भा तीर् मानक IS 4990 : 2024

Indian Standard

कंक्रीट शटर ं ग कार्य के लिए प्िाईवडु —

लवलशलि
( चौथा पुन ीक्षण )

Plywood for Concrete Shuttering

Works — Specification
( Fourth Revision )

ICS 79.060.10

 BIS 2024

भा तीर् मानक ब्र्ू ो

BUREAU OF INDIAN STANDARDS
मानक भवन, 9 बहादु शाह ज़फ मागय, नई लदल्िी - 110002
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI - 110002
www.bis.gov.in www.standardsbis.in

March 2024 Price Group 8

Wood and Other Lignocellulosic Products Sectional Committee, CED 20

FOREWORD

This Indian Standard (Fourth Revision) was adopted by the Bureau of Indian Standards, after the draft finalized
by the Wood and Other Lignocellulosic Products Sectional Committee had been approved by the Civil
Engineering Division Council.

Plywood for concrete shuttering works is a Boiling Water Proof (BWP) Grade plywood, preservative treated
and especially suited for use in concrete shuttering and form work. Concrete shuttering plywood is very
economic as it can be put to repeated use, depending upon the care taken during erection and dismantling. The
main requirements of such plywood are that it should be durable under alternate wetting and drying conditions,
its surface should be hard and it should possess adequate strength to withstand the load of concrete and the
forces caused by pouring of concrete and vibrations. This standard specifies the requirements of such plywood
for use in concrete shuttering and form work and provides guidance in the manufacture and use of the plywood.

This standard on plywood for concrete shuttering works was first published in 1969 and subsequently revised
in 1981, 1990 and 2011. In this revision, the following major modifications have been incorporated:

a) Material clause for timber has been modified;

b) Dimension clause has been modified;
c) Modulus of Rupture (MOR), Modulus of Elasticity (MOE) and tensile strength requirements have been
modified;
d) Requirements for formaldehyde content for oven dry board and the steady-state formaldehyde emission
(optional) have been added; and
e) Marking clause has been modified.

This standard also includes in Annex E, on the recommended method for handling, storing and use of
plywood for concrete shuttering and form work.

A scheme of labelling environment friendly products known as ECO-Mark has been instituted at the instance of
the Ministry of Environment, Forests and Climate Change, Government of India. The ECO-Mark is administered
by the Bureau of Indian Standards (BIS) under the Bureau of Indian Standards Act, 2016 as per the
Resolution No. 71 dated 21 February 1991 and Resolution No. 425 dated 20 October 1992 published in the
Gazette of the Government of India. For a product to be eligible for ECO-Mark, it shall also carry the Standard
Mark (ISI Mark) of BIS besides meeting additional environment friendly requirements. For this purpose, the
Standard Mark of BIS would be a single mark being a combination of the ISI Mark and the ECO-Mark.
Requirements to be satisfied for a product to qualify for the BIS Standard Mark for ECO-friendliness are
optional. Manufacturing units are free to opt for ISI Mark alone also.

The ECO criteria is based on the Gazette Notification No. 170 dated 16 May 1996 for wood substitutes as
environment friendly products published in the Gazette of Government of India, as revised/amended from time to
time.

This standard contributes to the United Nations Sustainable Development Goal 9 ‘Industry innovation and
infrastructure’ Build resilient infrastructure promote inclusive and sustainable industrialization and foster
innovation.

The composition of the Committee responsible for the formulation of the standard is given in Annex F.

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 or analysis shall be rounded off in accordance with
IS 2 : 2022 ‘Rules for rounding off numerical values (second revision)’. The number of significant places retained
in the rounded off value should be the same as that of the specified value in this standard.
 IS 4990 : 2024

Indian Standard
PLYWOOD FOR CONCRETE SHUTTERING WORKS —
SPECIFICATION
( Fourth Revision )
1 SCOPE 5 MATERIALS

