniform size and no dimension of a panel shall exceed 2 m and the area of a panel shall not be more than 2 sqm.

14.2.4.2. Laying of flooring with strips - Normally cement concrete flooring shall be laid in one operation using glass / plain asbestos / aluminium/ PVC / brass strips or any other strips as required as per drawing or instructions of the engineer, at the junction of two panels. This method ensures uniformly in colour of all the panels and straightness at the junctions of the panels. 4 mm thick glass strips or 5 mm thick plain asbestos sheet, 2 mm PVC strips or 2 mm aluminium or brass strips, shall be fixed with their tops at proper level, giving required slopes.  Cost of providing and fixing strips shall be paid for separately.

Concreting - Cement concrete shall be placed in the panels and be leveled with the help of straight edge and trowel.  The blows shall be fairly heavy in the beginning but as consolidation takes place, light rapid strokes shall be given.  Beating shall cease as soon as the surface is found covered with a thin layer of cream of mortar.  The evenness of the surface shall be tested with straight edge and made true to required slopes.  While laying concrete, care shall be taken to see that the strips are not damaged/disturbed by the labourers.  The tops of strips shall be visible clearly after finishing with cement slurry.

14.2.4.3. Laying of flooring without strips

Laying of cement concrete flooring in alternate panels may be allowed by the engineer in case strips are not to be provided.

14.2.4.3.2. Shuttering - The panels shall be bounded by angle iron or flats. The angle iron/flat shall have the same depth as the concrete flooring. These shall be fixed in position, with their top at proper level giving required slopes.  The surface of the angle iron or flats, to come in contact with concrete shall be smeared with soap solution or non-sticking oil (Form oil or raw linseed oil) before concreting.  The flooring shall butt against the unplastered masonry wall.

14.2.4.3.3. Concreting - The concreting shall be done in the manner as described.  The angle iron / flats used for shuttering shall be removed on the next day of the laying of cement concrete. The ends thus exposed shall be repaired, if damaged with cement mortar 1:2 and allowed to set for minimum period of 24 hours. The alternate panels shall then be cleaned of dust, mortar, droppings etc and concrete laid.  While laying concrete, care shall be taken to see that the edges of the previously laid panels are not damaged and fresh mortar is not splashed over them.  The joints between the panels should come out as fine straight lines.

14.2.5. Finishing

The finishing of the surface shall follow immediately after the cessation of beating.  The surface shall be left for some time, till moisture disappears from it or surplus water can be mopped up.  Use of dry cement or cement and sand mixture sprinkled on the surface to stiffen the concrete or absorb excessive moisture shall not be permitted. Excessive trowelling shall be avoided.

Fresh cement shall be mixed with water to form thick slurry and spread at the rate of 2 kg of cement over an area of one sqm of flooring while the flooring concrete is still green.  The cement slurry shall then be properly processed and finished smooth.

The edges of sunk floors shall be finished and rounded with cement mortar 1:2 (1 cement: 2 coarse sand) and finished with a floating coat of neat cement.

The junctions of floor with wall plaster, dado or skirting shall be rounded off where so specified.

The men engaged on finishing operations shall be provided with raised wooden platform to sit on so as to prevent damage to new work.

14.2.6. Curing - The curing shall be done for a minimum period of ten days. Curing shall not be commenced until the top layer has hardened.  Covering with empty gunnies shall be avoided as the colour of the flooring is likely to be bleached due to the remnants of cement dust from the bags.

14.2.7. Precautions - Flooring in lavatories and bath room shall be laid only after fixing of water closet and squatting pans and floor traps.  Traps shall be plugged while laying the floors and opened after the floors are cured and cleaned.  Any damage done to W.C.’s squatting pans and floor traps during the execution of work shall be made good.  During cold weather, concreting shall not be done when the temperature falls below 4 degree C. The concrete placed shall be protected against frost by suitable covering. Concrete damaged by frost shall be removed and work redone.  During hot weather, precautions shall be taken to see that the temperature of wet concrete does not exceed 38 degree C.  No concreting shall be laid within half an hour of the closing time of the day, unless permitted by the engineer.  To facilitate rounding of junction of skirting, dado and floor, the skirting / dado shall be laid along with the border or adjacent panels of floor.

14.2.8. Measurement - Length and breadth shall be measured before laying skirting dado or wall plaster. No deduction shall be made nor extra paid for voids not exceeding 0.20 sqm.  Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 sqm.

The flooring done either with strips (in one operation) or without strips (in alternate panels) shall be treated as same and measured together.

14.2.9. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above including application of cement slurry on RCC slab or on base concrete including roughening and cleaning the surface but excluding the cost of strips which shall be paid separately under relevant item.  Nosing of steps where provided shall be paid for separately in running meter.  Nothing extra shall be paid for laying the floor at different levels in the same room or courtyard and rounding off edges of sunken floors. In case the flooring is laid in alternate panels, nothing extra shall be paid towards the cost of shuttering used for this purpose.

14.3. SPECIFICATIONS FOR CEMENT CONCRETE FLOORING WITH TOPPING OF RED OXIDE OF IRON

14.3.1. Cement concrete - Cement concrete of specified mix shall be used and it shall generally conform to the specification described in Section 4 of KBS.

14.3.2. Base concrete - It shall be as specified in 14.2.2

14.3.3. Under layer

The under layer of flooring shall be of cement concrete of specified thickness. The mix shall be 1:2:4 (1 cement: 2 coarse sand:  4 graded stone aggregate 12.5 mm nominal size) by volume otherwise described in the item.  As regards laying, the work shall be carried out in the manner as specified except that

(a) Angle or flat iron used for shuttering shall be to the height of both the under and top layers of the floor. (b)The under layer shall not be left smooth but roughened with 2 mm deep diagonal lines at 7.5 cm centres both ways with a scratching tool to form a key for the finishing coat of red oxide of iron.  No cement slurry be added to the concrete surface, and (c) The angle or flat shall be removed only 24 hours after the top layer has been laid.  The surface of under layer shall be left even and true to slope.

14.3.4. Top layer

This shall consist of uniform and smooth layer of plaster of 10 mm minimum thickness unless otherwise specified and of mix 1:3 (1 cement: 3 coarse sand) unless otherwise specified, finished with a floating coat of neat cement. In both plaster and floating coat the ratio of cement to red oxide of iron specified in the description of item shall be adopted.  Normally 3.5 kg of red oxide of approved quality to 50 kg of cement shall be mixed. This ratio may, however, be adjusted to the tinge ordered by the engineer. The red oxide shall be dry mixed thoroughly with the cement and then sand added and mixed. The full quantity of dry mortar required for a room shall be prepared in one lot In order to ensure uniform colour. Wet mortar shall be prepared in the usual manner as and when required.

14.3.4.2. Laying - The top layer shall be laid, the following day after the under layer has been laid.  The plaster shall be done to a uniform thickness of 10 mm and finished smooth with cement slurry (2.0 kg of cement, red oxide mix per square meter of flooring mixed in the ratio used) for the plaster.  The surface shall then be brought to a fine polish by use of polishing stones.

The angle or flats used for shuttering of panels shall be removed the next day, after the laying of the top layer and broken edges repaired with the same coloured mortar as in plaster.

The under layers of the alternate panels and the coloured plaster on top shall then be laid as described above. In laying such alternate panels care shall be taken that concrete and coloured mortar droppings do not disfigure the coloured topping previously finished.

The junction of floor with wall plaster, dado or skirting shall be rounded off nearly where so required, up to 25 mm radius.  Men engaged on the finishing operations shall be provided with raised wooden platforms to sit on, so as to prevent damage to new work.

14.3.5. Thickness - The thickness of the under layer panels shall be as specified in the description of the item and shall be measured correct to 1 cm.  The thickness of the top layer shall not be less than that specified.

14.3.6. Curing - The curing shall be done for a minimum period of ten days. Curing shall not be commenced until the top layer has hardened. Covering with empty cement gunnies shall be avoided as the colour is likely to be bleached with the remnants of cement matter from the bags.

14.3.7. Precautions - These shall be as specified in 14.2.7.

14.3.8. Measurements - These shall be as specified14.2.8.

14.3.9. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above including application of cement slurry on base concrete including roughening and cleaning the surface of base concrete. The base concrete shall be paid for separately.  Strips and nosing of steps where provided shall be paid for separately in running meter.

Where the quantity of red oxide used is different from what is described in the item to get the tinge required by the engineer.  The difference in quantity shall be subject to corresponding adjustment in the rate for the item.

14.4. SPECIFICATIONS FOR CEMENT CONCRETE FLOORING WITH METALLIC HARDENER TOPPING

14.4.0. Wherever floors are required to withstand heavy wear and tear, use of floor hardener shall be avoided as far as possible by using richer mixes of concrete, unless the use of a metallic hardener is justified on the basis of cost. Where metallic hardener topping is used, it shall be 12 mm thick.

14.4.1. Metallic hardening compound - The compound shall be of approved quality consisting of uniformly graded iron particles, free from non-ferrous metal particles, oil, grease sand, soluble alkaline compounds. Where so directed by the engineer, it shall be tested as described in Appendix 14-A.1.

14.4.2. Base concrete - It shall be as specified 14.2.2

14.4.3. Under layer - Cement concrete flooring of specified thickness and mix shall be laid as under layer (14.3.1 and 14.3.3).  The top surface shall be roughened with brushes while the concrete is still green and the forms shall be kept projecting up 12 mm over the concrete surface, to receive the metallic hardening compound topping.

14.4.4. Topping - This shall consist of 12 mm thick layer of mix 1:2 (1 cement  2 stone aggregate 6 mm nominal size) by volume or as otherwise specified with which metallic hardening compound is mixed in the ratio of 1:4 (1 metallic concrete hardener  4 cement) by weight. Metallic hardener shall be dry mixed thoroughly with cement on a clean dry pucca platform.  This dry mixture shall be mixed with stone aggregate 6 mm nominal size or as otherwise specified in the ratio of 1:2 (1 cement:  2 stone aggregate) by volume, and well turned over.  Just enough water shall then be added to this dry as required for floor concrete.

The mixture so obtained shall be laid in 12 mm thickness, on cement concrete floor within 2 or 4 hours of its laying.  The topping shall be laid true to provide a uniform and even surface.  It shall be firmly pressed into the bottom concrete so as to have good bond with it.  After the initial set has started, the surface shall be finished smooth and true to slope with steel floats.

The junction of floor with wall plaster, dado or skirting and finishing operations shall be dealt with as described in 14.2.4.

The men engaged on finishing operations shall be provided with raised wooden platform to sit on, so as to prevent damage to new work.

14.4.5. Measurements and rates - The specifications for curing, precautions to be taken, ‘Measurements’ and ‘Rates’ shall be as specified in 14.2

14.5. SPECIFICATIONS FOR CEMENT PLASTER IN RISERS OF STEPS, SKIRTING, DADO

14.5.0. A band of plaster at the bottom of wall not exceeding 30 cm in height above the floor shall be classified as skirting. It shall be flush with wall plaster or projecting out uniformly by 6 mm from the wall plaster, as specified.  The work shall be preferably carried out simultaneously with the laying of floor.  Its corners and junctions with floor shall be finished neatly as specified.

14.5.1. Thickness - The thickness of the plaster specified shall be measured exclusive of the thickness of key i.e., grooves or open joints in brick work.  The average thickness shall not be less than the specified thickness. The average thickness should be regulated at the time of plastering by keeping suitable thickness of the gauges.  Extra thickness required in rounding of corners at junctions of wall shall be ignored.

14.5.2. Preparation of wall surface - The joints shall be raked out to a depth of at least 15 mm in masonry walls.  In case of concrete walls, the surfaces shall be roughened by hacking.  The surface shall be cleaned thoroughly, washed with water and kept wet before skirting is commenced.

14.5.3. Application - Skirting with specified mortar and to specified thickness shall be laid immediately after the surface is prepared.  It shall be laid along with the border or adjacent panels of floor. The joints in skirting shall be kept true and straight in continuation of the line of joints in borders or adjacent panels. The skirting shall be finished smooth and true, with top truly horizontal and joints truly vertical except where otherwise indicated.

14.5.4. Finishing - The finishing of surface shall be done simultaneously with the borders of the adjacent panels of floor.  The cement to be applied in the form of slurry for smooth finishing shall be at the rate of 2 kg of cement per litre of water applied over an area of 1 sqm.

Where skirting is flush with plaster, a groove 10 mm wide and up to 5 mm deep shall be provided in plaster at the junction of skirting with plaster.

14.5.5. Curing - Curing shall be commenced on the next day of plastering when the plaster has hardened sufficiently and shall be continued for a minimum period of 7 days.

14.5.6. Measurement - Length and height shall be measured correct to a cm and its area shall be calculated in sqm correct to two places of decimals stating the thickness. Length shall be measured as the finished length of skirting.  Height shall be measured from the finished level of floor correct to 5 mm.

14.5.7. Rate - Rate shall include the cost of all materials and labour involved in all the operations described above.

14.6. SPECIFICATIONS FOR CEMENT PLASTER SKIRTING FINISHED WITH RED OXIDE OF IRON

14.6.1. Under coat - The under coat of skirting shall be of cement plaster of the thickness and mix described in the item. Specifications as given shall apply. As regards application, the work shall be carried out in the manner as described except that the under coat shall be finished rough with a scratching tool to form a key for the top coat.

14.6.2. Top coat

14.6.2.1. Mortar - This shall consist of uniform and smooth layer of plaster of specified thickness and of mix 1:3 (1 cement:  3 coarse sand) unless otherwise specified, finished with a floating coat of neat cement. In both plaster and floating coat the ratio specified in the description of item shall be adopted. Normally 3.5 kg of red oxide of approved quality to 50 kg of cement shall be mixed.  This ratio may, however, be adjusted to the tinge ordered by the engineer.  The red oxide shall be mixed with the cement and then sand added and mixed.  The full quantity of dry mortar required for a room shall be prepared in one lot in order to ensure uniform colour.  Wet mortar shall be prepared in the usual manner as and when required.

14.6.2.2. Application - The top coat shall be done the next day after the under coat has been applied. 

The plaster shall be done with the thickness specified and finished smooth, by application of cement – rod oxide mix, at the rate of 1.0 kg. per square metre of surface. The ratio adopted for the mix being the same as that of the plaster. When the surface has hardened sufficiently it shall be brought to a fine polish by use of polishing stones.

14.6.3. Thickness - The thickness of the bottom and top coats shall be as specified. The total thickness of skirting specified is of total thickness of plaster as measured from the un-plastered face of the masonry.  Average thickness of the under coat shall not be less than 6 mm and minimum thickness over any portion of the surface shall not be less than 4 mm. The thickness of top coat shall not be less than the thickness specified.

14.6.4. Curing - Curing shall be commenced on the next day of plastering when the plaster has hardened sufficiently and shall be continued for a minimum period of 7 days.

14.6.5. Measurements -Length and height shall be measured correct to a cm and its area shall be calculated in sqm correct to two places of decimal stating the thickness. Length shall be measured as the finished length of skirting.  Height shall be measured from the finished level of floor correct to 5 mm.

14.6.6. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

Where the quantity of red oxide used is different from what is described in the item to get the tinge required by the engineer, the difference in quantity used will be subject to corresponding adjustment in the rate for the item.

14.7. SPECIFICATIONS FOR CEMENT CONCRETE PAVEMENT IN COURT YARD AND TERRACE ETC.

14.7.1. Specifications as described under 14.2.1, 14.2.2, 14.2.3, 14.2.4, 14.2.6., 14.7 shall hold good as far as applicable except that

i) The panels shall be of uniform size and no dimension of a panel shall exceed 1.25 m and the area of panel should not exceed 1.25 sqm for the thickness of panels up to 50 mm.

ii) Concreting shall be done in alternate panels only and no glass / asbestos strips shall be provided.

14.7.2. Finishing - The finishing of the surface shall follow immediately after the cessation of beating.  The surface shall be left for some time, till moisture disappears from it or surplus water can be mopped up.

Use of dry cement or cement and sand mix sprinkled on the surface to stiffen the concrete or to absorb excessive moisture shall not be permitted. Excessive trowelling shall be avoided. When the surface becomes fairly stiff, it shall be finished rough with wooden floats or where so specified chequered uniformly by pressing a piece of expanded metal of approved size.

14.7.3. Measurements - Same as 14.2.8 except that the volume will be calculated in cum nearest to two decimal places.

14.7.4. Rate -  The rate shall include the cost of all materials and labour involved in all the operations described above except the base concrete below flooring which shall be paid for separately. Chequering to pattern shall be paid for separately unless otherwise specified.

14.8. SPECIFICATIONS FOR TERRAZO (MARBLE CHIPS) FLOORING LAID IN-SITU .

14.8.0. Materials

a) Aggregates used in terrazzo topping shall be marble aggregates with size varying from 1 mm to 25 mm.  Marble powder used in terrazzo topping shall pass through IS sieve 300.  Aggregate for terrazzo under layer as well as the base concrete shall confirm to IS: 383-1970.

b) Cement – Cement shall confirm to IS: 269-1989, or IS: 455-1989, IS: 1489(part 1 and 2)-1991, or any other cement as specified.

c) White Cement- It shall confirm to IS: 8042-1989.

d) Pigments – The pigments shall be of permanent colour and shall conform to the requirements mentioned in Table 1.

e) Water – Water for use in terrazzo work shall be as specified.

f) Dividing strips – The material for dividing strips shall be such that it has similar resistance to wear as the flooring.  The dividing strips may be of aluminium, brass, copper, and glass, plastic or similar materials.  Aluminium dividing strips should have protective coating of bitumen.  The thickness of strip shall not be less than 1.5 mm and width not less than 25 mm for flooring.

14.8.1. General construction - The terrazzo finish normally consists of the topping and an under layer and is laid over a layer of base concrete or cushioning layer.  The arrangement of terrazzo finish laid directly over the ground shall be as various layers shown in Fig. 1 and when laid on structural slab, the arrangement shall be as shown in Fig. 2. The sub-base shall be well consolidated layer of earth is preferably sand.  The cushioning layer shall preferably be lime concrete.  The base concrete shall be lean cement concrete of 1510 mix or lime concrete.

Fig 1 Terrazzo finish over ground                         

Fig 2 Terrazzo finish on structural slab

The thickness of base concrete shall be not less than 100 mm and of cushioning layer not less than 75 mm.  The combined thickness of under layer and topping for flooring and dado/skirting shall not be less than 30 mm and 20 mm respectively.  The thickness of terrazzo topping shall be not less than the following depending upon the size of chips used.

Size of chips (mm)

Minimum thickness (mm)

1 to 2

2 to 4

6

4 to 7

9

7 to 10

12

Where chips of larger size than 10 mm are used, the minimum thickness of topping shall be not less than one and one-third times the maximum size of chips.

14.8.1.3. Mix proportions

a) The under layer shall be of cement concrete mix 12 4 by volume, the maximum size of aggregate shall not exceed 10 mm.

b) The mix for terrazzo topping shall consist of cement with or without pigments, marble powder, marble aggregates and water.  The proportions of cement and marble powder shall be three parts of cement and one part of powder by mass. For every part of cement marble powder mix, the proportion of aggregates shall be as follows depending on the size of aggregates

Size of aggregates parts (mm)

Proportion of aggregate of binder mix

1 to 7

One and three-fourths

7 to 15

15 to 22

One and one-half

The aggregates may be of required colour or may be a mix of aggregates of different colours in the required proportions.  The proportions of cement shall be inclusive of any pigments added to cement. 

The proportions in which pigments are mixed with cement or white cement to obtain different colours for the binder shall be as specified in Table 1.

14.8.1.4. Size of panels

  1. While laying the floor the joints in flooring shall always coincide with the expansion joints, if any, in the structural slab so that any movement of the base will be in the joint in the flooring instead of forming uncontrolled cracks.
  2. Differential shrinkage or expansion between terrazzo and the sub-floor may cause cracks in the flooring and floor joints shall be formed to that the positions of such cracks are controlled. The floor both while laying the under layer and later on the topping shall be divided into panels not exceeding 2 m2 so as to reduce the risk of cracking. The joints shall be so located that the longer dimension of any panel does not exceed 2 m. The panel shall preferably be separated by means of dividing strips.  However where butt joints are provided, the bays shall be laid alternately allowing for an interval for at least 24 h between the laying of adjacent bays.

Table 1   Cement pigment proportion for various colours of matrix in terrazzo work

Colour of cement

Pigment to be used

Proportion of pigment

Proportion of cement

Proportion of white

Red

Red oxide of iron

(see IS: 44-1991)

1

15-20

Nil

Black

Carbon black

(see IS:40-1971)

1

25-40

Nil

Bottle

Green

Green Chromium oxide(see IS: 54-1988)

1

15-30

Nil

Pink

Red oxide(see OS 44 " 1070)

1

Nil

100-300

Cream

Yellow oxide of iron (see IS: 44-1991)

1

Nil

100-400

Yellow

Yellow oxide of iron (see IS: 44-1991)

1

Nil

25-75

Light Green

Green chromium oxide (see IS: 54-1988)

1

Nil

50-150

French Grey

--

Nil

1 to 2

1

Fawn

Yellow oxide of iron (see IS 44 : 1991)

1

6

4

14.8.2. Preparatory work

14.8.2.1. Mixing of materials

  1. Mixing of materials is of great importance, for if this is not done thoroughly the work will not have a uniform appearance.  If done manually the mixing shall preferably be done in a trough or a tub.  With a view to avoid variation in colour the complete quantities of cement and pigment required for one operation shall be mixed at the beginning of work and stored properly.
  2. Where different coloured chips are used, they shall be first well mixed in required proportions of various colours and sizes.
  1. Coloured cement may be procured as ready mixed material or mixed at site; in the latter case the pigment and cement in the required proportions shall be mixed thoroughly and sieved before further mixing with marble powder and aggregates.
  2. The coloured cement shall be thoroughly mixed in dry state with marble powder. The binder so obtained and the mix of chips shall then be mixed dry together as given.
  3. While mixing the aggregates, care shall be taken not to get the materials into a heap, as this would result in the coarsest chips falling to the edge of the heap and cement working to the centre at the bottom.  The material shall be kept, as far as possible, in an even layer during mixing.
  4. After the materials have been thoroughly mixed in the dry state, water shall be added in small quantities, preferably in a fine spray, while the materials are being mixed until the proper consistency is obtained. The mixture shall be plastic but not so wet that it will flow; a rough indication for the addition of proper quantity of water in the mix is that it shall be capable of being moulded when squeezed in hard without water flowing out. A high water cement ratio will produce a mixture with a high dry shrinkage.
  5. Machine mixing may preferably be used but the common type of concrete mixer is not as suitable for terrazzo work as the mixer specially made for this purpose, in which segregation is prevented by blades with a lifting as well as rotating movement.  Only constant work justifies the installation of such special machines.
  6. The mix shall be used in the work within half an hour of the addition of water during preparation.

14.8.3. Under layer - Cement concrete of specified mix shall be used and the specifications as given shall apply.  The panels shall be of uniform size, not exceeding 2 sqm in area or 2 m in length for inside situations.  In exposed situations, the length of any side of the panel shall not be more than 1.25 meter.  Cement slurry at 2.00 kg per sqm shall be applied before laying of under layer over the cement concrete / RCC base.

14.8.4. Fixing of strips - 4 mm thick glass strips or 5 mm thick plain asbestos sheet or 2 mm thick PVC strips / aluminium strips /brass strips unless otherwise specified shall be fixed with their top at proper level to required slope.  Strips of stone or marble or of any other material of specified thickness can also be used if specifically required.  The fixing and laying shall be as specified.

14.8.5. Top layer

14.8.5.1. Mortar - The mix for terrazzo topping shall consist of cement with or without pigment, marble powder, marble aggregate (marble chips) and water.  The cement and marble powder shall be mixed in the proportion of three parts of cement to one part marble powder by weight.  For every part of cement marble powder mix, the proportion of aggregate by volume shall be as shown in Table 2 below The marble chips shall be white or pink Makran, black Bhainslana, Chittoor Black, Jaisalmer Yellow, Baroda green, Dehradun White, Chittoor Pink, yellow Patam Cherala (Madras), Grey Gadu (Surat), Chittoor Green and yellow and Alwar black or as specified. It shall be hard, sound, dense and homogeneous in texture with crystalline and coarse grains.  It shall be uniform in colour and free from stains, cracks, decay and weathering. The maximum thickness of the top layer for various size of marble aggregates (marble chips) shall be as shown in Table 2 below;

Table 2

Grade

No

Size of aggregates

In (mm)

Proportion of aggregates to binder mix

Minimum thickness of top layer (mm)

00

1-2

1.75:1

6

0

2-4

1.75:1

9

1

4-7

1.25:1

9

2

7-10

1.5:1

12

Where aggregate of size larger than 10 mm are used, the minimum thickness of topping shall not be less than 1-1/2 times the maximum size of the chips.  Where large size chips such as 20 mm or 25 mm are used, they shall be used only with a flat shape and bedded on the flat face so as to keep the minimum thickness of wearing layer.

Before starting the work, the contractor shall get the sample of marble chips approved by the engineer.  The cement to be used shall be ordinary grey cement, white cement, coloured cement with admixture of colouring matter of approved quality in the ratio specified in the description of the item in the ratio to get the required shade as ordered by the engineer. Colouring materials where specified shall be mixed dry thoroughly with the cement and marble powder and then marble chips added and mixed as specified above. The full quantity of dry mixture shall be stored in a dry place and well covered and protected from moisture.  The dry mortar shall be mixed with water in the usual way as and when required. The mixed mortar shall be homogeneous and stiff and to contain just sufficient water to make it workable.

The terrazzo topping shall be laid while the under layer is still plastic, but has hardened sufficiently to prevent cement from rising to the surface.  This is normally achieved between 18 to 24 hours after the under layer has been laid.  A cement slurry preferably of the same colour as the topping shall be brushed on the surface immediately before laying is commenced.  It shall be laid to a uniform thickness slightly more than that specified in order to get the specified finished thickness after rubbing.  The surface of the top layer shall be trowelled over, pressed and brought true to required level by a straight edge and steel floats in such a manner that the maximum amount of marble chips come up and are spread uniformly over the surface.

