WOOD WORK -2



WOOD WORK

Annexure 9-A.10

SPECIFICATIONS FOR COMMERCIAL VENEERS

(Extract of IS: 14315-1995)

1. Scope - The section covers the requirements for commercial veneers used for faces, core and cross bands in the manufacture of plywood, blockboard, veneered boards and flush door.

2. References - The Indian Standards listed in Annexure A are necessary adjuncts to this standard.

3. Terminology - For the purpose of this standard, the definitions given in IS:  707- 1976 shall apply.

4. Classification by appearance - Veneers shall be classified into two types of surfaces namely; type A and Type B. the quality requirements in terms of permissible defects for the two types of surface shall be as given in Table 1. However, the maximum number of categories of defects permitted on the veneer surface shall be restricted in accordance with the requirement given in Table 2.

Table 1 Quality requirements of veneers (Clause 4, 6 and 7 of IS: 14315-1995)

Sl. No

Defects categories

Types of surfaces

A

B

i)

Discolouration

 Nil

5 percent

ii)

Dote

50 mm/m2

150 mm/m2

iii)

Insect holes

Scattered up to 12 holes/m2

Scattered up to 12 holes/m2

iv)

Joints

One joint for every multiple of 200 mm provided no individual piece is less than 100 mm in width

No restriction

v)

Knots(dead)

2 No. up to 12 mm dia/m2

4 No. up to 20 mm dia/m2

vi)

Pin knots (dead)

2 no/m2

6 No./m2

vii)

Pin knots(live)

No restriction

No restriction

viii)

Knots(tight)

6 No. up to 25 mm dia/m2 No restriction

ix)

Patches

4 patches/ m2  provided they are all tight patches and do not mar the appearance Any number provided they are all tight patches ans do not mar the appearance

x)

Splits

2 splits each not more than 1 mm wide and length not more than 100 mm 3 splits, each not more than 4 mm wide and length not more than 150 mm

xi)

Swirl

Unlimited, provided they do not mar the appearance No restriction

 Table 2 Permissible categories of defects (Clause 4, 6 and 7)

Types of surfaces

Maximum number of categories of permissible defects per square meter

A

3

B

5

5. Manufacture

5.1. The veneers shall be either rotary cut or sliced. The veneer shall be tight, smooth and uniformly thick and free from other machining defects such as corrugation, wood lines, waviness, bulging of knots, buckle, knife-pressure bar marks, raised or torn grain, etc. One of the most important quality requirements of veneer is tightness. The veneer is called tight or loose on the basis of depth of penetration of checks which are small breaks known as lathe or slicer or knife checks formed on the knife side during cutting of veneer. Figure 1 shows the tight and loose side of veneer during peeling. The veneer is classified as tight if the depth of penetration of checks does not exceed 50 percent of veneer thickness when measured as per the procedure given in Annex B. Treatment as specified in 5.2 shall be given wherever necessary. Surface smoothness of veneer is directly related to tightness. As the tightness increases, smoothness of the veneer increases. The uniformity in thickness along and across the grain shall be checked with the help of dial thickness gauge, which is suitably spring loaded and suitable for this purpose. Veneers intended to be glued with phenolic and urea resins shall dried to a moisture content of 4 percent to 6 percent and 6 percent to 8 percent respectively. The dried veneer should be free from drying defects such as buckle, end waviness, splits, checks and case hardening.

5.2. Treatment - Veneers from non-durable species and sapwood of all species *see also IS:  401 -1982) shall be soaked in 1.25 percent solution of boric acid or 1.9 percent solution of borax at a temperature of 85°C to 90° C for a period of 10 to 40 minutes depending upon the thickness of the veneers or the veneers shall be dipped in 2 percent solution of boric acid or 3 percent borax solution for 2 minutes and block stacked at least for two hours before drying.

6. Face veneer - Face veneer shall be of Type A and / or Type B conforming to the requirements specified in Table 2.

7. Core and cross band veneer - Core and cross band veneer shall be of Type B conforming to the requirements specified in Table 1 and Table 2.

8.  Joints in veneers - Veneers that require jointing to form Type A or Type B surface shall be spliced (edge joint). Alternatively, the veneers may be taped on the face of the outer veneers in which case the tape shall be removed at a later stage. Metal clips or staples, if used shall be removed. Perforated taped may be used on the glue side of the veneers.

9.  Dimensions and tolerances

9.1. Unless otherwise specified, the first dimension is the dimension along the grain direction of the veneer and the second dimension is the dimension across the grain direction of the veneer.

9.2. Unless otherwise specified, the dimensions of veneers shall be as obtained by adding 50 mm (for trimming) to the dimensions for general purpose plywood given in IS:  12049-1987.

9.3. Maximum thickness of veneer shall be 6 mm.

9.4. Tolerances

9.4.1. The following tolerances shall be permissible on the dimensions

Fig. 1 Relative positions of knife, nose bar and veneer

Dimension

Tolerance

Length

+ 6 mm

0 mm

Width

+ 3 mm

0 mm

9.4.2. Squareness - 0.2 percent

9.4.3. Edge straightness – 0.2 percent

10. Sampling - The method of drawing representative samples and criteria for conformity shall be as prescribed in IS:  7638-1986 for general purpose plywood (IS:  303-1989).

11. Marking

11.1. Each veneer shall be legibly and indelibly marked or stamped with the following

(a)Indication of the source of manufacture; (b) Year of manufacture; (c) Batch No; and (d)Type of the veneer, that is, Type A or Type B.

11.2. All markings shall be done on the face of the veneer near one corner.

11.3. BIS certification marking - The product may also be marked with the Standard Mark.

11.3.1. The use of the Standard Mark is governed by the provisions of Bureau of Indian Standards Act, 1986 and the Rules and Regulations made there under. The details of conditions under which the licence for the use of Standard Mark may be granted to manufacturers or producers may be obtained from the bureau of Indian Standards.

12. Method of Evaluation of Lathe Checks. (Clause 5.1) [Extract of IS: 14315-1995]

Apply an alcohol-soluble dye to the checks by brushing it on the lose side of dry veneer surface. The dye penetrates into the checks. The depth of checks as a percentage of veneer thickness can be estimated from scarfed sections of the samples, using a magnifying glass as shown in the Fig.2.

Fig. 2 Scarred sample of veneer viewed through magnifying glass to show lathe checks on which dye was applied prior to scarfing to make the checks stand out

Annexure 9-A-11

BLOCK BOARDS

(Extract of IS: 1659-1979)

1.Scope – Requirements of commercial and decorative block boards meant for interior and exterior uses.

1.1 Grades and types

2.1. Grades

(a) Grade I Exterior grade meant for bus bodies, railways coaches, prefabricated houses, where it is likely to be exposed to rain, high humidity, etc.

(b) Grade 2 – Interior grade meant for furniture, partition, paneling, ceiling, etc.

2.2. Types – Each grade shall be of the following types

(a)Type 1 – Decorative type with faces of ornamental veneers on one or both faces for use in high class furniture, paneling, interior decoration, partitions, etc.

(b)Type 2 – Commercial type with faces of commercial timber for use for ordinary furniture, table tops, partitions and paneling, seats of bus bodies, railway carriages, etc.

2.3. Representation by symbols

Grade  and Type

Symbol

Grade 1,  Type 1

XDEC

Grade 1,  Type 2

XCOM

Grade 2,  Type 1

IDFC

Grade 2,  Type 2

ICOM

3. Materials

Adhesive – BWP Type for grade 1 and BWR or WWR Type for Grade 2.

Note : For details regarding timber for core, cross bands and face veneers of commercial types, refer to Appendix A and B of the standard.

4.  Dimensions and tolerances

Dimensions

(a)Length – 300, 270, 240, 210, 180, 150 and 120 cm;

(b) Width – 150, 120 and 90 cm; and

(c) Thickness – 12, 16, 20, 25, 30, 32, 35, 38, 40, 45 and 50 mm.

Tolerances

(a)Length ± 6 mm (b) Width ± 6 mm (c)Thickness  ± 5 percent up to 35 mm thickness ± 2.5 percent above 25 mm thickness.

Note: Length of diagonals shall not differ by more than 2.5 mm per meter length of diagonal

5. Tests

5.1. Dimensional changes caused by humidity – Dimensions shall not change by more than ± 1 mm at relative humidity of 90 percent and 40 percent compared to the dimensions of the block board conditioned at 65 percent relative humidity. There shall be no delamination and the changes in local planeness shall not be more than 1/150.

5.2. Resistance to water – Shall satisfy the prescribed test.

5.3. Adhesion of plies – Veneers shall offer resistance to separation and the fractured surface shall show some adherent fibre distributed more or less uniformly.

5.4. Mycological test – Shall show no appreciable signs of separation at the edges.

5.5. If required by the purchaser, additional tests, namely, central loading of plate test, flexural strength and deflection under sustained load test may be performed.

Annexure 9-A-12

PLYWOOD FOR GENERAL PURPOSES

(Second revision) (With Amendments No.1 to 3)

(Extract of IS: 303-1975)

Scope – Requirements of different grades and types of plywood used for general purposes.

Grades (Depending on type of adhesive used for bonding veneers)

AC, AD, BB, BC, BD, CC, CD, and DD based on quality of face and back surface in terms or permissible defects. For quality requirements see Table 1.

Boiling water proof or BWP Grade

Boiling water resistant or BWR grade

Species of timber used shall be those given in Class I of Appendix A of the standard.

Warm water resistance or WWR Grade    

Cold water resistance or CWR Grade 

Species of timber used shall be those given in Class I and II of Appendix A of the standard.

Types based on classification by appearance – Classified into 10 types, namely, AA AB, B 3, 6, 9 and ‘no limit’ for surface types A, B, C, D respectively.

Table 1 Quality requirements of plywood for general purposes

Sl. No

Defect

Types of surfaces

(1)

(2)

(3)

B(4)

C(5)

D(6)

I)

Blister

 Nil

Nil

Nil

Occasional

II)

Checks

Individual check not more than 25 mm in length, and the total length  not more than 3000/m2

Individual check not more than 50 mm in length, and the total length not more than 600 mm/m2

Individual check not more than 100 mm in length, and the total length not more than 1000 mm/m2

Individual check not more than 125 mm in length, and the total length not more than 1200 mm/m2

III)

Discoloration (sound not injurious)

3 percent of the area

25 percent of the area

50 percent of the area

75 percent of the area

IV)

Discoloration (unsound)

Nil

Nil

Nil

20 percent of the area.

V)

Dote

Nil

5 cm/m2

15 cm/m2

15 cm/m2

VI)

Insect

Hole

Nil

Scattered upto 12 holes per m2

Scattered upto 24 holes per m2

Scattered upto 50 holes per m2 may be permitted.

VII)

Joints

None in 250 mm wide face and in wider faces, one joint for every multiple of 200 mm in width provided no individual piece is less than 125 mm in width

Not more than one in 250 mm wide face and in wider faces one joint for every multiple of 200 mm provided no individual piece is less than 100 mm in width

No restriction

 No restriction

VIII)

Knots

(dead)

Nil

2 up to 12 mm dia/m2

4 up to 20 mm dia/m2

8 knots up to 20 mm in dia/m2 including drop out knot holes may be permitted

IX)

Pin knots (dead)

Nil

2/m2

6/m2

10/m2

X)

Pin knots (dead)

Permitted, provided they do not mar the appearance

No restriction

No restriction

No restriction

XI)

Knots (tight)

3 up to 25 mm dia/m2

6 up to 25 mm dia/m2

No restriction

No restriction

XII)

Patches

Nil

4 patches per m2 provided they are all tight patches and do not mar the appearance

Any number, provided they are all tight patches and are matched for colour

Any number, provided they are all tight patches and properly made

XIII)

Splits

One split, not more than 1.0 mm wide and not longer than 50 mm provided it is filled with a suitable filler

2 splits, not more than 6 mm wide and total length not more than 200 mm provided they are filled with suitable veneer inserts

3 splits, not more than 10 mm wide and total length not more than 300 mm provided they are filled with suitable veneer inserts. Splits up to 25 mm long and 0,8 mm wide may be ignored provided they are suitably filled

6 splits, not more than 25 mm wide and total length not exceeding 400 mm

XIV)

Swirl

Up to 4/m2 provided they do not mar the appearance

Unlimited, provided they do not mar the appearance

 No restriction

No restriction

3.. Dimensions and tolerances

a)

Size (in cm)

300 x 150

180 x 90

 

 

240 x 120

150 x 120

 

 

240 x 90

150 x 90

 

 

210 x 120

120 x 120

 

 

210 x 90

90 x 90

 

 

180 x 120

 

b)

Thickness (in mm)

 

 

 

 

Board

Thickness

 

 

3-ply

3,4,5,6

 

 

5-ply

5,6,8,9

 

 

7-ply

9,12,15,16

 

 

9-ply

12,15,16,19

 

 

11-ply

19,22,25

c)

Tolerance

 

 

 

Length 120 cm & below

+ 3 mm and

- 0 mm

 

 

Above 120 cm

+ 6 mm and

- 0 mm

 

 

Width 90 cm & below

+ 3 mm and

- 0 mm

 

 

Above 90 cm

+ 6 mm

- 0 mm

 

 

Thickness upto 5 mm

± 10 percent

 

 

                  6 to 9 mm

± 7 percent

 

 

            Above 9 mm

± 5 percent

 

 4.  Finish – Edge of the boards shall be trimmed square within 3 mm and sanded to a smooth finish.

5.  Tests

5.1. Glue adhesion – Shall have the following minimum shear strength (kg)

Sl No.

Grade

Dry state

Mycological

Resistance to moisture

i)

BWP  Average Individual

135

110

100

 80

100

 80

ii)

BWR Average Individual

135

110

100

 80

100

 80

iii)

WWR Average Individual      

100

  80

 80

 65

 80

 65

iv)

CWR Average Individual

  70

  55

 35

 30

 35

 30

5.2. Moisture content – Not less than 5 percent and not more than 15 percent.

Annexure 9-A-13

VENEERED DECORATIVE PLYWOOD

 (Extract of IS: 1328-1982)

Scope - Requirements of types of plywood with ornamental veneers on one or both faces used for decorative purposes, such as furniture making, paneling of all kinds, including paneling for railway coaches, buses and ships.

Types – Shall be two types, namely, Type 1 and Type 2.

Type 1 – Open splits, checks or open joints up to 150 x 0.5 mm permissible, provided these are rectified with a veneer insert bonded with synthetic resin adhesive. Shall be free from torn grain, dead knots, dote, discolouration and sapwood. Veneers shall be matched or mismatched to achieve decorative effect.