This standard covers the requirements of plywood 5.1 Timber

for concrete shuttering work and formwork in
construction. Any species of timber may be used for manufacturer
of plywood. It is recommended to use wood from
2 REFERENCES sources other than natural forests includes, Tree
Outside Forest (TOF), rubber, coconut, cashew,
The standards listed in Annex A contain provisions walnut, agroforestry, farm forestry, industrial and
which through reference in this text, constitute social forestry plantations, etc and shade trees from
provisions of this standard. At the time of tea and coffee estates in plywood manufacturing.
publication, the editions indicated were valid. All A list of timber species is given in Annex B for
standards are subject to revision and parties to guidance purpose. Imported timber may also be
agreements based on this standard are encouraged to used in manufacturing of plywood.
investigate the possibility of applying the most
recent edition of these standards. 5.2 Adhesives for Bonding of Veneers

3 TERMINOLOGY The adhesives used for bonding the veneers shall be

based on any suitable synthetic resin conforming to
For the purpose of this standard, the definitions BWP Grade of IS 848. Extender shall not be added
given in IS 707 shall apply. to the adhesive by the plywood manufacturer.
Addition of a dye to the adhesive to check that all
4 TYPES parts of the veneer are completely covered by
adhesive shall be permissible. Addition of a filler
4.1 Plywood for concrete shuttering work shall be not exceeding 5 percent shall be permissible
preservative treated, of BWP Grade and shall be of provided the filler does not detract from the water
three types as given below: resistance of the adhesive.

Sl No. Description Designation 6 MANUFACTURE

(1) (2) (3) 6.1 Veneers for the manufacture of plywood for
concrete shuttering works shall be either rotary cut
i) Plywood for concrete CS
or sliced, but preferably rotary cut. The veneers
shuttering work (plain)
shall be reasonably smooth to permit an even spread
ii) Plywood for concrete CSC of glue. The veneers shall be dried to a moisture
shuttering work with content in a range of 6 percent to 10 percent before
polymer coating (coated) bonding. The glue shall be evenly spread. The
iii) Plywood for concrete CSFF veneers shall then be assembled with alternate layers
shuttering work with at right angles to each other (except in the case of
suitable overlay (film even number of veneers when the two central
faced) veneers are in the same direction) and hot pressed
under controlled conditions of temperature, pressure
4.2 In terms of formaldehyde class, each type of and pressing time. The core veneers shall not have
plywood shall be further classified in two classes as open joints or splits beyond the limits prescribed
follows: in 8.2. No unglued area shall be found on
separation of the veneers.
a) Formaldehyde Class, 𝐸1
The veneers may have sound knots of diameter
b) Formaldehyde Class, 𝐸2 not exceeding 50 mm. Tight fitted patches, with

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IS 4990 : 2024

distance from one patch to the other not less than 7 DIMENSIONS AND TOLERANCES
600 mm, shall be permitted, but maximum diameter
of any patch shall not exceed 40 mm. The number 7.1 Any dimensions (length, width and thickness)
of pin-holes on face (top) veneers shall not be more and number of ply as agreed to between the
than 10 in any square metre of the surface. manufacturer and the purchaser may be used and
Discolouration may be permitted, but loose knots shall also be declared by the manufacturer.
and dry-rot shall not be permitted (see 8.1). Prevailing dimensions (length × width) of plywood
boards are as given below:
6.2 The thickness of all individual veneers shall be
uniform with a variation of ± 5 percent. The veneer a) 2 440 mm × 1 220 mm;
shall be straight grained within a permitted slope b) 2 135 mm × 1 220 mm;
of ± 10°.
c) 2 135 mm × 915 mm;
6.3 Corresponding veneers on either side of the d) 1 830 mm × 1 220 mm; and
central ply and those of face (top) and back (bottom) e) 1 830 mm × 915 mm.
veneers shall be of species having similar physical
and mechanical properties, such as thickness, 7.2 Thickness
density, modulus of elasticity, shrinkage, etc to
ensure balanced construction. The thickness of the plywood boards shall be 3 mm,
4 mm, 5 mm, 6 mm, 9 mm, 12 mm, 15 mm, 19 mm,
6.4 Plywood for concrete shuttering work shall be 22 mm and 25 mm.
preservative treated and bonded with BWP
Grade adhesive. When required, concrete shuttering NOTE — Any other thickness as agreed to between the
plywood may be supplied with or without any manufacturer and the purchaser may also be used.
polymer coating or suitable overlay (see 6.7
and 10.6). 7.3 Squareness and Edge Straightness