14.8.6. Polishing, curing and finishing - Polishing shall be done by machine.  About 36 hours after laying the top layer, the surface shall be watered and ground evenly with machine fitted with special rapid cutting grit blocks (carborundum stone) of coarse grade (No. 60) till the marble chips are evenly exposed and the floor is smooth.  After the first grinding, the surface shall be thoroughly washed to remove all grinding mud and covered with a grout of cement and colouring matter in same mix and proportion  as the topping in order to fill any pin holes that appear. The surface shall be allowed to cure for 5 to 7 days and then rubbed with machine fitted with fine grit blocks (No. 120).  The surface is cleaned and repaired as before and allowed to cure again for 3 to 5 days.  Finally the third grinding shall be done with machine fitted with fine grade grit blocks (No. 320) to get even and smooth surface without pin holes. The finished surface should show the marble chips evenly exposed.

Where use of machine for polishing is not feasible or possible, rubbing and polishing shall be done by hand, in the same manner as specified for machine polishing except that carborundum stone of coarse grade (No. 60) shall be used for the 1st rubbing, stone of medium grade (No. 80) for second rubbing and stone of fine grade (No. 120) for final rubbing and polishing. After the final polish either by machine or by hand, oxalic acid shall be dusted over the surface at 33 gm per square meter sprinkled with water and rubbed hard with a nemdah block (Pad of woollen rags). The following day, the floor shall be wiped with a moist rag and dried with a soft cloth and finished clean. Curing shall be done by suitable means such as laying moist saw dust or ponding water.

14.8.7. Precautions -  Flooring in lavatories and bathrooms shall be laid after fixing of water closet and squatting pans and floor traps. Traps shall be plugged, while laying the floors and opened after the floors are cured and cleaned. Any damage done to WC’s squatting pans and floor traps during the execution of work shall be made good.

During cold weather, concreting shall not be done when the temperature falls below 4 degree C. The concrete placed shall be protected against frost by suitable coverings. Concrete damaged by frost shall be removed and work redone. During hot weather, precautions shall be taken to see that the temperature of wet concrete does not exceed 38 degree C.  No concreting shall be laid within half an hour of the closing time of the day, unless permitted by the engineer.

14.8.8. Measurements - Length and breadth shall be measured correct to a cm before laying skirting, dado or wall plaster.  The area as laid shall be calculated in sqm correct to two decimal places.

The thickness of the under layer shall be measured correct to a cm.  The thickness of top layer shall not be less than that specified.

No deduction shall be made, nor extra paid for voids not exceeding 0.20 square meter. Deduction for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter.  Nothing extra shall be paid for laying the floor at different levels in the same room or courtyard.

Terrazzo (Marble Chips) flooring laid as floor borders, margins and similar bands up to 30 cm width and on staircase treads shall be measured under the item of terrazzo flooring but extra shall be paid for such work.  This extra in the case of staircase treads shall include the cost of forming the nosing also.  However, moulded nosing shall be paid extra in running meters except where otherwise stated; returned moulded ends and angles to mouldings shall be included in the description.  Extra shall also be paid for laying flooring in narrow bands not exceeding 7.5 cm in width and such bands shall be measured in running meters for this purpose.

Dividing strips inserted in terrazzo to form bays, patterns shall be described stating the materials, its width and thickness and measured in running meters.

Special surface finishes to treads, risers and the ends of concrete steps and the like shall be measured separately and given in square meters and shall include form work, if required.

14.8.9. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above including cleaning of surface of RCC slab or base concrete and application of cement slurry but shall not include the cost of base concrete and cost of providing and fixing strips of glass or aluminium or of any other material used for making panels, which shall be paid for separately.

14.9. SPECIFICATIONS FOR TERRAZZO (MARBLE CHIPS) SKIRTING IN SITU

14.9.1. Under coat - The under coat of skirting shall be of cement plaster of the thickness and mix described in the item. Specifications as given under 14.5.0, 14.5.1, & 14.5.2 shall apply. As regards application, the work shall be carried out in the manner as described under 14.5.3 except that the under coat shall be finished rough with a scratching tool to form a key for the top coat.

14.9.2. Top coat - The Specifications shall hold good as far as applicable and shall include cutting to line and fair finish to top edges of terrazzo and polishing.

14.9.3. Thickness - The thickness of the bottom and top coats shall be as specified.  The total thickness of skirting specified is of the total thickness of plaster including top coat as measured from the un plastered face of the masonry.  Average thickness of the under coat over any portion of the surface shall not be less than 4 mm.  The thickness of top coat shall not be less than the thickness specified.

14.9.4. Measurements - Length and height shall be measured correct to a cm and its area shall be calculated in sqm correct to two places of decimal.  Length shall be measured as finished length of skirting.  Height shall be measured from the finished level of floor correct to 5 mm where the height of skirting does not exceed 30 cm and when the height exceeds 30 cm it shall be measured correct to a cm.

14.9.5. Rates - The rate shall include the cost of all materials and labour involved in all the operations described above.

14.10. SPECIFICATIONS FOR CRAZY MARBLE FLOORING (FIG. 3)

14.10.1. Base concrete - Crazy marble stone flooring shall be laid on cement or lime concrete base.  The base concrete shall be provided with slope required for the flooring in verandahs and courtyards to drain off washing and rain water. The surface of base shall be roughened with steel wire brushes, without disturbing the concrete, wetted and smeared with a floating cost of cement slurry at 2 kg of cement spread over an area of one sqm shall be applied so as to get a good bond between RCC slab and floor.

14.10.2. Under layer - The under layer of crazy marble flooring shall be of cement concrete of thickness 25 mm or as specified.  The mix shall normally be 1:2:4 (1 cement:  2 coarse sand:  4 graded stone aggregate 12.5 mm nominal size) by volume unless otherwise specified.  It shall conform to the specifications given under Section 3 of sub-head ‘Cement Concrete’.

14.10.3. Top layer - The mix of crazy marble stone flooring shall consist of white cement with or without pigment, marble powder, marble chips of 00 Nos. and Marble stone pieces and water. The marble stone pieces shall be hard, sound, dense and homogeneous in texture with crystalline and coarse grains.  It shall be uniform in colour and free from stains, cracks, decay and weathering. 

Before starting the work the contractor shall get the sample of marble stone approved by the engineer.  The marble stone pieces shall be of sizes as approved by the engineer, but the thickness shall be according to the overall thickness specified which could be achieved when laid over the under layer as specified.  Thus for 50 mm thick floor, the thickness of marble pieces will be 25 mm while for 40 mm thick floor, the thickness will be 15 mm.

Fig. 3

The white cement and marble powder shall be mixed in proportion of three parts of cement and one part of marble powder by weight, and the proportion of marble chips to binder mix by volume shall be 7 parts of marble chips to 4 parts of binder mix.  The marble chips shall be as specified.  It shall be hard, sound, dense and homogeneous in texture.  It shall be uniform in colour and free from stains, cracks decay and weathering.

14.10.4. Laying - A coat of cement slurry at the rate of 2 kg of cement per sqm of area shall be spread and then the marble stone pieces shall be set by hand in such a manner that the top surface of all the set marble stones shall be true to the required level and slopes.  After fixing the stones, the cement marble chips mixture shall be filled in between the gaps of laid marble stone pieces.  The filled surface then shall be trowelled over, pressed and brought to the level of the laid marble stone pieces.

14.10.5. Polishing - Curing and finishing shall be as described.

14.10.6. Precautions - Flooring in lavatories and bathrooms shall be laid after fixing of water closet and squatting pans and floor traps.  Traps shall be plugged, while laying the floors and opened after the floors are cured and cleaned.

14.10.7. Measurements - Length and breadth shall be measured correct to a cm before skirting, dado or wall plaster and it shall be calculated in sqm correct to two decimal places. No deduction shall be made nor extra paid for voids not exceeding 0.20 square meter. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter. Nothing extra shall be paid for laying floor at different levels in the same room or courtyards.

14.10.8. Rate - The rates shall include the cost of all materials and labour involved in all the operations described above including the cost of cleaning of RCC slab surface and applying the cement slurry, but it shall not include the cost of base concrete.

14.11. SPECIFICATIONS FOR TERRAZZO TILE FLOORING

14.11.1. Terrazzo tiles - Terrazzo tiles shall generally conform to IS: 1237.  Requirements and methods of testing of tiles are described in Annexure 14-A.2.  Unless otherwise specified, the tiles shall be supplied with initial grinding and grouting of wearing layer. The size of tiles shall be as given in Table 3 or as shown in the drawings or as required by the engineer.  Half tiles for use with the full tiles shall be such as to make two half tiles when joined together, match with the dimensions of one full tile.

Table 3

Length

Nominal

Breadth

Nominal

Thickness

not less than

200 mm

200 mm

20 mm

250 mm

250 mm

22 mm

300 mm

300 mm

25 mm

Tolerance - Tolerances on length and breadth shall be plus or minus one millimetre, and tolerance on thickness shall be plus 5 mm.  The range of dimensions in any one delivery of tiles shall not exceed 1 mm on length and breadth and 3 mm on thickness.

The tiles shall be manufactured in a factory under pressure process subjected to hydraulic pressure of not less than 140 kg per square centimetre  and shall not be given the initial grinding with machine and grouting of the wearing layer shall be free from projections, depressions, cracks, holes, cavities and other blemishes. The edges of wearing layer may be rounded.

The proportion of cement to aggregate in the backing of tiles shall be not leaner than 13 by weight.  Where colouring material is used in the wearing layer, it shall not exceed 10 per cent by weight of cement used in the mix.

The finished thickness of the upper layer shall not be less than 5 mm for size of marble chips from the smallest up to 6 mm and also, not less than 5 mm for size of marble chips ranging from the smallest up to 12 mm, and not less than 6 mm for size of marble chips varying from the smallest up to 20 mm.

4.11.2. Laying - Base concrete or RCC slab on which the tiles are to be laid shall be cleaned, wetted and mopped.  The bedding for the tiles shall be with lime mortar of any of the following specifications prepared in conformity with provisions in relevant para of chapter on ‘Mortar’.

a) 112 (1 lime putty  1 surkhi  2 coarse sand), or (b)13 (1 lime putty:  3 surkhi), or (c) 13 (1 lime putty: 3 coarse sand) 

The ingredients shall be thoroughly mixed by volume in dry form.  Care shall be taken to ensure that there are no hard lumps present.  Water shall then be added and the ingredients thoroughly mixed.

Where lime putty of proper quality is not available, cement mortar 1:4 (1 cement: 4 coarse sand) bedding may also be used with prior approval of the engineer.

The average thickness of the bedding mortar shall be 30 mm and the thickness at any place shall not be less than 10 mm.

Lime mortar bedding shall be spread, tamped and corrected to proper levels and allowed to harden for a day before the tiles are set.  If cement mortar is laid in bedding the terrazzo tiles, these shall be set immediately after laying the mortar.  Over this bedding neat grey cement slurry of honey like consistency shall be spread at the rate of 4.4 kg of cement per square meter over such an area as would accommodate about twenty tiles.  Tiles shall be washed clean and shall be fixed in this grout one after another, each tile being gently tapped with a wooden mallet till it is properly bedded, and in level with the adjoining tiles.  The joints shall be kept as thin as possible not exceeding 1.5 mm and in straight lines or to suit the required pattern.

The surface of the flooring during laying shall be frequently checked with a straight edge at least 2 meter long, so as to obtain a true surface with the required slope.

Where full tiles or half tiles can not be fixed, tiles shall be cut (sawn) from full tiles to the required size and their edges rubbed smooth to ensure a straight and true joint.

Tiles which are fixed in the floor adjoining the wall shall enter not less than 12 mm under the plaster, skirting or dado. The junction between wall plaster and tile work shall be finished neatly and without waviness.

After the tiles have been laid, surplus cement grout that may have come out of the joints shall be cleared off.

14.11.3. Curing, polishing and finishing

The day after the tiles are laid all joints shall be cleaned of the grey cement grout with a wire brush or trowel to a depth of 5 mm and all dust and loose mortar removed and cleaned.  Joints shall then be grouted with grey or white cement mixed with or without pigment to match the shape of the topping of the wearing layer of the tiles.  The same cement slurry shall be applied to the entire surface of the tiles in a thin coat with a view to protect the surface from abrasive damage and fill the pin holes that may exist on the surface.

The floor shall then be kept wet for a minimum period of 7 days.  The surface shall thereafter be grounded evenly with machine fitted with coarse grade grit block (No.60).  Water shall be used profusely during grinding.  After grinding the surface shall be thoroughly washed to remove all grinding mud, cleaned and mopped.  It shall then be covered with a thin coat of grey or white cement, mixed with or  without pigment to match the colour of the topping of the wearing surface in order to fill any pin hole that appear.  The surface shall be again cured.  The second grinding shall then be carried out with machine fitted with fine grade grit block (No. 120).

The final grinding with machine fitted with the finest grade grit blocks (No.320) shall be carried out the day after the second grinding described in the preceding para or before handing over the floor, as ordered by the engineer.

For small areas or where circumstances so require, hand polishing may be permitted in lieu of machine polishing after laying.  For hand polishing the following carborundum stones, shall be used

First grinding – coarse grade stone (No. 60).

Second grinding – medium grade (No. 80)

Final grinding – fine grade (No. 120).

In all other respects, the process shall be similar as for machine polishing.

After the final polish, oxalic acid shall be dusted over the surface at the rate of 33 gm per square meter sprinkled with water and rubbed hard with a ‘Namdah’ block (pad or woollen rags). The following day the floor shall be wiped with a moist rag and dried with a soft cloth and finished clean. If any tile is disturbed or damaged, it shall be refitted or replaced, properly jointed and polished. The finished floor shall not sound hollow when topped with a wooden mallet.

14.11.4. Measurements

Terrazzo tiles flooring with tiles manufactured from ordinary grey cement without pigment and coloured terrazzo tile flooring shall be measured separately and classified. Terrazzo tile flooring shall be measured as laid in square meter correct to two places of decimal.  For length and breadth dimensions correct to a cm before laying skirting, dado or wall plaster shall be taken. No deduction shall be made nor extra paid for voids not exceeding 0.20 sqm. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter.  Nothing extra shall be paid for use of cut tiles nor for laying the floor at different levels in the same room or courtyard.

Terrazzo tile flooring laid in floor borders and similar band shall be measured under the item of terrazzo tile flooring.  Nothing extra shall be laid in respect of these and similar bands formed of half size of multiples of half size standard tiles or other uncut tiles.

Treads of stairs and steps paved with tiles without nosing, shall also be measured under flooring.  Moulded nosing shall be paid in running meter except where otherwise stated, returned moulded ends the and angles to mouldings shall be included in the description. Extra shall, however, be paid for such areas where the width of treads does not exceed 30 cm.

14.11.5. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.  Where cement mortar bedding is used in place of lime mortar the rate will be adjusted accordingly.

14.12. SPECIFICATIONS FOR TERRAZZO TILES IN RISERS OF STEPS, SKIRTING AND DADO

14.12.1. The terrazzo tiles shall be as specified, as far as applicable.  The minimum finished thickness of tiles shall, however, be 12 mm.  The finished thickness of the upper layer shall be not less than 5 mm for size of marble chips from the smallest into 12 mm and not less than 6 mm for size of chips varying from the smallest up to 20 mm.  Where the bigger sized chips are used the tiles shall be not less than 20 mm thick.  The requirements of transverse strength tests specified in Annexure 14-A.2, shall not apply when the tiles used are less than 20 mm thick. See Fig.4.

14.12.2. Preparation of surface - The specifications for this shall be same as specified in 14.6.2

14.12.3. Laying - 12 mm thick plaster of cement mortar 1:3 (1 cement 3 coarse sand) or mix as specified, shall then be applied and allowed to harden.  The plaster shall then be roughened with wire brushes or by scratching diagonal lines 2 mm deep at approximately 7.5 cm centres both ways.  The back of tiles shall be buttered with a coat of grey cement slurry and edges with grey or white cement slurry with or without pigments to match the shade of tiles, and set in the bedding mortar.  These shall be tamped and corrected to proper planes and lines.  The tiles shall be set be as fine as possible.  Top of skirting or dado shall be truly horizontal and joints truly vertical except where otherwise indicated.

The risers of steps, skirting or dado shall rest on the top of the tread or flooring.  Where full size tiles cannot be fixed, the tiles shall be cut (swan) to the required size and their edges rubbed smooth.

14.12.4. Curing, polishing and finishing - The specifications shall hold good as far as applicable. Polishing shall be done only with hand.

14.12.5. Measurements - The thickness of the skirting shall be as stated.  Length shall be measured along the finished face of riser, skirting or dado correct to a cm.  Height shall be measured from the finished level of tread or floor to the top (the underside of tread in the case of steps). This shall be measured correct to 5 mm in case of risers and skirting (not exceeding 30 cms, as in the case of dado and on walls, the height shall be paid for separately.  The area shall be calculated in square metre, correct to two places of decimal.

Where the height of risers, skirting or dado does not admit of full size or other finished size tiles and the tiles are to be cut (sawn), nothing extra shall be paid for the same.

14.12.6. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

Nothing extra shall be payable for use of cut (sawn) tiles to suit the size of risers, skirting, portions of dado etc.

14.13. SPECIFICATIONS FOR CHEQUERED TILE FLOORING

14.13.1. Chequered tiles - The tiles shall be of nominal sizes such as 20 x 20 cm 25 x 25 cm and 30 x 30 cm or of standard sizes with equal sides.  The size of tiles to be used shall be as shown in drawings or as required by the engineer.  The centre to centre distance of chequers shall not be less than 2.5 cm and not more than 5 cm.

The overall thickness of the tiles shall be not less than 22 mm. The grooves in the chequers shall be uniform and straight.  The depth of the grooves shall not be less than 3 mm. The chequered tiles shall be cement tiles, or terrazzo tiles as specified in the description of the item.  The thickness of the upper layer, measured from the top of the chequers shall not be less than 6 mm.

The terrazzo tiles shall be given the first grinding with machine before delivery to site.

The tiles shall conform to the specification for plain cement concrete or terrazzo tiles in respect of method of manufacture and the mix of the backing and wearing layers.

14.13.2. Laying , curing, polishing and finishing - Laying, curing, Polishing and Finishing shall be as specified in 14.11.2 and 14.11.3 except that the polishing of the tiles and the chequer grooves, after laying, may be done by hand. Special care shall be taken to polish the grooves in such a manner as to get a uniform section and that their finish shall match with the finish of flat portion of the tiles. Cement concrete tiles normally do not require polishing but where polishing is required the same shall be done as described above.

14.13.3. Measurement and rate - Shall be as specified in 14.11.4 and 14.11.5.

14.14. SPECIFICATIONS FOR CHEQUERED TILES FLOORING IN STAIR TREADS (FIG. 4)

(See Annexure -14 A.12)

14.14.1. Chequered tiles - The specifications for tiles shall be as specified 14.13.1 except in the following respects

(1)The length of the tiles including nosing shall be as specified. (2) The nosing edge of the tile shall be rounded. (3)The minimum thickness of the tile shall be 30 mm.(4) The front portion of the tile for a minimum length of 75 mm from and including the nosing shall have grooves running parallel to the nosing and at centres not exceeding 25 mm. Beyond that the tiles shall have the normal chequer pattern. (5) The nosing shall also have the same wearing layer as the top.

14.14.2. Preparation of surface and laying

RCC or brick work in treads on which the tiles are to be laid shall be cleaned wetted and mopped. The bedding for tiles shall be with lime mortar of either 1:1:1 (1 lime putty:  1 surkhi:  1 coarse sand) or 14 (1 cement:  4 coarse sand) or of specified mix. The minimum thickness of bedding mortar at any place shall be 10 mm. Bedding mortar shall be spread, tamped and corrected to proper levels.   After laying bedding mortar, neat grey cement slurry of honey like consistency shall be spread over the mortar at the rate of 4.4 kg of cement per square meter over each tread.  Tiles shall be washed cleaned and shall be fixed in this grout one at another.  Each tile being gently tapped with a wooden mallet till it is properly bedded, and is in level and line with the adjoining tiles.  The joints shall be kept as thin as possible and in straight lines.  The surface shall be checked with a straight edge during laying to obtain a true surface.

Fig. 4

The square end of the tile shall, as far as possible butt against the riser face of the concrete or brick tread and in any case shall be embedded under the side wall plaster, skirting or dado and under the riser tile or other finish to a depth of not less than 10 mm.

Where full size tiles cannot be fixed, these shall be cut (sawn) to the required size (along the groove of the chequers where the cut edge is exposed) and used.  The cut in the case of embedded edges will be neat and true while the cut in the case of exposed edges shall in addition be rubbed smooth to ensure straight and true joints. After the tiles have been laid surplus cement grout shall be cleaned off.

14.14.3. Curing, polishing and finishing - The specifications shall be as described  except that polishing of the treads nosing and chequered grooves, after laying, may be done by hand in the same manner as specified under terrazzo tile flooring.  Special care shall be taken to polish the nosing and the grooves in such a manner as to get a uniform, section for the grooves and the nosing and their finish shall match with the finish of the flat portion of the tiles.

14.14.4. Measurements -  Chequered tiles on stair treads shall be measured in square metre correct to two places of decimal.  Length shall be measured correct to a cm before laying skirting, dado or wall plaster.  Width shall be measured correct to a cm from the outer edge of the nosing, as laid, before providing the riser.  In the case of the edge tiles of the landing and wide steps, width shall be measured up to the near edge of the chequered stair tread tiles.  Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square metre.

14.14.5. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

Nothing extra shall be payable for cutting the tiles to suit the size of treads and also for nosing.

14.15. SPECIFICATIONS FOR GLAZED TILE FLOORING

14.15.1. White glazed tiles - The tiles shall be of approved make and shall generally conform to IS:  777.  They shall be flat, and true to shape and free from blisters crazing, chips, welts, crawling or other imperfections detracting from their appearance.  The tiles shall be tested as indicated in Appendix of IS:  777.

The tiles shall be square or rectangular of nominal size such as 150 x 150 mm, 100 x 100 mm, 100 x 200 mm or as directed by the engineer.  The thickness of the tiles shall be 5 mm, or 6 mm as specified.  The length of all four sides shall be measured correct to 0.1 mm and average length breadth shall not vary more than ± 0.8 mm from specified dimension.  The variation of individual dimension from average value of length/breadth shall not exceed  ± 0.5 mm.  Tolerance in thickness shall be ± 0.4 mm.

Note 1: Where tiles of nominal sizes of 150 x 150 mm or 100 x 100 mm are not available tiles of nominal sizes 152 mm x 152 mm or 108 mm x 108 mm may be allowed to be used with prior approval of the engineer.

Note 2: The actual size of tiles supplied shall be 1 mm less so that with 1 mm joint, the tile when laid shall conform to the nominal size.

The top surface of the tiles shall be glazed and glaze shall be either glossy or matt as specified.  The underside of the tiles shall not have glaze on more than 5% of the area in order that the tile may adhere properly to the base.  The edges of the tiles shall be preferably free from glaze. However, any glaze if unavoidable, shall be permissible on only up to 50 per cent of the surface area of the edges.

14.15.2. Coloured tiles - Only the glaze shall be coloured as specified. The sizes and specifications shall be the same as for the white glazed tiles.

14.15.3. Decorative tiles - The type and size of the decorative tiles shall be as follows

Decorated white black ground tiles

The size of these tiles shall be 152 x 152 x 6 mm and / or 108 x 108 x 6 mm.

ii)   Decorated and having coloured back ground

The sizes of the tiles shall be 152 x 152 x 6 mm and / or 108 x 108 x 6 mm.

14.15.4. Preparation of surface and laying 

Base concrete or the RCC slab on which the tiles are to be laid shall be cleaned, wetted and mopped.  The bedding for the tile shall be with cement mortar 1:3 (1cement: 3 coarse sand) or as specified.  The average thickness of the bedding shall be 10 mm while the thickness under any portion of the tiles shall not be less than 5 mm.

Mortar shall be spread, tamped and corrected to proper levels and allowed to harden sufficiently to offer a fairly rigid cushion for the tiles to be set and to enable the mason to place wooden plank across and squat on it.

Over this mortar bedding neat grey cement slurry of honey like consistency shall be spread at the rate of 3.3 kg of cement per square meter over such an area as would accommodate about twenty tiles. 

Tiles shall be soaked in water washed clean and shall be fixed in this grout one after another, each tile gently being tapped with a wooden mallet till it is properly bedded and in level with the adjoining tiles.  The joints shall be kept as thin as possible and in straight lines or to suit the required pattern.

The surface of the flooring during laying shall be frequently checked with a straight edge about 2 m long, so as to obtain a true surface with the required slope.

Where full size tiles cannot be fixed these shall be cut (sawn) to the required size, and their edge rubbed smooth to ensure straight and true joints.

Tiles which are fixed in the floor adjoining the wall shall enter not less than 10 mm under the plaster, skirting or dado. After tiles have been laid surplus cement slurry shall be cleaned off.

14.15.5. Pointing and finishing - The joints shall be cleaned off the grey cement slurry with wire / coir brush or trowel to a depth of 2 mm to 3 mm and all dust and loose mortar removed.  Joints shall then be flush pointed with white cement added with pigment if required to match the colour of tiles.  The floor shall then be kept wet for 7 days.  After curing, the surface shall be washed and finished clean.  The finished floor shall not sound hollow when tapped with a wooden mallet.

14.15.6. Measurements - Length and breadth shall be measured correct to a cm before laying skirting, dado or wall plaster and the area calculated in square meter correct to two places of decimal.  Where coves are used at the junctions, the length and breadth shall be measured between the lower edges of the coves.

No deductions shall be made not extra paid for voids not exceeding 0.20 square metre. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter.

Areas, where glazed tiles or different types of decorative tiles are used will be measured separately.

14.15.7. Rate - The rate for flooring shall include the cost of all materials and labour involved in all the operations described above.  Nothing extra shall be paid for the use of cut (sawn) tiles in the work.