Type 2 – Same as Type 1 except that the rectified open splits, checks or open joints may be up to 200 x 1 mm. Tight knots and patches not more than 25 mm in diameter, and pin knots not more than 4 mm in diameter shall be permissible. Sapwood would be permissible, if it does not affect appearance.

Material – Species of timber for decorative face shall be specified by the purchaser. Timber for cores and bricks shall be either of Class I or II specified in IS: 303-1985*. Adhesive shall be BWR or WWR synthetic resin. Decorative veneer shall be rotary cut or sliced not more than 1 mm thick.

Specification for plywood for general purposes (second revision)

Note: For species of timber commonly used for decorative veneers or decorative plywood, see Table 1 of the standard.

4.  Tolerances

Length

 

 

 

Upto 120 mm

± 3 mm

 

Above 120 mm

± 6 mm

Width

 

 

 

Upto 90 mm

± 3 mm

 

Above 90mm

± 6 mm

Thickness

 

 

 

+ 10 percent of nominal thickness

 

 

- 5 percent of nominal thickness

 

5. Tests

Moisture content – Not less than 5 percent and not more than 15 percent.

Water resistance test Shall not show delamination or blister formation after the specified test.

Test for adhesion of plics – shall show a minimum of ‘pass’ standard.

Note: For methods of tests see 9.1.2.1 of the standard.

6. Finish - Edges of decorative plywood shall be trimmed square within 3 mm and sanded to a smooth finish.

Annexure 9-A.14

Specifications for venetian blinds for windows

(Extract of IS: 1826-1961)

0.1. Protecting against excessive daylight and glare inside buildings without restricting ventilation is one of the problems confronting an architect. While a certain minimum area of window space is necessary from the point of view of adequate natural ventilation during daytime, the required window space creates often excessive glare and discomfort in the room. Window blinds, curtains, coloured glass and similar devices have been adopted to reduce the glare and cut down excessive daylight.

0.2. This section deals with window blinds of the Venetian type made of either wood or metal slats.

0.3. The components that go with a Venetian blind are of various materials and serve different purposes. In addition to the description of these components, illustrative sketches are also given in this standard. It is, therefore, to be appreciated that for the same purpose, any other shape or design of the component is permissible and the sketches as now included are only illustrative.

0.4. The preparation of this standard has taken into consideration the views of producers, consumers and technologists and has related the standard to the manufacturing and trade practices followed in the country in this field. Due weightage has also been given to the need for international compression-ordination among standards prevailing in different countries of the world.

0.5. Where a reference to any Indian Standard appears in this specification, it shall be taken as reference to the latest version of the standard.

0.6. Metric system has been adopted in India and all quantities and dimensions appearing in this standard have been given in this system.

0.7.For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of  a test, shall be rounded off in accordance with IS: 2-1960  Rules for Rounding Off Numerical Values (revised). The number of significant places retained in the rounded of value should be the same as that of the specified value in this standard.

0.8. This standard is intended chiefly to cover the technical provisions relating to Venetian blinds for windows, and it does not include all the necessary provisions of contract.

1.  Scope

1.1. This standard covers material, constructional details, sizes and requirements of open head custom-made Venetian blinds made of either wood or metal slats.

2. Terminology

2.0. For the purpose of this standard, the following definition shall apply.

2.1. Venetian blind – A blind capable of being raised or lowered, having thin parallel slats placed horizontally one above the other with two or more heavier cross members carrying operating devices, one at the top and one at the bottom. It is equipped with a mechanical tilting device and a cord lock which will permit simultaneous adjustments of slats and bottom rails at any desired angle and height, thereby giving maximum control of light and privacy while allowing ventilation.

3.  Grade

1.2. The Venetian blinds shall be two grades, namely. Grade 1 and Grade 2; and the requirements of the two grades shall be as specified in3.2 and 3.3.

1.3. Venetian blinds of Grade 1 (se Fig.1) shall

(a) have aluminum slats, (b) have a suitable provision either for locking the slats to the ladders or have a dual ladder for each slat so that the slats may not flutter,(c)  be capable of being removed instantaneous from their mountings without the need of any tools  for cleaning, repairs and replacements,

1.4. Venetian blinds of Grade 2 (see Fig 2) shall have wooden slats. They neither need be removable instantaneously nor have a provision for interlocking of the slats as in Grade 1 blinds.

4.  Material

4.1. Timber – Timber used for the slats, top rails, tilting rails and bottom rails shall be free from knots and insect holes. The wooden slats and rails shall be made from any of the timbers having durability of Class I and an II timber as given in IS: 399-1952 Classification of Commercial Timber and Their Zonal Distribution (Tentative).

4.1.1..  All timbers shall be seasoned to an average moisture content not exceeding 14 percent except for slats in which case it shall not exceed 10 percent.

4.2. Metal

4.2.1. Aluminium alloy used for rolling of slats shall conform to NS 4 of IS: 737-1955 Specification for Wrought Aluminium and Aluminium Alloys, Sheet and Strip and shall have the following properties

Hardness

Zero

Ultimate tensile strength

17.3 to 22 kg/cm²

Elongation

18 percent, Min

4.2.2. All hardware including pulleys, guide channels and other fittings, unless otherwise specified, shall be of corrosion-resistant materials; if made of steel the hardware shall be hot galvanized. All screws used for mounting hardware and installation of blinds and guide channels shall be of brass suitably electroplated.

5. Sizes

5.1. The size of Venetian blind shall be defined by the width (length) and height (drop) of the blind as ordered for the position of fixing (see 5.2)

5.2. The size of Venetian blind shall depend upon the method of fixing. Venetian blinds may be fixed in any one of the three positions. Depending upon the method of fixing, the size shall be as defined for each position and each individual Venetian blind shall made to the required size of the corresponding window or opening.

5.3. Maximum sizes of Venetian blinds

5.3.1. Venetian blinds of Grade 1 shall not exceed 500 cm in width and 10 m² in area.

5.3.2 .Venetian blinds of Grade 2 shall not exceed 275 cm width and 7.5 m² in area.

6.  Construction

6.0. Components – Components of Venetian blinds shall be as specified in 6.1 to 6.13.

6.1. Installation brackets

The installation brackets (se Fig.4A and 4B) shall be of such a design as to provide a minimum back clearance of 16 mm to the blind. They shall have provision to hold the facia board in position and in a manner that would facilitate the easy removal and refixing of the facia boards.

The installation brackets shall be of sufficient strength to support the weight of the entire Venetian blind and shall be so designed as top install the blind in any of the positions as specified in 5.2

6.2. Title rail, bottom rail and top rail

6.2.1. Material – Tilt, bottom and top rails for both the grades of blinds shall be made from any of the timbers specified in 4.1.

6.2.2. Sizes

Tilt rails shall be 50 ± 1 mm wide and 20 ± 1 mm thick (see Fig. 4C).

Bottom rails for blinds of Grade 1 and for blinds of Grade 2 up to a width of 250 cm shall be 50 ± 1 mm wide and 20 ±1 mm thick. For blinds of Grade 2 exceeding 250 cm in width, the thickness of the rail shall be increased to 25 mm (see Fig, 4D).

Top rails, wherever required, shall be 62 ± 1 mm wide and 22 ± 1 mm thick. (see Fig. 4E)

6.2.2. The rails shall be free of twist and shall be reasonably straight.

6.3. Slats

6.3.1. Wooden slats shall be made from the timbers specified in 4.1. Wooden slats shall be reasonably flat and be free twist and cup or bow in width. The slat shall be held at ends on a base board of an angle of 85° to the horizontal and the slat shall not be clear of the base board by more than 1/500th of the width of the slat.

6.2.3. Aluminium slats shall be of convex, M or S shape and shall be made from aluminium alloy of quality specified in 4.2.1.

6.3.4.   Sizes

1. Wooden slats (see Fig. 4F) shall be 48 ± 0.5 mm wide and 2.5 ± 0.3 mm thick.

2. Aluminium slats shall be 48 ± 0.5 mm wide when formed (see Fig. 4G). The thickness of coated aluminium slats shall be 0.300 ± 0.004 mm.

3. The number of slats per blind of different heights (drops) shall be as shown in Table 1.

6.4. Route holes

6.2.5. Route holes in the slats for the passage of lifting cord shall conform to the size and shape shown in Fig. 4H. The route holes shall be clean-cut with all edges free from burrs.

6.2.6. Route holes in top, tilt and bottom rails shall be of sufficiently large size to accommodate the pulley and provide for free passage of lifting cords.

6.5. Ladder web

6.5.1. The face and cross tapes shall be made of high grade cotton or synthetic yarn. Yarn shall be clean and free from motes.

6.5.2. Construction – the ladder web shall consist of two vertical tapes with cross tapes placed within them. The ends of the cross tapes shall be interwoven in the back of the face tapes to form ladders 50 mm long (see Fig. 4J)

6.5.3. The successive ladder shall be placed on alternative sides of 40 ± 0.5 mm centres to permit 10-mm overlap of the slats. The cross tapes shall be interwoven at a minimum distance of 3 mm from the edge of the face tapes and shall on each side is in a straight line one over the other. (see Fig.4J).

6.5.4. The ladder webs shall be so spaced in Venetian blinds as not exceed 75 cm between centres. The number of ladder webs per blind of different widths shall be as shown in Fig.5A to 5F.

6.6. Tilting device

6.6.1. The tilting device shall be of synchronized worm and gear design capable of lifting the blind including the slats from one extreme to the other. It shall allow slats to be changed from horizontal plane to vertical plane when tilted both frontward and backward. The titling operation shall be smooth and positive.

6.6.1.1. Where tilting device is of a type in which the tilting cord is locked to the tilting pulley to provide a positive pull, the minimum gear ratio shall be 71.

6.6.1.2. In other cases, the tilting device shall have a self-adjusting clutch mechanism for maintaining the level of the tilting cord, the cord having limit beads attached at its two ends to avoid its slipping beyond a given height and the pulley carrying the tilt cord shall be so designed and finished that there is no undue wear on the tilt cord. The minimum gear ratio in such a type of tilter shall be 171.

6.7.  Cord lock  - The blind shall be provided with automatic cord lock so designed that it will hold the blind at any desired height without the need for fastening the lifting the cords on hooks. The cord lock shall lock both the ends of the lifting cord simultaneously without slippage and with a single pull of the lifting cords. The cord lock shall be so mounted that the lifting cords can be operated without interference and without undue wear and tear.

6.8 .Tilting and lifting cords

6.8.1. The cords shall be made of good quality cotton yarn or a combination of cotton and rayon or of nylon yarn.

6.8.2. The cords shall be of sufficient length for convenient and efficient use.

6.8.3. Cords shall be attached in a neat and secure manner and shall be easily detachable and replaceable. Unless otherwise indicated, the tilting cords shall be near the end of the left side of the blind and the lifting cords shall be near the end of the right side of the blind.

6.8.4. Cords shall be No. 4 ½, hollow or filled, uniformly braided and of smooth finish to minimize wear, stretch and abrasion. Cord No 4 ½ shall be 3.5 ± 0.4 mm in diameter

Table 1 Number of slats per blind of different heights (drops) (Clause 6.3.4)

Height   (Drop)

Total no.  of slats

Height   (Drop)

Total No. of slats

Height   (Drop)

Total No. of slats

Height     (Drop)

Total No.   of slats

Cm

 

cm

 

cm

 

Cm

 

30

4

32.5

5

35

6

37.5

6

40

7

42.5

8

45

8

47.5

9

50

10

52.5

10

55

11

57.5

12

60

12

62.5

13

65

13

67.5

14

70

14

72.5

15

75

16

77.5

16

80

17

82.5

17

85

18

87.5

19

90

20

92.5

20

95

21

97.5

21

100

22

102.5

22

105

23

107.5

24

110

24

112.5

25

115

26

117.5

26

120

27

122.5

27

125

28

127.5

29

130

30

132.5

30

135

31

137.5

31

140

32

142.5

32

145

33

147.5

33

150

34

152.5

35

155

35

157.5

36

160

37

162.5

37

165

38

167.5

39

170

39

172.5

40

175

41

177.5

42

180

42

182.5

42

185

43

187.5

44

190

44

192.5

45

195

45

197.5

46

200

47

202.5

48

205

49

207.5

49

210

49

212.5

50

215

50

217.5

51

220

51

222.5

52

225

52

227.5

53

230

54

232.5

54

235

55

237.5

56

240

56

242.5

57

245

58

247.5

58

250

59

252.5

59

255

60

257.5

61

260

61

262.5

62

265

63

267.5

63

270

64

272.5

64

275

65

277.5

66

280

66

282.5

67

285

67

287.5

68

290

69

292.5

69

295

70

297.5

71

300

71

302.5

72

305

72

307.5

73

310

74

312.5

74

315

75

317.5

75

320

76

322.5

77

325

78

327.5

78

330

79

332.5

79

335

80

337.5

80

340

81

342.5

82

345

82

347.5

83

350

84

352.5

85

355

85

357.5

86

360

86

 

 

 

 

 

 

6.9. Cord equalizer – The lifting cord of each blind shall be provided with a cord equalizer for maintaining equal pull on both the ends of the cord.

6.10. Pulleys

6.2.7. The pulleys shall be made of a suitable material, that is, strong and hard and which needs no oiling.

9.2.8. Multi-lift blinds shall have ball bearing pulleys on the bottom rail.

6.11. Centre supports

6.11.1.  Title rail supports – Every blind over 90 cm in width shall have one tilt rail centre support for the tilt rail; and for each additional width of 75 cm, an additional centre support as shown in Fig. 5A to 5F shall be provided.

6.11.2. Installation support – There shall also be provided installation centre support brackets of a design and shape as to allow for ample safety factor and to prevent sagging of the blind.

Every blind without top rail shall be provided with equal number of installation centre supports of a suitable design as the tilt rail centre supports and shall be suitably attached to the same.

Every blind with top rail but 135 cm and over in width shall be provided with installation centre supports for every additional width of 90 cm suitably attached to the top rail.

The installation centre supports shall be screwed to the back wall or the ceiling as may be found convenient.

The installation centre support shall be so designed as to hold the facia board in line.

6.12. Side guide channels – wherever specially ordered, blinds shall be provided with side guide channels (see Fig. 4M). the side guide channels shall consists of guide rails and slat-end clips (see Fig. N) and wherever required, wooden battens. The guide rails shall permit free up and down movement of the slats without allowing undue play of the slat-end clips. The slat–end clips shall be of nylon, stainless steel or equivalent non-rusting material and shall be of a design that will hold the slats firmly without damaging or deforming them. The slat-end clips shall be removable easily. One slat-end clip shall be provided for each alternate slat at opposite ends.

6.13. Facia boards (pelmets) – Facia board (see Fig.4P) shall be of wood, metal or plastic of sufficient width and thickness to fit the installation bracket, and shall be of the colour matching the blind, unless otherwise specified.