6.5 When boards of a size larger than the available Edge straightness and squareness shall be tested
press size are required, these may be made by scarf as per Annex C.
jointing the finished board, the scarf being through
the thickness of the board. 7.4 Tolerances

All scarf joints shall be bonded with adhesives The tolerances on the dimensions of finished
conforming to IS 848, having similar properties to plywood boards shall be as given in Table 1.
those used in the bond of veneers. Scarf joints
shall be made with 1 : 8 slope. Table 1 Tolerances on Dimensions of Plywood
for General Purposes
6.6 The plywood after manufacture shall be given (Clause 7.4)
a preservative treatment as given in IS 5539 and
conditioned to a moisture content not exceeding
Sl No. Dimension Tolerance
15 percent. The preservative used shall have a
copper-chrome-boron (CCB) composition or acid-
copper-chrome (ACC) composition, with retention (1) (2) (3)
of not less than 12 kg/m3. i) Length + 6 mm
– 0 mm
6.7 Plywood for concrete shuttering work with ii) Width + 3 mm
polymer coating, or with suitable overlay shall be – 0 mm
made with a surface film of phenol formaldehyde or
creosol formaldehyde resin, either carried by tissue iii) Thickness
paper or evenly spread by a mechanical spreader a) less than ± 10 percent
with resin content not less than 100 g/m2 (paper 6 mm
weight: total weight shall be at least 1 : 1.5), which b) 6 mm and ± 5 percent
is subsequently cured under heat and pressure to above
give a smooth and waterproof surface. The film iv) Squareness, Max 2 mm/1 000 mm
shall be applied on the surface of preservative or 0.2 percent
treated plywood after manufacture. The pressing
shall be such that the film uniformly melts and v) Edge straightness, 2 mm/1 000 mm
finishes into a smooth and hard surface on the Max or 0.2 percent
plywood.

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 IS 4990 : 2024

8 WORKMANSHIP AND FINISH 10.4 Glue Adhesion in Dry State

8.1 The plywood for concrete shuttering work shall 10.4.1 Glue Shear Strength
be smooth and the face (top) and back (bottom)
shall be free from discolouration, pleats, overlaps Six test specimens from each pair of glue lines shall
and loose knots. The edges shall have smooth be tested in accordance with the method described
uniform finish. in IS 1734 (Part 4). The average failing load shall
be not less than the corresponding values specified
8.2 Gaps and open joints shall be permitted as in Table 2.
follows:
10.4.2 Adhesion of Plies
a) In face (top) — The gap or opening shall
not exceed a width of 0.4 mm. If it Adhesion shall be tested by knife test method
exceeds 0.4 mm, this may be rectified by described in IS 1734 (Part 5). The adhesion of plies
well-fitted veneer inserts of suitable width may also be tested by forcibly separating the layers.
provided the grain of the veneer insert does The veneers shall offer appreciable resistance to
not deviate by more than 10 percent from separation and the fractured samples shall show
the grain direction of the surrounding some adherent fibres distributed more or less
veneer. uniformly.