Extra over and above the normal rate for white tiles shall be paid where coloured or any other type of decorative tiles have been used.

14.16. SPECIFICATIONS FOR GLAZED TILES IN SKIRTING AND DADO

14.16.1. The tiles shall be of approved make and shall generally conform to IS:  777.  The tiles shall be of earthenware covered by a glaze thoroughly matured and fitted to the body.  The tiles shall be sound, true to shape, flat and free from flaws and other manufacturing defects affecting their utility.

The top surface of the tiles shall be glazed.  The underside of the tiles shall not have glaze on more than 5% of the area that the tile may adhere properly to the base.  The edges of the tiles shall be free from glaze; however, any glaze if unavoidable shall be permissible on only up to 50 per cent of the surface area of edges.

The glaze shall be free from welts, chips, craze, specks, crawling or other imperfections detracting from the appearance when viewed from a distance of one meter. The glaze shall be either glossy or matt as specified.  The glaze shall be either glossy or matt as specified.  The glaze shall be white in colour except in the case of coloured tiles when colours shall be specified by the engineer.  There may be more than one colour on a tile.

14.16.1(a) Dimensions and tolerances - Glazed earthenware tiles shall be made square or rectangular in sizes such as 149 x 149 mm and 99 x 99mm or 99 x 199 mm or as specified and shall

Half tiles for use as full tiles shall have dimensions which shall be such as to make the half tiles when jointed (with 1 mm joint) match with dimensions of full tiles.  Tiles may be manufactured in sizes other than those specified above.

Note: Commonly manufactured sizes include 108 x 108 mm, 152 x 152 mm, 200 x 200 mm, 200 x 150 mm and 200 x 100 mm.

The thickness of the tiles shall be 5 mm or 6 mm as specified.

The dimensions of fittings associated with the glazed tiles namely cove base, round edge tile, angles corner cups, ridge and legs, cornices and capping beads shall be of the shape and dimensions as required and the thickness of fittings shall be the same as the thickness of tiles given above.

14.16.1 (b) Tolerances 

Facial dimensions – The lengths of all the four sides of the tile shall be measured to the nearest 0.1 mm.  The average value of lengths / breadth shall not vary more than ± 0.8 mm from the above specified dimension.

The variation of individual dimensions from average value of length / breadth shall not exceed ± 0.5 mm.  Tolerances on thickness shall be ± 0.4 mm.

Tiles shall be checked for squareness and warpage as described thereafter.

Method of checking squareness of tiles

Fig. A – Trueness of Shape (Squareness) [Clause 14.16.1(c)]

14.16.1 (c) Trueness of shape (Squareness) - Any variation from a right angle in the angle contained by any two adjoining sides shall be limited so that if a builder’s steel square is placed against the angle, the distance between the inner edge of the square and the adjacent side of the tile or fitting shall not be more than 0.5 mm per 100 mm run.

14.16.1 (d) Warpage - The tiles when tested for warpage on the edges and on the diagonal as per Appendix – A  of  IS:  777 shall not have warpage exceeding the value as specified below

Size of tile (mm)

Warpage (mm)

149 x 149

- 0.4

+ 0.7

99 x 99

- 0.3

+ 0.5

14.16.1 (e)  Performance requirements water absorption - The average water absorption of the tiles when tested and evaluated in accordance with IS:  777 shall not exceed 20 per cent.

Crazing - Tiles subjected to two cycles of crazing test as per IS:  777 shall not show any sign of crazing.

Impact resistance - Tiles when tested for impact resistance as per IS:  777 shall remain intact, apart from surface marking.

Chemical resistance - When tested as per IS:  777, the glazed surface of tiles and / or the fittings having a white or cream coloured glossy glaze shall show no modification.

14.16.2. Preparation of surfaces - The joints shall be raked out to a depth of at least 15 mm in masonry walls.

In case of concrete walls, the surface shall be hacked and roughened with wire brushes.  The surface shall be cleaned thoroughly, washed with water and kept wet before skirting is commenced.

14.16.3. Laying - 12 mm thick plaster of cement mortar 1:3 (1cement: 3 coarse sand) mix as specified shall be applied and allowed to harden.  The plaster shall be roughened with wire brushes or by scratching diagonal at closed intervals.

The tiles should be soaked in water, washed clean, and a coat of cement slurry applied liberally at the back of tiles and set in the bedding mortar. The tiles shall be tamped and corrected to proper plane and lines.  The tiles shall be set in the required pattern and jointed. The joints shall be as fine as possible. Top of skirting or dado shall be truly horizontal and joints truly vertical except where otherwise indicated. Skirting and dado shall rest on the top of the flooring.  Where full size tiles cannot be fixed these shall be cut (sawn) to the required size and their edges rubbed smooth.

14.16.4. Curing and finishing - The joints shall be cleaned off the grey cement grout with wire / coir brush or trowel to a depth of 2 mm to 3 mm and all dust and loose mortar removed. Joints shall then be flush pointed with white cement added with pigments if required to match the colour of tiles. The work shall then be kept wet for 7 days.

After curing, the surface shall be washed and finished clean.  The finished work shall not sound hollow when tapped with a wooden mallet.

14.16.5. Measurements - Length shall be measured correct to a cm. Height shall be measured correct to a cm in the case of dado and 5 mm in the case of riser and skirting.  The area shall be calculated in square meter, correct to two places of decimal. Length and height shall be measured along the finished face of the skirting or dado including curves where specials such as coves, internal and external angles and beads are used.  Where cornices are used the area of dado shall be measured excluding the cornices.  Nothing extra will be paid for cutting (sawn) the tiles to sizes.

In addition to payment for areas of skirting and dado, specials such as coves, internal and external angles and beads shall be measured separately and paid for in running meters. Cornices shall also be similarly measured for payment in running meters.  Areas where coloured tiles or different types of decorative tiles are used will be measured separately to be paid extra over and above the normal rate for white tiles.

14.16.6. Rates - The rate shall include the cost of all materials and labour involved in all the operations described above. The specials such as coves, internal and external angles and beading shall be measured and paid for separately. The rate shall not include cost of cornices which shall be measured and paid for in running meters separately.

14.17. SPECIFICATIONS FOR GLAZED TILE SPECIALS

14.17.1. Specials - The specials consist of coves, internal and external angles, beads cornices and their corner pieces.

Cover beads and angles shall be of thickness not less than the thickness of the tiles with which they are used. The size of coves, beads, angles refer to the greatest width of the special measured in a straight line.  The stipulated size of cornices is their height. The lengths of specials shall be 15 cm, 10 cm or other standard size available conforming to the size of tiles available.

In other respects the general specifications as described in 14.15.1 shall be applicable.

14.17.2. Preparation of surface, laying, curing and finishing shall be as specified in 14.16.2, 14.16.3, 14.16.4 as far as applicable.

14.17.3. Measurements - Special tiles to form coved internal angles of any radius, rounded external angles, architraves moulding, ceiling ribs, cornices and the like shall each be measured in running meters correct to a cm.  Railing members and vertical members shall each be so described.  Ends, angles and internal sections shall be enumerated separately.

14.17.4. Rate - It shall include the cost of all materials and labour involved in all the operations described above.  Nothing extra shall be paid for corner pieces at junctions of coves, beads, cornices etc. or for using cut lengths of specials.

14.18. SPECIFICATIONS FOR MARBLE FLOORING

14.18.1. Marble - It shall be as specified.

14.18.2. Dressing of slabs - Every stone shall be cut to the required size and shape, fine chisel dressed on all sides to the full depth so that a straight edge laid along the side of the stone shall be fully in contact with it. The top surface shall also be fine chisel dressed to remove all waviness. In case machine cut slab are used, fine chisel dressing of machine cut surface need not be done provided a straight edge laid any where along the machine cut surfaces is in contact with every point on it.  The sides and top surface of slabs shall be machined rubbed or table rubbed with coarse sand before paving.  All angles and edges of the marble slabs shall be true, square and free from chippings and the surface shall be true and plane.

The thickness of the slabs shall be 20, 30 or 40 mm as specified In the description of the item.  Tolerance of + 3% shall be allowed for the thickness.  In respect of length and breadth of slabs a tolerance of + 2% shall be allowed.

Fig. 5 Glazed Earthware tiles - Specials

14.18.3. Laying -Base concrete or the RCC slab on which the slabs are to be laid shall be cleaned, wetted and mopped.  The bedding for the slabs shall be with cement mortar 1:4 (1 cement 4 coarse sand) or with lime mortar 1:1:1 (1 lime putty:  1 surkhi:  1 coarse sand) as given in the description of the item.

The average thickness of the bedding mortar under the slab shall be 20 mm and the thickness at any place under the slab shall be not less than 12 mm.

The slabs shall be laid in the following manner - Mortar of the specified mix shall be spread under the area of each slab, roughly to the average thickness specified in the item.  The slab shall be washed clean before laying.  It shall be laid on top, pressed, tapped with wooden mallet and brought to level with the adjoining slabs.   It shall be lifted and laid aside.  The top surface of the mortar shall then be corrected by adding fresh mortar as hollows. The mortar is allowed to harden a bit and cement slurry of honey like consistency shall be spread over the same at the rate of 4.4 kg of cement per sqm. The edges of the slab already paved shall be buttered with grey or white cement with or without admixture of pigment to match the shade of the marble slabs as given in the description of the item.

The slab to paved shall then be lowered gently back in position and tapped with wooden mallet till it is properly bedded in level with and close to the adjoining slabs with as fine a joint as possible. Subsequent slabs shall be laid in the same manner.  After each slab has been laid, surplus cement on the surface of the slabs shall be cleaned off. The flooring shall be cured for a minimum period of seven days.  The surface of the flooring as laid shall be true to levels, and, slopes as instructed by the engineer.

Due care shall be taken to match the grains of slabs which shall be selected judiciously having uniform pattern of Veins / streaks or as directed by the engineer.

The slabs shall be matched as shown in drawings or as instructed by the engineer.

Slabs which are fixed in the floor adjoining the wall shall enter not less than 12 mm under the plaster skirting or dado.  The junction between wall plaster and floor shall be finished neatly and without waviness.

14.18.4. Polishing and finishing - Slight unevenness at the meeting edges of slabs shall then be removed by fine chiseling  and finished in the same manner as specified except that cement slurry with or without pigments shall not be applied on the surface before each polishing.

14.18.5. Measurements - Marble stone flooring with different kind of marble shall be measured separately and in square meter correct to two places of decimal.  Length and breadth shall be measured correct to a cm before laying skirting, dado or wall plaster. No deduction shall be made nor extra paid for voids not exceeding 0.20 square meter. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter. Nothing extra shall be paid for laying the floor at different levels in the same room. Steps and treads of stairs paved with marble stone slabs shall also be measured under the item of Marble Stone flooring.  Extra shall, however, be paid for such areas where the width of treads does not exceed 30 cm.  Nosing for treads shall be measured in running meter and paid for extra. The width of treads shall be measured from the outer edge of the nosing, as laid, before providing the riser.

Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

14.19. SPECIFICATIONS FOR MARBLE STONE IN RISERS OF STEPS AND SKIRTING

14.19.1. Marble Stone Slabs and Dressing of Slabs shall be as specified, except that the thickness of slabs shall be 30 mm. A tolerance of ± 3 mm shall be allowed, unless otherwise specified in the description of the item.

14.19.2. Preparation of surface - It shall be as specified where necessary; the wall surface shall be cut uniformly to the requisite depth so that the skirting face shall have the projection from the finished face of wall as shown in drawings or as required by the engineer.

14.19.3. Laying - The risers of steps and skirting shall be in grey or white cement admixed with or without pigment to match the shade of the stone, as specified in the description of the item, with the line of the slab at such a distance from the wall that the average width of the gap shall be 12 mm and at no place the width shall be less than 10 mm, if necessary, the slabs shall be held in position by temporary M. S. hooks fixed in to the wall at suitable intervals. The skirting or riser face shall be checked for plane and plumb and corrected. The joints shall thus be left to harden then the rear of the skirting or riser slab shall be packed with cement mortar 1:3 (1cement: 3 coarse sand) or other mix as specified in the description of the item.  The fixing hooks shall be removed after the mortar filling the gap has acquired sufficient strength.

The joints shall be as fine as possible. The top line of skirting and risers shall be truly horizontal and joints truly vertical, except where otherwise indicated.

The risers and skirting slab shall be matched as shown in drawings or as instructed by the engineer.

14.19.4. Curing, polishing and finishing - It shall be as specified in 14.11.3 as far as applicable, except that cement slurry with or without pigment shall not be applied on the surface and polishing shall be done only with hand.  The face and top of skirting shall be polished.

14.19.5. Measurements - Length shall be measured along the finished face of riser or skirting, correct to a cm. Height shall be measured from the finished level of tread or floor, to the top (the underside of tread, in the case of steps) correct to 1 mm. The areas shall be calculated in square meter correct to two places of decimal.

Dado and lining of pillars etc. shall be measured as Marble Work in wall lining. If the thickness is up to 25 mm or as “Marble Work” in Jambs, walls, columns and other plain work if the thickness is more.

14.19.6. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

14.20. SPECIFICATIONS FOR KOTA STONE FLOORING

14.20.1. Kota stone slabs - The slabs shall be of selected quality, hard, sound, dense and homogeneous in texture free from cracks, decay, weathering and flaws. They shall be hand or machine cut to the requisite thickness. They shall be of the colour indicated in the drawings or as instructed by the engineer.

The slabs shall have the top (exposed) face polished before being brought to site, unless otherwise specified. The slabs shall conform to the size required.  Before starting the work the contractor shall get the samples of slabs approved by the engineer.

14.20.2. Dressing - Every slab shall be cut to the required size and shape and fine chisel dressed on the sides to the full depth so that a straight edge laid along the side of the stone shall be in full contact with it.  The sides (edges) shall be table rubbed with coarse sand or machine rubbed before paving.  All angles and edges of the slabs shall be true, square and free from chippings and the surface shall be true and plane.

The thickness of the slab after it is dressed shall be 20, 25, 30 or 40 mm as specified in the description of the item. Tolerance of ± 2 mm shall be allowed for the thickness. In respect of length and breadth of slabs Tolerance of ± 5 mm for hand cut slabs and ± 2 mm for machine cut slabs shall be allowed.

14.20.3. Preparation of surface and laying - The specification shall be as described in 14.18.3 except that the edges of the slabs to be jointed shall be buttered with grey cement, with admixture of pigment to match the shade of the slab.

14.20.4. Polishing and finishing - The specifications shall be as described in 14.11.3 except that (a) first polishing with coarse grade carborundum stone shall not be done, (b) cement slurry with or without pigment shall not be applied on the surface before polishing.

14.20.5. Measurements and rates - These shall be as described above in 14.18.5 & 14.18.6.

14.21. SPECIFICATIONS FOR KOTA STONE IN RISERS OF STEPS, SKIRTING AND DADO

14.21.1. Kota stone slabs and dressing shall be as specified except that the thickness of the slabs shall be 25 mm or as specified in the description of the item.  The slabs may be of uniform size if required.

14.21.2. Preparation of surface shall be as specified.

14.21.3. Laying shall be as specified in 14.19.3 except that the joints of the slabs shall be set in grey cement mixed with pigment to match the shade of the slabs.

14.21.4. Curing, polishing and furnishing shall be as specified in 14.19.4 except that first polishing with coarse grade carborundum stone shall not be done.

14.21.5. Measurements - Length shall be measured along the finished face of riser, skirting or dado correct to a cm.  Height shall be measured from the finished level of tread of floor to the top (the underside of tread in the case of steps). This shall be measured correct to a mm in the case of risers of steps and skirting and correct to a cm in the case of dado.  The area shall be calculated in square meter correct to two places of decimal. Lining of pillars etc. shall also be measured under this item.

14.21.6. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.

14.22. SPECIFICATIONS FOR RED OR WHITE ROUGH DRESSED SAND STONE FLOORING

14.22.1. Stone slabs - The slabs shall be red or white as specified in the description of the item.  The stone slabs shall be hard, sound, durable and tough, free from cracks, decay and weathering. In case of red sand stone, white patches or streaks shall not be allowed.  However, scattered spots up to 10 mm diameter will be permitted. Before starting the work the contractor shall get samples of slabs approved by the engineer.

The slabs shall be hand or machine cut to the requisite thickness along planes parallel to the natural bed of stone and should be of uniform size if required.

14.22.2. Dressing of slabs - Every slab shall be cut to the required size and shape, and rough chisel dressed on the top, so that the dressed surface shall not be more than 6 mm from a straight edge when placed on it. The edge of depressions or projections shall be chisel dressed in a slant so that the surface does not have sharp unevenness. The sides shall also be chisel dressed to a minimum depth of 20 mm so that the dressed edge shall at no place be more than 30 mm from a straight edge butted against it.  Beyond this depth the sides may be dressed slightly splayed so as to form inverted ‘V’ shaped joint with adjoining slabs.  All angles and edges of the slabs shall be true, square and free from chippings and the surface reasonably true and plane. Where slabs are used for treads without nosing, the exposed edges shall be rough chisel dressed to full depth and cut to uniform thickness. The thickness of the slabs after it is dressed shall be 40 mm or as specified in the description of the item with a permissible tolerance of  ± 2 mm.

14.22.3. Laying

Base concrete on which the slabs are to be laid shall be cleaned, wetted and mopped.  The bedding for the slabs shall be with cement mortar 1:5 (1 cement: 5 coarse sand) or with the lime mortar 1:1:1 (1 lime putty: 1 surkhi:  1 coarse sand) or as given in the description of the item.

The average thickness of the bedding mortar under the slabs shall be 20 mm and the thickness at any place under the slabs shall not be less than 12 mm.

The slab shall be laid in the following manner - Mortar of specified mix shall be spread under each slab.  The slab shall be washed clean before laying.  It shall then be laid on top, pressed and carried, so that all hollows underneath get filled and surplus mortar works up through the joints. The top shall be tapped with a wooden mallet and brought to level and close to the adjoining slabs, with thickness of joint not exceeding 5 mm.  Subsequent slabs shall be laid in the same manner.  After laying each slab surplus mortar on the surface of slabs shall be cleaned off and joints finished flush.

In case pointing with other mortar mix is specified, the joint shall be left raked out uniformly and to a depth of not less than 12 mm when the mortar is still green.  The pointing shall be cured for a minimum period of 7 days.  The surface of the flooring as laid shall be true to levels and slopes as instructed by the engineer.

Slabs which are fixed in the floor adjoining the wall shall enter not less than 12 mm under the plaster, skirting or dado.  The junction between wall plaster skirting and floor shall be finished neatly and without waviness.

The finished floor shall not sound hollow when tapped with wooden mallet.

14.22.4. Finishing - Any unevenness existing between the edges of slabs at joints shall be removed by chiseling in a slant.

14.22.5. Measurements - These shall be as specified in 14.18.5.

14.22.6. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above.  Where pointing is to be done, this will be paid extra unless specifically included in the description of the item.

14.23. SPECIFICATIONS FOR RED OR WHITE FINE DRESSED SAND STONE FLOORING

14.23.1. Stone Slabs shall be as specified.

14.23.2. Dressing - Every slab shall be cut to the required size and shape and chisel dressed on all sides to a minimum depth of 20 mm.  The top and the joints shall be fine tooled so that straight edge laid along the face is fully in contact with it.  In case machine cut stones are used, chisel dressing and fine tooling of machine cut surface need not be done provided a straight edge laid anywhere along the machine cut surface is in contact with every point on it.

The thickness of the slabs after dressing shall be 40 mm or as specified in the description of item with a permissible tolerance of ± 2 mm.

14.23.3. Laying - Shall be as specified.

Finishing - In case of chisel dressed stone flooring slight unevenness, if any existing between the edges of slabs at joints shall then be removed by chiseling in a slant.

14.23.4. Measurement and rate - Shall be as specified in 14.22.5 and 14.22.6

14.24. SPECIFICATIONS FOR RED OR WHITE FINE DRESSED AND RUBBED SAND

14.24.1 Stone flooring

14.24.1. Stone slabs shall be as specified.

14.24.2. Dressing - The specifications for dressing the top surface and the sides shall be as described in 14.22.2. In addition the dressed top and sides shall be table rubbed with coarse grade carborundum stone before paving, to obtain a perfectly true and smooth surface free from chisel marks. The thickness of the slabs after dressing shall be as specified with a permissible tolerance of ± 2 mm.

14.24.3. Laying - The slabs shall be laid with 3 mm thick or 5 mm thick joints as specified in the description of the item.

Where the joints are to be limited to 5 mm thickness, the slabs shall be laid as specified except that the bedding mortar shall be as specified and sides of the slabs to be jointed shall be buttered with cement mortar 1:2 (1 cement: 2 stone dust) admixed with pigment to match the shade of the slab.

Where the slabs are to be laid with 5 mm thick joints the specifications for laying shall be as described in 14.22.3.

14.24.4. Finishing shall be as specified in 14.22.4 except that chisel marks and unevenness shall be removed by rubbing with coarse grade carborundum stone.

Measurement and Rate shall be as specified in 14.22.5 and 14.22.6.

14.25. SPECIFICATIONS FOR PVC SHEET / TILES FLOORING

14.25.1. Materials - P. V. C. Flooring material is normally used for covering floor from decorative point of view in residential and non-residential buildings. This material gives a resilient and non-porous surface which can be easily cleaned with a wet cloth as dust and grime do not penetrate the surface. Since a burning cigarette will damage the neat surface of the PVC sheet, special care should be taken to prevent burning cigarette stumps to come in contact with the P. V. C. flooring materials.

It shall be laid on the base that is finished even and smooth such as concrete, metal or timber boarding. Unevenness or undulations in the base will show badly on the surface and are liable to damage the P. V. C. sheet / tiles. The PVC flooring material shall conform to IS:  3462.  It may be in the form of tiles, sheets or rolls as specified. It shall consist a thoroughly blended composition of thermoplastic binder, filler and pigments. The thermoplastic binder shall consist substantially of one or both of the following;

Vinyl chloride polymer, Vinyl chloride copolymer

The polymeric material shall be compounded with suitable plasticisers and stabilizers.

Thickness - The preferred thickness of PVC tiles for normal floor covering shall 1.5, 2.0, 2.5, 3.0 or 4.0 mm. Thickness of P. V. C. sheets shall be measured with micrometer of Ratchet type or a dial gauge graduated to 0.02 mm.  The micrometer shall have flat bearing surfaces of at least 6.5 mm diameter at both contact points.

For sheets and rolls the thickness of the specimen shall be measured at twenty scattered points.

For polystyrene wall tiles, the cavity depth of the test specimen shall be measured at five points taken at random on the rear surface of each tile with a suitable depth gauge.

The width of flooring sheets and rolling in continuous length shall be 1000, 1500 and 2000 mm.  When supplied in rolls the length of the rolls shall not be less than 10 meter.

The measurement shall be carried out with a travelling microscope or suitable scale graduated to 0.02 mm. Each tile shall be measured for length and width at the three quarter point in each direction.

Tolerance

a) Thickness  ± 0.15 mm

b) Width

i) 300 mm square tiles    ±  0.2 mm

ii) 600 mm square tiles   ±  0.4 mm

iii) 900 mm square tiles  ±  0.6 mm

iv) Sheets and rolls        ±  0.1 per cent

Adhesive - Rubber based adhesives are suitable for fixing PVC flooring over concrete wooden and metal sub-floors. PVA based adhesives shall be used for concrete and wooden sub-floors. PVA based adhesives are not suitable for metallic surfaces and also for locations where there is constant spillage of water.

14.25.2. Preparation of sub floors - Before laying PVC sheets/tiles, it is essential to ensure that the base is thoroughly dry and damp proof as evaporation of moisture can not take place once the PVC flooring is laid. Moisture slowly damages the adhesive resulting in PVC sheet / tiles being separated from the base and curled up.  In case of new work a period of 4 to 8 weeks shall be allowed for drying the sub-floor under normal conditions.

Concrete sub-floors on the ground floor shall be laid in two layers. The top of the lower layer of concrete shall be painted with two coats of A-90 grade (conforming to IS:  1580) applied at the rate of 1.5 kg/sqm. The top surface of the lower layer shall be finished smooth while laying the concrete so that the bitumen can be applied uniformly.  The bitumen shall be applied after the concrete has set and is sufficiently hard.  Bitumen felt conforming to IS: 1322 shall be sand-witched in the sub-floor laid in two layers.

In new concrete floor, the smooth finish required shall be produced by using cement slurry spread on fresh concrete floor and finished smooth.  If the concrete floor is old and surface not even, the surface should be made smooth by first cleaning it free of all foreign material and then a layer of cement mortar 1:2 (1cement 2 coarse sand) of average thickness of 6 mm shall be applied on the surface finishing the surface smooth. The finished surface shall be cured for 7 days and then allowed to dry thoroughly.

Where it is expected that the dampness may find its way from the surrounding walls, the same shall also be effectively damp-proofed up to at least 150 mm above the level of the sub-floor and the damp-proof treatment below the floor shall be extended over the walls.

14.25.3. Laying and fixing

Prior to laying, the flooring tiles/rolls/sheets shall be brought to the temperature of the area in which it is to be laid by stacking in a suitable manner within or near the laying area for a period of about 24 hours.

Where air conditioning is installed, the flooring shall not be laid on the sub-floor until the conditioning units have been in operation for at least seven days.  During this period the temperature shall neither fall below 20 degree C nor exceed 30 degree C.  These conditions shall be maintained during laying and for 48 hours, thereafter.

Before commencing the laying operations, the sub-floor shall be examined for evenness and dryness. The sub-floor shall then be cleaned with a dry cloth.  The PVC flooring shall not be laid on a sub-floor unless the sub-floor is perfectly dry.  Methods of testing for dryness are specified in Annexure 14-A.4. The layout of the PVC flooring on the sub-floor to be covered should be marked with guidelines. The PVC flooring shall be first laid for trial, without using the adhesive, according to the required layout.