6.14. General

6.14.1. Venetian blinds shall be generally assembled as shown in Fig. 1.

6.14.2. The route holes in the top rail and /or tilt rails, slats and bottom rail shall match each other so that they are centered correctly in relation to each other and the width of the blind.

6.14.3. The ladder webs shall be centered equidistant from the ends of the blind and from each other.

6.14.4. The slats after assembly shall be parallel to each other in horizontal position.

7.  Installation

7.1. All blinds shall be secured to their proper places with screws conforming to IS 451-1953 Specification for Wood Screws and all Work shall be performed in a workmanlike manner. Installation brackets and installation centre supports shall be fixed in a workmanlike manner. If installed on wood, 2.5 cm  No. 8 screws or larger size may be used. If installed on masonry, plaster, brick, cement blocks or tile, drill a neat hole 2.5 cm deep by using a No.8 drill, insert a fibre or plastic plug or lead shield and use 2.5 cm No.8 screw or larger as in wood.

7.2. Nails shall not be used in the installation of brackets and centre supports.

8. Finish

8.1. Aluminium slats – The aluminium slats shall be given a pretreatment to provide a permanent bond between the aluminium and the finishing paint and then given suitable coats of primer and upper coats of paint which shall be high gloss and of a baked enamel type.

8.2. Wooden slats and rails – The wooden slats and rails shall be sanded smooth before painting. For finishing wooden slats and rails, one end coat of sealer, one coat of primer-surfacer, putty and two coats of paint shall be applied. The paint used shall be semi-gloss good quality enamel or cellulose paint.

8.3. The final paint finished surface shall be smooth and even.

9. Testing

9.1. Aluminium slats

9.1.1. Physical tests – the finished aluminium slats shall be tested for the following properties before painting

Tensile strength, Min

3375   kg/cm²

Yield strees, Min

3100   kg/cm²

Elongation, Max  (5cm gauge)

2.5 percent

9.1.2.  Salt water test – Aluminium slats shall be sprayed with 5 percent salt solution at       40°C for 500 hours and shall not show blistering, corrosion, chalking, change of colour and loss of gloss or adhesion (between metal and finish) after a recovery period of 30 minutes.

9.1.3. Cold and hot water test for enamel – The backed enamel finish shall resist soaking in cold water for 48 hours and for 30 minutes in boiling water. The enamel shall not blister and shall recover the same hardness after being out of water for 2 hours

9.1.4. Light test - The enamel finish shall withstand exposure to a twin-arc weatherometre operated on a cycle of 17 minutes to light without water spray and 3 minutes to light with water spray, for a

minimum period of 200 hours without blistering, corroding, chalking, loss of gloss, changing of colour, and without loss of adhesion after a recovery period of 30 minutes.

9.1.5.  Rigidity test – The slats shall be of flexible aluminium having sufficient flexibility to permit a 180 degree bend around a 7.5 cm diameter cylinder without harm or permanent deformation of the slats, or injury to the finish when released to their original shape. Bend test shall be made on both the convex and concave sides, but shall not include the route holes. After the bend test, the slat shall be placed on a plane surface with the concave side down, and in this position the perpendicular distance from the supporting surface to any point on either edge of the slat shall not exceed 3 mm. With the slats similarly supported, the maximum difference in the perpendicular distance from the supporting surface to the edge of the slats for any two points 75 mm apart, along either edge, shall not exceed 1 mm. The crown of the slat shall be sufficient to support an extended length of at least 90 cm.

9.2. Ladder web

9.2.1. Colour fastness and shrinkage – The face and cross tapes of the ladder web shall have good colour fastness to light and water, and shall not shrink more than 7 percent. Colour fastness shall be determined by standard Fadometre tests for at least 200 hours.

9.2.2. Breaking strength – Face tapes of ladder web when tested individually shall have a breaking strength of not less than 100 kg. Cross tapes (or ladders) when tested of individually shall have minimum strength 7 kg without breaking or tearing away from the face tapes. The testing procedure shall be in accordance with IS: 243-1951 Method of Determination of Breaking Load (strength) and Elongation of Woven Cotton Fabrics (by constant-rate-of traverse machine).

9.3. Breaking strength of cords – When tested on single strand method, the breaking strength of cords shall be least 80 kg.

10. Inspection and testing

10.1. The manufacturer shall provide all facilities for the inspection of the blinds at his premises.

10.2. The manufacturer shall, at the request of the purchaser or his representative, give free of charge a certificate to the effect that the blinds supplied conform to the requirements of this standard.

10.3. The purchaser shall have the option of rejecting or asking for replacement of any article found to be defective or not complying with the requirements of this standard during assembly, irrespective of his prior inspection and approval provided the defect is found to have been in existence in the manufacturer’s works and stores and not due to subsequent handling.

10.4. The purchaser shall have the right to conduct tests to determine the quality of material, construction and finish as agreed to between the purchaser and the manufacturer.

11. Packing

11.1.   All Venetian blinds shall be supplied duly assembled.

11.2. When Venetian blinds are to be dispatched, each assembled blind shall be suitably warped in paper. Slats coming into contact with hardware shall be suitably protected guide channels, when ordered, shall be separately warped. The blinds shall be separately warped. The blinds shall be packed in cases with gross weight not exceeding 55 kg.

11.3. All packing shall be done in such a way that it will not lead to damage to the finished assembly or its components.

12. Information to be furnished by the purchaser

12.1. The purchaser shall specify the following information to the supplier

(a)Type and class of Venetian blinds, (b) Size of Venetian blinds [width x weight (outside dimension)], (c) Size of opening and position of fixing, (d) Whether guide channels are required or not, and (e) Colour of slats, ladder web and cord.

13. Marking

13.1. All Venetian blinds shall be marked on top rail (tilt rail) with a suitable mark identifying the manufacturer, type and size of blind.

13.2. The Venetian blinds may also be marked with the ISI Certification Mark.

 Fig.1 Venetian blind assembly (Fixed type-wooden slats)

Fig. 2 Venetian blind assembly

(Fixed type-wooden slats)

Fig. 4 A to F. Typical illustration of components of Venetian blinds (contd)

Fig. 4G to 4P

Fig. 4 Typical illustration of components of Venetian blinds

Fig. 5 A to F Multi-lift Venetian blinds

Annexure 9-A-15

PLYWOOD FOR CONCRETE SHUTTERING WORK

(Extract of IS: 4990-1981)

1. Scope – Requirements of plywood for concrete shuttering work.

1.1. Recommended method for handling, storing and use of plywood of concrete shuttering and formwork is covered in Appendix A of the standard.

2. Dimensions and tolerances

2.1. Size (length x width) - 240 x 120, 240 x90, 210 x 120, 210 x90, 180 x 120, 180 x90, x150 x 120,  150 x 90, 120 x 120, 120 x90, 120 x 60 and  90 x90 cm.

2.2. Thickness - 4, 5, 6 mm for 3-ply; 6, 8, 10 mm for 5-ply; 13, 16 mm for 7-ply; 16, 19 mm for 9-ply; 22, 25, 30 35, 40 mm for more than 9-ply.

2.3. Tolerances

Length upto 120 cm and Width upto 90 cm

± 3 mm

Length above 120 cm and Width above 90 cm

± 6 mm

Thickness upto 5 mm 

± 10 percent

Thickness above 5 mm

± 15 percent

Finish

3.1. Shall be smooth and the faces and back shall be free from harmful discolouration, plates overlaps and loose knots. Edges shall be of smooth uniform finish.

3.2. Gaps and open joints shall be permitted as follows

Inface – Provided the gap or opening does not exceed a width of 0.4 mm, if it exceeds 0.4 mm, this may be rectified by well fitted veneer inserts of a minimum width 4.8 mm provided the grain of the veneer does not exceed in deviation by more than 10 percent from the grain direction of the surrounding veneer.

In Core (cross-band) - Width of opening shall not exceed 0.8 mm in the case of 3- ply or 3.2 mm in the case of multi-ply, provided the openings are not less than 30 cm apart in any veneer and staggered not less than 15 cm between any veneer and the next one with the same grain direction.

3.3. Face with plastic coating, or with suitable overlay shall be dense, smooth, without blister and without patch marks and shall be of uniform colour.

Tests

4.1. Moisture content – Shall be between 5 and 15 percent,

4.2. Glue adhesion in dry state

4.2.1. Glue shear strength – Average failing load shall be not less than 1323.9 N and no individual value shall be less than 1078.7 N.

4.2.2. Adhesion of plies – The veneers shall offer appreciable resistance to separation and the fractured samples shall be show some adherent fibres distributed more or less uniformly.

4.3. Water resistance test

4.3.1. Glue shear strength – Average failing load shall be not less than 980.7 N and no individual value shall be less than 784 N.

4.3.2. Adhesion of plies – Requirements shall be same as given in 4.2.2.

4.4. Plywood for concrete shuttering work with plastic coating or with suitable overlay after being subjected to 72 hours boiling shall not show any softening, checking, cracking or deterioration of the surface layer.

4.5. Plywood manufactured from species not naturally durable, shall show more or less uniform absorption of preservative on the entire surface,

4.6. Tensile strength

(a)Not less than 318 kN/m², parallel to grain direction of face veneers; (b)Not less than 220kN/m² at right angles to grain direction of face veneers; and (c)Sum of tensile strengths in both directions not less than 588 kN/m².

4.7. Mycological test – Test piece shall show no appreciable signs of separation at edges of veneers and shall comply with requirements given in 4.3.1 and 4.3.2.

Note – for test procedures, refer to IS: 1734 Method of test for plywood

IS:1734 (part I)-1983 Part I Determination of density and moisture content (first revision)

IS:1734 (part IV)-1983 Part IV Determination of glue shear strength (first revision)

IS:1734 (part V)-1983 Part V Test of adhesion of plies (first revision)

IS:1734 (part VII)-1983 Part VII Mycological test (first revision)

IS:1734 (part IX)-1983 Part IX Determination of tensile strength (first revision)

Annexure 9-A.16

FIRE RETARDANT PLYWOOD

(Extract of IS: 5509-1980)

1. Scope – Fire retardant formulations, method of treatment retentions and requirements of fire retardant plywood.

2. Flame retardants

Type 1 Ammonium phosphates

Type 2 Boron compounds

Type 3 Ammonium sulphate

Type 4 Combination of ammonium phosphates and boron compounds

Type 5 Combination of ammonium sulphate and ammonium phosphate

2.1. Where flame retardant and preservative treatment is required together, types of chemical and their retention shall be as follows.

Type

Flame Retardant

Preservative

Retention of Preservative kg/m2 Min.

6

Ammonium phosphate

Copper / chrome

6

7

Ammonium phosphate /ammonium sulphate

Copper / chrome

6

8

Ammonium phosphate /ammonium sulphate / boron compounds

Copper / chrome

6

9

Ammonium phosphate /ammonium sulphate /boron compounds

Copper / chrome

8

3. Preparation of plywood for Treatment – Plywood for treatment shall conform to BWR type and shall have moisture content not over 16 percent.

4.  Recommendation treatment for different situations

a)

For interior use against fire hazard, namely, interior linings, partitions and filaments of ship cabins, boiler houses, kitchen, ceiling of houses, kitchens, ceiling of rail coaches, vehicle body interiors, exhibition stall etc.

Type 1 to 5 with retention of fire retardant

20 kg/m2 Min.

b)

For interior or exterior use not subject to leaching by rain and water against fire hazard and high risk of decay or insect attack; namely wall and roof linings, external roofing, cladding or ceilings of building, vehicle bodies etc.

Type 6 to 9 with of fire retardant and preservative.

15 kg/m2 Min.

5.  Workmanship and finish – Finished plywood shall be reasonably clean to handle and free of dirt and stain other than any uniform colour of flame retardant solution.

6. Test requirements

6.1. Moisture content – Shall be between 5 and 15 percent.

6.2. Flammability – Time taken for second ignition, not less than 30 minutes.

6.3. Flame penetration- Not less than 15 minutes for every 6 mm thickness.

6.4. Rate of burning – Time taken to lose weight from 30 percent to 70 percent shall be less than 20 minutes.

6.5. Retention of preservatives – Not value shall not be less than the values specified in 2.1 and 4.

Note 1: Dimensions and tolerances of fiber retardant plywood shall conform to IS: 303-1975 Specification for plywood for general purposes (second revision)

Note 2: For  test procedures for the tests specified, refer to IS: 1734 (part I)-1983 Method of test for plywood  part I Determination of density and moisture content (first revision);  IS: 1734 (part III) -1983 Method of test for plywood  part III Determination of fire resistance (first revision) ; and IS: 2753 (part I)-1991 Methods of estimation of preservatives in treated timber and in treating solution Part I Determination of copper, arsenic, chromium, zinc, boron, creosote and fuel oil.

Note 3: Plywood when tested for glue shear strength in dry state, mycological test, water resistance test and for any other mechanical property as agreed to shall meet requirements of BWR grade general purpose plywood conforming to IS: 303-1975 Specification for plywood for general purposes (second revision).

Annexure 9-A.17

PRESERVATIVE TREATED PLYWOOD

(Extract of IS: 5539-1969)

1. Scope –Treatment of plywood for protection against fungi, termites and other insects and marine bores and requirements of preservative treated plywood.

2. Types of preservatives

a. Type I (oil type) – Coal tar creosote with or without admixture with various grades of petroleum and other oils having high boiling point.

b. Type 2 (organic solvent type) – Copper/ zinc naphthenate, pentachlorophenol, benzene hexachloride and DDT.

c. Type 3 (water soluble non-fixing type) – Zinc chloride, boric acid, borax, sodium fluoride and sodium pentachlorophenate.

d. Type 4 (water soluble ‘fixed’ type) – Copper-chrome arsenic composition, acid-copper-chrome composition, chromated zinc chloride and copper chrome boric composition.

3. Preparation of plywood for treatment – plywood for preservative treatment shall have moisture content not exceeding 16 percent and shall have been bonded with water resistant glue of BWR type.

4. Choice of treatment – This is governed by the timber species in the plywood, sapwood content and use after treatment. Recommended practice on choice of preservative and amount of absorption and service conditions is given in Table 1.

Note: For information regarding natural durability and degree of treatability of different species of timber see Appendix B of the standard.

5. Modes of treatment

(a) By pressure impregnation after manufacture. (b) By soaking or surface application after manufacture (c) By treatment of dry or wet veneers before assembly.

6. Conditioning – Plywood after treatment shall be conditioned to a moisture content of not more than 14 percent for interior use and 18 percent for exterior uses. If the plywood is to be painted subsequently, the moisture content shall be between 6 and 14 percent.