b) In core (cross-band) — The width of the NOTE — If a definite result is not obtained by the method
described in IS 1734 (Part 4), the result of knife test
opening shall not exceed 1 mm in the case described in IS 1734 (Part 5) shall be considered as decisive.
of 3 ply and 5 ply, and 2 mm in the case of In case of even number of plies, where the grains of central
plywood of more than 5 ply, provided such plies follow the same direction the result as obtained from
openings are not less than 300 mm apart in knife test shall be considered as final.
any veneer and staggered not less than
150 mm between any veneer and the next 10.5 Resistance to Water Test
one with the same grain direction.
Six test pieces each approximately 250 mm × 100 mm,
8.3 The faces (top/bottom) of plywood for concrete shall be cut from any position in the board such that the
shuttering work with polymer coating, or with grains of the face veneer are parallel to the length of the
suitable overlay, shall be dense, smooth and piece. Six test specimens from each pair of glue lines
without blisters and patch marks. It shall be of shall be prepared as given in IS 1734 (Part 4). The
uniform colour. specimens shall be subjected to any one of the tests
specified in 10.5.1 and 10.5.2.
9 SAMPLING
10.5.1 The specimens shall be kept submerged
The method of drawing representative samples, horizontally in a pan of boiling water for a period of
sample size and the criteria for conformity shall be 72 h. The period of 72 h of boiling may be a
as prescribed in IS 7638. continuous period or an aggregate of smaller periods
of boiling, if the test piece is left in cold water
10 TESTS between these smaller periods. The test pieces shall
then be removed from the boiling water and cooled
10.1 The plywood shall conform to the requirements down to room temperature by plunging them in cold
given in 10.3 to 10.12. water. These test specimens, while still in wet
condition, shall be subjected to tests described
10.2 Unless otherwise specified in this standard, six under 10.5.1.1 and 10.5.1.2.
test specimens, cut from each of the plywood
selected as in 9 for tests specified in 10.3 to 10.10. 10.5.1.1 Glue shear strength
For formaldehyde content and steady-state
formaldehyde emission test, specimens shall be When tested for glue shear strength by the method
taken as per IS 13745 and IS/ISO 12460 (Part 1) described in IS 1734 (Part 4), the average failing
respectively. load shall be not less than the corresponding values
specified in Table 2.
10.3 Moisture Content
10.5.1.2 Adhesion of plies
The average moisture content of three test pieces cut
out from each board selected as in 9, when tested in Adhesion shall be tested by knife test method
accordance with IS 1734 (Part 1), shall be described in IS 1734 (Part 5). The adhesion of plies
not less than 5 percent and not more than 15 percent. may also be tested by forcibly separating the layers;

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IS 4990 : 2024

the veneers shall offer appreciable resistance to NOTE — In case a definite result is not obtainable by the
method described in IS 1734 (Part 4), the result of knife test
separation and the fractured sample shall show described in IS 1734 (Part 5) shall be considered as decisive.
some adherent fibres distributed more or less In case of even number of plies, where the grains of central
uniformly. plies follow the same direction the result as obtained from
knife test shall be considered as final.
NOTE — In case a definite result is not obtainable by
the method described in IS 1734 (Part 4), the result of 10.8 Tensile Strength
knife test described in IS 1734 (Part 5) shall be
considered as decisive. In case of even number of plies,
where the grains of central plies follow the same The tensile strength, when determined by the
direction the result as obtained from knife test shall be method described in IS 1734 (Part 9), shall comply
considered as final.
with the following requirements:

10.5.2 The specimens shall be subjected to constant a) Tensile strength shall be not less than
steam pressure for a definite duration inside a 28 N/mm2 in the direction parallel to the
vacuum steam pressure test apparatus as described grain direction of the face veneers;
in Annex D and thereafter subjected to tests as
per 10.5.1.1 and 10.5.1.2. b) Tensile strength shall be not less than
26 N/mm2 in the direction at right angles to
10.6 Plywood for concrete shuttering work with the grain direction of the face veneers; and
polymer coating or with suitable overlay (see 6.4),
c) The sum of the tensile strengths in
after being subjected to 72 h boiling, shall not show
both directions shall be not less than
any softening, checking, cracking or deterioration of
60.0 N/mm2.
the surface layer.

10.7 Mycological Test 10.9 Static Bending Strength

The test for resistance to micro-organisms shall be Three test specimens taken in each direction from
carried out by the method described in the sample of plywood, when tested in accordance
IS 1734 (Part 7). The test piece shall; with IS 1734 (Part 11) shall have an average and a
minimum individual modulus of elasticity and
a) show no appreciable signs of separation at modulus of rupture not less than the values
the edges of the veneers; and specified in Table 3.

b) comply with the requirements specified 10.10 Wet Bending Strength

in 10.7.1 and 10.7.2.
Three test specimens taken in accordance with
10.7.1 Glue Shear Strength
IS 1734 (Part 11) and from each direction of a
When tested for glue shear strength by the sample of plywood, shall be subjected to cyclic test
method described in IS 1734 (Part 4), the for 3 cycles, each cycle consisting of 4 h boiling in
average failing load shall be not less than the water and 16 h drying in an oven at 65 °C ± 2 °C or
corresponding values specified in Table 2. shall be subjected to 72 h of boiling in water. The
samples shall be then kept in water at 27 °C ± 2 °C
10.7.2 Adhesion of Plies for 1 h and thereafter tested as per IS 1734 (Part 11).
The duration of boiling/drying in oven may be split
Adhesion shall be tested by knife test method into shorter intervals by keeping the samples at
described in IS 1734 (Part 5). The adhesion of plies 27 °C ± 2 °C, in water (in case of boiling) or in air
may also be tested by forcibly separating the layers; (in case of drying). The sample shall have an
the veneers shall offer appreciable resistance to average and minimum individual modulus of
separation and the fractured sample shall show some elasticity and modulus of rupture not less than the
adherent fibres distributed more or less uniformly. values specified in Table 4.