The adhesive shall be applied by using a notched trowel (see Fig. below) to the sub-floor and to the back side of the PVC sheet or tile flooring.  When set sufficiently for laying, the adhesive will be sticky in touch, but will not mark the fingers. In general, the adhesive will require about half an hour for setting. It should not be left after setting for too long a period as the adhesive properties will be lost owing to dust films and other causes.

Care should be taken while laying the flooring under high humidity conditions so that condensation does not take place of the adhesive.  It is preferable to avoid laying under high humidity conditions.

The area of adhesive to be spread at one time on the sub-floor depends entirely upon local circumstances. In case of a small room, adhesive may be spread over the entire area but relatively small areas of tile s/ sheets flooring should be treated in a larger room.

When the adhesive is just tack free, the PVC flooring sheet shall be carefully taken and placed in position from one and onwards slowly so that the air will be completely squeezed out between the sheets and the back ground surface. After laying the sheet in position, it shall be pressed with suitable roller weighing about 5 kg to develop proper contact with the sub-floor. The next sheet with its back side applied with the adhesive shall be laid to edge with the sheet already laid and fixed in exactly the same manner as the first sheet was fixed.  The sheets shall be laid edge to edge so that there is minimum gap between joints.

The alignment should be checked after laying of each row of sheet is completed. If the alignment is not perfect, the sheets may be trimmed by using a straight edge.

The tiles shall be fixed in exactly the same manner as for the sheets. It is preferably to start laying of the tiles from the centre of the area. Care should be taken that the tiles are laid close to each other with minimum gap between joints. The tiles should always be lowered in position and pressed firmly on to the adhesive.  Care should be taken not to slide them as this may result in adhesive being squeezed up between the joints. PVC tiles after laying shall be rolled with a light wooden roller weighing about 5 kg to ensure full contact with a under layer.  Any undulations noticed on the PVC surface shall be rectified by removing and relaying the tiles after thorough cleaning of the underside of the affected tiles.  The adhesives applied earlier in such places shall be thoroughly removed by using proper solvents and the surface shall be cleaned to remove the traces of solvents used.  Work should be constantly checked against guidelines in order to ensure that all the four edges of adjacent tiles meet accurately. Any adhesive which may squeeze up between sheets or tiles should be wiped off immediately with a wet cloth before the adhesive hardens. If, by chance, adhesive dries up and hardens on the surface of the sheet or tile, it should be removed with a suitable solvent.  A solution of one part of commercial butyl acetate and three parts of turpentine oil is a suitable solvent for the purpose.

A minimum period of 24 hours shall be given after laying the flooring for developing proper bond of the adhesive.  During this period, to lay the PVC flooring after completion of plastering, painting and other decorative finish works so as to avoid any accidental damage to the flooring.

When the flooring has been securely fixed, it shall be cleaned with a wet cloth soaked in warm soap solution (two spoons of soap in 5 litres of warm water).

Where the edges of the PVC sheets or tiles are exposed, as for example, in doorways and on stair treads, it is important to provide protection against damage of flooring materials.  Metallic edge strips may be used and should be securely fastened to the sub-floor to protect edges of the flooring.

14.25.4. Precaution for maintenance - PVC flooring subject to normal usage may be kept clean by mopping with soap solution using a damp cloth.  Water shall not be poured on the PVC flooring for cleaning purpose as the water may tend to keep through the joints and cause the adhesive to fail. To maintain a good wearing surface a good appearance, the flooring may be periodically polished. When polish is applied frequently, a thick layer builds up which collects dirt and dust and is tacky to walk on.

If the traffic is light, the floor shall be given frequent brushing regular polishing by an application of new polish every 4 to 6 weeks. Under moderate traffic conditions the floor shall be given an occasional wash with a wet mop but no detergents shall be used so that the polish is not removed.

Application of polish may be done every one to three weeks. P. V. C. flooring should not be over-waxed.  When this condition develops, the coatings should be cleared off with white spirit or paraffin and a light even coat of polish applied.  When the PVC flooring has been polished, it will remain bright for a considerable period if dry mop is applied each day.  It is this daily ‘dry polish’ that maintains the glossy surface. After exceptionally heavy traffic, PVC flooring should be swept with a hair groom, rubbed with a mop or cloth frequently rinsed in clean water and finally rubbed dry.

14.25.5. Measurements - Length and breadth shall be measured correct to a cm and its area shall be calculated in sqm correct to two places of decimal. No deduction shall be made nor extra paid for voids not exceeding 0.20 square meter. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter. Nothing extra shall be paid for providing PVC flooring in borders and margins, irrespective of their width.

14.25.6. Rate - The rate shall include cost of all materials and labour involved in all the operations described above, except those as described.  The rate does not include the cost of sub-floor or damp proof treatment if any.  It also does not include the cost of metallic edge strip to protect edge of flooring, wherever provided, it shall be paid separately.

14.25.7. PVC asbestos floor tiles - Material, dimensions and tolerances, colour and finish, physical requirements and test shall be as per IS:  3461 and the rest shall be as per above.

14.26. SPECIFICATIONS FOR STONE SLABS FLOORING-SECOND CLASS

14.26.1. The plinth filling shall be brought to the proper level, watered and thoroughly consolidated by ramming.  For inner floor, the surface of the consolidated plinth filling shall be perfectly levelled, but for verandahs it shall be at a slope of 1 in 40 which is also to be the slope of the finished flooring.  Slab shall be laid on 75 mm of concrete, (if so specified).  The slabs shall be laid so as to cover the inner plinth.  For this purpose, the inner plinth should be built about 150 mm lower than the floor level.

14.26.2. Stone slabs for flooring shall be obtained from the quarry specified or approved.  They shall be of the best quality available, hard even sounding, durable, free from cracks or flaws and 75 mm thick (unless otherwise specified).  They shall be rectangular or square in shape with clean square edges.  The bottom face of the stone may be left quarried but the top surface shall be either one or two line dressed as specified.  The joints shall be dressed back square with the top surface at least two inches without hollows.  A sample of the stone shall be got approved by Executive Engineer.  The sizes of the slabs shall be described in the specification of work.

14.26.3. The slabs shall be laid in courses of uniform width parallel to the shorter side of the room or verandah.  They shall break joints.

14.26.4. Each slab shall be thoroughly wetted by water before being laid.  It is to be well bedded in sand or lime mortar as the case may be and tapped down with a wooden mallet so that it cannot be shaken, and so that no hollow is left beneath it.

14.26.5. For second class work, the slab stone shall be chisel-dressed on the edges and made to the rectangular shape.  For third class work, quarry faced surfaces may be used when they are smooth and even.  For second class work, the surface should be evened by being dressed one or two lines according to specifications.  Joints must not be more than 15 mm in width, and must be dressed true and square and pointed with cement mortar 1:3.

14.26.6. The cement pointing should be kept thoroughly watered for 7 days after it is laid.

14.26.7. The above specification will suit floors of offices; but for floors of machine shops and stores subject to heavy loads it may be necessary to adopt slabs of larger area and thickness, laid on 100 mm to 150 mm of concrete.

14.26.8. The specification for 1st class slab stone flooring shall be as for 2nd class except that all stones are to be laid in squares of uniform size measuring not less than 350 mm x 350 mm or any other size ordered.  All surfaces and edges are also to be fine chisel-dressed.  Joints are to be not more than 6 mm in width, and are to be dressed true and square.  They are to be set in lime or cement mortar as specified.

14.26.9. Dressing of underside of stone slabs is necessary when laid on lime or cement concrete.

14.27. SPECIFICATIONS FOR VAJRAGARE FLOORING

14.27.1. The preparation of the plinth surface shall be as described in specification for stone slabs.

14.27.2. Vajragare flooring, unless otherwise specified, shall be 100 mm thick after finishing.

14.27.3. The concrete shall be as specified except that 40 mm ballast shall be mixed with 0.45 cm of quick lime to form 1 cum of beaten concrete.

14.27.4. When the concrete is thoroughly mixed, but not in too fluid a state, it shall be laid in a thickness of 100 to 125 mm and shall be rammed until it is reduced to 125 mm.  The surface must be frequently tested and be kept perfectly true and even.

14.27.5. While the ramming is in progress the surface of the concrete shall be liberally sprinkled with water in which Gur and Beel fruit are dissolved in the proportions (7 liters of Gur or 14 liters of molasses and 4 liters of Beel fruit and 125 of water).  Water used for mixing concrete should also be added with Gur and Beel in the same proportion.

As soon as the cream has thoroughly come to the surface, the ramming is complete and the mortar shall then be rendered smooth with the trowel sprinkling it with Gur and Beel water if necessary.

The surface shall then be polished a little lime or cement slurry being used during the process.  No plaster is to be laid over the concrete.

After the surface has been polished it shall be covered with 50 mm of sand or grass and kept damp for 7 days. 

14.28. SPECIFICATIONS FOR WOODEN FLOORING

14.28.0. Seasoning and preservation - All timber used for timber floors shall be thoroughly seasoned in accordance with IS1141.  After seasoning the timber shall be treated with preservative in accordance with IS:  401.  Seasoning and preservative treatment shall be paid for separately unless otherwise specifically included in the description of the item of flooring.

14.28.1. Supporting joists - Main beams and joists of the class of wood sections specified in the description of the item for beams and joists, or as instructed by the engineer shall be fixed in position to dead levels.  The width of the joints shall not be less than 50 mm.  The arrangement and spacing of beams joists etc shall be as per design furnished.

14.28.2. Boards - It shall be of the class of timber and thickness specified in the description of the item. The timber shall be as specified.  Only selected boards of uniform width shall be used.  Unless otherwise specified or shown in the drawings, the width of boards selected shall not be less than 100 mm nor more than 150 mm.  The same width of boards shall be maintained throughout except where the width of the room is not an exact multiple of the boards.  In the latter case, the difference shall be equally adjusted between the two end boards (adjacent to walls).  The length of the boards shall not exceed 3 metre anywhere.  Ordinarily, the minimum length of boards shall be such that the boards shall rest at least on three supports, except where otherwise required by the pattern specified in the drawings or as directed by the engineer.

The boards shall be planed true on the top face only unless otherwise specified in the description of the item.  Where the bottom face is exposed and it is also required to be planed, then such planing shall be paid for extra.

Unless otherwise described in the item, the longitudinal joints of planks shall be tongued and grooved to a minimum depth of 12 mm while the heading joints shall be of the square butt type and shall occur over the centre line of the supporting joists.  Heading joists in adjacent boards shall be placed over the same joists.

14.28.3. Iron screws - Iron screws shall be of the slotted counter sunk head type, of length not less than the thickness of planks plus 25 mm, subject to a minimum of 40 mm, and of designation No.9 conforming to IS:  451.

14.28.4. Fixing - The joists on which the planks shall be fixed shall be checked and corrected to levels. The end boards shall be accurately fixed with the sides parallel and close to the walls. Each adjoining board shall be carefully jointed and shall be tightened in position and screwed.  For fixing the boards to the joists, two screws shall be used at each end of the boards and one screw at each of the intermediate joists in a zig zag manner. The screws shall be countersunk and screw holes filled with approved stopping.

The junction between timber flooring and adjacent flooring shall be formed by inserting a metal strip (brass or aluminium) at the junction.  The metal strip shall be fixed to the end of the planks by screws.  The strips shall be paid for extra.

The flooring shall be truly level and plane. The joints shall be truly parallel and or perpendicular to the walls, unless otherwise specified.

The floor shall be planed in both directions and made perfectly even, true and smooth.

Note: No wood of any kind shall be placed within 60 cm of any fire place or flue.  Provision shall be made for ventilation the space below the floor in case of ground floor and between floor and top of ceiling in the case of upper floors. Such arrangements shall be paid for separately,

14.28.5. Finishing - The surface of the floor shall be bees waxed or finished otherwise as directed by the engineer.  The lower face shall be painted or treated with wood preservative as directed.  The finishing shall be paid for separately unless specifically included in description of the flooring item.

14.28.6. Measurements - Length and breadth of superficial area of the finished work shall be measured correct to a cm.  The area shall be calculated in square meter correct to two places of decimal. No deduction shall be made nor extra paid for voids not exceeding 0.20 square meters.  Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meters.

14.28.7. Rate - The rate shall include the cost of the labour and materials involved in all the operations described above, with the exceptions noted in the relevant sub-paras.

14.29. SPECIFICATIONS FOR WOOD BLOCK FLOORING (FIG. 6)

14.29.1. Wood blocks - The wood blocks shall be of the class of timber specified in the description of the item and shall be in accordance with the general specifications for ‘Wood Work’ as given. The size of blocks shall be as shown in the drawings.  The longitudinal edges of the blocks shall be truly rectangular in shape with clean sharp edges and true faces. The top and sides shall be planed true.  The thickness of the blocks shall be 38 mm unless otherwise specified.  The timber used for making the blocks shall be thoroughly seasoned in accordance with IS: 1141. After seasoning, the timber shall be treated with preservatives in accordance with IS: 401.

14.29.2. Base concrete - The specifications shall be same as in 14.2.2

14.29.3. Leveling concrete - The leveling layer of concrete shall be of cement concrete 124 (1 cement  2 coarse sand  4 stone aggregate 10 mm nominal size) by volume unless otherwise described in the item.  Its thickness shall be 25 mm.  Cement concrete shall be placed in position and levelled up with the help of a straight edge and trowel.  It shall then be beaten with wooden float to give a sand paper finish, plane and true to level.  The finished level of the concrete shall be lower than the proposed finished level of the flooring by the specified thickness of the wooden blocks plus a minimum of 1.5 mm.  The leveling layer shall be cured for a weak and then allowed to dry thoroughly, before paving with wood blocks.

14.29.4. Laying - The wood blocks shall be first laid ‘dry’ to the margin and pattern shown in the drawings or as directed by the engineer.  The blocks shall fit closely and sides and end shall be corrected by further planing if necessary to get closed and even joints. After the blocks have been fitted and matched they shall be removed and stacked in such a way as to facilitate their repaving in the same order.

The surface of the leveling course shall be thoroughly cleaned and a small area of the surface shall be coated with a thin layer of a hot bitumen such as blown type petroleum bitumen grade 85 /25 of IS:  702 or other equivalents, applied at a temperature of not less than 180 degree C and at the rate of 2.45 kg per square metre. The wood blocks shall then be taken in turn serially and be dipped in the same hot bitumen for about half their depth so as to coat thoroughly the bottom and part of the sides and quickly set and pressed into place to required patterns, on the previously coated concrete surface so that the dovetailed grooves at the edges of the blocks get filled up and bitumen.  The joints of the work shall be a very thin and fine.

When all the blocks shall have been set in position the surface shall be cleaned of any bitumen droppings and planed or machined level and smooth.

The floor shall then be given a final smooth finish by rubbing down with sand paper.

Note: No wood of any kind shall be placed within 60 cm of any fire place or flue.

Fig. 6 Wood block flooring

14.29.5. Finishing - The floor shall be Bees waxed or polished with ready made wax polish or given by any other finish as required.

14.29.6. Measurements - Length and breadth of superficial areas of the finished work shall be measured correct to a cm.  The area shall be calculated in square meter correct to two places of decimal.  No deduction shall be made nor extra paid for voids not exceeding 0.20 square meters. Deductions for ends of dissimilar materials or other articles embedded shall not be made for areas not exceeding 0.10 square meter.

14.29.7. Rate - The rate shall include the cost of all labour and materials involved in all the operations described above but shall not include the cost of base concrete bees waxing or other finishing as referred  to the paras 14.29.2, 14.29.3, and 14.29.5 unless otherwise specifically described in the

14.30. SPECIFICATIONS FOR CAST IRON GRID TILES FLOORING

Cast Iron Grid tiles flooring shall consist of cast iron grids to give design, laid on a strong base, with the hollows filled with cementing materials. This type of flooring is suitable in factories, bakeries dairies and similar structures where resistance to abrasion from iron tyred trolleys is a prime consideration.

14.30.1. Cast iron grid tiles - Tiles shall be manufactured from cast iron conforming to IS 210.  The tile shall be of the dimensions and weight per square metre specified in the description of then item. Variation in weight to the extent of 5% on either side shall be permissible. The ribs of the tiles shall be tapering down with the thicker end at top so that the cementing material filling the hollows between them is held fast and prevented from getting loose on the top. The tiles shall be of size such as 20 x 20 cm, 30 x 30 cm or 38 x 38 cm as shown in the drawings or as directed by the engineer. Where the room lengths and widths are not exact multiples of the size of the tiles, the end rows shall be laid with fractional tiles. The top surface of the tiles shall be ground smooth while sides of the hollows shall be left in the rough cast state.

14.30.2. Base concrete - The cast iron grid flooring shall be laid on a base which shall conform to the specifications as given of cement concrete flooring.  The base shall be designed to withstand the load coming on the floor.

14.30.3. Laying

The base concrete or the RCC slab on which the grid tiles are to be laid shall be cleaned, wetted and mopped. The bedding for the grid tiles shall consist of 1:2 cement and concrete (1 cement: 2 stone aggregate 6 mm nominal size) laid to 12 mm thickness tamped and corrected to proper levels. The bedding concrete shall be laid each time, over such an area as would accommodate about 8 to 10 tiles.  The grid tiles shall be laid one by one pressed into the bedding and tapped with a wooden mallet so that the concrete works up into the hollow of the grid tiles about 3 mm and the top face of the tile is at the correct finished level and plans.

The hollow shall be immediately filled in with cement concrete of the same mix tamped with 10 mm dia iron bars and the entire surface including width of joints finished 6 mm below the top.  Subsequent tiles shall be laid in the same manner, the joints between adjacent tiles being not more than 3 mm wide. The joints and top 6 mm of the hollows shall then be grouted with neat cement slurry.  The surface of the flooring shall be frequently checked with a straight edge at least 2 meter long during laying, so as to obtain a true surface. The surface shall then be cleaned of all mortar droppings.  The finished surface shall have no raised edges.  The surface of the flooring shall be made smooth where necessary.

Tiles which are fixed adjoining the wall shall enter not less than 12 mm under the plaster, skirting or dado.

The surface shall be kept wet for a period of not less than seven days.

In special cases it may be required that the concrete bedding and the filling of the hollows and joints shall be acid or alkaline resistant, in which case special type of cement to meet the particular requirements shall have to be used instead of ordinary grey cement.  In such cases, the types of special cement shall be specified in the description of the item.

14.30.4. Measurements - Length and breadth shall be measured correct to a cm before laying skirting, dado or wall plaster. The area shall be calculated in square meter correct to two places of decimal. No deduction shall be made nor extra paid for voids not exceeding 0.20 square meter.

Deductions for ends for dissimilar material or other articles embedded shall not be made for areas not exceeding 0.10 square meter.

14.30.5. Rate - The rate shall include the cost of all materials and labour involved in all the operations described above except the cost of base concrete.  Nothing extra shall be paid for use of fractional tiles.

14.31. SPECIFICATIONS FOR REINFORCED BRICK AND BRICK CONCRETE FLOORS

14.31.1. General

Reinforced brick and brick concrete floors are widely adopted, particularly in north India. This type of construction consists of laying high strength bricks directly over the form work with reinforcements in between the joints and filling up the joints with concrete. This type of construction has been found to be strong, durable and it also facilitates quick construction. However, in this type of construction, reinforcement deteriorates due to corrosion, unless otherwise protected.

14.31.2. Preparatory work

Bricks shall be kept immersed in water for 4 to 6 h and removed about 15-20 min before they are used so that their skin is dry when concrete is poured.

Reinforcement shall be so placed, that they do not touch bricks at any point. A minimum cover of 25 mm shall be provided all round the reinforcement.  Corrosion of reinforcement shall be prevented by taking measures recommended in IS: 9077-1979 which deals with corrosion protection of reinforcement in RB and RBC construction. In general two bars shall not be used in the same joint.

Details of corrosion protection are as below:

a) Quality of concrete mix, should be higher than M -15.

b) Cover to reinforcement as specified in IS: 456 - 1978 subject to severe conditions of exposure.

c) Protective coatings may be as follows

  1. Cement – sand – asphalt / coal tar pitch mixture coating – A dry mixture of cement, molten asphalt or coal tar pitch and dry sand in the ratio of 1:1:3 by mass should be applied on the steel surface to a thickness of 6 mm and surface should be finished by flaming.
  2. Cement – sand – mortar with neat cement finish – 1:3 cement mortar to a thickness of 6 mm shall be applied. The surface should be finished with a neat cement slurry finish with a 2:1 water cement ratio.
  3. Empty resin/mortar rendering may also be applied in existing structures.

4) Steel reinforcement may be coated with cement slurry to inhibit corrosion.

d) Reinforcement shall be free from rust; heavy rust shall be removed by brushing or by de-rusting jellies.

14.31.3. Construction of RB and RBC roof or floor

Centering shall be erected to support the RB floor or roof from below.  The centering shall be smooth, clean and to correct alignment. The top surface of the form work shall be given an upward camber of 1 mm for every 150 mm of span subject to a maximum of 30 mm to allow for initial settlement.  Before laying the slab, the form work and the supports shall be checked to prevent undue sag and to ensure overall safety and stability of the form work.

All main and distribution bars shall be placed in the position in Fig. 7 and shall be completely embedded in concrete.  They shall be rigidly secured against any displacement and arrangement shall be made to ensure proper cover to reinforcement. Splices in adjacent bars shall be staggered. Horizontal spacing of bars shall not be more than 3 times the effective depth or 450 mm whichever is smaller. The pitch of the distribution bars shall be not more than 5 times the effective depth or 450 mm whichever is smaller. The reinforcement in either direction shall not be less than 0.20 percent of the cross section of slab for mild steel and 0.16 per cent for deformed bars.

The bricks, as prepared shall be laid as shown in Fig. 7.with cement mortar 1:3. Preferably a minimum spacing of 60 mm in between bricks should be maintained for preventing corrosion.

14.31.4. Laying of bricks and reinforcement

a) The bricks for single brick thickness of floor or roof shall be laid directly on the forms without bedding of any kind. After one or two bricks have been laid the next row is similarly laid providing the gap for concrete joint. Cement concrete shall be poured into the joints after the placement of reinforcement.

Fig 7 Typical RB and RBC slab.

The concrete shall be fluid enough to run freely around the reinforcing bars and fill the joints completely. 

The joints shall be puddled sufficiently with a trowel or a sharp ended 16 mm bar to allow free flow of concrete.

b) If a slab of two courses of bricks is laid, a fresh layer of concrete shall be placed over the first course to make the middle horizontal joints and screeded properly to the desired thickness of the joint.  The top course is laid in the same manner as the first course.

14.31.5. Curing -  The brickwork shall be kept wet means of wet straw or wet sand or merely be sprinkling water gently over the surface for about 24 h after finishing. The slab shall then be watered profusely for a period of at least 10 days.

14.31.6. Removal of form work - The form work shall not be removed before 14 days after laying.

14.31.7. Finishing - The completed floor or roof shall be finished with a water proofing course of lime concrete or mud phuska with tiles.  The ceiling shall be rendered or plastered, after drying, with cement mortar (1:3) or lime mortar (1:2) as specified. The plaster may be in a single coat of 12 mm thick and shall be done in accordance with IS: 1661-1972.  The finished surface of the floor or roof shall be cured with water for a period of not less than 3 weeks.

14.32. Types of floor finishes - Types of floor finish shall be as in Table 4, depending on the expected load, wear of the floor and whether the top is monolithic with base or laid separately on a set and hardened base.  In either case special precaution is necessary to ensure bond between topping and the base.

14.32.1. Monolithic floor finish (Finishes Type 1 and Type IV) - In case of monolithic construction even a small thickness of topping is sufficient because of strength imparted to it by the base concrete and such type of finish is quite suitable as moderately strong and economical finish (see figure 8 & 9 ) with good wearing quality.

14.32.2. Bonded floor finish (Types II, III, V and VI) - In case of bonded construction, where floor finish is laid separately over a set and hardened base, the topping has to be laid to greater thickness, care shall be taken to ensure a good bond between the topping and base; otherwise it may lead to cracking, curling and warping of the floor finish.  The higher thickness adds to the dead weight of slab (see figure 10, 11 & 12)

a) The advantage of this type of bonded finish is that it is not damaged since it is done after all the work of base and structural slab is done much in advance. Close tolerances can be maintained and levels of finished floor can be controlled.  This type of finish is also suitable to be laid on old concrete.

b) Where very dense and smooth surface is desired, the topping can be laid in two layers (finishes Types III and VI).  The under layer consisting of a leaner mix is first laid separately on the hardened base; and the wearing layer of very stiff and richer mix, but of thickness smaller than the under layer, is bonded to the green concrete of under layer and finished smooth.

Fig. 8 A Without hard core sub-base

Fig. 8-B With hard core sub-base

c)In case of bonded finish on structural slabs where it is not possible to obtain proper levels within the thickness of topping; a cushioning layer of about 50 to 75 mm thick lime concrete is laid and well compacted over the structural slab.  Lime concrete layer may also be necessary to obtain a level surface over structural floors other than that of concrete or for embedding dead weight to the structure.

14.32.3. Mix proportions -  Mix proportions of base concrete and the topping for different types of floors shall be as specified in Table 9.1. The topping finish mix of 1:2:4 is being replaced by 1:2.5:3.5 mix since this gives a much better workability and finish.

14.32.4. Durability - Concrete floors possess good durability and resistance to abrasion and wear depending upon the following factors.

(a) Choice of aggregate – Hard tough aggregate is essential for good durability as well as abrasion resistance.

(b) Water-cement ratio – The lower the water cement ratio the greater the durability and wear resistance provided the flooring is fully compacted.

(c)Density of flooring – Durability increases with density of finish.  The staining of floor surface that may result from absorption of oils is reduced by increasing the density of floor finish.

(d)Curing – Adequate curing is very essential to ensure good wear resistance.

Fig. 8-C Sub-base for regions having expansive soil

 Fig. 9 Structural slab

14.32.5. Resistance to attack by chemical reagents - Concrete flooring is slowly attacked by acids, vegetable oils, sugar solution and various other agents; prolonged exposure to these reagents will bring about gradual deterioration.