Table 1 Recommendation practice for preservative treatment of plywood for various service conditions

Sl. No

Service conditions for treated plywood

Timber used in plywood according to the relevant IS on plywood required to be treated

Types of preservative recommended

Mode treatment recommended

Minimum retention

i)

Plywood in direct contact with water or ground and required to be painted as for pontoons, boats, rafts, tugs, fence posts, box, columns, etc (IS: 710-1976*)

All

Type 4 (Copper-chrome arsenic composition or acid copper chrome composition)

Pressure process

Veneer treatment

12.0

 

12.0

ii)

Plywood in direct contact with water or ground and  required to be painted as for pontoons, boats, rafts, tugs, fence posts, box, columns, etc (IS: 710-1976*) but plywood requiring light painting or only back coal tar base (IS: 1976*)

All

a)Type 4 (Copper-chrome arsenic composition or acid copper chrome composition)

 

b) Type 1 [Creosote or creosote fuel oil mixture(5050)]

Pressure process

 

 

 

 

Pressure process

12.0

 

 

 

 

100.0

iii)

Marine structures exposed to marine borer danger (IS: 710-1976*)

All

b) Type 1 [Creosote or creosote fuel oil mixture(5050)]

Pressure process

200.0

iv)

Concrete shuttering plywood (IS: 4990-1969?)

All

Type 4 (Copper-chrome arsenic composition or acid-copper chrome-composition)

Pressure process

Veneer treatment

12.0

12.0

v)

Plywood for outer cladding of houses, roofing, bunkers and shutters, and in other conditions exposed to rain, sun and outer weather but requiring painting(IS: 303-1989 BWR Grade)

All

-do-

Veneer treatment

 

12.0

vi)

Plywood for outer cladding of houses, roofing, bunkers and shutters, and in other conditions exposed to rain, sun and outer weather but requiring painting, but paint and colour not import-ant (IS:  303-1989‡ BWR  grades)

All

Type 1 [Creosote or creosote fuel oil mixture(5050)]

Pressure process

100.0

vii)

Plywood for buses flooring or rail coach flooring (IS:  303-1989BWR  grades)

All

Type 4 (Copper-chrome-arsenic composition or acid copper chrome -composition)

Type 1 [Creosote or creosote fuel oil mixture(5050)]

Pressure process

75.0

 

 

75.0

viii)

Plywood not indirect contact with ground or water but exposed and given paint or varnish regularly as in plywood for rail coach ceiling, partitioning and other interior use, bus interior, ammunition boxes, exterior,   doors, etc(IS: 303-1989‡ BWR  grades)

All timbers except when only heartwood of durable timber is used

Type 4 (Copper-chrome-arsenic composition or acid copper chrome-composition)

 

Pressure or soaking

5.5

ix)

Decorative paneling on rail coaches and ship building (IS: 303-1975‡ BWR  grades)

Do

Type 2 or type 3 not colour imparting

Pressure process or soaking

4.0

x)

Plywood for internal uses in dry localities, such as inner partitions, paneling, wall boarding, ceiling and furniture (IS: 303-1989 and IS: 1328-1970§))

Do

Type 2 or Type 3 or  Type 4

Pressure process or soaking

4.0

Specification for marine plywood (first revision).

Specification for plywood for concrete shuttering work.

Specification for plywood for general purposes (second revision).

Specification for veneered decorative plywood (first revision)                                  

Note: For information regarding natural durability and degree or treatability of different species of timber see Appendix B of the standard.      

Annexure 9-A.18

DECORATIVE PLYWOOD USING PLURALITY

OF VENEERS FOR DECORATIVE FACES

(Extract of IS:  7316-1974)

1. Scope – Covers decorative plywood with ornamental faces produced by use of plurality veneers meant for decorative use, such as interior paneling of buildings, buses, ships, etc, and for decorative furniture of all types.

2. Material

i. Timber – Class I, II or III specified in IS: 303-1975*. Non-durable timbers and sapwood of all other timbers shall be given a preservative treatment.

ii. Adhesive – synthetic resign adhesive BWR or WWR.

iii. Plywood, when used, shall be BWR or WWR synthetic resign bonded type.

3.  Permissible defects – Open splits, checks or open joints not more than 150 mm long and 0.5 mm wide, provided the same are rectified with a matching veneer insert bonded with BWR or WWR adhesive. Decorative veneered surface shall be free from torn grain, dote, worm hole, discoloration or other visual defect

4.  Standards dimensions

Length: 240, 210, 180, 150, 120 and 90 cm           

Width :120 and 90 cm

Thickness : 3,4,6,12,19 and 25 mm

* Specification for plywood for general purposes (second revision).

5.  Tolerances

Length up to 120 cm  + 3 mm

                                     - 0 mm

Length above 120 cm + 6 mm

                                      - 0 mm

Width up to 90 cm + 3 mm

                                 - 0 mm

Width above 90 cm + 6 mm

                                  -  0 mm

Thickness +0.2 mm + 5 percent of nominal thickness

               -0.1 mm + 2.5 percent of nominal thickness

Rectangular panels shall have their diagonal lengths not varying beyond 9 mm.

6 .Finish - Trimmed square and sanded to a smooth finish.

7. Tests

7.1. Moisture content - Not less than 5 percent and not more than 15 percent when tested in accordance with IS: 1734 (part I)-1983*.

7.2 .Water resistance test – Shall not show delamination or blister formation       

*Methods of test for plywood part I Determination of density and moisture content (first revision)

Annexure 9-A.19

WOOD PARTICLE BOARDS (MEDIUM DENSITY) FOR GENERAL PURPOSES

(Extract of IS: 3087-1985)

1. Scope – Material, methods of manufacture, grades, types, sizes, construction and finish of medium-density wood particle boards for general purposes. It does not cover high-density practical boards of specific  gravity exceeding 0.9, veneered particle board and also specially treated boards like moulded particle boards, compregnated boards or particle boards faced by impregnated paper surface.

2. Types and designation

3. Materials

 

Type

Designation

a)

Flat pressed, single-layer board

FPSI

b)

Flat pressed, three-layer board

FPTH

c)

Extrusion pressed, solid board

XPSO

d)

Extrusion pressed, tubular core board

XPTU

a) Wood particles shall be produced by cutting wood into shaving, flakes, splinters or slivers on a chipping machine.(b) Adhesive shall be BWR, WWR or unextended CWR type.(c) Sizing material (introduced primarily to increase water resistance) – Paraffin wax.

4. Dimensions and tolerances

a. Length – 485 (480), 365 (360). 300. 270, 240, 210, 180, 150, 120, 100 and 90 cm.

Tolerance ± 6 mm up to 150 cm and ± 9 mm  above 150 cm.

b. Width – 180, 150, 120, 100, 90, 60 and 45 cm. 

Tolerance ± 6 mm up to 150 cm and ± 9 percent above 150 cm.

c. Thickness – 6, 9, 12, 16, 19, 20, 21, 22, 25, 27, 30, 35, 40, 45 and 50 mm.

Tolerance ± 5 percent up to 25 mm and ± 2.5 percent above 25 mm.

d. Length of two diagonals of a wood particle board, rectangular panel, shall not differ by more than 2.5 mm.

e. Edges of the board shall be straight with a tolerance of 3 mm.

Strength and other characteristics of various types of wood particle boards are given in Table 1 of the IS: 3087-1965 may be referred.

5. Physical characteristics

5.1. Density – shall be between 500 to 900 kg / m³.  Variation in density shall not exceed 10 percent.

5.2. Moisture content – Shall be between 7 and 16 percent. Variation of individual from mean shall not exceed ± 3 percent.

5.3. Water absorption (see Table 1of IS: 3087-1965)

5.4. Swelling in water (see Table 1 of IS: 3087-1965)

5.5. Swelling due to surface absorption (see Table 1of IS: 3087-1965)

5.6. Modulus of rupture (see Table 1of IS: 3087-1965)

5.7. Tensile strength perpendicular to surface (see Table 1of IS: 3087-1965)

5.8. Thermal conductivity (see Table 1of IS: 3087-1965)

5.9. Workability – shall not crack or split when drilled, sawed and nailed perpendicular to the surface.

6. Finish – Shall be of uniform thickness and density throughout the length and width. These shall be flat and sanded to a smooth finish on both the faces.

Note:1) For test procedures, IS: 2380-1963 Methods of test for wood particle boards and boards from other lignocellulosic materials and IS: 3129-1965 Specification for particle board for insulation purposes may be referred.

Annexure 9-A.20

VENEERED PARTICLE BOARDS

(Extract of IS: 3097-1980)

1. Scope – Requirements such as grades and types, materials, manufacture, dimensions and tests for veneered particle boards.

2. Grades and types – Shall be two grades, namely, exterior (Grade I) or interior (Grade II).

Each grade of veneered particle boards shall be of the following four types

a. Type 1 – Solid core, general purpose (boards with faces of veneer of general purpose type).

b. Type 2 – Solid core, decorative (boards with solid core but faced with ornamental veneers on one or both sides).

c. Type 3 – Tubular core, general purpose (boards with tubular core and faced with veneer of general purpose type).

d. Type 4 – Tubular core, decorative (boards with tubular core faced with decorative veneers on one or both sides).

2. Designation – The grades and types shall be designated as follows

Sl No.

Grade

Type

Designation

1.

Exterior (Grade I)

Solid core, general purpose

EX SO GP

2.

Exterior (Grade I)

Solid core, decorative

EX SO D

3.

Exterior (Grade I)

Tubular core, general purpose

EX TU GP

4.

Exterior (Grade I)

Tubular core, decorative

EX TU D

5.

Interior (Grade II)

Solid core, general purpose

IN SO GP

6.

Interior (Grade II)

Solid core, decorative

IN SO D

7.

Interior (Grade II)

Tubular core, general purpose

IN TU GP

8.

Interior (Grade II)

Tubular core, decorative

IN TU D

3.  Material

  1. Particle boards shall be of medium density.
  2. Veneers for cross-band and faces shall be either sawn or rotary cut or sliced and shall be smooth.
  3. Adhesive used for bonding veneers shall be BWP or BWR for exterior grade (Grade I) boards and WWR or CWR for interior grade (Grade II) boards.

4.  Finish – All boards shall be flat and squarely cut. Both faces shall be sanded to a smooth even surface.

5.  Dimensions and tolerances

  1. Length – 480, 365, 300, 270, 240, 210, 180, 150, 120, 100 and 90 cm. Tolerance ± 5 mm up to 150 cm and ± 10 mm above 150 cm.
  2. Width – 180, 150, 120, 100, 90 and 45 cm. Tolerance same as for length.
  3. Thickness – 6, 10, 12, 20, 25, 30, 35, 40, 45 and 50 mm. Tolerance ± 1 mm.
  4. Length of two diagonals shall not differ by more than 2.5 mm.
  5. Edges shall be straight with maximum deviation of 3 mm.

6. Tests

6.1. Density – Density of each specimen shall not vary from mean density by more than ± 10 percent.

6.2. Moisture content – Average values shall be between 7 to 16 percent.

6.3. Water absorption – Value shall not exceed 25 percent for 2 h soaking and 50 percent for 20 h soaking.

6.4. Water resistance test – Boards shall not show signs of disintegration and/or shall not delaminate.

6.5. Swelling in water - Swelling in thickness in percentage of original thickness shall not be more than 7 percent due to general absorption and this shall be 5 percent in case of swelling due to surface absorption.

6.6. Adhesive of piles – Adhesive of face veneers to the board core shall offer appreciable resistance and the exposed surface of veneer shall show sizes of some adherent fibres distributed more or less uniformly.

6.7. Static bending strength (maximum transverse strength or modules of rupture in bending) Average value of modulus of rupture shall not be less than 300 kg/cm².

6.8. Deflection under sustained load (long time loading test) – The deflection under load and residual deflection after removal of load shall be as agreed to mutually.

Note: For test procedures, refer to the standard and IS: 2380 Method of test for wood particle boards and boards from other lignocellulosic materials

Annexure 9-A.21

PARTICLE BOARD FOR INSULATION PURPOSES

(Extract of IS:  3129-1965)

1. Scope – Requirements of insulation type of particle boards.

2.  Materials

  1. Timber or other lignocellulosic material like bagasse and solapith and jute sticks of density not exceeding 400 kgPm³.
  2. Following materials may be added to the particle mix

(1) A preservative such as sodium pentachlorophenate or pentachlorophenol to the extent of 0.2 percent. (2) Sizing material like paraffin wax emulsion (to increase water resistance), not exceeding 1.5 percent. (3) Flame retardant chemical like ammonium phosphate and borax.

Adhesive – BWR or WWR (unextended) type.

3.  Dimensions and tolerances

  1. Length – 365, 300, 270, 240, 210, 180, 150, 120, 100, 90, 60, 45and 30 cm.
  2. Width – 180, 150, 120, 100, 90, 60, 45 and 30 cm.
  3. Thickness – 50, 45, 40, 35, 30, 27, 25, 22, 20, 16 and 12 mm.
  4. Tolerance

Length and width ± 9 mm up to 150 cm and ± 15 mm above 150 cm.

Thickness ± 0.8 mm up to 25 mm and ± 1 mm above 25 mm.

4.  Physical requirements

4.1. Density – Shall not exceed 400 kg/m³. Variation shall be….. ± 10 percent.

4.2. Moisture Content – Shall not exceed 16 percent

4.3. Thermal Conductivity – K value shall not exceed 7 kcal.cm/m²h° C thickness (or 0.81 mW/cm.°C).

4.4. Transverse Strength – Modulus or rupture not less than 15 kgf/cm².

4.5. Sound absorption

Frequency, c/s    125   250   500   1000  2000

Absorption           0.1   0.2    0.3     0.5

Coefficient, Min

Note: For test procedures, refer to IS: 2380 (Parts I to XXI)-1977 Methods of tests for wood particle boards and boards from other lignocellulosic materials (first revision), IS: 330 -1969 Methods of wood wool building slabs and Appendix A of the standard.

Annexure 9-A.22

WOOD WOOL BUILDING SLABS

(Extract of IS: 3308-1981)

1. Scope – Requirements regarding dimensions, weight and strength for wood wool building slabs.

2. Types

a. Type 1 – Light weight slabs, intended for non-load bearing partitions, ceilings, wall linings, permanent shuttering and roof insulation.

b. Type 2 – Heavy duty slabs, intended for load bearing situations and for use in roof construction.

3. Form and texture – Slabs shall be of uniform thickness with rectangular parallel faces and shall have clean reasonably square edges and shall be of uniform texture.