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 IS 4990 : 2024

Table 2 Minimum Average Failing Load and Percentage Wood Failure Requirements of
Structural Plywood
(Clauses 10.4.1, 10.5.1.1 and 10.7.1)

Sl No. Average Wood Failure Average Failure Load,

N

percent Dry State Resistance to Resistance to

Water Micro-Organisms
(1) (2) (3) (4) (5)
i) No requirement ≥ 1 350 ≥ 1 000 ≥ 1 000
ii) Not less than 60 1 250 to 1 349 900 to 999 900 to 999
iii) Not less than 80 1 100 to 1 249 800 to 899 800 to 899
iv) Sample to be considered as failed < 1 100 < 800 < 800

Table 3 Average and Minimum Individual Values of Modulus of Elasticity (MOE) and Modulus
of Rupture (MOR) in Static Bending Strength

(Clause 10.9)

Sl No. Grain Direction MOE, MOR,

N/mm2 N/mm2

Average Minimum Average Minimum

Individual Individual
(1) (2) (3) (4) (5) (6)
i) Along (parallel to the grain direction of the 6 400 5 700 43 38
face veneer)
ii) Across (perpendicular to the grain direction 4 600 4 100 35 31
of the face veneer)

Table 4 Minimum Average and Minimum Individual Values of Modulus of Elasticity (MOE)
and Modulus of Rupture (MOR) for Wet Bending Strength
(Clause 10.10)

Sl No. Property Along the Across the

Face Grain Face Grain
(1) (2) (3) (4)
i) Modulus of Elasticity (MOE), N/mm2
a) Average 3 200 2 300
b) Minimum individual 2 900 2 100
ii) Modulus of Rupture (MOR), N/mm 2

a) Average 21 17
b) Minimum individual 19 15

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IS 4990 : 2024

10.11 Retention of Preservative 11 ADDITIONAL REQUIREMENTS FOR

ECO-MARK
Plywood shall be treated as per 6.6 and shall have a
retention of not less than 12 kg/m3, when tested in 11.1 General Requirements
accordance with IS 2753 (Part 1).
11.1.1 The plywood shall conform to the
10.12 Formaldehyde Content Test requirements of quality and performance as
specified in this standard.
Test of free formaldehyde content in the sample
shall be done by perforator method as per IS 13745 11.1.2 The manufacturer shall produce to Bureau
and test results of drawn sample shall meet the of Indian Standards environmental consent
requirements of formaldehyde content as follows: clearance from the concerned State Pollution
Control Board as per the provisions of the Water
a) Formaldehyde < 8 mg/100 g of oven dry (Prevention and Control of Pollution) Act, 1974
Class, 𝐸1 sample; and and Air (Prevention and Control of Pollution) Act,
1981 and Water (Prevention and Control of
b) Formaldehyde > 8 mg/100 g of oven Pollution) Cess Act, 1977 along with the
Class, 𝐸2 dry sample and authorization, if required under the Environment
< 30 mg/100 g of oven (Protection) Act, 1986, while applying for
dry sample. ECO-Mark appropriate with enforced Rules
and Regulations of Forest department.
10.13 Steady-State Formaldehyde Emission Test
11.2 Specific Requirements
(Optional Test)
The plywood shall conform to the
Manufacturer will offer a stack of plywood made
specific requirements given for ECO-Mark under
under a batch (not less than 50 pieces) bearing the
relevant clauses of the standard.
batch number and date of manufacture along with
details of plywood that is grade, size and thickness, NOTE — The manufacturer shall provide documentary
adhesive used and any other (the manufacture wish evidence by way of certificate or declaration to Bureau of
to inform). After sampling, the sample shall be Indian Standards while applying for ECO-Mark.
immediately covered in airtight polythene with date
12 MARKING
of sampling on the plywood.
12.1 Each plywood shall be legibly and indelibly
Sample must be taken for test within 24 h of opening
marked or stamped with the following:
the airtight cover and within one month from the
date of sampling and test shall be done by the test a) Manufacturer’s name or its initials or his
method as given in IS/ISO 12460 (Part 1). The test recognized trade-mark, if any;
results of drawn sample shall meet the requirements b) Words ‘PLYWOOD FOR SHUTTERING
of formaldehyde emission value as follows: WORKS’;
a) Formaldehyde Class, 𝐸1 < 0.124 mg/m3; c) Designation of plywood (see 4.1) and
and Formaldehyde Class;