14.32.6. Slipperiness - The slipperiness of concrete surface depends mainly upon the surface treatment, highly polished type of floor finish is likely to be slippery. A trowel finished floor is reasonably non-slip. Non-slip surfaces may be obtained by trowel finish or by providing non-slip inserts. Floor finishes over ramps, stairs and other similar situations, especially if they are liable to get wet, shall be finished in chequered pattern to make them non-slip.

14.32.7. Surface hardening solutions - It is not necessary, generally, to apply any further treatment to the cement concrete floor topping but dusting may be reduced by application of one of the surface hardening solutions of sodium silicate, magnesium silico-flouride or zinc silico-flouride or proprietary materials consisting mainly of one or more of these compounds. These treatments are likely to need renewals at intervals of one year. Manufacturer’s advice should be followed when proprietary materials are used.

14.32.8. Size of panels - Floor finish shall be divided into panels so as to reduce the risk of cracking. The size of the panel is governed by the thickness of floor finish, the type of construction (monolithic or bonded), local conditions of temperature, humidity and the season in which the flooring is laid.  For floor finish laid in hot and dry climates or in exposed situations, the size of the panels for floor finish shall be smaller than those laid in less exposed situations or in cold and humid climates. The size of

panels for monolithic floor finish can be larger than that of bonded floor finish. Generally no dimension of a panel shall exceed 4 m in case of monolithic floor finish and 2 m in case of bonded floor finish. 

The length of the panel shall not exceed 1 ½ times its breadth.  Dividing strips may be used to form panels.

Fig.10 Bonded floor finish over ground

a) The joints of floor finish shall extend through the border skirting. If the skirting is laid monolithic with the flooring, a border of about 300 mm width must be provided all-round the floor.  The width of the border provided around the floor when the skirting is not monolithic with floor finish shall not exceed 450 mm.

b) Construction joints between bays of the floor finish should be placed over any joints in the base concrete.

14.32.9. Protection against dampness - The layer of sand provided under the base concrete will generally serve as a damp-proof course under normal conditions. However in more severe conditions, damp-proofing shall be provided.

14.32.10. Finish over stairs - For risers 6 mm thick mortar finish will be sufficient; 10 mm thickness may be provided when the surface of structural concrete is uneven. At treads, the thickness shall be not less than 20 mm for monolithic type of construction and 40 mm for bonded construction.

Fig. 11 Bonded floor finish over structural slab

Fig. 12-A

Fig. 12-B – Floor finish on structural slab laid over Cushioning layer of lime concrete

Table 1 Recommended specification for different types of concrete floors

Type

Sub-base

Base concrete

Topping

Minimum thickness (mm)

Mix proportion (by volume)

Minimum thickness (mm) 

Mix proportion

(by volume)

A

Cement concrete flooring laid over ground

 

 

 

I

Thoroughly consolidated ground covered with 100 to 150 mm well rammed preferably course sand

100

Cement concrete 1:4:8 (stone aggregate 40 mm and below)

20

Cement concrete 1:2 to 3 (fine aggre-gate)

IA.

100 mm thick hard core of well consolidated dry brick or stone aggregate blended with Moorum or coarse sand, laid over well rammed sand filling of 100 mm thick.

100

-do-

20

Cement concrete 1:2:4 (coarse aggre-gate 12.5 mm and below)

IB.

Stone ballast (40 mm graded aggregate) mixed with locally available yellow or red soil or soft moorum in 1:1 proportion shall be compacted to about 300 mm thickness and thoroughly saturated with water.

100

-do-

20

Cement concrete 1:2 to 3 (fine aggre-gate)

II

Thoroughly consolidated ground covered with 100 to 150 mm well rammed (preferably coarse) sand

100

Cement concrete 1:5:10 (aggregate size  40 mm and below)

25

Cement concrete 1:2:5:3.5 (coarse aggre-gate 12.5 mm and below)

III

-do-

100

-do-

Under layer

25

Under layer cement concrete 1:3:6 (coarse aggre-gate 12.5 mm and below)

Wearing layer

15

Wearing layer cement concrete 1:2 to 3 (fine aggregate)

B

Floor topping laid over structural slabs

 

 

 

IV

--

--

--

15

Cement concrete 1:2 to 3 (fine aggre-gate)

V

--

--

--

25

 

Cement concrete 1:2.5:3.5 (coarse aggre-gate 12.5 mm and below)

VI

--

--

--

Under layer

25

Under layer cement concrete 1:3:6 (coarse aggre-gate 12.5 mm and below)

 

 

 

 

Wearing layer

15

Wearing layer-cement concrete 1:2 to 3 (stone aggregate 4.75 mm and below)

VII

--

50.75

Lime concrete

Same as for Type V or VI

 

Notes:

1. In regions having expansive soils, the sub-base shall be laid as given in Type IB for both Type II and Type III flooring.

2. For Type I, the cement concrete topping shall be laid monolithic with the base concrete. For Type IA, in places such as garages, where wheeled traffic comes into contact with t flooring, the sub-base shall have a hard core over the well rammed sand filling.  For Type IB, in regions having expansive soils, Note 1 will apply.

3. For Type III, under layer shall be laid separately over specially prepared surface of set and hardened base concrete. The wearing layer shall then be laid over the green surface and finished/monolithic with it.

4. For Type VII, a cushioning layer of lime concrete shall be laid over the prepared surface of structural slab.

14.33. SPECIFICATIONS FOR IN-SITU GRANOLITHIC CONCRETE FLOORING TOPPING

14.33.1. General

a)  Granolithic concrete floor topping is adopted for heavy engineering factories, workshops, garages, warehouses, etc. where the floor is subject to heavy loads and severe abrasion combined with impact.  The granolithic concrete essentially consists of rich concrete made with specially selected aggregate of high hardness, surface texture and particle shape suitable for use as a wearing finish to the floors.  Although plain concrete laid as per specification would be satisfactory for many purposes, granolithic concrete is chosen because of its high abrasion resistance and used for floor toppings wherever abrasion combined with impact is likely to be severe.

b)  The base concrete shall be laid as per and here only the laying of granolithic topping is described.

c)  There are two methods of laying in-situ granolithic concrete floor topping.  The topping shall be laid within 3h of the laying of the base, that is, monolithically with the base concrete; or alternatively shall be laid anytime after the base has begun to harden, in such a way as to produce the maximum possible bond between the bases and topping, that is, it shall be laid separately from the base.  In ground floors it is advisable to lay the granolithic concrete topping monolithically with base concrete.  In the case of bonded construction extreme care shall be taken to ensure no breaking of bond between the base and topping.

d)  Floor finish to be laid depends on nature of use and performance expected of the topping.  Therefore the thickness, selection of mix proportions, panel sizes and the type of construction shall be carefully decided.

14.33.2. Materials

a)  Cement to IS: 269-1989 or IS: 455-1989 or IS: 1489 (Parts 1 & 2)-1991 or any other cement as specified.

b) Aggregates - The aggregates shall consist of one or more of the following groups: I) Granite, ii) Basalt, iii) Trap and iv) Quartzite.

The aggregates shall conform to IS: 383-1970 and the crushing value when determined as per IS: 2386 (Part 4)-1963 shall not exceed 30 percent.  The grading of the aggregates for granolithic concrete shall conform to Table 5 for coarse aggregate and Table 6 for fine aggregate.

Table 5 Coarse aggregate (Clause 14.33.2)

IS sieve designation

Percentage by mass passing IS sieves

12.5 MM

90-100

10 MM

40-85

4.75 MM

0-10

2.36 MM

 

Table 6 Fine aggregate (Clause 14.33.2)

IS sieve designation

Percentage by mass passing IS sieves

Grading zone 1

Grading zone 2

10 mm

100

100

4.75 mm

90-100

90-100

2.36 mm

60-95

75-100

1.18 mm

30-70

55-90

600 micron

15-34

35-59

300 micron

5-20

8-30

150 micron

0-10

0-10

c) Admixtures - Integral additions are not normally required; but may be advantageous in certain circumstances.

d)  Abrasives - Metallic or non-metallic materials of high abrasion resistance may be incorporated in the floor topping mix to increase the abrasive resistance of floor topping.

e)  Surface hardening solutions - These solutions, as described in Annex A of this part may be used.

14.33.3. Preparatory work

a)  Mix proportions - The mix proportion for granolithic concrete floor topping for different types of floor finishes shall be 1:1:2 (by volume).

b)  Joints - Construction joints between bays of the floor finish need only be plain untreated vertical butt joints and should be placed over any joints in the base.

Where expansion joints are necessary in the walls and roof of a building, there should be corresponding joints in the floor.  The floor finish should not be allowed to cover the joint filler of the expansion joint in the base concrete; either joint filler should be extended through the full thickness of the base concrete and finish or the space above it should be filled with a suitable sealing compound.

c)  Protection against dampness - Protection against dampness shall be as specified.

14.33.4. Laying of floor over base concrete

Floor topping laid monolithically with the base concrete (see Table 7 and clause14 33.4)

On clean green surface of the base concrete laid in accordance with specification, the topping shall be placed in position as soon as possible but generally not later than 2 to 3 h of laying base concrete, depending upon the temperature and atmospheric conditions. The base concrete at the time of laying the topping shall be still green but sufficiently firm to enable the workmen to walk over it by placing planks on its surface.  The granolithic mix (1:1:2) shall be deposited on the base concrete in the screed strips already laid and thoroughly compacted to the finished thickness.  The surface shall be tested to detect any undulation in the surface, if any, and shall be made good immediately.  The topping shall be floated with a wooden float to render the surface even and after the surface is slightly hardened it shall be finished smooth.

Floor topping laid separately on hardened base concrete (see Table 7) - Before the operation of laying the topping is started, the surface of the base concrete shall be thoroughly cleaned of all dirt, loose particles, laitance, etc. by scrubbing with coir or steel wire brush, where the concrete is hardened, the surface shall be roughened by chipping or hacking.  The surface shall be wetted with water for several hours and surplus water shall be removed immediately before topping is laid. 

Neat cement slurry shall be thoroughly brushed into the prepared surface of base concrete before laying the granolithic topping.  The screed strips shall be so arranged that the joints, if any, in the base concrete shall coincide with the joints in the topping.  The topping shall be tested for evenness, floated and finished smooth.

14.33.5. Laying of floor topping on suspended slab -Floor topping and monolithically with the suspended slab (see Table 7) - The frame work for the suspended slab shall be erected to the full thickness of the floor finish.  Structural concrete shall be deposited in the forms thoroughly consolidated and surface finished below the top edge of the form to accommodate the required thickness of the topping.  Any slope required in the floor finish shall be given the structural concrete itself when it is still green.  The surface shall be finished smooth but   rough enough to provide an adequate bond for the topping. On the green surface of the structural concrete, granolithic concrete (1:1:2) shall be placed in position immediately after the structural concrete has stiffened enough (but is still plastic) to allow workmen to tread over it by placing planks.  Laitance and foreign matter, if any, shall be removed and then granolithic concrete placed in position.  The topping shall be thoroughly compacted and screeded to the finished grade.  The topping shall be floated with a float to render the surface even.  The mix for the structural concrete as well as the topping shall be as stiff as possible consistent with workability so as to prevent accumulation of excess of water or laitance on the surface.  After the surface is hardened it shall be finished smooth.

Notes: 1. In the monolithic method of construction, the granolithic topping may be regarded as contributing to the structural strength of the suspend bed slab.

2.  The monolithic construction of granolithic concrete floor topping presents certain difficulties in construction due to activities, such as plastering of walls and ceilings, fixing of joinery, movement of scaffoldings, ladders, etc., which are likely to damage the floor finish.

Floor topping laid over the hardened suspended slab (see Table 7) - The surface of the base concrete shall be thoroughly brushed with a coir or steel wire brush to remove any scum or laitance before the topping is laid; the surface shall be swept clean to expose coarse aggregate.  Where the concrete is hardened, the surface shall be roughened by chipping or hacking.  The surface shall be wetted with water for several hours and surplus removed by mopping immediately before the topping is laid.

Neat cement slurry shall be thoroughly brushed into the surface before depositing the topping.  The surface shall be tested for unevenness and made good immediately.  The top surface shall be finished smooth.

Floor topping laid over cushioning layer (see Table 7) - The surface of the suspended slab shall be prepared as indicated above.  Lime concrete (see Note) shall be spread evenly thoroughly tamped and levelled.  Lime concrete shall be prepared as per specifications.

The surface of lime concrete shall be prepared as described in 14.33.4 before laying the topping.  The surface shall be brushed with a layer of near cement slurry.  The granolithic concrete shall be laid and finished smooth, as a 14.33.4. 

Note: Where lime and good qualities of bricks are not available 1:4: 8 cement concrete may be used.

Table 7 Different types of granolithic concrete floor topping (Clause 14.33.4 & 14.33.5)

Sl

No

Type of topping

Thickness of granolithic concrete floor topping in mm, min

Remarks

A

Floor topping laid over base concrete on ground

 

i)

Floor topping laid monolithically

With base concrete

20

Granolithic concrete floor topping shall be laid monolithic with base concrete.

ii)

Floor topping laid separately on

40

Granolithic concrete floor topping shall be laid over separately prepared surface of set and hardened base concrete.

B

Floor topping laid over suspended slabs

 

iii)

Floor topping laid monolithc

20

Granolithic concrete topping shall be laid and finished monolithic with the suspended slab

iv)

Floor topping laid over hardened suspended slab

40

The granolithic topping shall be laid separately over the specially prepared surface of set and hardened concrete

v)

Floor topping laid over cushioning layer

40

Cushioning layer of lime concrete of 40 to 50 mm thickness shall be spread over the prepared surface of suspended slab.  Topping shall be laid as in Sl.No. (iv)

4.33.6. Curing - The surface shall be kept moist at least for 10 days; no traffic shall be permitted on the surface during this period.

14.33.7. Maintenance - Except for oil and grease, frequent washing of the surface with water may be sufficient to maintain the floor finish in a clean condition.  Grease stains may be removed by means of sodium metasilicate, caustic soda, some phosphates or other proprietary materials.

14.34. SPECIFICATION FOR SURFACE TREATMENT TO CEMENT CONCRETE FLOOR TOPPING

14.34.1. Cleaning the surface

The top surface of concrete shall be clean and free from grease or oil to enable the hardening solutions to penetrate.  Thorough cleaning of the surface shall be ensured particularly in old surfaces. The top surface shall be wetted with water and scrubbed with coir or steel wire brush and cleaned with water. The floor shall be allowed to dry before applying hardening solution.

14.34.2. Treatments

14.34.2.1. Sodium silicate - A solution containing one part by volume of sodium silicate and four parts of water should be spread evenly over the concrete top surfaces with a mop or soft brush.  Any excess material shall be wiped off and the floor allowed to dry.  After washing the floor with clean water, a second coat, containing one part of sodium silicate to three or four parts of water should be applied and this should be allowed to dry similarly.  After drying, a third coat shall be applied after washing the floor if it is still porous.  After drying, the floor should be washed with clean hot water. Effective results are obtained if the treatment is applied 7 to 10 days after the end of curing.

14.34.2.2. Silica–flouride - The crystals of magnesium silico-flouride or of zinc silico-flouride should be dissolved in water at the rate of 0.1 g/cm3 for the first coat and 0.2 g.cm3 for subsequent coats. Three coats are usually applied after 24 h intervals. There is no need to wash the top surface between coats, but it is advisable to wash with clean water after the final treatment.

14.34.2.3. Drying oil and surface sealers - Drying oils, either neat or thinned with turpentine or white spirit, or surface sealers, may be applied to the top surface by brushing.  Any excess should be wiped off about 2 h after application.

Calcium chloride shall not be used with high alumina cement.

14.35. SPECIFICATIONS FOR INDUSTRIAL FLOOR FINISHES

14.35.1. General - In industrial floors finishes the following are covered

(a)Industrial floors to IS: 4971 - 1968. (b)Daily floors to IS: 7956 -1975. (c)Bitumen mastic flooring for industries handling LPG and other light hydrocarbon products to IS: 13074 - 1991. (Annexure 14 A.6)

In the selection of industrial floor finishes, special care is required in view of diversity of the requirements to be met with and the different characteristics of individual floor finishes.  The strength and stability of finishes will depend on the structural floor, the sub-floor or the foundation.  Over loading, thermal expansion and movements due to bad design may cause failure of an otherwise satisfactory floor finish.  Spillage of chemical solutions, acids, alkalis, etc. on the floor contributes towards the failure of a floor finish.

14.35.2. Types of industrial floor finishes

14.32.2.1. Types  - This will deal with the selection of industrial floor finishes where the floor is subject to heavy abrasion, impact, chemical action; floor finish under special circumstances, such as, non-slippery, dustless, noiseless, non-sparking, anti-static, etc.

A finish for the floor of an industrial building may be generally selected out of the following types to suit the requirements of particular case; (a)Plain concrete (b) Granolithic concrete (c)Precast concrete tile (d) Paving brick (e) Magnesium oxychloride (f) Bitumen mastic (g) Linoleum (h) Rubber, PVC sheets (i) Epoxy resin (j) Fire clay brick – conforming to IS: 6727-1972,(k) Ceramic unglazed vitreous acid resistant tiles – conforming to IS:  4457-1982, (l) Stones,(m) Steel or cast iron units – conforming to IS: 3502-1981,(n) Wooden block with lead lining, and(o) Acid resistant brick – conforming to IS: 4860-1968.

14.35.2.2. Consideration for selection of floor finish - The important features that govern the selection of industrial floor finish are durability, incidence of loading, safety, resistance to chemical action, convenience of the user, appearance and overall economy.  Table 9.6 gives in general a summary of requirements of floor finishes for various industrial buildings.

a) Durability

  1. Wear – The nature of mechanical wear that a floor has to resist varies considerably. For general information the type of wear may be classified as below

Table 8 (Clause 14.35.2.2)

Type of wear

Examples

Very severe abrasion together with heavy impact

Heavy engineering workshops and places where milk cans are being handled in dairies.

Very severe abrasion

Places where steel-tyred trucks constantly move.

Severe abrasion

Floors having traffic of more than 2000 persons per day in definite traffic lanes.

  1. Impact – Considerations should be given to impact, as many flooring materials that will stand abrasion may suffer rapid damage under impact.
  2. Load carrying capacity – Depending on the nature of loading and type of traffic, such as foot, rubber, tyred, metal wheeled, etc. the flooring should be selected to withstand the severe condition.

b) Safety

1) Resistance to high temperature or fire – In industrial structures high temperatures occur without spread of fire. Floor finishes do not by themselves add to fire risks provided the floor superstructure has adequate resistance to fire. In certain special circumstances, however there may be risks arising from the usage of the floor. For example, oil or other flammable liquids spilled on floor will lead to greater fire risks with floors which are absorbent of themselves combustible, such as timber or bitumen, than with inert dense materials, such as concrete or tiles.

2) Sparking – In factories or stores where explosives and substance liable to cause explosions are being handled, sparks caused by friction on a floor surface may cause fire or explosion.  Therefore, it is essential to use non-sparking floor finishes, such as rubber or special grade of bitumen mastic or magnesium oxy-chloride composition. A lead lining may be provided over the base concrete or wooden flooring where explosives are being stored.

c) Resistance to chemicals and water – The spillage or splashing or chemical solutions acids, etc. may cause corrosion, deterioration, induce slipperiness or give to other fire or health risks.  The possibility of wetting or flooding the floor with water may be taken into account.

14.35.2.3. Properties of floor finishes

Properties of floor finishes are listed in Table 8.

Cement concrete finishes – Plain cement concrete is used for a wide variety of  industrial is resistant to a wide variety of chemicals, including mineral oils and greases but is slowly attacked by acids, vegetable oils, fats and sugar solutions. Frequent cleaning reduces the attack, but prolonged exposure will bring about a gradual deterioration of the cement concrete flooring.

Granolithic flooring is hard wearing resists impact and is resistant to alkalis and mineral oils. On the other hand, it is hard to the feet, cold, noisy and susceptible to chemical attack including acids, sulphate and vegetable oils and fats.

Brick and tile finishes – They have good resistance to wear and impact.

Paving brick to IS: 3583-1988 may be used for heavy duty and industrial floors, loading and unloading platforms where the floor is subjected to heavy wear and tear.

Fire clay bricks to IS: 6727-1972 may be used in situation where high temperatures are to be met with, such as those around metallurgical furnaces. Acid resistant bricks conforming to IS: 4860-1968 has good resistance to all acids except hydrofluoric acid and per chloric acid and other chemicals. 

They are suitable for flooring subject to acid attack and abrasion.

Ceramic unglazed vitreous acid resistant tiles conforming to IS: 4457-1982 has good resistance to acids and is suitable for floorings subject to acid attack, impact and abrasion.

b)  Stone flooring – The types of stones useful for flooring are granite, basalt, quartzite and sandstone. Granite is very hard and resistant to wear by abrasion or impact, and to attack by chemical agents.

It is readily cleaned and if kept clean, it is non slippery till unworn; after considerable wear, it may become smooth and slippery and mechanical roughening may be necessary. It is used in thick slabs of various sizes depending upon the conditions of use.  Granite slabs are suitable for the flooring of loading and unloading platforms in workshops, god owns, etc.

Basalt flooring will be suitable for heavy engineering factories and garages as it may withstand impact and wear and where the floor need not be too smooth and even.

Quartzite slabs are used mainly for entrance halls or where a decorative appearance combined with good wearing properties under heavy foot traffic is required.  The stone is easy to clean and does not become slippery.

Sand stones, (see IS: 3622-1977) of suitable variety and thickness may be used for light duty flooring.

c)  Steel and cast iron floor finish – Metal floor finishes are used where severe wearing conditions are encountered. Several types of steel or cast iron units are used for heavy duty flooring.  This type of finish includes

1) Open metal grids embedded in granolithic concrete or in bitumen mastic,

2) Solid tiles or solid plates, and

3) Open metal grid suspended floors.

Open metal grids embedded in granolithic concrete are suitable for loading platforms subject to impact and wear caused by movements of trolleys with iron wheels, under wet or greasy conditions as in the case where bottled milk are handled. Steel tiles with a smaller proportion of open space than the grids embedded in granolithic concrete are suitable for situations subject to heavy abrasion and impact. The open metal grids and steel tiles tend to become slippery when oily and to corrode when wet. Solid faced metal tiles (usually made of cast iron) are highly resistant to wear and impact and to action of oils, fats; salts and alkalis provided the joints are filled with appropriate chemical resistant material (see Part 4).  The plain surface types are liable to become slippery if wet or even when dry if polished by wear, and hence special types with patterned surface shall be used under these conditions. The solid metal tiles are particularly useful, on loading bays where there is heavy trucking and in diaries where a high standard of cleanliness combined with high resistance to wear and chemical attack is required.

Steel or cast iron grid suspended floors are used for elevated platforms or walk ways around large machinery.  Floors on which liquids or solids are continuously being spelled may be made of supported steel grids with suitable channels beneath, from which the spilled material may be drained or recovered.

Wooden block with lead lining – This provides a non-sparking floor finish and is suitable for floors where explosives are stored.

Magnesium oxychloride – The flooring mix gives a fairly strong and durable floor with good appearance. However, the flooring is affected by continued exposure to water, acids, and salt solution. Too wet a mix with excessive magnesium chloride results in sweating of the floor surface. Mineral oils, greases, vegetable, oils, milk products and mild alkalis do not affect the floor.

Bitumen mastic flooring – Bitumen mastic flooring is considered suitable for industrial buildings, storage houses, etc, because of its resiliency, wearing quality and ease of maintenance. Bitumen mastic flooring to IS: 1196-1978 is dustless, odourless, jointless and impervious to the transmission of moisture either in liquid or vapour form. The flooring is easily cleaned, quiet under traffic and resilient. Bitumen mastic flooring is also durable. While it may carry heavy loads, concentrated loads may

cause indentation. In selecting bitumen mastic flooring consideration may be given by the type of traffic and possible contact with mastic flooring is liable to become slowly softened by prolonged contact with greases, fats and oils. Contamination with such materials shall be avoided.

Linoleum flooring – Linoleum provides clean, dust free and resilient flooring.  In light industry, such as, in electronic industry, linoleum flooring may be used as the risk of damage by cutting to which linoleum is vulnerable is small. If linoleum gets wet, it expands mildews and eventually rots.

Rubber flooring – The flooring is resilient and noiseless. The flooring is suitable for electronic industry, computer rooms, etc.

Flexible PVC flooring – The PVC flooring provides clean, dust free and resilient flooring.  The flooring may be easily cleaned with wet cloth, as dirt and grime do not penetrate the surface.

Epoxy resin floor topping – The use of epoxy resin floor toppings is characterized by its exceptional physical and chemical properties, such as, chemical resistance, hardness, abrasion resistance ; compressive, impact and structural strengths; dimensional stability and adhesion to concrete, metal and other surfaces. This is suitable for use on industrial floors, such as chemical plans manufacturing fertilizers, pharmaceuticals, acids, solvents, etc., in dairies, tanneries, breweries, garages, service stations, warehouses, metal plating and pickling areas.

14.35.2.4. Recommendations for floor finish for industrial buildings   

Floors for heavy engineering factories, workshops and garages Floors in heavy engineering factories, workshops and garages shall be resistant to impact, abrasion and attack by lubricating oils. The epoxy resin floor topping is suitable for heavy industrial floors. The extent to which the floors will be subjected to heavy wear and impact will often vary widely in different parts and since the more important type of finishes are more expensive it is advisable to ascertain as far as possible, before laying the finishes, where trucking gangways or processes involving impact will be located and to provide accordingly.  Steel or cast iron tiles or plates, embedded in granolithic concrete may be used for areas of heavy abrasion by steel-tyred trucks or where a high resistance to impact is required.

Granolithic concrete with suitable materials and good workmanship will provide in light industrial workshops and garages a floor finish of reasonable durability. Special aggregates and metallic floor hardeners may be added to the granolithic concrete where heavy impact and wear is expected.

14.35.2.5. Loading and unloading platforms - The requirements of loading and unloading platforms and industrial loading bays are primarily high resistance to impact and abrasion and non-slipperiness.

Steel tiles or ‘anchor-plates’ or metal grids embedded in granolithic concrete are suitable for loading and unloading platforms subjected to heavy impact.