4.  Dimensions, weight and tolerances

Length

Width

Type

Thickness

Weight of the Slab, Max

Mm

Mm

 

Mm

Kg

2 000

500

1

12

5

20

8

25

11

40

12.5

50

16

75

22

100

27.5

2000

500

2

40

25.0

50

30.0

75

40.0

1220

610

1

12

3.5

20

6

25

8

40

9.5

50

12

75

16

100

20

1220

610

2

40

18.5

50

22

75

30

4.1. Tolerances

± 6 mm in length, ± 4 mm in width and ± 2 mm in thickness,

Deviation from rectangular shape not more than 5 mm.

5.  Requirements

5.1. Deflection under Test Load – Shall not exceed the following

Type

Size Mm x mm

Thickness (mm)

Test Load (Kg)

Test Span (Cm)

Deflection   (Max)

 

 

1

2000x500

25

100

45

6

1220x610

25

165

27.5

6

2000x500

40

90

75

6

1200x610

50

90

75

6

 

75

120

75

5

 

100

150

75

5

 

2

2000x500

40

120

75

6

1200x610

50

160

75

6

 

75

240

75

5

5.2. Thermal conductivity – Shall not exceed 0.08 W/m. °C.

5.3. Sound absorption

Frequency Hertz

Minimum Sound Absorption Coefficient For 25 mm Thickness with Rigid Backing

125

0.1

250

0.2

500

0.2

1000

0.3

2000

0.5

4000

0.5

Note: For test procedures, refer to Appendix B of the Standard, IS: 3346-1966 Method for the determination of thermal conductivity of thermal insulation materials (two slab, guarded hot-plate method) and IS: 8225-1976 Method of measurement of absorption coefficient in a reverberation test.

Annexure 9-A.23

FIBRE INSULSATION BOARDS

(Extract of IS: 3348-1965)

1. Scope – Requirements for insulating boards made of wood or sugar cane fibre. It also covers the following special types of fibre insulation boards

a. Bitumen – Bonded fibre insulating board, and

b. Flame – Retardant treated fibre insulating board.

2. Dimensions and tolerances

Types of board

Nominal      Thickness    mm

Tolerance    on   Thickness mm

Length    Cm

Width    Cm

Fibre insulation

Board, ordinary

or flame

retardant type.

9

± 0.75

365, 300

180, 150

12

18

25

± 0.75

± 1.00

± 1.25

270, 240

210, 180

150,120

120, 100

90, 60

45 and 30

Bitumen-bonded

Fibre insulation

Board

9

12

18

25

± 0.50

± 0.50

± 0.75

± 0.75

100, 120

60, 45

and 30

 

30

Tolerance on         ± 3 mm upto 120 cm and

Length and width   ± 6 mm above 120 cm

3 . Requirements

3.1. Density – shall not exceed 0.4g/cm³.

3.2. Transverse strength

Types of boards

Thickness    mm

Mean breaking load Min. kg

Approximate modulus of rupture for nominal thickness. kg/cm2

Fibre insulation Board ordinary or flame retardant type

9

12

18

25

7.2

12.8

23

44

20

20

16

16

Bitumen bonded fibre insulating board

9

12

18

25

13

23

45

86

38

38

32

32

3.3. Water absorption

Types of board

Nominal Thickness Mm

Mean water absorption At 27 ± 2o C. Max

Fibre insulation board, Ordinary or flame Retardant type

9

12

18

25

30

30

25

25

Bitumen-bonded fibre Insulation board

9

12

18

25

25

25

20

20

3.4. Thermal conductivity – Shall not exceed 5.6 kcal.cm/m²h°C.

3.5. Sound absorption

Frequency, c/s Absorption                       125   250   500   1000   2000

Coefficient, Min                                       0.1    0.1     0.2      0.3    05

4. Special requirement for flame-retardant boards – Average maximum area of char, when tested for surface spread of flame, shall not exceed 75 cm².

Note: For test procedures, refer to IS: 3308-1981 Specification for wood wool building slabs and Appendix A to E of the standard.

Annexure 9-A.24

HIGH DENSITY WOOD PARTICLE BOARDS

(Extract of IS: 3478-1966)

1. Scope – Requirements of high density wood particle boards in flat sheet or moulded forms.

2. Types (depending on Synthetic Resin Used) and Grades (depending on extent of resin content)

Type 1 – BWR type of resign – Grades A and B.

Type 2 – WWR or CWR type of resign – Grades A and B.

Each type and grade may be in flat sheet form or moulded form.

3.  Materials

3.1. Timber – Any suitable species.

3.2. Adhesive – As in Grade A resin content is 20 to 50 percent and in grade B, 8 to 12 percent.

3.3. Sizing – Paraffin wax up to 1 percent. Max.

4. Dimensions and tolerances for flat sheets

a)   Length – 180,   150, 120, 100,   90, 60 and 45 cm.

b)   Width – 150, 120,   100,   90 and 45 cm.

c) Thickness – 50, 45,  40,  35,  30,  25,  22,  20, 16,  12,  9,  6  and 4 mm.

d) Tolerance

Length and width, ± 6 mm.

Thickness ± 5 percent up to 25 mm, ± 2.5 percent above 25 mm.

Length of diagonals of a board shall not differ by more than 2.5 mm/m length of diagonal. Edges shall be straight with tolerance of 3 mm.

5. Physical requirements – Shall be as specified in the IS standard.

Note: For test procedures, refer to IS: 2380 (Part I to XXI)-1977 Methods of test for wood particle boards and boards from other lignocellulosic materials (first revision) and 9.3 of the standard.

Annexure 9-A.25

TIMBER PANELLED AND GLAZED SHUTTERS

PART I DOOR SHUTTERS

(Extract of IS: 1003 (Part 1)-1977)

1. Scope – Requirements regarding material. sizes, construction, workmanship, finish, inspection and testing of timber door shutters with timber, plywood, blockboard, veneered particle board, hardboard and asbestos cement board panels used in domestic buildings, offices, schools, hospitals, etc. This standard does not cover timber door shutters for industrial and other special buildings, such as workshops and garages.

2. Timber – Moisture content 10 to 16 percent for thickness 50 mm and above and 8 to 14 percent for thickness below 50 mm. All timbers shall be kiln-seasoned. Sapwood of durable species and heartwood and sapwood of non-durable species shall be treated with suitable non-leachable type preservative.

Note – For suitable species of timber see Table 1 of the standard.

3. Requirements

3.1. Timber paneling – No single panel shall exceed 0.5 m² in area.

3.2. Plywood paneling – Shall be of BWP grade minimum thickness 12 mm for single panel construction and 9 mm for 2 or more panel construction.

3.3. Blockboard paneling – Thickness not more than 10 mm.

3.4. Particle board paneling – Shall be made of one piece of veneered particle board. Thickness shall be 12 mm, Min.

3.5. Hardboard paneling – Tempered quality. Thickness 12 mm, Min.

3.6. Asbestos cement paneling – Minimum thickness 12 mm in case of single panel shutters and 10 mm in case of 2 more panels’ construction.

3.7. Lock rail centre line – 80 cm from bottom of shutter.

4. Dimensions, sizes and tolerances

4.1. Dimensions of door shutters (in mm)

\

Width

Height

8  DS 20

700

1 905(1945)

8 DS 21

700

2 005(2045)

9 DS 20

800

1 905(1945)

9 DS 21

800

2 005(2045)

10 DS 20

900

1 905(1945)

10 DS 21

900

2 005(2 045)

12 DT 20

1 100*

1 905(1 945)

12 DT 21

1 100*

2 005(2 045)

Note 1: In arriving at the standard widths and heights for panel doors, and allowance of 6 cm has been made for door frames, 4 cm for floor finish and 0.5 cm for clearance all round between door opening and door frames and 1.5 cm for rebate all round for the shutter into the frame. In case the modular height is taken from the finished floor level, the height shall be as given in bracket.

Note 2: Type of shutter is designated by symbols denoting, in sequence, width (number of modules in width of door opening); type (D= door, W = Window, S= single shutter, T = Double shutter) and height (number of modules in height of door opening).

4.3. Tolerance – Shall be ± 3 mm on size of door.

4.4. Dimensions of components (finished dimensions in mm )

 

Width

Thickness

Vertical Stile, top and Freeze rail

100± 3

40 ± 1

Lock rail

160 ± 3

40 ± 1

Bottom rail

250 ± 3

40 ± 1

Mounting

100 ± 3

40 ± 1

Glazing bar

40 ± 1

1

5. Glazing – Glass used for panels shall weigh not less than 7.5 kg/m².

6. Finish

6.1. Defective knots, when permitted on surfaces exposed to view shall be completely bored or cut out and tightly plugged with the same timber species and properly glued in. Grains of plug shall run in direction of the grains of the piece.

6.2. Surfaces of door shutters which are required to be painted ultimately shall be covered by brush painting with a priming coat. Doors to be polished or varnished shall be given a priming coat of polish or varnish.

*Combined width of two shutters in closed position.

For detailed information, refer to BIS: 1003 (Part I)-1977 Specification for timber paneled and glazed shutters Part I Door shutters (second revision).

Annexure 9-A.26

TIMBER PANELLED AND GLAZED SHUTTERS

PART II WINDOW VENTILATOR SHUTTERS

(Extract of IS: 1003(Part II)-1966)

1. Scope – Requirements regarding material, construction, sizes, workmanship, finish, inspection and testing of timber window and ventilator shutter with timber plywood, particle board, hardboard and asbestos cement panels used in domestic buildings, offices, schools, hospitals, etc. It  does not cover timber window and ventilator shutters for industrial buildings, workshops and garages.

2. Dimensions

a) Window shutters

Type

Width (mm)

Height (mm)

6 WS 12

500

1 100

10 WT 12

460

1 100

12 WT 12

560

1 100

6 WS 12

500

1 100

10 WT 13

460

1 100

12 WT 13

560

1 200

 b) Ventilator shutters

Type

6V6

10V6

12V6

Width (mm)

500

900

1 100

Height (mm)

500

500

   500

c) Components

Vertical stiles, top and freeze rails : Width 80 mm

Bottom rails : Width 80 mm

Glazing bars : Width 40 mm

Mounting width for window shutter : 60 mm

d)   Thickness of shutter 20, 25 or 30 mm depending on size.

      Tolerance ± 1 mm.

e)   Tolerances:

± 1 mm on dimensions up to 40 mm

± 3 mm on dimensions over 40 mm.

Note 1: Size are divided after allowing for thickness of frame and a margin of 5 mm all round for fitting into a modular opening based on 10 cm module.

Note 2: Type of shutter is designated by symbols, denoting width (number of modules in width of opening); type W=window; V=Ventilator, S=single shutter, T=double shutter, and height (number of modules in height of opening).

f) Tolerance on overall dimensions ± 3 mm.

Note: For details regarding materials, finish and glazing refer to IS: 1003(Part I)-1977 Specification for timber paneled and glazed shutters Part 1 Door shutters (Second revision)

Annexure 9-A.27

WOODEN FLUSH DOOR SHUTTERS

(CELLULAR AND HOLLOW CORE TYPES)  PART I PLYWOOD FACE PANELS

(Extract of IS: 2191(Part 1)-1980)

1. Scope – Requirements regarding types sizes, materials, construction, workmanship and finish, and tests of cellular and hollow core wooden flush door shutters with face panels of plywood for cross-band face veneers.

2. Types (a)Cellular decorative type (CD) (b) Cellular non-decorative type (CN) (c) Hollow decorative type (HD) (d)Hollow non-decorative type (HN)

3. Sizes

Width and height

Designation

Width (mm)

Height (mm)

8  DS 20

700

1 905

8 DS 21

700

2 005

9 DS 20

800

1 905

9 DS 21

800

2 005

10 DS 20

900

1 905

10 DS 21

900

2 005

12 DT 20

1 100*

1 905

12 DT 21

1 000*

2 005

Note: If modular height is taken from the finished floor level, the height of door shall be 40 mm more.

Thickness – 25, 30 or 35 mm, nominal.

Tolerances- On nominal width and height shall be +3 and -0 mm tolerance on nominal  thick ness shall be ± 1.2 mm. Thickness of door shutter shall be uniform throughout with a permissible variation of 0.8 mm maximum.

Note 1: In arriving at standard widths and heights, an allowance of 6 cm has been made for door frames, 4 cm for floor finish and 0.5 cm for clearance all round and 1.5 cm for rebate all round for the shutter into the frame.

Note 2:  Type of shutter is designed by symbols denoting width (number of modules in width of door opening) type (D= door; S= single shutter; T= double shutter) and height (number of modules in height of door opening).

4. Materials

4.1. Timber – Moisture content shall not exceed 12 percent.

Note: For species of timbers see Appendix A of the standard.

Timber shall be free from decay and insect attack. Knots and knot holes less than half the width of cross section may be permitted. Pitch pockets, pitch streaks and harmless pin-holes shall be permissible except in the exposed edges of the core members where they shall be cut out and filled in with carefully fitted glued pieces of wood of similar species and character with their grains running in the same direction.

4.2. Plywood – Commercial plywood shall be of BWP grade, at least type BC. Decorative plywood shall be of Grade I.

4.3. Cross-bands – BWP grade.

4.4. Adhesives – Phenol formaldehyde synthetic resin, BWP type.

4.5. Particle board – Flat-platen pressed or extrusion pressed type. Swelling of particle board in thickness and length shall not exceed 5 percent.

5. Requirements

5.1. Plywood for face panels

Minimum thickness for cellular core shutters – 3 mm,

Minimum thickness for hollow core shutters for 25 mm thickness – 4 mm,

Minimum thickness for hollow core shutter over 25 mm thickness – 6 mm,

5.2. Rebating – One third thickness for double leaved shutters.

5.3. Shutters shall be shop-prepared for taking mortice locks or latches.

6. Workmanship and Finish – All the four edges shall be square. Shutter shall be free from twist or warp.

7. Tests

7.1. End immersion test – There shall be no delamination.

7.2. Knife Test

7.3. Adhesive Test

7.4. Types Tests - Combined width of two shutters in closed position.

Note: For test procedures, refer to BIS: 1659-1979 Specification for blackboards (second revision), IS:4020-1967 Methods of tests for wooden flush doors Type tests and 9 of the standard.

Annexure 9-A.28

WOODEN FLUSH DOOR SHUTTERS

(CELLULAR AND HOLLOW CORE TYPES)

PART II PARTICLE BOARD FACE PANELS AND HARDBOARD FACE PANELS

(Extract of IS:  2191(Part II)-1980)

1. Scope – Requirements regarding material, grade, types, sizes, construction, finish and tests of cellular and hollow core wooden flush door shutters with particle board face panels of veneered and un-veneered types of particle board and hardboard face panels.

2.Types and designation

Core

Type

Designation

Cellular

Decorative with skins of decorative veneered particle boards.

Non-decorative with skins of particle boards

Un-veneered Non-decorative with skins of particle boards

Veneered with commercial veneers

CDPV

CNP

CNPV

Hollow

Decorative with skins of decorative veneered particle boards

Non-decorative with skins of particle boards un-veneered.