b) Formaldehyde Class, 𝐸2 > 0.124 mg/m3. d) Nominal length, width and thickness of
plywood;
10.14 Re-test e) Month and year of manufacture;
f) Batch No.; and
If any specimen fails to fulfil the test requirements
specified under 10.3 to 10.12, a further two sets of g) Criteria for which the plywood has been
samples on the basis prescribed in 9 shall be labelled as ECO-Mark (if applicable).
selected by the purchaser from the same batch and
tested in the same manner. Test specimens 12.2 Following additional information may be
prepared from these two further samples shall marked on each plywood:
comply with the requirements specified in 10,
otherwise the batch shall be rejected. a) Number of plies; and

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 IS 4990 : 2024

b) Trade name of timber species used in 14 INFORMATION TO BE SUPPLIED BY

manufacturing of plywood (see IS 1150). THE MANUFACTURER

12.3 BIS Certification Marking The manufacturer shall supply on demand to the
purchaser full technical data and recommended
The product(s) conforming to the requirements of method of use and loading. This information shall
this standard may be certified as per the conformity cover in particular the following:
assessment schemes under the provisions of the a) Type of preservative used;
Bureau of Indian Standards Act, 2016 and the
Rules and Regulations framed there under, and the b) Radii to which the plywood of given
products may be marked with the Standard Mark. dimensions is recommended as bendable
for architectural concrete work;
13 DELIVERY c) Loading and deflection tables for the
purpose of calculating the supports, that is,
Unless otherwise specified, the plywood boards the sizes of bearers and distances of
shall be delivered in a clean condition and shall be bearers;
suitably packed according to normal trade. For
d) Density or mass per square metre of the
ECO-Mark the material used for packaging of the
plywood; and
plywood shall be recyclable, reusable or
biodegradable. e) Species of timber.

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IS 4990 : 2024

ANNEX A
(Clause 2)

LIST OF REFERRED STANDARDS

IS No. Title IS No. Title

IS 707 : 2011 Timber technology and IS 2753 (Part 1) : Methods for estimation of
utilization of wood, bamboo 1991 preservatives in treated
and cane — Glossary of timber and in treating
terms (third revision) solutions: Part 1
Determination of copper,
IS 848 : 2006 Synthetic resin adhesives for arsenic, chromium, zinc,
plywood (phenolic and boron, creosote and fuel oil
aminoplastic) — Specification (first revision)
(second revision)
IS 5539 : 1969 Specification for preservative
IS 1150 : 2000 Trade names and abbreviated
treated plywood
symbols for timber species
(third revision) IS 7638 : 1999 Wood/lignocellulosic based
IS 1734 Methods of test for plywood: panel products — Methods of
sampling (second revision)
(Part 1) : 1983 Determination of density and
moisture content (second IS/ISO 12460-1 : Wood based panels —‒
revision) 2007 Determination of
formaldehyde release: Part 1
(Part 4) : 1983 Determination of glue shear Formaldehyde emission by
strength (second revision) the 1-cubic-metre chamber
(Part 5) : 1983 Test for adhesion of plies method
(second revision)
IS 13745 : 2020 Method for determination of
(Part 7) : 1983 Mycological test (second formaldehyde content in
revision) wood-based panels by
extraction method called
(Part 11) : 1983 Determination of static perforator method (first
bending strength (second
revision)
revision)

To access Indian Standards click on the link below:

https://www.services.bis.gov.in/php/BIS_2.0/bisconnect/knowyourstandards/Indian_standards/isdetails/