Food factories, Factories processing meat, Vegetables, Animal or Vegetable oils, Breweries, Beer cellars, etc.

There are many factories making soap, candles and lubricating oils, in which the floors are subject to the action of animal or vegetable oils or fats due to spillage combined with abrasion. The epoxy resin floor topping is suitable in such situations.  Magnesium oxychloride flooring or heavy duty brick flooring may also be adopted.

14.35.2.5. Factories using process involving sugar solutions and weak acids In factories processing fruits and vegetables or using sugar syrups, as for example, preserve, canning, pickle, fruit drink, sweet or sugar factories, the floors are subject to chemical action by fruit acids, vinegar and sugar syrup and often to impact and abrasion by movement of casks and by trucking. Unglazed vitreous acid-resistant tiles or acid-resistant bricks properly bedded and jointed with chemical resistant mortar IS: 4832(Parts1 & 2)-1969, IS: 4832 (Part 3)-1968 provide a satisfactory floor for such situations. Epoxy resin floor topping is also suitable for such situations.

14.35.2.6. Factories handling or using salts or salt solutions and fertilizers

The risk of deterioration of floors upon which salts or salt solutions may be spilled as in tanning, bacon curing, or chemical factories depends on the nature of the salts, chlorides, as in common salt when spills are not very harmful to the floor finishes. Bitumen mastic flooring is suitable for such situations because of its impermeability and resistance to chemical action. Granolithic concrete may also be used.

Nitrates, sulphate and phosphates which are widely handled in the fertilizer industry, may lead to rapid deterioration of the cement concrete floor.  Epoxy resin floor topping or floor paved with ceramic unglazed vitreous acid-resistant tiles or acid-resistant bricks will be suitable in such situations.

14.35.2.7. Bedding and jointing materials - Appropriate choice of bedding and jointing materials is essential if the risk of defective floors or premature failure is to be avoided, even when the main flooring material, that is, block, slab or tile, is of type which would otherwise be satisfactory.

The various materials used for bedding and jointing materials and their resistance to deterioration is indicated in Table 9.  The material shall adhere properly to the base on which the finish is laid and to the finishing units. It shall be durable and resist chemical attack.

Bedding materials and jointing materials could be different in the same floor.  If spillage of harmful material is not likely to be appreciable or where the floor may be cleaned frequently, it may be sufficient to point the joints with the chemical resistant mortar and to use cement mortar for bedding. It may also sometimes be an advantage to bed the units in a bituminous waterproof compound and to point the joint with a chemical resistant mortar. In general, the use of one type of mortar with very thin joints requiring no pointing should be preferred even if separate bitumen or other waterproof layer is laid before bedding and jointing the tiles.

Table 9   Properties of Bedding and jointing materials

Sl

No

Type of

Material

Manner

of use

Hard-

ness

Adhesion

To Smooth

Surfaces

Resistance to Wear

1

2

3

4

5

6

i

Portland cement

Mortar

1:3

Hard

F

F

ii

Bituminous

Mastics

Hot, as

supplied

Plastic

G

G-F

iii

Rubber latex

Cement mortar

Rubber, latex  with Portland cement

Resilient

VG

G

iv

Chemical

Resistant Silicate type Mortars

Silicate

solution &

fillers

Hard  and

rather

brittle

G

F

 

 

v

Chemical resistant

Sulphur type

Mortars

Sulphur &

fillers, dry mortar

to be melted  before use

Hard

G

G

vi

Chemical resistant

resin type mortars

Resin syrup-fillers & hardners

 

 

 

a

Epoxy resin

Mortars /

Furnac resin

Mortars

-

Hard

and

tough

VG

VG

b

Cashew nutshell

liquid resin

-do-

-do-

VG

VG

c

Other resin

Mortars

-do-

-do-

G

G

 

Resistance to attack by

Resistance to

Temperature

Water

Mineral acids

Orga

nic

Acids

Alkalis

Solutions

Of sulphate

Phosphate & Nitrates

Mineral

Oil &

Greases

Vegetable

Oils &

fats

Weak

Strong

7

8

9

10

11

12

13

14

15

VG

VP

VP

F.P

VG

P

G

P

G

VG

F

P

P

G

G

P

P

P

G

G-P

P

P

G

F

F

F

F

P

VG

VG

VG

P

G

G

G

G

VG

G

G-F

G

G

G

G

F

F

VG

VG

G-F

G

VG

G

G

G

VG

VG

VG

G-F

P

G

VG

P

P

VG

G

G

F

G-P

G-P

G-F

G

G

VG-P

Note - VG = Very good;  G=Good;  F=Fair;  P=Poor; VP=Very poor

14.35.3.1. General - Floors in dairies and other premises used for processing milk and milk products are subject to heavy impact, abrasion and chemical attack.  Selection of suitable floor finishing materials and design of drains are, therefore, important for low maintenance coat and long life of the floor.  For small dairies, processing up to 10000 1itres of milk per day floor finishes for different sections of a dairy floor may be adopted.

14.35.3.2. Structural base - The structural base should be so constructed that a slope of not less than 1 in 80 is imparted to the floor surface. This fall should such liquid spillage on the floor surface will be drained quickly by the shortest route. It is essential to have a waterproof membrane between the base and the floor finish.  The joints in the structural base shall be provided in accordance with the details given section 0.6.  All laitance shall be removed and the surface roughened before laying the floor finish.

Group I This group consists of the following sections:

a) Loading dock and dispatch dock, and  b) Cold storage room.

These sections are subject to very heavy impact and abrasion. Spillage of milk and milk products also takes place. Floor finishes recommended for these sections are steel or cast iron tiles or solid steel plates. The floor finish of steel or cast iron tiles may be supported structurally by sub-floor. Solid steel plates may be used as a structural finish supported on a under floor frame work.

Group II

This group consists of the following sections:

  1. Milk can reception room, (b) Empty can and bottle reception desk, and (c) Empty can and bottle washing room.

These sections are subjected to very heavy impact and abrasion, but little spillage of milk and milk products. Floor finishes recommended for these sections are steel or cast iron tiles or metal grids with filling materials, such as, cement concrete, cement rubber latex, etc. There are two main types of metal tiles used for industrial purposes which are suitable for dairy floors. They withstand impact, abrasion and resist the action of alkalis but are liable to attack by weak acids.

a) One type, called on anchor plate, is in the form of a shallow tray, made of steel. The wearing surface is punched to give trowel anchors or grips which form the key for the bedding and when bedded in the concrete give a floor which is generally 40 mm thick. A typical illustration is given in Fig. 13. It is essential for the success of this type of floor finish that the tiles are completely filled with concrete. Tiles which are not solid by embedded give continuous trouble because the steel is not strong enough to bridge hollow places and is bent under traffic.

Fig. 13 Illustration of one of the typical steel flooring tiles for Dairy Floors

b) Another type of tile is called honeycomb cast iron tile.  These types of tiles are manufactured with a taper in honeycomb for better grip with concrete. A typical illustration of such a tile is shown in Fig. 14.

Fig. 14 Illustration of one of the typical honeycomb cast iron tiles

Dairy Floors - Metal grids are frequently used as a surface reinforcement to increase the impact resistance.  The grids may be of cast iron or steel and hexagonal to square mesh. The usual matrix into which they are laid may be either granolithic concrete (see Part 2) or cement rubber latex. The grid may be supplied either as a roll of interlocking metal trips from which a grid can be formed or a small units.  Mats framed on two sides only are best because this avoids the weak joints between sections.

The top edges of the grid form part of wearing surface of the floor and distribute impact and wear. Because of uneven wear between the grid and the material in which it is embedded such floors may become noisy in use.

Group III

This group consists of the following sections:

(a) Milk drum tank pit ; (b)Milk storage room ; (c)Processing hall, milk pasteurization section ;(d)Butter, ice-cream, cheese and ghee section ;(e)Milk filling section ;(f)Roller drier room ;(g)Toned milk room ; (h)Corridors ; and (i) Laboratory rooms.

Floor finishes in these sections should be resistant to normal impact and wear, to frequent spillage of milk and milk products, to mild acids, and alkalis and good resistance to hot and cold water as the floors are subject to frequent washing.  The general choice may be made from the floor finishes as given.

Portland cement concrete is slowly attacked by milk and milk products particularly by lactic acids and therefore is not suitable for these sections.  However in such areas where acidic action is not pre-dominant, cement concrete flooring tiles, as described in Para 2 or stones, such as, Kotah stones may be used.

14.35.3.3. Acid and alkali resistant stones laid with phenolic type resin mortar for bedding and jointing - Sand stones of highly siliceous and compact variety containing low quantity of aluminium oxide, calcium oxide and magnesium oxide, etc, have good acid and alkali resisting quality.  Such stones are found in places like Dholpur, Gwalior, Rewa, Cuddapah and Mandana, etc.  The stones may be tested for acid resistance in accordance with methods of test described in IS: 4457 - 1982. However a maximum of 4 per cent weight loss during acid treatment may be accepted as adequate acid resistance for the purpose of dairy floors.  These floors give long life but become slippery in due course and hence would require periodical roughening.

14.35.3.4. Ceramic unglazed vitreous acid resistant tiles or acid resistant bricks - Vitreous ceramic tiles (IS: 4457-1982) or acid resistant bricks (IS: 4860-1968) could be used for floor finish.  These tiles and bricks could provide over a long period, a good resistance against acidic conditions provided by milk and milk products.  These materials would also offer adequate resistance against the mild alkaline conditions provided by washing soaps, detergents, etc.

a) The life of a good quality brick or tile floor is largely determined by the material used for bedding and jointing and to some extent by the width of the joints. Hence careful selection shall be made in the choice of bedding and jointing mortar, and the thickness of the joints. Whatever be the choice of mortars these should necessarily show adequate strength when tested according to IS: 4456 (Part 1 or 2)-1967 as appropriate.

b) For bedding and jointing mortars, selections may be made from the following

(1) Chemical   resistant resin type of mortars (see IS: 4832 (Part 2)-1969)   (2) Rubber latex cement mortars, and (3) Super-sulphate cement (see IS: 6909-1990) or Portland blast furnace slag cement (see IS: 455-1989).

c) Among the resin based chemical resistant mortars, epoxy resins and phenol formaldehyde type (see IS: 4832 (Part 2)-1969) are quite suitable as joint mortar.

d) Sodium silicate or potassium silicate and resistant mortars (see IS: 4832 (Part 1)-1969) although have good properties under dry conditions, are not suitable  as jointing mortars in these sections of the dairies as these mortars are slowly attacked by cold water and rapidly by hot water. However, these may be used as bedding mortars in conjunction with resin type mortar.  

14.35.3.5. Jointless cement latex rubber finish -  This is prepared from a mixture of rubber latex or synthetic rubber and Portland cement or Portland slag cement. The resistance of these mixes to milk and milk product is generally much higher than that of corresponding mixes without latex. The choice of type of latex will also determine the properties of the floor, such as, water-tightness and resistance to oil.  The techniques of mixing and laying is different than that of ordinary concrete and therefore advice of an expert, would be required when using these floor finishes.

Note: The latex normally takes the form of dispersion in water of natural rubber latex, but for a special circumstance, for example, for oil resistance, synthetic rubber may be used.

a) The latex is stabilized against premature coagulation. It should not contain vulcanizing ingredients.  If these are required they should be incorporated at the time of preparing the mixture.

b) The emulsion is diluted with water as required and is then mixed with cement and aggregate to form a mix of the desired rubber latex used varies 8 to 25 per cent by weight of the total mix.

14.35.3.6. Group IV - This group consists of the following:

a) Boiler room b) Refrigeration room c) Stores and godowns and d) Workshops.

These sections require good wear resistance and occasionally resistance to alkalis and very mild acidic conditions.

The choice of floor finishes for these sections may be made from

a) Granolithic cement concrete to IS: 5491-1969 (see Part 2). b) Power compacted concrete grade M150 with iron chippings mixed with the aggregates, or c) Hydraulic pressed cement concrete tiles to IS: 1237-1980 (see Part 2).

Wherever slippery conditions prevail, cement concrete tiles with chequered surface finish would be suitable.  Where in-situ concrete is provided and non-slip surface finish is desired, a hard abrasive material, such as, silicone carbide or aluminium oxide may be sprinkled evenly on the concrete surface at the rate of 2 kg/m2 and worked into the surface by power floats and finally by steel trowelling.  Iron particles may also be used in the same way to increase the wear resistance of the surface.

14.35.3.7. Group V - This group consists of chemical stores for storage of concentrated acid and other chemicals.  Ceramic unglazed vitreous acid resistant tiles conforming to IS: 4457-1982 or acid resistant bricks conforming to IS: 4860-1968 may be used.

14.35.3.8. Waterproof membrane for dairy floors - The floor finish of any section of the dairy should necessarily prevent the leakage of effluents to the base concrete.  To install a permeable floor finish is dangerous as the point of attack is not visible.  Even more dangerous than the attack of concrete is the possibility of corrosion of reinforcement in a suspended floor.  A water tight membrane should be resistant to all mild acids and alkalis.  Bitumen mastic laid on saturated bitumen felt to IS: 1322-1993 or fibre glass based saturated bitumen felt (see IS: 7193-1974) can be considered.  Chapter 12 details the membrane treatment based on IS: 1196-1978.

14.35.3.9. Drainage in diaries 

A slope of 1 in 80 is adequate if the floor finish is smooth and even and little spillage. A slope of 1 in 40 would be required if the floor finish is rough with much spillage.

There are three methods of arranging the drainage as below

The floor finish may slope from each of the side walls into centre channel which runs along the length of the building or from the centre of the floor to the side of wall channels.

The floor finish may be laid in bays with channels across the width of the building.

The floor may be divided into a series of triangular troughs each with a certain drain.

The drains should be open channel covered by a grid, discharging into an ordinary closed drain.  The edges and corners of the floors and drains should be rounded off to prevent dirt from harboring there.

The most suitable material for the drains is chemically resistant salt glazed pipes to IS: 651-1992 and similar chemical resistant resin mortar.

14.35.3.10. Maintenance of dairy floors

a) The floors should be scrubbed several times a day to remove milk waste and grit which not only causes in-sanitary conditions but also is detrimental to the floor finish.

b) Use of straight soaps is not recommended since they tend to precipitate insoluble salts if the water is hard or acidic or alkaline, resulting in slippery floors. Detergents may be used; they need only to be sprinkled.  Scrubbing with machines shall be followed with rinsing.

c) Use dip trays under machines to limit areas of spillage of milk.

14.36. SPECIFICATIONS FOR BITUMEN MASTIC FLOORING FOR LPG

14.36.1. General - Bitumen mastic is joint-less and impervious to the transmission of moisture.  The anticipated service conditions for bitumen mastic flooring for hydrocarbon services shall be as given in IS: 13026-1991 (Annexure 14-A.7), which is a specification for bitumen mastic for flooring for industries handling LPG and other hydrocarbon products. The material shall be anti-static and electrical conducting grade (see IS: 8374-1977).

14.36.2. Thickness - The total thickness to which bitumen mastic should be laid shall be between 20 mm to 25 mm as specified.

14.36.3. Preparatory work

Preparation of base - The base on which the bitumen mastic is to be laid shall be able to receive the mastic and to sustain the anticipated load on it.

The base shall have an even and dry surface which has been roughened with stiff broom or wire or coir brush and should be free from ridges and hollows.  The base may be provided with a suitable slope for drainage.

14.36.4. Laying 

The molten mastic shall be carried in flat mortar pans.  The pans are sprinkled with lime stone dust, to prevent sticking of mastic.  Grease or oil shall not be used.

The mastic should be laid in bays in one or more layers.  The specified thickness shall be maintained.  The multi-layered work should be treated in the same manner as single layer mastic.  Bubbles formed during laying should be punctured and the area rectified while mastic is hot.

The laid surface shall be protected from damage due to movement of heavy loads, spillages, etc during laying.  The mastic shall not be opened to traffic until the material has cooled down to ambient temperature. Damaged areas shall be cut into rectangular strips and replaced with a new mastic.  Blow lamp techniques to remove damaged layers are preferred.

Bitumen mastic flooring requires little maintenance. Dirt and dust shall be removed periodically.

14.37. SPECIFICATIONS FOR SPECIAL FLOORS AND FLOOR COVERINGS

General - The following Indian Standards cover the use of various types of special floors and floor coverings

(a) Magnesium oxychloride composition floors – IS: 658-1982. (b)Bitumen mastic flooring – IS: 1196-

1978. (c ) Rubber floors – IS: 1197-1970 (See Annexure 14 A.10) (d) Linoleum floors – IS: 1198-1982 (See Annexure 14 A.8) (e) Chemical resistant mortar, Silicate type – IS: 4441-1980.(f) Chemical resistant mortar, Sulphur type – IS: 4442-1980 (g) Chemical resistant mortar, Resin type – IS: 4443-1980 (h) Epoxy resin floor toppings – IS: 4631-1986 (i) Flexible PVC sheet and tile flooring – IS: 5318-1969 (j) Parquet flooring – IS: 5389-1969 and IS: 9472-1980.

14.37.1. Magnesium oxychloride composition floors

14.37.1.1. General - Magnesium oxychloride composition consisting of mixture of calcined filler and pigments provides a good floor if proper ingredients are mixed in correct proportions and skilled labour is employed in laying the floor.  Too wet a mix with excess magnesium chloride results in sweating of the floor surface.  Mineral oils, greases or vegetable oils do not affect the floor.  The flooring is not seriously affected by alkalis, but strong alkalis, such as, soda or harsh cleaning agents tend to attack the protective dressing and thus exposing the flooring to action of water.  However, the finished floor tends to be protected from excessive water or moisture by periodic applications of wax – polish or oil at regular intervals.

Magnesium oxychloride flooring should not be used in any situation where it would be exposed to damp conditions for long periods, unless other suitable protective measures are taken; it should not be used in places where it will be exposed to acids or salts continuously.

14.37.1.2. Types

a)  General purpose floor (Trowel finish) – This type of floor shall contain an adequate amount of calcined magnesite,  fillers such as, talc, saw dust and asbestos ; and fine aggregates which with magnesium chloride of suitable strength make a product which may be trowelled to a dense smooth glossy finish.  The composition may be applied monolithically. It has wearing properties which make it adaptable for service conditions in offices, ship decking, railway carriages, hospital rooms and wards, residential and industrial floors.

b)  Heavy duty floor (Trowel finish) - This type is closely related to the general purpose floor.  The principal difference is that the quantity of fillers used in minimum and the proportion of aggregates is increased, the aggregates being of hardness similar to crushed granite.  It is adapted for special service conditions in industrial and restaurant kitchens, light industrial plants, corridors, lobbies and business establishment having the large usage.

c)  Non-spark static discharging floor (Trowel or ground finish) – This type of floor is similar to heavy duty floor except that the aggregates used are not siliceous and do not contain materials which will produce a spark when struck with any object.  This type of floor is suitable for hospital operation theatre, ammunition and chemical plants or other areas subject to explosion hazards.

d)  Non-slip floor (General purpose) – This type of floor is similar to heavy duty floor except that certain proportion of the aggregates is of abrasive type.  This floor is specially adaptable to areas, such as, entrance lobbies, ramps, stair treads, landings, etc.

e)  Mosaic or Terrazzo floor (Ground finish) – The matrix in this case is the same as in general purpose, non-sparking or non-slip floors but the aggregate used in marble chips with each 100 kg of the dry mix, 125 to 200 kg of coarse aggregate is used.  The floor is adaptable for places where a highly decorative effect coupled with wear resistance is required. 

f)  Industrial granolithic floor – This type of floor is essentially the same as mosaic or terrazzo floor in which the matrix is the same as in the heavy duty floor and the coarse aggregate consists  of granite chips or similar hard stone chips.  With each 100 kg of dry mix, 200 to 225 kg of coarse aggregate is used.  This type of floor is recommended for the most severe and abrasive service conditions.

g)  Base coat – This type has the maximum resilience and is employed as a light-weight base for the types of oxychloride floors as mentioned.  Two sub-types are generally employed

Sub-type: 1 – General purpose base coat, and Sub-type: 2 – Heavy duty base coat.

14.37.1.3. Materials

a) All materials used in the manufacture of magnesium oxychloride floor finish should comply with IS: 657-1982. The test limits for calcined magnesite in this standard are based on a notional mix of calcined magnesite and saw dust gauged with magnesium chloride and do not obviate the need to check compliance with IS 658-1982.  Materials for magnesium oxyflouride composition floors shall be supplied in two parts namely, dry mix and magnesium chloride.

b) Dry mix 

1) Dry mix for all types of floors – The dry mix shall consist of an intimately mixed composition of dry ingredients.  If talc is used as filler it shall not exceed 5 per cent by weight of dry mix.

2) Dry mix of non-spark static discharge floors – The dry mix for non-spark static discharging floor shall contain only such materials in its composition which are free from substance capable of producing a spark when struck or abraded with a steel tool.

3) Dry mix for non-slip floor – About 35 per cent  by weight of the aggregates used in the dry mix for non-slip floors shall be of non-rusting natural (emery) or manufactured (fused alumina) product, the particles of which are of irregular shape and of slightly open texture.

14.37.1.4. Properties of magnesium oxychloride floors

  1. Magnesium oxide floor should not be exposed to action of sea water; and is not recommended where it may be exposed to high humidity or damp conditions; damp proof course should be incorporated if the base is in direct contact with the ground.
  2. Floor finish should be selected by sample size of 300 mm x 300 mm x 20 mm which finished work should conform in hardness (as per IS: 658-1982) near to colour, texture, number and thickness of coats.

c)  Resistance to chemical attack

  1. The floor finish, if not adequately protected by oiling or waxing gradually disintegrates under continuous exposure to water.
  2. The floor finish is not affected by alkalis but strong alkalis such as soda or harsh cleaning agents attack the protective dressing and exposure the floor finish to the action of water.
  3. The floor finish is subject to attack by acids.  Adequate protection against occasional contact with dilute acids may be obtained by oiling or waxing.
  4. The floor finish is subject to attack by continuous exposure to salts; under normal conditions of use, some protection may be obtained by oiling or waxing.
  5. It should not be slippery when treated as described.  Special non-slip surfaces may be obtained by incorporating abrasive grit in the floor finish.
  6. Sweating of magnesium oxychloride floor finish is characterised by beads of magnesium chloride solution forming on the surface in humid atmospheres and is not merely the result of the condensation of moisture on a cold surface.  The tendency to sweat is inherent in the material, since magnesium chloride takes up readily moisture from damp air.
  7. If the ingredient of the floor finish mixes with free lime tends to cause expansion. The floor finish is likely to crack or lift if laid on light weight concrete base or on a dense screed which not firmly bonded to the base.
  8. The thickness of floor finish shall be not less than 10 mm.
  9. Contamination of the floor finish mixes with free lime tends to cause expansion.  The floor finish is likely to crack or lift it laid on light weight concrete base or on a dense screed which h is not firmly bonded to the base.
  10. Coves and skirtings can be formed with magnesium oxychloride finishing material.  Contact between the oxychloride mix and the wall plaster should be avoided by the use of an intervening fillet of wood or other suitable material. Sand cement rendering on the wall surface is desirable as a backing.
  11. Metalwork, such as, partitions, or gas, water and electrical services in contact with a magnesium oxychloride floor finish is liable to corrode and should be isolated from the floor finish, by not less than 25 mm of uncracked dense concrete or protected by a coating of bitumen or coal tar composition or by a suitable material.

14.37.1.5. Application

14.37.1.5.1. Preparation of the base - The base shall be rigid, sound, free from rising damp and not unduly porous.  Highly absorbent materials, such as, pumice concrete, breeze or clinker concrete and aerated concrete shall not be used unless a layer of damp-proof course is laid between the base and the main floor.

a)  New cement concrete base – The base shall be true and even and slightly coarsened by stiff brush or broom.  A steel trowel finish is not desirable.  The cover to steel of base concrete shall not be less than 25 mm, since the reinforcement would be damaged by magnesium oxychloride compound.  New concrete should age for 28 days before receiving the flooring.  No lime admixture shall be allowed in concrete.

b)  Existing concrete base – The existing concrete base should be roughened to a suitable degree by chiseling, picking or by any other suitable process before oxychloride composition is laid.  Absorption may be checked and if porous screed may be spread on the base.

c) Timber base – A suitable mechanical key should be provided between timber base and floor finish, such as dovetailed wooden battens or galvanized wire netting firmly screwed to the base at approximately 200 mm centre.  An equal number of galvanized clout nails should be used at 200 mm centres and be left proud of the base.

14.37.1.6. Preparation of floor finish mixture - Magnesium chloride both before and after it is dissolved should not be allowed to come into contact with any floors and walls.   The solid chloride should be broken up and dissolved in water tight vessel by covering the same with clean water, that is, clean and free from deleterious acids, alkalis, salts or organic material and stirring the same from time to time.  The solutions should be allowed to stand over night so that the residue, dust, impurities, etc, may settle to the bottom.  The clean concentrated solution shall be well stirred after each dilution.  The solution shall be prepared sufficiently early so that it is cooled to room temperature before use.  The specific gravity of the solution should be maintained at the value selected from the table given below.  This value will depend on the type given of work, the nature of the base and ambient and temperature conditions.

Floor finish mix

Baume (BE) scale

Specific gravity

Single coat and top coat

20 degree to 24 degree

1.16 to 1.20

Bottom coat, coves and Skirtings

18 degree to 20 degree

1.14 to 1.16

14.37.1.7. Proportions of dry materials - The proportions of dry materials may be varied within certain limits in order that the properties of the finished product may be suited to the conditions of use.  Proportions shall be by weight and the dry material should be thoroughly mixed by machine.

a)  Proportion of chloride solution – A strong floor finishing material may be formed by addition of any sufficient magnesium chloride solution to make the dry mixed materials damp.  For single coat and top coat some additional solution is usually required to enable the mix to be placed and brought to a smooth finish.  The extra chloride does not improve the strength of the mixture and the use of excessive amount will have harmful effects.

b)  The amount of solution required for a given weight of dry mix cannot be stated accurately; however, the following guidelines may be used;

1)  Bottom coat floor finish mixes – Bottom coat finish mixes should be gauged to a damp but not plastic consistency; just sufficient solution should be used to enable the mix to bind together when thoroughly compacted by tamping.  As a guide, a mix from which liquid can be squeezed by hand should be considered as suitable.