Non-decorative with skins of particle boards veneered with commercial veneers.

HDPV

HNP

HNPV

3. Sizes and tolerances – Shall be same as given in IS: 2191 (Part I)-1980*

4. Material

4.1. Timber – Same as in IS: 2191 (Part I)-1980*.

4.2. Particle Board – Shall be made with phenol-formaldehyde adhesive. Swelling in thickness and length shall not exceed 5 percent.

4.3. Fibre Hardboard – Tempered.

4.4. Adhesive – Phenol formaldehyde synthetic resign, BWP type.

5. Requirements

5.1. Face Panel – Particle board thickness not less than 6 mm for cellular core and 9 mm for hollow core shutters. Hardboard thickness not less than 4 mm for cellular core and 6 mm for hollow core flush doors.

5.2. Shutters shall be shop prepared for taking mortice locks or latches.

6. Workmanship and Finish – All four edges shall be square. Shutter shall be free from twist or warp in its plane.

7. Tests – Requirements laid down in 9 of IS: 2191 (Part I)-1980* shall be complied with.

Specification for wooden flush door shutters (cellular and hollow) core type Part I Plywood face panels 9third revision).

Annexure 9-A.29

WOODEN FLUSH DOOR SHUTTERS

(SOLID CORE TYPE) PART I PLYWOOD FACE POANELS

(Extract of IS: 2202(Part 1)-1980)

1. Scope – Requirements regarding types, sizes, material, construction, workmanship and finish, and tests of solid core wooden flush door shutters with face panels of plywood or cross-band and face veneers.

2. Types: (a) Blockboard, decorative, BD (b) Blockboard, non-decorative, BN (c) Particle board with or without blockboard, decorative, PD. (d) Particle board with or without blockboard, non-decorative, PN.

3. Sizes

a. Dimensions

Designation

Width (mm)

Height (mm)

8  DS 20

700

1 905

8 DS 21

700

2 005

9 DS 20

800

1 905

9 DS 21

800

2 005

10 DS 20

900

1 905

10 DS 21

900

2 005

12 DT 20

1 100*

1 905

12 DT 21

1 100*

2 005

Note: If Modular height is taken from finished floor level, height of flush door shall be 40 mm more.

b. Thickness 25, 30 or 35 mm, nominal.

c. Tolerances – Width and height, ± 3 mm Thickness, ± 1.2 mm.

Thickness of door shall be uniform throughout with a permissible variation of not more than 0.8 mm.

Note 1: In arriving at the standard widths and heights for flush doors, an allowance of 6 cm has been made for door frames 4 cm for floor finish and 0.5 cm for clearance all round between the door opening and door frame and 1.5 cm for rebate all round for the shutter into the frame.

Note 2: Type of shutter is designated by symbols denoting width (number of modules in width of door opening) type (D=door; S= single shutter; T= double shutter) and height (number of modules in height of door opening).

4. Materials

4.1. Timber – Moisture content shall not exceed 12 percent.

Note: For species of timbers see Appendix A of the standard.

Knots and knot holes less than half the width of cross section of members in which they occur may be permitted. Pitch pockets, pitch streaks and harmless pin-holes shall be permissible except in the exposed edges of the core members where they shall be cut out and filled in with carefully fitted glued pieces of wood of similar species and character with their grain running in the same direction.

4.2. Plywood – Commercial BWP grade, at least type BC Decorative Grade I.

4.3. Cross-bands – BWP grade.

4.4. Adhesives – Phenol formaldehyde synthetic resin, BWP type.

4.5. Particle Board – Flat-platen pressed or extrusion pressed type. Swelling of particle board in thickness and length shall not exceed 5 percent.

5. Requirements

5.1. Face Panel- Thickness of cross-band as such or in plywood shall be 1 to 3 mm. Face veneer 0.5 to 1.5 mm thick for commercial and 0.5 to 1 mm for decorative.

5.2. Rebating – One third thickness is double leaved shutters.

5.3. Locks – Shutters shall be shop-prepared for taking mortise locks as may be ordered.

6.  Workmanship and Finish – All the four edges of the door shutter shall be square. Shutter shall be free from twist or warp in its plane.

7.  Tests

7.1. End immersion test – There shall be no delamination.

7.2. Knife test

7.3. Glue adhesive test

7.4. Types tests

* Combined width of two shutters in closed position.

Note: For test procedures, refer to BIS: 1659-1979 Specification for block boards (second revision), IS:  4020-1967 Methods of tests for wooden flush doors Type tests and 9 of the standard.

Annexure 9-A.30

WOODEN FLUSH DOOR SHUTTERS

(SOLID CORE TYPE)PART II PARTICLE BOARD AND HARDBOARD FACE PANELS

(Extract of IS: 2202 (Part II)-1980)

1. Scope – Requirements regarding material, grade, types, sizes, construction, finishes and tests of wooden flush door shutters of solid core type with particle board face panels of both veneered and un-veneered  particle boards.                                                      

2.Types and designation

Core

Type

Designation

Blockboard

Decorative with skins of decorative veneered particle boards

Non-decorative (paintable) with skins of particle boards un-veneered.

Non-decorative (paintable) with skins of particle boards veneered with commercial veneers

BDPV

BNP

BNPV

 

Particle board

With or without

block board

Decorative with skins of decorative veneered particle board.

Non-decorative with skins of particle boards un-veneered.

Non-decorative with skins of particle boards veneered with commercial veneers.

PDPV

PNP

PNPV

* Where particle board headed care is used, the designations will be PED, PV, PE, NP and PE N PV respectively.

3. Sizes and tolerances –Same as in BIS: 2202 (Part I)-1980*

4. Material

1.1.Species of timber, moisture content and permissible defects therein and preservative treatment required for use in core and lipping shall conform to relevant requirements laid down in BIS:  2202(Part I)-1980?.

1.2. Particle boards –Made with phenol formaldehyde adhesive. Swelling in thickness and length not exceed 5 percent.

1.3. Hardboard – Tempered.

1.4. Adhesive –For bonding particle board or hard board face panels to the core shall be phenol formaldehyde synthetic resin (BWP type).

5. Requirements

5.1. Face panel – Thickness of each face panel of particle board shall be at least 4 mm and of hardboard at least 3 mm.

5.2. Shutters shall be shop-prepared for taking mortice locks or latches.

6. Wokmanship and finish – All the four edges of door shall be square. Shutter shall be free from twist or warp in its plane.

7. Test- Same as given in IS: 2202 (Part I)-1980*.

Specification for wooden flush door shutters (solid core type) Part I Plywood face panels (third revision).

Specification for wooden flush door shutters (solid core type) Part I Plywood face panels (third revision).

Annexure 9-A.31

WOODEN SIDE SLIDING DOORS

(Extract of IS: 4962-1968)

1. Scope – Requirements regarding material, type, shape, fabrication, assembly and finish of wooden side sliding doors (of the straight sliding type), its gear components and fittings.

2. Type and size – Classified in accordance with mode of sliding of panels into the frame unit. Types 1 to 5of the IS standard gives clear opening, while Types 6 and 7 need no space at the sides. Overall size of door shall be such as to cover modular opening completely.

Note: For typical arrangement of panels of side sliding door see Fig. 2 of the standard.

3. Materials

3.1. Rolled steel sections shall be of weldable quality conforming to IS: 2062-1969*.

3.2. Tracks – Made of 2 mm thick structural steel sheet galvanized.

3.3. Roller – Grade 15 of BIS   210-1970†.  Prelubricated or self-lubricating type.

3.4. Guides - Gun metal.

3.5. Brackets – cast iron.

3.6. Shutter – Made of wood in accordance with IS: 1003 (Part I)-1977, IS: 2191 (Part I)-1973, IS:  2191 (Part II)-1966, IS: 2202 (Part I)-1973 and IS: 2202 (Part II)-1966.

4. Operation – Shall be capable of being operated in either direction with force not exceeding 3 kg / m of panel width, when panel is in motion.

5. Finish – Al components machined and finished smooth. Roller guides, fittings for locking arrangements, brackets, etc, may be hot-dip galvanized.

Annexure 9-A.32

SPECIFICATIONS FOR FINISHING OF WOOD AND WOOD-BASED MATERIALS

PART I OPERATIONS AND WORKMANSHIP

(Extract of IS: 2338(Part I)-1967)

1. Scope

1.1 This standard (Part I) deals with operations and workmanship for the finishing of wood and wood-based materials with the pigmented and clear finishes.

1.1.1 In this standard clear finishes, such as nitro-cellulose, polyester, polyurethane, acid catalysed cold cure amino-plast and similar type of finishes are not covered.

2. Terminology

2.1 For terms relating to paints and allied materials reference may be made to IS: 1303-1983†.

2.2 For terms relating to wood and wood-based materials reference may be made to  IS: 707-1976‡.

3. Necessary information

3.1. For the efficient application of finishes on wood and wood-based materials the following information is necessary and shall be furnished to the person in-charge of the work:

a) The type of wood and wood-based materials; the nature of their pretreatment, namely, preservation, seasoning, etc;

b) The location of the member to give an idea of the extent of exposure to weather;

c) The type of finish to be applied pigmented, clear, etc;

d) Information on the nature of previous finish would be desirable for re-decoration; and

e) Atmospheric conditions in the locality, namely, temperature, humidity, incidence of sunlight, etc.

3.2. Necessary drawings and instructions shall also be furnished to the person in-charge of the work.

3.3. Arrangement shall be made for proper exchange of information between those engaged in woods finishing work and those whose work will affect or will be affected. 

Glossary of terms relating to paints (revised).

Glossary of terms applicable to timber, plywood and joinery.

4. General characteristics of wood and wood based materials

4.1 The decorative and protective value of a finish may be influenced by the nature of the surface on which it is applied.  There are several species of wood and an increasingly large number of wood-based panel products often differing from each other in surface characteristics.  They may be hard, soft, resinous or porous in varying degrees.

4.1.1. Wood is a hygroscopic material and tries to reach a state of equilibrium with the atmosphere in so far as its moisture content is concerned. Changes in moisture content are accompanied by swelling and shrinkage, which is most pronounced across the grain of the wood. Due to moisture movement the summerwoods swell to a greater extent than springwoods and this sets up stress-concentration at the sharply defined junctions between one year’s summer growth and the next year’s spring and the failure commences about this region.  The resulting stresses on the film of finishing material are such as to cause fissures to develop along the grain under adverse circumstances.

4.1.2. Before painting, wood shall be properly seasoned and the moisture content shall be brought as near as possible to the equilibrium moisture content as given in IS: 287-1993* so as to prevent uneven shrinkage during drying which may result in distortion or even in cracks in the paint finish. It is also advisable not to finish excessively dry wood.

4.1.3. The cellular structure of wood has a strong influence on the absorption of liquid components of finishes.  Non-uniform absorption of vehicle by the wood upsets pigment-binder ratio, impairing the appearance and life of the coating.

4.1.4. Plywood, blockboard, hardboard and particle board have greater dimensional stability than solid wood and provides more uniform surface for finishing.

4.1.5. The trade and botanical names of different Indian timbers are given in IS 399-1963.  The painting characteristics of some of the soft and hardwoods are given in Appendix A.

5. Design considerations

5.1. Design and detailing of joinery timber – Since water can find access through unpainted surface or joints and may encourage decay, in all cases where the wood surface is in contact with surfaces which are likely to get wet, such as brickwork or concrete, one or two priming coats shall be applied to wood surfaces before fixing to minimize absorption of water.  Special attention is drawn to the following:

* Recommendations for maximum permissible moisture content of timber used for different purposes for different climatic zones (revised).

Classification of commercial timbers and their zonal distribution (revised).

a) Window and door frames, flush with the wall face may allow ingress of moisture between the structural walling and the woodwork, and the paint is then likely to fail unless two prime coats are applied to the surface and allowed to dry before fixing.

b) The rails of gates shall preferably be beveled to shed water and help to prevent it from entering the joints between vertical and horizontal members.

c) Door posts and sash frames resting on steps or sills are liable to absorb water unless the steps or sills are so designed and built as to drain away water. Door posts, sash frames and similar joinery shall be adequately primed all over, taking special care to prime any cut surfaces before fixing.

d) Wherever required, in joinery exposed to weather, tenons and other concealed surfaces shall be primed before assembly.  Members shall be assembled while the paint is wet.  When surfaces are to be glued, priming may not be possible and hence the use of waterproof glue is recommended.  Any painted beads or stops shall be primed on the underside and fixed in position while the paint is wet.

e) In design, consideration shall always be given to the grain direction and the effects of shrinkage; swelling and warping which may tend to open joints and break the paint film.  Wide boards shall be fixed centrally or at one edge only, bearing in mind that movement may be sufficient to rupture the paint film or may cause the board, and with it the paint to split if the movement is unduly restrained in fixing.  End grain shall receive special care in painting.

5.2. Selection of coating materials

5.2.1. Prime coat

5.2.1.1. A suitable wood primer shall adhere firmly to the surface, form a sound foundation for further coating and fulfill special functions, such as acting as a sealer on porous wood and hardboard.

5.2.1.2. Wherever the timber has large pores, a preliminary priming with a quick drying varnish of the gold size type conforming to IS: 198-1978*is desirable.  The varnish shall be forced with a brush well into the pores so that the pores are completely filled.  This filling of the pores shall not be regarded as a substitute for normal priming and shall be followed by a coat of the primer.

5.2.1.3. Pink wood primer (see IS: 3536-1966**) or the mixture of white and red lead primer may be used in painting structures containing a slight excess of moisture as they allow minute quantities of moisture to pass through without disrupting it.

* Specification for gold size varnish.

** Specification for ready mixed paint, brushing, wood primer, pink.

5.2.1.4. Aluminium primer may be used for priming wood having knots and resinous matter.  The primer prevents the resin of the wood from bleeding.

5.2.2. Stoppers and fillers – For deep holes, plastic wood conforming to IS: 423-1961† shall be used.  Stopping may be generally confined to large holes or cavities.  Shallow indentations shall be made up with the paste filler conforming to IS: 426-1961‡.  For high class work filling operation shall be done over the whole surface by using the filler conforming to IS: 110-1983§.  For clear finishes, filler conforming to IS: 345 - 1952|| shall be used.

5.2.3. Undercoat and finishing coat materials – Before considering the application of undercoat and finishing coat it shall be made sure that those selected are compatible with each other.  If a non-elastic finishing coat is applied over an elastic primer coat it may lead to cracking or alligatoring of the finishing and the primer coat may become visible through cracks in the finishing coat.  Similarly, if the finishing coat contains a strong solvent, it may attack the primer coat and lead to shriveling (wrinkling) of the entire paint structure.  It is, therefore, essential to specify and ensure that the various types of paints to be used are compatible with each other, and as Indian Standard specifications on paints allow enough latitude for the; manufacturer to adjust his materials, it is advisable to consult the paint manufacturer and obtain his guarantee that the paints purchased not only satisfy the specified requirements but are also compatible with each other.  As a general rule, it is safer to use primer and finishing paints made by the same manufacturer.