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 IS 4990 : 2024

ANNEX B
(Clause 5.1)
LIST OF PREVALENT TREE OUTSIDE FOREST (TOF) SPECIES FOR PLYWOOD

Sl No. Botanical Name Trade Name Abbreviation

(1) (2) (3) (4)

i) Acrocarpus fraxinifolius Mundani MUN
ii) Ailanthus spp. Maharukh MAH
iii) Albizia chinensis Merr. Siris SIR
iv) Alstonia scholaris Chatian CHT
v) Anacardium occidentale Cashew CAH
vi) Bischofia javanica Uriam URI
vii) Chukrasia tabularis Chickrassy CHI
viii) Delonix spp. Gulmohur GUM
ix) Duabanga grandiflora Lampati LAP
x) Eucalyptus Eucalyptus EUC
xi) Grevillea robusta Silver oak SOA
xii) Hevea brasiliensis Rubber wood RUB
xiii) Khaya spp. Lambu LAB
xiv) Leucaena leucocephala Subabul SUB
xv) Macaranga spp. Vatta MCR
xvi) Maesopsi seminii Umbrella tree UMB
xvii) Melia azedarach Linn. Bakain PLI
xviii) Melia composita/dubia Malabar neem MNE
xix) Neolamarckea cadamba Kadam KAD
xx) Pinus spp. Pine PNE
xxi) Populus spp. Poplar POP
xxii) Samanea saman Saman SAM
xxiii) Toona ciliata Toon TOO
xxiv) Swietenia spp. Mahogony MAG

ANNEX C
(Clause 7.3)

METHOD OF TEST FOR EDGE STRAIGHTNESS AND SQUARENESS

C-1 PROCEDURE FOR EDGE STRAIGHTNESS nearest millimetre and recorded.

The straightness of the edges and ends of plywood C-2 PROCEDURE FOR SQUARENESS
shall be verified against a straight edge not less than
the full length of the plywood. If the edge on the end The squareness of plywood shall be checked with
of plywood is convex, it shall be held against the a 1 200 mm × 1 200 mm square, by applying, one
straightedge in such a way as to give approximately arm of the square to the plywood. The maximum
equal gap at each end. The largest gap between the width of the gap shall be recorded.
straightedge and the edge shall be measured to the

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IS 4990 : 2024

ANNEX D
(Clause 10.5.2)

ALTERNATE METHOD FOR WATER RESISTANCE TEST

D-1 Pure water shall be filled in the boiler of the chamber, the vacuum pump shall be switched off,
vacuum steam pressure test (VPT) apparatus as the vacuum inlet valve closed and boiler valve
shown in Fig. 1 to the marking of minimum water connected to main chamber opened. The time shall
level on glass water level indicator and the boiler be noted the moment the steam pressure in the main
shall be switched on with the valve connecting the +10
chamber reaches 220 kPa and same pressure
boiler and main chamber in closed condition. The −0
test specimen(s) shall be placed in the working shall be maintained for 6 h. The system and boiler
(main) chamber and shall be closed air tight with then shall be switched off. The steam release valve
cover. The vacuum pump shall then be switched and vacuum release value shall slowly be opened
on and vacuum inlet valve shall be kept in open until the steam in the chamber is completely
condition. The steam release valve shall be kept in evacuated. The samples shall then be kept in water
closed condition. After the required vacuum of for 1 h at 27 °C ± 2 °C. The samples shall
+10 thereafter be tested as per 10.5.1.1 and 10.5.1.2.
110 kPa has been created inside the main
−0