2)  Bottom coat mixes for coves and skirtings – These mixes should be gauged to a consistency just sufficiently plastic to allow the mix to be spread on the wall.

3)  Single coat and top coat mixes – These mixes should be gauged with no more solution than is needed to produce a stiff mix which is just sufficiently plastic to be spread with a trowel.

14.37.1.8. Final mixing - The final mixing of the chloride solution with the dry mix shall be done in a container and not on the floor.  The quantity of mix should be sufficient to be laid in one batch before it sets; no solution should be added during laying.  If the mix is too stiff it should be discarded.

14.37.1.9. Laying the floor finish

  1. Size of bay will depend on the temperature conditions generally; the controlling factor would be the time taken to obtain adequate compaction of the floor finish.
  2. Joints shall be provided if the floor dimensions are more than 5 m in either direction.  The joints may be mastic insertions or strips of hardwood, vulcanite, non-ferrous metal or other suitable material, 5 mm wide, bedded flush with the surface of the flooring material.  These joints should coincide with the joints of the base, if any.
  1. The concrete base should be dampened before laying; excessive flooring should be avoided. The dampening should be done either with a solution of magnesium chloride which should not be weaker than 12 degree BE nor stronger than 14 degree BE; or a wash composed of a 14 degree BE magnesium chloride solution and magnesia mixed to the consistence of cream and brushed over the base.
  1. If a thickness of 40 mm or more is required, additional coats may be laid, each of which should not be more than 20 mm thick.
  2. For skirting on sand cement rendering, the mix may be applied in a single coat not less than 5 mm thick; then the backing is un-rendered. The mix should be applied in two coats to a total thickness of not less than 15 mm.
  3. Each coat should be thoroughly compacted ensuring no formation of laitance.
  4. When the top coat has hardened sufficiently, its surface shall be felt finished after trowelling. Scraping shall be undertaken on ornamental work such as mottled finishes.

14.37.1.10. Curing - Rapid drying of floor shall be avoided at least for 24 h after laying the floor.

It should be allowed to set and harden at least for 3 days before opening it to traffic.  It should not be allowed for heavy traffic for some weeks till it is fully dried and hardened.  During hardening it should not be exposed to sun or rain.

14.37.1.11. Surface treatment - The floor finish should be washed with clean warm water changed frequently and wiped dry at regular intervals until the efflorescence has ceased. At this stage the finish may be treated with a mixture of linseed oil (double boiled) (see IS: 77-1977) and turpentine (see IS: 533-1973) in equal volumes or with a suitable wax or drying oil.  For mottled floor finish, the finish

should be laid in two coat work.

14.37.1.12. Testing - Testing shall be carried out on samples mixes from three different parts of the vessel.  The tests should be done as per IS: 658-1982.

14.37.1.13. Maintenance - The floor surface shall be cleaned with warm water only.  Mild house soap free from alkali may be used occasionally; but strong household cleaning powders, soda, etc., should not be used.

14.37.1.14. Protection of metal work - Metal work may receive anti-corrosive treatment; suitable materials are bituminous coal tar composition with or without added fillers, intended for hot application.  For cold application a solution of bitumen or of coal tar in a volatile solvent with or without added fillers but excluding bituminous paints with drying oils may be used.

14.37.2. SPECIFICATIONS FOR BITUMEN MASTIC FLOORING

14.37.2.1. General - Bitumen mastic is a dustless, odourless, joint less flooring and impervious to the transmission of moisture, either in liquid or vapour form.  The surface is easily cleaned, noiseless under traffic conditions and resilient. While it may carry heavy loads, application of concentrated point loads may cause indentation.  Bitumen mastic is, therefore, suitable for a variety of uses under a wide range of climatic and service conditions, except as detailed below

a) The surface of bitumen mastic is liable to become gradually softened by prolonged contact with greases, fats and oils.  Contamination with such materials shall be avoided.

b) Susceptibility of bitumen mastic floor finishes to chemical attack is given in Table below

Susceptibility of bitumen mastic floor finishes to chemical attack

Sl.No.

Agency

Susceptibility to attack

1

Acids and vegetable extracts

Normal grades subject to attack by acids, special grades can withstand attack by dilute solutions.

2

Alcoholic liquors

Normal grades are subject to attack by certain alcoholic liquors. Special grades may be used in breweries and distilleries.

3

Alkalis

Not affected by low concentration alcoholic solutions.

 

 

Alcoholic solutions above 38 degree C will affect.

4

Brine (sodium and calcium chloride) and sulphate salts

Unaffected under normal circumstances

5

Complex industrial liquors

Conduct tests to choose the grade of bitumen mastic.

6

Radio active materials

Special grades of bitumen

are used.

7

Dairy products and milk

Normal grade where hygienic conditions are maintained (see Part 3)

8

Mineral, animal and vegetable oils, fats and greases.

Subject to attack

9

Sugar syrup, sugar

Unaffected by low concentration sugar solutions syrup, molasses, etc. will affect at all temperatures.

10

Water

Unaffected unless the water is hot, for which high temperature mastic may be used.

14.37.2.2. Materials

a) Bitumen mastic shall conform to the requirements given in IS: 1195-1978.

b) Special types of metal armoring may be incorporated in bitumen mastic flooring for industrial purposes to increase resistance to abrasion (see Part 3).

14.37.2.3. Preparatory work

Base

a) The base shall be adequately strong to receive the bitumen mastic and to carry the anticipated load over it.  The base shall be true, even and dry surface which has been slightly roughened by means of a stiff broom or wire brush and should be free from ridges and hollows.  A steel trowelled finish is not desirable.  The levels of the base should be such that the specified thickness of bitumen mastic may be applied uniformly.

b) The total thickness to which bitumen mastic should be laid depends on the traffic conditions to which the floor will be subjected.

c) Usually bitumen mastic should be laid in one coat, but two-coat work may be used depending on the thickness of floor finish.  As a general guide the thickness given below are recommended.

Light duty -15 mm to 20 mm thick

Medium duty - 20 mm to 25 mm thick

Heavy duty - 25 mm to 30 mm thick

d) There may be a slope of not less than 1 in 75, in the base, if the finished floor is likely to have water or industrial liquors upon it.  Channels should be provided to ensure adequate drainage.

e) The base may be treated in any of the following ways;

1) A screed bed of cement concrete or lime concrete not less than 25 mm thick;

2) An isolation membrane or underlay or

3) On metal floors, a thin priming coat of bitumen paint applied over a clean and dry surface.  The paint should be dry before the mastic is laid.

Isolating membrane - An isolating membrane conforming to IS: 1322-1993 is normally used where bitumen mastic up to 20 mm in thickness is laid where the base is in direct contact with the ground ; glass fibre felt  (see IS: 7193-1974) may be used as an alternative.  Thickness of bitumen mastic exceeding 20 mm on new concrete is usually laid without an isolating membrane.  Isolating membranes should be laid loose.

Underlay - The underlay, when required, should be laid loose. Remolding of broken bitumen mastic blocks is permitted.

14.37.2.4. Laying

When the material is sufficiently molten to be workable, it should be carried in flat mortar pans, to the point of laying.  To prevent sticking of mastic to the pans, inorganic dust may be sprinkled on the pans. Bitumen mastic should be generally laid in bays of one coat.  It should be spread to the specified thickness by means of hand tools.  Bitumen mastic should then be floated to a uniformly level surface by a heavy wooden float and should be free from roughness and imperfection.  If ‘blowing’ occurs, the bubbles should be punctured and the area affected shall be made good while the mastic is still hot.

Two –coat of single-coat work, but care should be taken to arrange that the joints in successive layers are staggered.

Surface finish

Surface Finish could be either matt finish or polished finish, or as desired.

Immediately after laying, the bitumen mastic shall be protected from damage till it cools to the surrounding temperature.  Bitumen mastic should be allowed for traffic after the material has cooled.  Frequent polishing, should be avoided as it will become slippery.

Bedding - Special care shall be taken to effect proper bond between new and old sections of work.  The contact edges of the previously laid work should be cleaned and warmed by additional applications of hot mastic.  This procedure also should be adopted for joints between the floor finish and skirts and coves or fillets.

Skirting should be executed in not less than two-coat particular care being taken to ensure proper adhesion of the first coat to the base.  Special care shall be taken at external angles to ensure the full thickness of material.

Maintenance - Bitumen mastic surface requires relatively little maintenance.  Superficial dirt may normally be removed by washing with warm water and suitable detergents.  After the dirt is removed, the floor should be mopped with clean water.

Repairs - The correct method, to remove damaged area, is to place hot mastic around and over the area concerned and after this has softened the area concerned, it should be cut away and made good.

14.37.3. SPECIFICATIONS FOR RUBBER FLOORS

14.37.3.1. General - 

Rubber floor coverings are mainly suitable for use in domestic buildings and those of a non-industrial character, such as, schools, hospitals, offices, where traffic is expected to be essentially pedestrian and also in buses and ships.  It provides a resilient and noise –free floor surface.  The life of rubber floor is related to its thickness, since it is not possible to be specific about wear resistance.  Provision of mats will reduce the amount of abrasive grit carried to the floor.  The durability of rubber floor is increased if the material is laid correctly and maintained carefully.  IS: 809-1992 (Annexure 14 A.9) lays down the requirements for rubber flooring materials both in sheet and tile form. (See also Annexure 14 A.10)

Flooring made of natural rubber is not recommended in situations where it may came into contact with fat, grease, oil or petrol, as these substances may cause swelling, softening or other deterioration.  To meet such situations, flooring made from various kinds of synthetic rubber may be utilized.

14.37.3.2. Preparatory work

Sub–floor and base

a)  New concrete floors – In the case of newly concrete floors in contact with the ground, a damp-proof membrane or a bitumen mastic layer shall be incorporated in the thickness of the floor and it shall be properly joined with the damp-proof course in the walls.  Special precautions, such as, tanking may be necessary against water pressure and to prevent the entry of moisture into floors below ground level.

b)  Existing concrete floors – If the floor surface is not smooth and true, it shall be well hacked to provide key for the screeding.  It shall then be brought to an even surface with a screeded bed at least 25 mm thick.  Concrete floors which are in contact with the ground but have been damp-proofed shall be covered with a bed of at least 15 mm thick bitumen mastic conforming to IS: 1195-1978.  Over the bitumen mastic 40 mm thick cement concrete shall be laid.

c)  New timber floor – Timber floors shall be constructed with tongued and grooved boarding and shall be adequately ventilated to prevent dry set.  There should not be any gap between the planks which may permit air to penetrate from bottom and affect the bonding of the rubber flooring material with the timber base.  Where plywood is used as a base, it shall be of the moisture proof grade.

d)  Existing timber floors – Damaged and worn floors should be repaired and brought to an even and smooth surface; an underlay also may be used.

e)  Metal floors – The surface of metal floors shall be smooth. Screws, bolts, etc, used in the flooring shall be of counter sunk type.  When they project above the surface, the metal floor on level before the rubber flooring is laid on.  The metal floors should be rust free and a rust proof coating should be applied before the rubber flooring is used.

Underlay - An underlay shall be used where the base is of timber.  It may also be used when it is necessary to make the flooring quieter, warmer and more resilient.  Underlay shall be either fibre-based saturated bitumen felt (Type I) conforming to IS: 1322-1993 or other suitable material.

The underlay shall be butt joined and so laid that the joints are at 45 degree to the principal joints in the rubber flooring.  The underlay shall be secured by a suitable adhesive except on a timber base in which case it may be nailed.

14.37.3.3. Laying and fixing of rubber flooring

a) The sub-floor shall be cleaned with dry cloth.

b) The lay out of the rubber flooring shall be first laid on the sub-floor to be covered and should be marked with guidelines.  The rubber flooring shall be first laid for trial without using the adhesive according to the layout.

c) The adhesive shall then be applied by using a notched trowel, to the sub-floor and to the backside of the rubber sheet or tile flooring.  When set sufficiently for laying, the adhesive will be tacky to touch, but will not mark fingers.  In general, the adhesive will set in about half an hour; but it should not be left for too long a period as the adhesive properties will be lost owing to dust film and other causes. It is preferable to avoid laying the flooring under high humidity conditions so as to prevent condensation.  The area of adhesive to be spread depends on the local circumstances; in a small room the area can be covered at one stretch.

d) When the adhesive is tack free, the rubber flooring sheet shall be carefully  taken and placed in position  from one end onwards slowly so that air will be completely squeezed out between the sheet shall be pressed with suitable roller to develop proper contact with the sub-floor.  The next sheet with it backside applied with adhesive shall be laid edge to edge with the sheet already laid so that there is a minimum gap between joints.

e) Alignment should be checked and if not perfect, the sheets may be trimmed.

f) The tiles should be laid in exactly the same manner as the sheet.  Any adhesive contaminating the face of the rubber shall be removed as the work proceeds within 24 h.  A minimum period of 24 h shall be allowed for proper development of bond and no traffic should be allowed.  Thereafter the flooring shall be cleaned with a wet cloth, soaked in warm soap solution (two spoons of soap in 5 1 of warm water).

g) In case of stairs, where rubber nosing are to be laid as separate units and are of heavier gauge, the difference in thickness shall be made up in design, or by screed or with plywood or bitumen mastic.  Rubber in sheet form is not used for coves and skirting; suitably moulded units should be used.

h) Rubber shall not be cleaned by soft soaps, soaps containing essential oils, soaps with free alkalis, pastes or powders containing coarse abrasives, scrubbing brushes or petrol benzene, naphtha and similar solvents.

i) A wax-polish shall be used for polishing rubber floors; polishes containing organic solvents shall not be used.

14.37.4. SPECIFICATIONS FOR LINOLEUM FLOORS

14.37.4.1. General - Linoleum provides a satisfactory floor for residential and public buildings, railway coaches, ships, etc.  It is also suitable for most type of non-industrial floors.  In light industry, such as, electronic industry linoleum may be used, as the risk of damage by cutting, to which linoleum is vulnerable, is small.  However, if it gets wet, it expands and eventually rots.

Linoleum is not suitable for locations subjected to rising damp, external exposure, exposure to traffic with indentations from heels or static loads, and where high polish is required because it becomes slippery.

14.37.4.2. Materials

Flooring material shall conform to IS: 653 -1992. (See Annexure 14-A.7)

Underlay shall be as below;

For timber

Plywood at least 4 mm thick

Sub-floors

Hardboard at least 3 mm thick

 

Fibre based bitumen felt atleast 1 mm thick to IS: 1322-1993

Concrete floors

Bitumen mastic to IS: 1195-1978

Adhesives shall be as per recommendations of the manufacturer.

14.37.4.3. Preparatory work

Sub-floor - Sub-floors should be thoroughly dry before laying of linoleum since entrapped moisture cannot escape.  It should also be even to ensure thorough bonding with the linoleum.

a)  Timber sub-floors – A timber sub-floor should be sound, rigid and dry.  It should be well ventilated to discourage fungal attack.

In case of new constructions, tongued and grooved boarding shall be used.  All nails shall be punched down and timber floor made even.

In existing floors, when it is not possible to obtain an even surface, use of diagonal boarding is recommended, after removing and replacing badly affected boarding; alternatively plywood may be used to get an even surface.

b)  Concrete sub-floor – Concrete sub-floor may be finished as mentioned in Para 2, to give an even and dry surface.  Rising damp may be protected by using bitumen mastic, 15 mm thick, conforming to IS: 1196-1978 as described.

c)  Other sub-floors – They should be dry and even.

14.37.4.4. Laying (See Annexure 14-A.8)

a) Linoleum should be stored at room temperature of not less than 20 degree C for at least 48 h before unrolling; after unrolling, it shrinks in length and expands in width.  When two widths of linoleum are to meet, they shall be left with an overlap until the expansion has stopped and then cut to fit.

b) The linoleum should be laid either loose or fixed to the sub-floor by means of suitable adhesives.  Any priming coat should be allowed to dry before the adhesive is spared. Adhesives should be spread evenly as per manufacturers’ instructions. Naked light should be avoided, if the adhesives having low flash solvent (containing petroleum and naptha) are used.  The area shall be well ventilated and smoking shall be prohibited.

c) The underlay shall be fixed to the sub-floor in such a way that a smooth surface is available.  The finished underlay shall be cleaned of all dirt and dust, chemicals, paints, etc.  The linoleum shall be firmly pressed into the adhesive spread over the underlay.  To ensure good bond, the surface can be rolled with a roller of 70 kg weight, washing from centre to the walls.  If necessary, sand bags may be placed at some points.

When laid on concrete floors it is desirable to prime the back of linoleum with the adhesive.  Cork tiles should be fixed with the adhesive.

Normally 4.5 and 3.2 mm thick linoleum can be used for commercial and institutional buildings respectively; for domestic buildings 1.6 mm thick linoleum may be used.

d) The surface, after cleaning of all debris, etc, may be wax-polished or a coat of emulsion polish may be applied. No traffic shall be permitted till the completion of all related works.

e) All surfaces shall be swept clean and washed with a cloth dampened with an aqueous solution of neutral detergent.

14.37.5. SPECIFICATIONS FOR EPOXY RESIN FLOOR TOPPINGS

14.37.5.1. General - Epoxy resins are suitable for use on industrial floors, such as, in chemical plants manufacturing fertilizers, pharmaceuticals, acids and solvents, in dairy industry, tanneries, breweries, garages, service stations, warehouses, metal plating and pickling areas.  They have good qualities of adhesion and chemical resistance, hardness, abrasion resistance; physical properties, such as, compressive, impact and flexural strength, negligible shrinkage, dimensional stability and adhesion to cured concrete, metals and other surfaces.

14.37.5.2. Materials

(a) Epoxy resin shall conform to IS: 9197-1979,(b) Hardness shall conform to IS: 9197-1979,(c) Accelerator shall conform to IS: 9197-1979,(d) Plasticizers and non-reactive diluents shall conform to IS: 9197-1979, (e)Liquid coal tar shall conform to IS: 9197-1979, and (f) Aggregates shall conform to IS: 9197-1979. ) (See also Annexure 14 A.11)

14.37.5.3. Types of epoxy resin toppings - There are two types of epoxy resin floor toppings :

a)  Trowel type – This is usually heavily filled with sand or other suitable aggregates and the compound is applied by trowel.  Such compounds are often referred to as mortars or screeds. 

b)  Flow type – This is usually a solventless compound containing filler and pigment and the mixture is poured directly on to the surface when the blend will flow and level itself with little assistance to form a smooth continuous coating. 

Terrazzo floors - The Portland cement in conventional terrazzo is replaced by epoxy resin binder.  Such flooring formulations serve the dual purpose of providing a good appearance and chemical resistance. 

Non-skid floors - This type of floor may be prepared by sprinkling a suitable grit on an epoxy resin floor topping when the latter is still in a tacky state. 

The following minimum thicknesses are recommended: trowel type – 4 mm for normal use and 6.5 mm in areas of thermal shock and heavy traffic on horizontal surfaces.

a) Flow type - 2 mm (b) Terrazzo floors - 10 mm.

14.37.5.4. Preparatory work

Concrete surfaces shall be properly cured and dried and kept rough.  Laitance shall be removed.  All cracks and broken areas of an existing base shall be sealed, fresh concrete applied and cured.  Grease and oil shall be removed with solvents, such as, acetone or a suitable detergent. 

The concrete surface shall be even.

Mild steel and cast iron surfaces shall be washed with a suitable solvent or detergent solution to remove grease or oil.  The surface shall then be sand blasted or abraded with emery cloth, abrasive disc or with wire brushes. 

14.37.5.5. Laying

Mixing of epoxy resin blend - The mixing shall be carried out at the site as follows:

  1. The constituents required shall be mixed in the correct proportions as specified by the formulator.
  2. Unless otherwise specified, the order of addition of the constituents shall be resin, hardener and aggregate. 
  1. Aggregates, when required, shall be added to the blend in a mixer in dry condition.
  2. The duration of mixing shall be adequate to ensure thorough mixing, the quantity mixed at one time shall be such that a uniform thickness of epoxy resin topping may be applied over the whole floor. 

Application

  1. The blended epoxy resin mix shall be applied uniformly, over the area prepared, to a uniform thickness.
  2. For some areas where heavily filled trowelling compound is to be applied, the prepared area shall be first covered with a tack coat of unfilled resin-hardener mix applied by brush which shall be allowed to cure to a tacky stage. 
  3. Where heavily filled trowelling compound is used, it is advisable to apply a seal coat of unfinished resin to ensure that pores, if any, are sealed adequately.
  4. As mild steel tools are liable to cause stains on light coloured surfaces, it is recommended that stainless steel, chromium on rigid PVC tools should be used after laying of epoxy resin floor toppings.
  5. After application of the epoxy resin topping, the floor shall be allowed to set without disturbance for a minimum period of 24 h.  the floor can be brought to normal use after a period of 7 days at a temperature of 20° C and above though light traffic may be permitted after 24 h of laying the floor topping.  Below 20° C special hardeners may be used as recommended by the formulator in order to obtain proper setting of the floor topping. 
  6. Expansion joints to coincide with those in the base concrete should be provided in epoxy resin toppings.  The expansion joints in the epoxy topping shall be filled with flexible putty that shows appropriate water and chemical resistance as recommended by the formulator. 

Safety precautions - Epoxy resins cause irritation to persons having sensitive skin.  Good ventilation is necessary and the most effective precaution is the use of rubber or polyethylene gloves.  It is preferable to wear thin cotton gloves underneath for comfort.  Other methods recommended are regular washing hands, arms and face with soap and luke warm water followed by thorough drying with a clean towel and the use of a barrier cream.  Splashes on skin should be removed immediately by washing with soap and luke warm water.  On no account should a solvent be used for this purpose. 

Polyamide hardeners should be used where floors are exposed to frequent impact stress and fluctuations in temperature.  The performance of floor will, however, depend on whether the chemical and mechanical stress occurs simultaneously.  Variations in temperature would also affect the performance of the floor topping.

Maintenance - Very little maintenance is required for epoxy floor toppings.   However, the following precautions would prolong the service life of the topping.  (a)Usual house hold detergents, soap and warm water (up to 60° C) may be used for cleaning the floor.  Use of powerful oxidizing agents should be avoided. (b)The resin flooring tends to develop cracks when subjected to quick thermal cycles.  Hence frequent use of alternate cold and hot water hosing should be avoided. (c)  Dragging of heavy.

14.37.6. SPECIFICATIONS FOR CHEMICAL RESISTANT MORTARS

14.37.6.1. There are three types of chemical resistant mortars for different end uses, covered by the following Indian Standards:

(a)Use of Silicate Type by IS: 4441-1980. (b)Use of Sulphur Type by IS: 4442-1980, and (c) Use of Resin Type by IS: 4443-1980.

14.37.6.2. A mortar suitable for a particular environment is unsuitable for another.

a) Chemically setting silicate type of mortars are resistant to most acids and have been found to be satisfactory against nitric, chromic, sulphuric and hydrochloric acids.  They are used for acid proof bricks or tiles.  These mortars are not suitable for hydrofluoric and concentrated orthophosphoric acids.  They are also not resistant to alkalis, boiling water or steam and are likely deteriorate by continuous exposure to water or frequent washing with water.  In view of the fact that silicate types of

mortars develop chemical resistance by physical bond formed by the chemical action of the acid with the mortar, the acid should have a pH value of 4 or less.  Manufacturer should be consulted regarding usage of these mortars. 

b) Sulphur mortars have good resistance against most of the acids except for concentrated oxidizing acids, but have very poor resistance to alkalis.  The Sulphur mortar shall always be used at less than 90°C.  Where conditions are questionable, specific recommendations of the manufacturer shall be obtained. 

c) Resin mortars have fairly good resistance to non-oxidizing mineral acids but have a poor resistance to oxidizing mineral acids.  They are fairly resistant to inorganic alkalis.  Manufacturer should be consulted on the usage of these mortars. 

14.37.6.3. Clauses 14.37.7, 14.37.8 and 14.37.9 would over the use of these mortars, namely, silicate type, resin type and Sulphur type.

14.37.7. SPECIFICATIONS FOR SILICATE TYPE CHEMICAL RESISTANT MORTARS

14.37.7.1. Material - Silicate type mortar shall conform to IS: 4832 (Part I)-1969.

14.37.7.2. Mortar - The chemically setting silicate type chemical resistant mortar is an intimate mixture of chemically inert solid filler, a setting agent usually contained in the filler and a liquid silicate binder.  When the filler and binder are mixed at ordinary temperatures, a trowel able mortar is formed, which subsequently hardens by the chemical reaction between setting agent and the liquid silicate binder. 

14.37.7.3. Storage - The filler shall be protected from water during storage.  The filler shall be kept in the containers if it cannot be protected otherwise.  The liquid binder shall be protected from freezing during storage until used.  Under unavoidable circumstances liquid binder that has frozen may be used, provided the liquid binder is thawed and thoroughly re-mixed before use and it can be restored to its original consistency. 

14.37.7.4. Mixing - Unless otherwise specified by the manufacturer, two to three parts by weight of filler to one part by weight may be used.  The optimum proportions might vary slightly due to climatic conditions, but it is important to have a mortar that is fluid enough to be workable and sufficiently stiff for the masonry unit to retain its position without slipping or sliding or without the mortar being exuded from the joint after the masonry unit has been placed in position. 

  1. Weigh the filler and binder in separate containers according to the recommended proportion.
  2. Add approximately three-fourths of the filler to the liquid binder in a clean container and mix with a trowel until all the filler has gone into paste.  Add the remaining filler to the paste and continue mixing until the mortar is uniform. In any batch only that quantity of mortar that could be used before it starts setting shalki be mixed.
  3. Mortar that has begun to set shall not be tempered by adding liquid binder or water but shall be discarded before preparing fresh batches. 
  4. Portland cement or water shall not be added to the silicate type of mortar.  Care shall be taken that the mortar does not come into contact with cement concrete surface. 
  5. Special precautions shall be taken when silicate mortars are exposed to temperatures below 10° C or above 27° C during mixing, application or setting. 