6. Painting new wood work

6.1. Surface preparation

Wood that is to be painted should be well seasoned and free from discoloured sapwood and from large resinous or loose knots.  If the wood is not properly seasoned, the surface may become uneven on drying and cracks may also develop.  Paint applied over discoloured sapwood is liable to become discoloured; resin from knots tends to exude through the paint.  Any such unsound portions should, therefore, be cut out and replaced with sound wood.

Nails should be punched well below the surface to provide a firm key for stopping.

Moldings should be carefully smoothed with abrasive paper and projecting fibres left after machining should be removed.  Quirks need particular attention since paint collects on any rough projections and the finished appearance is then marred.

Specifications for ready mixed paint, wood primer, pink.

Specification for plastic wood for joiner’s filler (revised).

Specification for paste filler for colour coats (revised).

Specification for ready mixed paint, brushing, gray filler, for enamels for use over primers.

Specification for wood filler, transparent, liquid.

Flat portions should be smoothed off with abrasive paper used across the grain prior to painting and with the grain prior to staining or if the wood is to be left in its natural colour.  Woodwork which is to be stained is sometimes smoothed by scrapping instead of by glass papering. 

Any knots, resinous streaks or bluish sapwood that are not large enough to justify cutting out should be treated with two coats of pure shellac knotting, applied thinly and extended about 25 mm beyond the actual area requiring treatment.  Aluminium primer may be used in the place of shellac knotting.  If the area is small and the wood is not highly resinous, it is permissible instead of applying two coats of knotting, to apply one coat slightly pigmented with aluminium powder.

6.2. Priming

If there is dirt or any other extraneous material this shall be removed.  If the woodwork is not already primed, a priming coat shall be applied.  In case there is already a primer coat but an unsatisfactory one, it shall be rubbed down to bare wood and the surface reprimed.  Primer shall be applied by brushing.

Care shall be taken to prime not only the surface of the wood that will be visible after fixing but also any surface which will be in contact with materials, such as brickwork or concrete from which the wood may absorb moisture.  It would be an advantage to give such surfaces a further coat of primer, before fixing.

Unless specified otherwise, all joinery work, which is intended to be painted, shall receive at least two priming coats.  It is particularly important that end grains be so treated and, if it is necessary to cut the joinery before fitting, all cut ends shall be painted with two priming coats.

6.3. Stopping and Filling – Stopping and filling should be done after priming.  If the surface is not first primed, the filler or stopping may shrink and fall away, owing to absorption of some of the binder. 

Stopping is made to the consistency of stiff paste and is used to fill holes and cracks, while the function of the filler is to level up slight irregularities of surface.  Filler is usually applied with a putty knife and is subsequently rubbed down to a level surface with abrasive paper, pumice stone or other suitable abrasive.  For certain work, fillers are mixed to the consistency of thick paint and applied with a brush.

The filler coat should be of an optimum thickness and should be allowed to fully harden and flatten before subsequent coat is applied.  Apply as many layers as necessary allowing the coats to harden and flatten between coats.

6.4. Application of undercoat – Undercoat shall be applied after the surface has been primed, stopped, filled and rubbed down to a smooth surface.  Undercoat may be brushed or sprayed.  After drying the coat shall be carefully rubbed down and wiped clean before the next coat is applied. 

6.5. Finishing – The application paint varies according to the type of paint employed.  Cleanliness is essential and as far as possible the application should be carried out in normal dry conditions.  The finishing coat may be applied either with the brush or sprayed.

7. Application of clear finishes

7.0. General – Clear finishes for wood are generally used for interior surfaces as their durability when used on external surfaces is less than that of pigmented coating.  This is mainly because of the destructive action on the clear finishes by the ultraviolet rays present in the sunlight.  The ultraviolet radiation is to a great extent absorbed by the pigments present in the coatings while it may cause considerable damage to clear finishes.

7.1. For the application of clear finishes the following procedure shall generally be adopted: (a) Filling, (b) Staining, (c) Sealing, and (d) Finishing.

7.2. Filling

The primary function of fillers is to fill the opened cells of the wood in the surface layer. This is necessary to prevent the excessive penetration of the finish, that is, subsequently applied and to level off the surface of a porous wood to make a smooth top finish possible. 

On hardwood with large open vessels a suitable filler conforming to BIS: 345 – 1959* may be used. For special stain effects coloured fillers shall be used.

A combination of filler and stain may be used for reasons of cost, that is, to eliminate a separate staining operation.  However, the result lacks the grain and colour contrast characteristic of wood stains.

One fine-textured woods having minute pores that do not require filling, unfilled drying oils, thin varnishes, lacquer or shellac may be used.

Filler or stain filler shall be heavily applied to the wood surface by hand, using hessian or jute rag across the grain.  It may be rubbed when still wet to get better penetration.  After 5 to 10 minutes it shall be wiped off by hand across the grain followed by a light wipe with the grain.  Picking out of corners and carvings may be done with a rag wrapped around the end of a sharpened wood dowel.  The filled surface shall be dried preferably overnight, and smoothened with abrasive paper.  Wipe with a clean soft rag to remove dust and nibs.

* Specification for wood filler, transparent, liquid.

7.3. Staining

Staining of wood may be resorted for indoor fittings and even then only for subsequent clear finishes.  The object of staining wood is to darken it as part of a decorative scheme.  If skillfully carried out, staining may be used with good effect to enhance the natural grain or figuring of the wood.

The depth of colour produced by staining will depend not only on the concentration of the stain but also on the extent to which it is absorbed by the surface.  Stain is readily absorbed by soft porous springwood but comparatively little by the harder and denser summerwood.  Hardwoods, being less absorbent, will present less difficulty; the stain may be applied liberally and allowed to remain until sufficient quantity is absorbed, the excess being then wiped off, if necessary.  The effects produced by knots, resinous portions and other markings may be similarly accentuated.  The different types of stains as water, spirit and oil stains have different penetrating properties and, therefore, shall be selected to suit the performance required.

7.3.1. Water stains – Water stains are made with water-soluble dyes.  They emphasize the grain, especially that of softwoods, since they are readily absorbed by the porous portions but less readily by the denser, more resinous portions.  They will raise the grain of the wood thus spoiling the smoothness of the finish if a highly polished effect is required; this difficulty can be overcome by first wetting the surface with water to raise the grain and then, after drying, smoothing it with abrasive paper before staining.  Where it is necessary to provide a temporary staining treatment on wood, that is, damp or unseasoned, water stain is preferable to other types of stain.

7.3.2. Spirit stains – Sprit stains are solutions of spirit soluble dyes in industrial methylated spirit.  Like water stains, spirit stains penetrate more into the softer portions of the wood and so accentuate the grain but they do not cause the fibres to swell nor raise the grain.  They will dry very quickly and shall be applied quickly and skillfully to avoid patchy effects.  If applied to damp wood the dyes in the stains are liable to be thrown out of solution.  The surface after staining with spirit stains may be finished in the same way as after treating with water stains. 

7.3.3. Oil stains – Oil stains may be solutions of oil soluble dyes in linseed oil but usually, to give a range of colours, they consist of insoluble, semi-transparent pigments ground in linseed oil and thinned with turpentine or other solvent. Sometimes wax is added to make the stain less penetrating.  Oil stains will give a softer effect than water stains or spirit stains.  Generally they may be finished with gloss or flat oil varnish.  If wax polished, the stain shall first be given time to dry hard.  If applied to damp wood they are likely to develop a milky effect or bloom.  The application of oil stains and varnish will retard the drying of the wood.  Oil stains will not take well on certain resinous or oily woods, such as teak.  Sometimes, these woods are pretreated with solvents to remove the greasy matter from the surface prior to oil staining or varnishing.

7.3.4. Wash Coating – If grain raising stains have been employed or if it is desired to reduce to a minimum the risk of stain bleeding into top coats and to prevent discoloration of wood by absorption of oil and stains from the filler, a thin coat of shellac or lacquer shall be applied on the stained surfaces before sanding.

The stain may also be mixed with varnish to produce the combined effect in one operation; the result will, however, not be as satisfactory as when the ‘finishing’ follows as a separate operation after staining.  Alternatively, the stain may also be mixed with wax so that after application in one operation the wax may be polished.  Here again the results will not be as satisfactory as in a two-stage system. 

7.3.5. Preparation of wood for staining

Surface intended for staining shall be kept scrupulously clean and free from greasy finger marks. It shall be prepared by careful smoothing with fine abrasive paper, used in the direction of the grain; scratches across the grain are likely to become stained darker than the rest of the surface and so spoil the finished appearance.  If water stain is to be used, the surface of the wood shall be wetted with water to raise the grain and then be allowed to dry before finally smoothing.

Small cracks or nail holes may be stopped with plastic wood, fine plaster of paris or other suitable stopping, if water stain or spirit stain is to be used.  The stopping shall be rubbed down with fine abrasive paper when hard and touched with a little thinned knotting before staining. Where oil stain is to be used, stopping shall preferably be done after staining, using tinted putty or wood filler.

If necessary, softwood may be treated with hot weak size before staining to prevent undue absorption of stain, but an excess of size should be avoided.  To a certain extent the degree of penetration of a stain may be controlled by pretreatment of the absorbent surface with a hot weak size of thinned shellac varnish.  Size shall preferably be not used where the stained surfaces are likely to come into contact with water, which may smear it.  To control the depth of colour, however, diluted stain may be made to soak well into the wood.  Where size is used, the surface shall be allowed to dry thoroughly before staining.  In general, flat surfaces shall be treated first and mouldings and edges last, that is, reversing the order recommended when applying paint, the object being to avoid double staining along the edges.

7.3.6. Application of stains

Stains may be applied by brushing and wiping or by spraying. The stain shall be so thinned that it can be applied fairly liberally without over-staining. Care shall be taken, especially on absorbent softwoods, to apply the stain evenly and without overlapping.  Spirit stains; in particular require careful and quick application as they dry very quickly.

The stained surface shall be varnished, wax-polished or french polished as required after it has dried.  For reasons of economy, the surface shall be sized before varnishing, in which case it is important to allow the size to dry thoroughly.  Where a more durable finish is required two or three coats of finishing clear varnish is recommended. 

7.4. Sealing – A suitable sealer shall be applied on the filled and sanded surface to prevent absorption by the wood of the succeeding coats of finish and to seal stain and filler and thus preclude their bleeding into the finish coat. 

Sealer may be sprayed on taking care not to flood the surface.  It is allowed to dry hard.

A stain (toner) may be incorporated with the sealer for special colour effects. 

When fully dry the surface shall be sanded taking care not to cut through at corners and edges.  Dust shall be blown off and surface wiped with a clean rag.

7.5. Varnishing

7.5.1. Surfaces to be varnished should be prepared to produce a smooth, dry, matt surface.  Previous coats of paint or stain, if any, should be allowed to dry and be rubbed down lightly, wiped off and allowed to dry. 

The operation of varnishing calls for careful attention to cleanliness.  All dust and dirt should be removed from the surface to be varnished and also from the neighborhood.  If the surfaces are dampened to avoid rising of the dust, they should be allowed to dry thoroughly before varnishing is commenced.  Damp atmosphere and draughts should be avoided.  For exterior work, a normal dry day should be chosen.  Exposure to extremes of heat or cold or to a damp atmosphere will spoil the work.

In handling and applying varnish care should be taken to avoid forming froth or air bubbles.  Brushes and containers should be kept scrupulously clean.

7.5.2. Application – The varnish should be applied liberally with a brush and spread evenly over a portion of the surface with short light strokes to avoid frothing.  It should be allowed to flow out while the next section is being laid-in.  Excess varnish should then be scraped out of the brush and the first section be crossed, re-crossed and then laid off lightly.  Too much or too little varnish left on the surface will mar the appearance of the finish.  The varnish, once it has begun to set, should be retouched.  If a mistake is made, the varnish should be removed and the work started afresh. 

Where two coats of varnish are specified, the first should be a hard-drying undercoating or flatting varnish; this should be allowed to dry hard and then be flatted down before applying the finishing coat.  If two coats are applied, sufficient time should be allowed between coats.

When flat varnish is used for finishing, a preparatory coat of hard drying undercoating or flatting varnish should first be applied and should be allowed to harden thoroughly. It should then be lightly rubbed down before the flat varnish is applied.  Sections of the work, such as panels, should be cut in clearly, so as to avoid any overlapping during application, as this is likely to impart some measure of gloss to partially dried areas, worked up in lapping.  On larger areas, the flat varnish should be applied rapidly, and the edges of each patch applied should not be allowed to set, but should be followed up whilst in free working condition. 

8. French polish

Pure shellac varying from pale orange to lemon yellow colour, free from resin or dirt should be dissolved in methylated spirit at the rate of 0.15 kg of shellac per litre of spirit (see BIS: 348 – 1952*).  Suitable pigment should be added to get the required colour.

8.2. Preparation of surface – All unevenness should be rubbed down to smoothness with sandpaper and the surface should be well dusted.  Fill up the pores in the wood with a filler made of a paste of whiting in water or methylated spirit (with a suitable pigment like burnt seinna or umber, if required) otherwise the French polish will get absorbed and a good gloss will be difficult to obtain.

8.3. Application of polish – A pad of woolen cloth covered by a fine cloth should be used to apply the polish.  The pad should be moistened with polish and rubbed hard on the surface in a series of overlapping circles applying the polish sparingly but uniformly over the entire area to give an even surface.  A trace of linseed oil on the face of the pad facilitates this operation.  The surface should be allowed to dry and the remaining coats applied in the same way.  To finish off, the pad should be covered with a fresh piece of clean fine cloth, slightly damped with methylated spirit and rubbed lightly and quickly with circular motions.  The finished surface should have a uniform texture and high gloss. 

9.  Finishing of wood-based materials

9.1. Plywood – Plywood is similar to solid wood in its finishing characteristics.

9.2. Hard board

9.2.1. Painting characteristics – hard board is made up of fibres which are capable of swelling under the influence of oil paints.  Tempered hard board may be varnished or painted, if required.

9.2.2. Treatment – A suitable treatment to prevent swelling under the influence of oil paints is necessary; one such treatment is to use plastic emulsion paint thinned with water, another is shellac varnish as the first coat and when dry rub down with fine grade glass paper and follow with required undercoating and finishing coats as for solid wood.

9.3. Particle board – The surface shall be filled with a thin brushable filler and finished as for solid wood.

* Specification for French polish.