14.37.7.5. Application

a)  Surface preparation – The surface on which bricks to IS: 4860-1968 or tiles to IS: 4457-1982 are to be laid shall be free from dirt and dampness and shall be properly cured and dried.

b)  Application of membrane – A coat of bitumen primer conforming to IS: 3384-1986 be applied, and then covered with a coat of bitumen conforming to IS: 1580-1991.  If the bedding material is epoxy or polyester resin, the tiles or bricks may be laid directly on the surface without application of bitumen primer.  In case of furane, cashewnut shell liquid and phenolic types resins, a coat of bitumen primer conforming to IS: 3384-1986 shall be subject to service conditions.  Other membranes such as lead, polyisobutane and fibre reinforced plastics may also be used. 

c)  Mortar application with the same bedding and jointing materials

1)  For floors – Spread the silicate type of mortar 6 to 8 mm thick on the back of the tile or brick.  Smear two adjacent sides of the unit with 4 to 6 mm thick mortar.  Press the unit into the bed and push the unit until the joint in each case is 2 to 3 mm thick.  Trim off excess mortar and allow it to harden fully.  Cure the joints as given in 14.37.8.6 (b).

2)  For walls – Spread the silicate mortar 6 to 8 mm thick on the back of the unit.  Smear the two adjacent sides of the unit with 4 to 6 mm mortar.  Press the unit against the wall until joint in each case is 2 to 3 mm thick.  Trim off excess mortar.  While carrying out the jointing allow sufficient time to avoid the joints at bottom getting disturbed and sliding of the unit.  Only one course of unit shall be laid during the initial setting.  Cure joints as given in 14.37.8.6 (b).

d)  Mortar application with different bedding and jointing materials – when the job has to come into contact with water weaker acid solutions and alkalis, silicate type of mortar may be used for bedding and resin type of mortar for jointing.  The job shall be carried out with only class I bricks, if used. 

1)  On floors – Spread on two adjacent sides of the tile or brick the silicate type of mortar 6 to 8 mm thick.  Press the unit on the bed until the joint in each case is not more than 6 mm.  Before the silicate mortar sets completely, remove the mortar in the joints to a depth of 20 mm.  Cure the joints as in 14.37.8.6 (b) and fill the joints full with jointing mortar taking care to full up the entire length of the joint.  Trim off the excess mortar and make the joints smooth and plane. 

2)  On walls – Spread on to the back and two adjacent sides of the unit the silicate type of mortar 6 to 8 mm thick.  Press the unit against the wall until the joint in each case is not more than 6 mm.  Only one course of the unit shall be laid during the initial setting time to avoid the joints at the bottom getting disturbed and sliding of the unit.  Cure the joints as given in 14.37.8. 6 (b) and fill the joints full with the jointing mortar to fill up the entire length of the joint.  If Sulphur mortar is used, seal the vertical and horizontal joint with a strip of gummed paper 25 mm wide to prevent the flow of Sulphur mortar from the joints.  Strip off the gummed paper after the mortar has set.  Trim off excess mortar to make the joints smooth and plane. 

14.37.7.6. Acid–curing

a) Acid-curing shall be carried out as per manufacturer’s instructions, using safety precautions normally used when handling such acids.  The operators shall be provided with suitable aprons, gloves, boots, etc.  The mortar joints shall be cured with 20 to 25 percent hydrochloric acid or with 30 to 40 percent sulphuric acid no sooner than 2 days and not later than 6 days after the masonry units have been bonded with the mortar.  The curing time shall be at least 60 min.  If the constructed unit is designed to contain a liquid, it may be  filled with acid of the type and concentration stated above, with the time interval stated, in lieu of washing the joints.  In no case shall the acid solution be made by partially filling the tank with water and then adding acid.  When sulphuric acid is used for curing, the solution shall not be prepared inside the unit. 

Note: (a) 20 percent hydrochloric acid can be made by mixing 3 parts by volume of commercial 20° Baume hydrochloric acid with 2 parts by volume of water.  Forty percent sulphuric acid can be made by mixing 2 parts by volume of commercial 66° Baume sulphuric acid with 5 parts by volume of water. 

(b) When the bedding material is silicate type mortar and the jointing material is epoxy resin type or polyster type or Sulphur type mortar, no acid curing is required.  When the bedding material is silicate type and the jointing material is phenolic resin type or furane type or cashew nut shell liquid type, the joints shall be cured as in 14.37.8.6 (a) before applying the jointing material. 

14.37.7.7. Chemical resistance of silicate type mortars - A general guide for chemical resistance of silicate type of mortars to various substances is given in Table 11.  The ratings are for immersion service at ambient temperature and may be usually upgraded for spillage only.  The chemical resistance of silicate type of mortars shall be determined by IS: 4456 (Part I)-1967. 

14.37.8. SPECIFICATIONS FOR RESIN TYPE CHEMICAL RESISTANT MORTAR

14.37.8.1. Material -  The resin shall conform to the requirements laid down in IS: 4832 (Part 2)-1969.

14.37.8.2. Storage - The resin shall be stored in a clean dry place away from open flame and under roof with containers tightly closed.  The resins could be generally stored without deterioration at 27 ±2° C for periods not exceeding the values given below.  The filler or resin that has become wet shall not be used. 

Type of resin

Storage period in months

i)

Cashewnut shell liquid

9

ii)

Epoxy

12

iii)

Furane

12

iv)

Phenolic

3

v)

Polyester

3

14.37.8.3. Safety precautions -   Both the liquid and powder ingredients may contain materials that may affect the skin.  Therefore either gloves or barrier cream shall be used while handling these materials.

Vapour is present in most of the resin mortars and same produce gases during curing.  Adequate ventilation shall be provided in the mixing and working areas.  Under confined areas like vessel lining, etc, forced air draught may be used. 

Resin mortars, labeled as inflammable by manufacturers shall be used with adequate safety precautions against fire.  Solvents used for cleaning tools are generally inflammable.  Fires shall be kept away from the area in which such solvents are used and ‘No Smoking’ sign shall be posted in these areas. 

14.37.8.4. Mixing

  1. For hand mixing required quantity of liquid resin shall be poured into a basin. The powder shall then be added gradually and the mixture shall be well stirred working out all lumps and air bubbles.  The mortar shall be mixed to the proportion as specified by the manufacturer for a particular type of job.  A stainless steel spatula may be used for mixing purposes. 
  2. Only such quantity of mortar that could be consumed within 15 to 20 min shall be prepared unless otherwise recommended by the manufacturer.

14.37.8.5. Handling

  1. Resin mortars cure slowly at low temperatures.  If the work is to be carried out at temperature below 15° C, to masonry units should be warmed and the area of work shall be enclosed and heated to above 15° C by using infrared lamp, to obtain proper curing.
  2. Mixed mortar, that has become unworkable shall not be re-tempered with liquid resin, but shall be discarded.

14.37.8.6. Application

a)  Surface preparation – The surface on which bricks conforming to IS: 4860-1968 or tiles conforming to IS: 4457-1982 is to be laid shall be free from dirt and dampness and shall be properly cured and dried. 

b)  Application of membrane – A coat of bitumen primer conforming to IS: 3384-1986 shall be applied on the prepared surface.  A uniform coat of bitumen conforming to IS: 1580-1991 shall then be applied.  If the bedding material is epoxy or polyester resin, the tiles or bricks can be laid directly on to the surfaces without application of bitumen primer.  In case of furane, cashew nut shell liquid and phenolic resin, a coat of bitumen primer shall be used subject to service conditions.  Other membranes, such as, rubber, lead, polyisobutane and fibre-reinforced plastics can be used in place of bitumen primer.  

c)  Mortar application with the same bedding and jointing materials

1)  On floors – Spread the resin type of mortar 6 to 8 mm thick on the back of the unit.  Smear two adjacent sides of the unit with 4 to 6 mm thick mortar.  Press the unit into the bed and push against

the floor and the unit until the joint in each case is 2 to 3 mm thick.  Trim off excess mortar and allow it to harden fully.  Cure with acid as given in 14.37.9.7, except for epoxy and polyester resins. 

2)  On walls – Spread the resin type mortar 6 to 8 mm thick on the back of the unit.  Smear two adjacent sides of the unit with 4 to 6 mm mortar.  Press the unit against the wall until the joint in each case is 22 to 3 mm thick.  Trim off excess mortar and allow it to harden fully.  While carrying out the jointing allow sufficient time to avoid the joints at the bottom getting disturbed and sliding of the unit.  Only one course of tile or brick shall be laid during the initial setting.  Cure with acid as in 14.37.9.7 except for epoxy and polyester resin.  

d)  Mortar application with different bedding and jointing materials

1)  On floors – Spread on to the back and two adjacent sides of the unit the silicate type mortar 6 to 8 mm thick.  Press the unit on the bed until the joint in each case is 3 to 6 mm thick.  Before the silicate mortar sets completely, the jointing material is removed to a depth of 20 mm.  The material thus removed may be used for bedding providing it is trowelable and has not hardened.  After the bedding mortar is properly set cure the joints as given in 14.37.9.7 and fill the joints full with resin type mortar taking special care to fill up the entire length of the joint.  Trim off excess mortar to make the joints smooth and plane. 

2)  On walls – Spread to the back and two adjacent sides of the tile or brick the silicate type mortar 6 to 8 mm thick, press the unit against the wall until the joint in each case is 3 to 6 mm thick.  Only one course of the unit shall be laid during the initial setting time to avoid the joints at the bottom getting disturbed and sliding of the unit.  Before the silicate mortar sets completely, the jointing material shall be removed to a depth of 20 mm which may be used for bedding provided it is trowelable and has not hardened.  Cure the joints as given in 14.37.9.7 and fill the joints full with resin type of mortar taking care to fill the entire length for the joint.  Trim off excess mortar to make the joints smooth and plane. 

14.37.8.7. Acid-curing - Except for epoxy and polyester resins, cure the joints for a minimum period for 72 h with 20 to 25 percent hydrochloric acid or with 30 to 40 percent sulphuric acid before applying the resin type of mortars.  After acid-curing, wash the free acid in the joints with clean water and allow sufficient time for thorough drying.  Resin mortars shall then be filled into the joints. 

Resin mortars are normally self curing and do not generally require an auxiliary curing.  They should not be put to use before 48 h in the case of furane, epoxy and polyester resin type mortars.  They may be put to use after 48 h provided the setting temperature is at least 20° C.  in the case of phenolic and cashew nut shell liquid resin and for lower temperatures the period of curing shall be extended as recommended by the manufacturer.  Without any heat treatment phenolic resin and the cashew nut shell liquid resin shall not be put to use for 7 to 28 days respectively.  With the treatment phenolic resin and the cashew nut shell liquid resin may be put to use after 2 to 6 days respectively.  The construction shall be protected from weather and water and from accidental mechanical damage until the mortar is cured.  Heat treatment may be given with infrared lamp. 

14.37.8.8. Chemical resistance of resin type mortars - As a general guide the chemical resistance of resin type mortars to various substances is as given in Table 12.  The ratings are for immersion service at ambient temperature and may be upgraded for spillage only.  Manufacturer’s instructions shall generally be followed.  IS: 4456 (Part 1)-1967 may be used for testing. 

14.37.9. SPECIFICATIONS FOR SULPHUR TYPE CHEMICAL RESISTANT MORTAR

14.37.9.1. Material - Sulphur type mortar shall conform to IS: 4832 (Part 3)-1968.

14.37.9.2. Storage - Sulphur mortar shall be kept in a dry place prior to use.  The mortar shall not deteriorate during storage.

14.37.9.3. Safety precautions

a) Sulphur mortar is melted and poured between bricks or tiles.  If overheated, it ignites and burns with a low blue flame.  When the blue flame is observed, heating shall be stopped and the vessel shall be covered with a tight fitting lid or wet gunny bags until the fire is extinguished.  When applying Sulphur mortar in a confined space, each pail or molten material shall be checked to ensure that the mortar is not burning.  The blue flame shall be checked in a dark place. 

b) All Sulphur coming into contact with molten Sulphur mortar shall be kept dry.  Adequate safety precautions shall be taken during melting and pouring of Sulphur mortars.  The operators shall be provided with leather aprons, asbestos gloves, asbestos boots, goggles and masks.  The areas where melting and pouring is carried out shall be checked for flammable or explosive a gases and a flame permit shall be issued before the fires are lit or molten Sulphur mortar is carried into the area.  Soda acid type fire extinguisher and wet cloth shall be made available for extinguishing fire or preventing its spread.  Water shall be kept away from molten Sulphur mortar in order to avoid foaming.  Adequate ventilation should be provided wherever Sulphur mortars are used.

Table 12 - Chemical resistance of resin type mortars

Sl

No

Substance

Epoxy

Polyester

Phenolic

Furnae

Cashew

Nut Nutshell

Liquid

 

Acids

 

 

 

 

 

i

Acetic acid 10%

R

R

R

R

R

ii

Chromic acid 10%

N

R

L

N

L

iii

Hydrochloric acid (conc)

R

R

R

R

R

iv

Hydrofluoric acid (see Note)

N

N

R

R

R

v

Lactic acid 2%

R

R

R

R

R

vi

Nitric acid (10%)

L

N

L

N

L

Vii

Nitric acid (conc)

N

N

N

N

N

Viii

Phosphoric acid 10%

R

R

R

R

R

ix

Sulphuric acid 10%

R

R

R

R

R

x

Sulphuric acid 40%

R

R

R

R

R

xi

Sulphuric acid (conc)

N

N

L

N

N

 

Alkalis

 

 

 

 

 

i

Ammonia 0.880

R

N

L

R

R

ii

Sodium hydroxide 40%

R

N

L

R

L

ii)

Sodium carbonate

R

L

R

R

R

iv

Calcium hydroxide

R

N

R

R

R

 

Salt solutions

 

 

 

 

 

i

Salt solution (acidic)

R

R

R

R

R

ii

Salt solution (alkaline)

R

L

R

R

R

 

Solvents

 

 

 

 

 

i

Aliphatic hydrocarbons

R

R

R

R

N

ii

Aromatic hydrocarbons

L

N

R

R

N

iii

Alcohols

R

R

R

R

R

iv

Ketones

L

N

L

R

R

v

Chlorinated hydrocarbons

L

L

R

R

N

 

Wet gases (oxidizing)

N

N

N

N

N

 

Wet gases (reducing)

R

R

R

R

R

 

Mineral oils

R

R

R

R

L

 

Vegetable oils and fats

R

R

R

R

L

 R = Generally recommended.  L = Limited use.  N = Not recommended.

Note: Carbon and graphite fillers should be used for hydrofluoric acid service.

14.37.9.4. Melting and pouring

  1. The mortar shall be melted in a clean vessel made of cast iron, or steel, or aluminium.  It shall be filled with dry Sulphur mortar to not more than one half and heated slowly until the mortar has melted to a black, smooth liquid with a mirror bright surface and the liquid is almost as free flowing as water, while stirring frequently with a steel ladle.  The Sulphur mortar must be dry at the time of use to avoid foaming.  The mortar shall be heated to a temperature of about 135° C.  Below 130° C some of the liquid will congeal over the top or around the sides of the vessel.  If the mortar is heated much above 135° C, the viscosity increases until the mortar thickness and loses its mirror like appearances.
  2. If the mortar thickens on overheating, it should be allowed to cool and stirred until thin; then more cold mortar may be added, if necessary, overheating for long periods may permanently damage the mortar.  Care shall be taken that water or damp mortars do not get into the heating vessel so as to avoid foaming. 
  3. The molten Sulphur mortar shall be taken in galvanized bucket.  The nose of the bucket shall be directed towards the joint and the hot and viscous mortar is poured slowly into the joint without air entrapment.  Any entrapped air should be removed while the mortar is hot by poking with a thin mild steel rod. 

14.37.9.5. Application

a)  Surface preparation – The surface to receive the acid resistant bricks and tiles shall be free from dirt and dampness and shall be cured and dried. 

b)  Mortar application with same bedding and jointing materials

1)  On floors – Spacer chips with a surface area of about 1 cm2 and 6 mm thick and made of Sulphur mortar conforming to IS: 4832 (Part 3)-1968 shall be made available.  The chemical resistant brick or tile shall be placed on spacer chips, 3 chips being used under each tile.  Between the floor and tile or brick 6 mm space shall be provided.  The molten Sulphur mortar shall be poured in a maximum of two operations in spaces between floor and the units avoiding air pockets till it completely fills the joints.  Trim off excess mortar to make the joints smooth and plane using a hot trowel. 

2)  On walls – The chemically resistant unit shall be placed 6 mm away from the wall and the adjacent unit using spacer chips with a surface area of 1 cm2 and 6 mm thick and made out of Sulphur mortar.  The vertical and horizontal joints are sealed with gummed strip of paper 25 mm wide to prevent molten Sulphur mortar flowing from the joints.  The mortar shall be filled leaving a gap of 25 mm from the top and avoid air entrapment.  A further course of the unit shall be laid in the same way immediately thereafter.  The gummed paper can be stripped off as soon as the Sulphur mortar has hardened. 

c)  Mortar application with different bedding and jointing materials

1)  On floors – Spread on to the back and two adjacent sides of the unit the silicate type of mortar 6 to 8 mm thick.  Press the unit on the bed and push against the floor and the unit until the joint is not more than 6 mm thick.  Before the silicate mortar sets completely, the jointing material is removed to a depth of 20 mm.  The material thus removed may be used for bedding provided it is trowelable and has not hardened.  Cure the joints with acid for a minimum period of 72 h and dry.  If the bedding material is silicate mortar, the laying and curing shall be done as per 14.37.9.6.  Fill up the joint completely to its entire length with Sulphur mortar.  Trim off excess mortar to make the joints smooth and plane with a hot trowel. 

2)  On walls – Spread on the back and two adjacent sides of the unit, silicate mortar 6 to 8 mm thick.  Press the unit against the wall and with the adjacent unit until the joint in each case is not more than 6 mm thick. Only one course of the unit be laid during initial setting time to avoid the joints at the bottom getting disturbed and the unit getting slided. Before the mortar sets completely remove the jointing material to a depth of 20 mm.  The material thus removed may be used for bedding provided it is trowelable and has not hardened.  After the bedding mortar has set, cure the joints with resin for a minimum period of 72 h and dry.  If the bedding material is silicate type the laying and curing shall be as per 9.6.  Seal the vertical and horizontal joints with a strip of gummed paper 25 mm wide to prevent the flow of Sulphur mortar from the joints.  Fill up the joints completely with molten Sulphur mortar avoiding air entrapment.  Strip off the gummed paper after the mortar has hardened.  Trim off excess mortar with a hot trowel to make the joints smooth and plane. 

d)  Protecting the units from mortar – Various methods are available for masking the masonry units to prevent Sulphur mortar from adhering to them.  Paraffin wax, paper, etc, may be used to cover the masonry units.  The paraffin wax or paper shall be removed after use. 

e)  Floors laid with Sulphur mortar shall not be put into service before 8 hours of laying. 

14.37.9.6. Chemical resistance of Sulphur type mortars

A general guide for chemical resistance of Sulphur type mortars is given in Table below.  The ratings are for immersion service at ambient temperature and may usually be upgraded for spillage.  The chemical resistance of Sulphur type mortar shall be determined in accordance with the method described in IS: 4456 (Part 2)-1967.

Chemical resistance of Sulphur type mortar

Sl.No

Substance

Chemical resistance

 

Acids

 

i

Hydrochloric acid (concentrated)

R

ii

Sulphuric acid (70%)

R

iii

Sulphuric acid (above 70%)

L

iv

Nitric acid (40%)

R

v

Nitric acid (above 40%)

N

vi

Organic acid

L

vii

Hydrofluoric acid (40%) (see Note)

R

 

Alkalis

 

i

Sodium hydroxide (1%)

R

ii

Sodium hydroxide (above 1%)

N

iii

Sodium carbonate (concentrated)

R

iv

Salt solutions (acidic)

R

v

Salt solutions (alkaline)

L

 

Solvents

 

i

Aliphatic hydrocarbons

L

ii

Aromatic hydrocarbons

L

iii

Alcohols

R

iv

Ketones

L

v

Chlorinated hydrocarbons

L

 

Fats and Oils

L

R = Generally recommended, L = Limited use, N = Not recommended.

Note: Graphic and carbon filler should be used for hydrofluoric acid service.

14.37.10. SPECIFICATIONS FOR PARQUET FLOORING

14.37.10.1. General – Parquet flooring is covered by the following Indian Standards:

IS: 5389-1969 - Hardwood parquet and wood block floors

IS: 9472-1980 - Mosaic parquet flooring

a) Parquet flooring are used in auditorium, squash courts, skating rinks, dancing halls, etc.

b) Mosaic parquet floors consists of many small pieces of (slats) which are liable to compensate very successfully the inevitable warping of wood due to variations in humidity without resulting in gaps so

objectionable in strip parquet; at the same time gluing also remains perfect.  New patterns may be provided with mosaic parquet which are not possible with conventional strip parquet. 

14.37.10.2. Materials

a)The species of timber for hardwood parquet and wood block floors are given in Annexure 14-A.3 along with the indentation index, compared to teak as 100.   The sawn timber shall be non-refractory and the thickness of floor blocks and parquets shall be 25 to 40 mm.  Nails used shall be diamond pointed (see IS: 723-1972).

b) The percentage indentation for hardness shall be not less than 55 so as to withstand constant wear and tear. 

c) Timber shall be seasoned as per IS: 1141-1993 and thereafter treated with preservatives as per IS: 401-1982.  In case water soluble preservatives are used, timber shall be seasoned a second time after preservation.  Termite control and damp proofing shall be as per specifications.

14.37.10.3. Classes of mosaic parquet flooring - They shall be of two classes.

Class I: Slats may be quarter, half quarter or rectangular sawn provided that the number of tangential sawn slats does not exceed 30 per cent of the slats in each panel. 

Face shall be free from sound knots exceeding 2 mm in diameter and loose knots exceeding 1 mm in diameter.  Knots up to 5 mm diameter may be permitted in the back. 

Class II: Only one of the defects mentioned from i) to v) below, apart from sound knot is permitted on the face of a slat; back may exhibit knots and other defects of a larger size. 

(i) Sound knots, of a colour very nearly approaching that of adjoining wood; ½ width of slat. 

(ii) Loose knots, of a colour contrasting with that of adjoining 1/5 of width of slat.

(iii) Cross gain, (iv) Waned wood; maximum 1/25 width of slat, and (v) Stains.

14.37.10.4. Parquet floor patterns - They shall be as given in Figure 15 and Figure 16.

Fig. 15 Different designs of panel for parquet flooring

14.37.10.5. Wood Block flooring Patterns (Types of blocks and wood block floor)

They shall be as given in Fig.17, Fig. 18 and Fig. 19.

14.37.10.6. Mosaic parquet panel -  It shall be as In Fig. 20.

14.37.10.7. Dimensions - Mosaic parquet floors shall be of 6, 8 and 10 mm thickness; 6 mm thickness is not suitable for softwood and softer grades of hardwood; width shall be 18 to 25 mm.  Length shall be 100 to 165 mm.

Fig 16 Parquet floor laid in panels

14.37.10.8. Fabrication and laying

a) Parquet floor shall be consisting of the following:

1)  Sub floor – The sub-floor shall be planed of timber boarded floor 50 to 75 mm thick (see IS: 3670- 1989 or Part 5).  The sub-floor may also be of cement concrete. 

Fig. 17 Patterns of wood block flooring

Fig. 18 Different types of wood blocks

1) Panels – These shall be generally 30 to 35 cm2.

2) Square edged hardwood battens – These shall be generally 15 to 50 cm in length, 5 to 10 cm in width and 5 to 10 mm in thickness.

Fig 19 Wood floor block

Fig. 20 Typical illustration of Mosaic parquet panel

b) The laying of parquet floor shall be done as below:

1) Border shall be fitted first to a width of 60 cm and the area is laid and fitted dry. 

2) Every individual piece of parquet is taken up in turn and placed in position with mastic;

3) Before the mastic hardens, nails are driven in;

4) The floor is scraped or planed to an even surface and sand papered; and

5) The nail holes punched in area filled with putty and the floor is polished with the use of power-driven machines.

c) The wood block floors shall be in herring-bone or basket patterns.  The blocks shall of the types given below:

  1. Simple square end block with dove-detailed grooves on the bottom,
  2. Tongued and grooved,
  3. Tongues on the ends, and
  4. Dovetailed groove on the bottom and with a narrow groove. 

d) Laying of woodblock floor shall be done as below :

1) Sub-floor shall consist of cement concrete flooring of 5 to 7.5 cm thick, finished smooth. 

2) The wood blocks, sizes from 25cm X 7.5 cm to 30 cm X 7.5 cm, shall be dipped in liquid mastic composition adhering to cement. 

3) The centre of the floor shall be laid first with the border cut and fitted to it.  Generally two rows of wood blocks shall be laid longitudinally to serve as border.  The floor is scraped and planed to an even surface and sand papered.

4) The pores in the floor shall be sealed by an appropriate floor seal. 

e) Mosaic parquet floors shall be laid as below:

1) Adhesives for gluing parquet shall be of solvent and dispersion type, such as, epoxy resin or phenolic resin (resorcinol formaldehyde), or urea formaldehyde synthetic adhesives.  All parquet adhesives are diluted (mixed) with various mineral components; they are applied by means of a toothed steel trowel as thin as possible.  Only a limited area shall be primed in order to prevent setting. 

2) Mosaic parquet are laid over battened floors which are even.  The mosaic parquet shall be laid diagonally to the direction of battens.  In old and uneven battened floors, plywood or other boards may be inserted between the floor and mosaic parquet.  The boards may be glued or nailed to the floor and the old batten floor be made even. 

3) Adhesive shall be applied on the prepared and dry surface and the back of parquet.  Apply pressure on the parquet panel to get a good bond.  Joints shall be very thin and fine.

4) Mosaic parquet floors shall be finished as in section on finishes of wood work.

* * * *