9.4. Insulation board – Two thin coats of water-based paints shall be applied by spraying

9.5. Wood treated with preservative

9.5.1. Painting characteristics – Wood treated with the commonly used water soluble preservatives may be painted satisfactorily after it is dried.  The life of the coating may, in some instances, be slightly less than it would have been on untreated wood, but the loss in durability is not such as to offer any practical objection to the use of treated wood for purposes where preservation against decay is necessary and the appearance of painted wood and protection against weathering are desired.  Coal-tar creosote or other dark oily preservatives tend to bleed through paint unless the treated wood has been exposed to the weather for many months before it is painted. 

9.5.2. Treatment – Fairly satisfactory results may be obtained on creosoted wood with rough surfaces (sawed or weather-beaten surfaces) by applying exterior water thinned paints, such as case-in paints or resin emulsion paints.

Creosote-treated wood shall not be painted with ordinary paint as discolouration of the latter may result.  One or two sealing coats of aluminum paint or shellac knotting clear or pigmented with aluminium powder shall be applied before it is finished with other paints.

In the case of wood treated with other preservatives, such as copper napthenate, chlorophenol and zinc silico fluoride, a high quality aluminium primer is desirable.

Alternatively, advice may also be sought of the manufacturers of these preservatives for information as to the suitable primer that may be applied over these.

10. Inspection

10.1. While the finishing is in progress, inspection shall be made to ascertain that the right type of finishing material is being used, and the number of coats and the sequence of operation are carried out as specified.  The points as laid down in 10.1.1 to 10.1.4 shall be specially noted.

10.1.1. As the first signs of failure of paint may not appear until some time after the work has been completed, inspection of work can only be directed towards ascertaining as far as possible that the types of paints and number of coats applied are as specified, and that the standard of work is satisfactory.

10.1.2. The chief points on which the general quality of paint work should be judged by visual inspection are as follows:

(a)Uniformity of finish and colour;(b) Uniform and complete obscuration of the ground;(c) Freedom from blemishes (for example, rums, sags, wrinkling, fat edges, entrained paint skins, dust, bare or starved patches and cracks); (d) Freedom from tackiness;(e) Freedom from brush marks and ladders; and (f) General cleanliness and neatness of finish.

10.1.3. Should the paint appear faulty during application any defects in the following properties should be noted and the matter reported to those responsible:

(a)Colour,(b) Consistency,(c) Drying time, or (d) General quality of finish.

10.1.4. Since it is the final coat of paint which claims attention it is a common error to blame the paint or workmanship for any defects.  These are by no means the only factors which may influence the final result.  In attempting to diagnose a paint failure the following details should be ascertained and taken into consideration:

(a)Nature, history and condition of the painted surface; (b)Materials used; (c)Climatic conditions before, during and after painting; (d)Technical correctness of work in relation to conditions; and (e) Workmanship.

11. Maintenance

The principle given in Table 3 of IS: 2338 (Part II) -1967* shall generally be adopted for maintenance work.  All unsound work should be burnt off or otherwise removed and brought forward as for new work.

The surface should be cleaned and rubbed down with pumice stone or abrasive paper.  All holes and cracks should be prepared for stopping by touching them up with primer paint, with undercoat paint; when dry, the stopping should be completed with a suitable filler and the appropriate paint as given in IS: 2338(Part II)-1967* should then be applied.

* Code of practice for finishing of wood and wood-based materials: Part II Schedules.

APPENDIX A

(Clause 4.1.5)

PAINTING CHARACTERISTICS OF TIMBERS

A-1. Some of the soft and hard woods given in A-1.1 and A-1.2 are resinous or show oily exudation occasionally and hence they require special treatment.  In general, hardwoods are porous and require filling.  However, some of the hardwoods given in A-1.3 do not require filling as their pores are less than about 100-microns in diameter or are filled with gum. 

A-1.1. The following softwoods are resinous and may exude resin through paint films;

Trade name

Botanical name

Chir

Cypress

Deodar

Kail

Spruce

Pinus roxburghii Sargenl

Cupressus torulosa Don

Cedrus deodara Loudon

Pinus wallichiana A.B.Jacks

Picea smithiana Boiss

Annexure 9-A.33

SPECIFICATIONS FOR FINISHING OF WOOD AND WOOD - BASED MATERIALS

PART II SCHEDULES

(Extract of IS: 2338 (Part II)-1967)

1. Scope

1.1. This standard (Pat II) lays down schedules for finishing of wood and wood-based materials with paints, varnishes, polishes and other organic coatings.

2. Terminology

2.1 For the purpose of this standard, the terms pertaining to painting material, finishes, tools and accessories as given in IS: 1303-1963* and IS:  707-1958 shall apply.

3. Necessary information

3.1 The necessary information required for the efficient application of finishes on wood and wood-based materials shall be provided as given in 3 of IS: 2338 (Part I)-1967.

4. Schedules for finishing woodwork

4.1. New woodwork

4.1.1. Preparation – The surface shall be prepared as specified in IS: 2338 (Part I)-1967.  However, the following points shall be noted;

a) The surface shall be cleaned and smoothened with abrasive paper,

b) The surface shall be primed,

c) Knots shall be treated with two coats of shellac knotting, and

d) Deep holes shall be filled with plastic wood conforming to IS: 423-1961.

4.1.2. Finish – The different coats as specified in Tables 1 and 2 shall be applied along with stopping and filling where necessary for the corresponding type of finish.

4.2. Maintenance Work – In the case of painting or finishing relating to maintenance work, the principles given in Table 3 should generally be adopted.

Table 1 Schedules for finishing new woodwork –Interior

Sl.No.

Final finish Required

Primer (One or two coats as Required)

Under   coat

First finishing    Coat

Second finishing coat

i

Enamel

IS:103-1962

or

IS:3536E-1966

or

IS:106-1962

or

IS:3585-1966

IS:133-1965

IS:133-1965

IS:133-1965

ii

Oil Gloss

IS:103-1962

or

IS:3636E-1966

or

IS:3585-1966

IS:3539E-1966

or

IS:113-1950

or

IS:114-1950

IS:3537E-1966

or

IS:129-1950

IS:3537E-1966

or

IS:129-1950

iii)

Flat

IS:103-1962

or

IS:3536E-1966

or

IS:3585-1966

IS:133-1965

or

IS:3539-1966

or

IS:113-1950

or

IS:114-1950

IS:137-1965

or

IS:3537E-1966

IS:137-1965

or

IS:3537E-1966

iv)

Varnish

IS:345-1952

IS:338-1958

or

IS:339-1952

IS:337-1952

or

IS:524-1954

or

IS:525-1954

IS:337-1952

or

IS:524-1954

or

IS:525-1954

v)

Grained Work

----

Merging type glaze

or

Stains (see Appendix B)

Merging type glaze

or

Stains

IS:337-1952

or

IS:524-1954

or

IS:525-1954

Note 1: For finishes (i), (ii) and (iii) fillers conforming to IS: 426-1961 or IS: 110-1950 may be applied after the prime coat as required.

Note 2: When proprietary materials are used the finishing and the adjuncts shall be obtained from the same manufacturer.

Note 3: When French polish is used for finishing, it shall conform to IS: 348-1952 and the finishing shall be carried out as given in IS: 2338 (Part I)-1967.

Note 4: Titles of Indian Standards referred to in this table are given in Appendix A.

Table 2 Schedules for finishing new woodwork – Exterior (Clause 4.1.2)

Sl. No.

Final finish required

Primer

Under   coat

First finishing    coat

Second finishing coat

i

Enamel

IS:103-1962

or

IS:3536E-1966

or

IS:106-1962

or

IS:3585-1966

IS:2932-1964

or

IS:2933-1964

IS:2932-1964

or

IS:2933-1964

IS:2932-1964

or

IS:2933-1964

ii

Oil Gloss

IS:103-1962

or

IS:3636E-1966

or

IS:3585-1966

IS:3539E-1966

or

IS:111-1950

or

IS:112-1950

IS:3631E-1966 (alkyd)

or

IS:117-1964

or

IS:119-1962

or

IS:124-1962

or

IS:125-1962

or

IS:127-1962

or

IS:128-1962

or

IS:1188-1957

IS:3631E-1966 (alkyd)

or

IS:117-1964

or

IS:119-1962

or

IS:124-1962

or

IS:125-1962

or

IS:127-1962

or

IS:128-1962

or

IS:1188-1957

iii

Flat

Proprietary materials to be used

 

 

iv

Varnish

IS:345-1952

IS:339-1952

Or

IS:339-1952

IS:524-1954

IS:524-1954

v

Grained Work

----

Merging type glaze or

Stains (see Appendix B)

IS:524-1954

IS:524-1954

Note 1: For finishes (i), (ii) and (iii) fillers conforming to IS: 426-1961 or IS: 110-1950 may be applied after the prime coat as required.

Note 2: When proprietary materials are used the finishing and the adjuncts shall be obtained from the same manufacturer.

Note 3: Titles of Indian Standards referred to in this table are given in Appendix A.

Table 3 Recommended practices for maintenance painting (Clause 4.2)

Sl. No.

Condition of surface

Cleaning and painting practice

 

Blistering

Cracking

Checking

Chalking

 

i)

Nil

Nil

Nil

Yes

Clean; rub with sand paper, apply one reviver coat

ii)

Nil

Nil

Yes

Nil

Flat down to remove checked film; clean; apply one or two reviver coats

iii)

Nil

Yes, localized

Nil

Nil

Rub down with steel wool/sand paper to remove cracked/crazed film; touch up with primer where damaged; apply two coats of finishing

iv)

Yes, localized

Nil

Nil

Nil

Scrape and rub down (with sand paper) the spot to bare wood, feather out the edges of paint, allow the surface to breathe out; touch up with primer; apply two coats of finishing (with a coat of under-coat, if necessary)

v)

Yes, localized

Nil

Nil

Yes

Treatments in (i) and (iv) combined

vi)

Yes, localized

Nil

Yes

Nil

Treatments in (i) and (iv) combined

vii)

Yes, localized

Yes, deep

Nil

Nil

Completely remove paint to bare wood and follow the full schedule

viii)

Nil

Yes, deep

Nil

Nil

---do----

ix)

Yes, heavy

Nil

Nil

Nil

---do----

Note: Quality of paints for interior and exterior as in tables 1 & 2.

APPENDIX A

(Tables 1 and 2)

INDIAN STANDARDS ON PAINTS, ENAMELS, FILLERS, ETC

A.1. The titles of Indian Standards on paints, enamels, fillers, etc, referred to in Tables 1 and 2 are given below;

IS:103- 1962

Specification for ready mixed paint, brushing, white lead, for priming and general purposes (revised)

IS:106- 1962

Specification for ready mixed paint, brushing, priming, for enamels, for use on wood (revised)

IS:110- 1983

Specification for ready mixed paint, brushing, gray filler, for enamels, for use over primers

IS:111-  1950

Specification for ready mixed paint, brushing, undercoating, exterior to Indian Standard colours

IS:112- 1950

Specification for ready mixed paint, spraying, undercoating, exterior, to Indian Standard colours

IS:113- 1950

Specification for ready mixed paint, brushing, undercoating, interior, to Indian Standard colours

IS:114- 1950

Specification for ready mixed paint, spraying, undercoating, interior, to Indian Standard colours

IS:117- 1964

Specification for ready mixed paint, brushing, finishing, exterior, semi-gloss, for general purposes, to Indian Standard colours

IS:119- 1962

Specification for ready mixed paint, brushing, finishing, semi-gloss, for general purposes, to Indian Standard colours

IS:124- 1962/

IS:125- 1962

Specification for ready mixed paint, brushing, finishing, semi-gloss, for general purposes, to Indian standard colour No.106 Royal blue (revised)Part I-1976, Part II-1979, Part IV  1979

IS:127- 1962

Specification for ready mixed paint, brushing, finishing, exterior, semi-gloss, for general purposes, white (revised)

IS:128- 1962

Specifications for ready mixed paint, brushing, finishing, semi-gloss, for general purposes, black (revised).

IS:129- 1950

Specification for ready mixed paint, brushing, finishing, interior, oil gloss, for general purposes, to Indian Standard colours

IS:133- 2004

Specification for enamel, interior (a) undercoating, (b) finishing, colour as required (revised)

IS:137- 1965

 

Specification for ready mixed paint, brushing matt or egg shell flat, finishing, interior, to Indian Standard colour, as required (revised)

IS:138- 1992

Specification for varnish, finishing, interior

IS:338- 1952

Specification for varnish, undercoating, exterior, natural resin

IS:339- 1952

Specification for varnish, undercoating, exterior, synthetic resin

IS:345- 1952

Specification for wood filler, transparent, liquid

IS:348- 1968

French polish

IS:426- 1961

Specification for paste filler for colour coats (revised)

IS:524- 1983

Specification for varnish, finishing, exterior, type1 (synthetic (tentative)

IS:525- 1968

Specification for varnish, finishing, exterior, and general purposes, type 2 (tentative)

IS:1188- 1957

Specification for ready mixed paint, brushing, oil gloss, genuine zinc oxide, for general purposes

IS:2338 (Part I) -1967

Code of practice for finishing of wood and wood based materials; Part I operations and workmanship

IS:2932 -2003

Specification for enamel, synthetic, exterior, type 1 (a) undercoating, (b)finishing, colour as required

IS:2933 -1975

Specification for enamel, exterior, type 2 (a) undercoating, (b) finishing, colour as required

IS:3536E -1999

Specification for ready mixed paint, brushing, wood primer, pink

IS:3537E -1966

Specification for ready mixed paint, finishing, interior, for general purposes, to Indian Standard colours

IS:3539E -1966

Specification for ready mixed paint, undercoating, for use under oil finishes, to Indian Standard colours, as required

IS:3585 -1966

Specifications for ready mixed paint, aluminium, brushing, priming, water resistant, for woodwork.

IS:3631E -1966

Specification for ready mixed paint, finishing, exterior, (i) Alkyd and (ii) Non-alkyd, for general purposes, to Indian Standard colours

APPENDIX B

[Table 1 and 2 (Item V)]

MERGING TYPE GLAZE AND STAINS

B-1. Merging type glaze

B-1.1. Merging type glaze - (Which facilitates the blending of various colour after application) is transparent pigment bound with a medium having good flowing properties, thinned with volatile solvent.

B-2. Stains

B-2.1. Stains are soluble fast dyes or transparent, pigment, dissolved or suspended in an oil, water or spirit medium.  The consistency shall be such as to ensure complete penetration.

B-2.2. Stains are supplied either in liquid form ready for application or as powders to be dissolved in a suitable medium (water, spirit or oil) as indicated.  If the medium is oil, driers and thinners may also be needed.