FIG. 1 TYPICAL SKETCH OF VACUUM STEAM PRESSURE TEST (VPT) APPARATUS

10
 IS 4990 : 2024

ANNEX E
(Foreword)
RECOMMENDED METHOD OF HANDLING, STORING AND USE OF PLYWOOD FOR
CONCRETE SHUTTERlNG AND FORM WORK

E-1 GENERAL The plywood panels shall not be dragged,

particularly those supplied with polymer coating or
E-1.1 Plywood for concrete shuttering work is a with suitable overlay over one another as this would
preservative treated, BWP-bonded plywood and has scratch the surface if the edges are dragged on faces
its economy in use for concrete shuttering because or any extraneous matter like sand or small stone
of its re-use value. It is claimed that concrete particles lie in between the surfaces.
shuttering plywood is capable of being re-used many
times. However, the re-use value of the plywood E-3 OILING THE SURFACE
depends on the care taken in handling the boards and
following the manufacturer’s instructions. Plywood for concrete shuttering work gives much
longer service life if the surfaces are coated with
E-1.2 Another important advantage claimed for suitable mould oil which acts both as a parting agent
plywood for concrete shuttering works is that it and also gives surface protection. The mould oil for
gives to the concrete work smooth surface, requiring use in coating of the plywood should have the
very little additional plastering. The retention of this following basic characteristics:
quality of plywood again depends on the care taken
during use. Cleaning of the surface of the plywood a) It shall be a solution of preservative in a
and oiling occasionally, go a long way in increasing heavy mineral oil with a viscosity of
the life of the plywood. The large sized panels in 70 centipoise to 80 centipoise; and
which the plywood is available increases economy,
but only if nails and screws are fixed carefully and b) It shall be free from dark and other
not allowed to unduly damage the plywood. suspended particles and shall be of light
Plywood for concrete shuttering has an advantage grey colour.
over steel sheeting in very hot or very cold climatic
conditions as the external heat or cold does not Some manufacturers supply the boards already
penetrate through plywood as it does in case of metal shop-coated with mould oil. After 3 to 4 uses and
sheeting. also in cases when plywood has been stored for a
long time, it should be re-coated with mould oil
E-2 RECEIVING AND STORING before the next use.

E-2.1 At the time of dispatch from the factory, the Cut edges of the plywood at the time of making
plywood panels shall be carefully loaded to prevent concrete former should also be coated with suitable
any damage. Extra care should be taken in the case sealants like chlorinated rubber paint, for longer life
of coated and film faced plywood to avoid any of the board.
scratches. Preferably a sheet of thick water proof
paper/polythene sheet may be inserted between the E-4 DRYING OF PANELS
two surfaces to prevent scratches. The plywood
should be properly secured and covered with The plywood for concrete shuttering work may be
tarpaulin to ensure delivery to destination in clean used repeatedly. However, if it has to be stored for
and serviceable condition. a long time after one use, the panels should be dried
by stacking in free circulation of air and on suitable
E-2.2 The plywood panels shall be unloaded spacers before storage.
carefully from the carrier truck or wagon. These
shall be lifted, carried and stacked in a careful E-5 DESIGN DATA
manner to avoid damage to the corners of surfaces.
These shall be stored in packs on a level, flat and E-5.1 The following data are generally applicable to
raised surface in a clean, dry and covered place with plywood for concrete shuttering work. However, as
free circulation of air. The boards and stacks shall the species of timber used vary from manufacturer
be protected from rain and dampness. The edges of to manufacturer and with that the density and
a board in a pack shall be in a straight vertical line. strength, the instructions of the manufacturers would
The top of the stack shall be covered with a cover be helpful for individual cases.
board and weighed down suitably.

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IS 4990 : 2024

E-5.1.1 Mass E-5.3 Bending Radii

Generally, density of plywood for concrete The following are approximately the minimum
shuttering work may be taken as 650 kg/m3. bending radii for plywood for concrete shuttering
work, when dry:
The mass per square metre in various thickness is
given below: Sl Thickness Across the Parallel with
No. Group of the Group of
Sl No. Thickness Mass the Outer the Outer
mm kg/m2 Plies Plies
(1) (2) (3) mm m m
i) 6 3.90 (1) (2) (3) (4)
ii) 9 5.85 i) 6 0.90 1.25
iii) 12 7.80 ii) 9 1.65 2.15
iv) 19 12.35 iii) 12 2.55 3.30
v) 25 16.25
NOTE — When in wet condition, the mass may increase E-5.3.1 Plywood without any polymer coating or
by 30 percent or more. The accuracy of the above mass suitable overlay may be bent to still smaller radii by
can be taken only within a tolerance of ± 10 percent
because of varying species and also variation in the
soaking in cold or hot water (temperature up to
moisture content. 70 °C) before fixing.
E-5.2 Loading and Deflection E-5.4 Fixing
Taking the maximum permitted deflection as 1 : 270 It is advised that, wherever possible, screws or nuts
(that is 1/270th of the span between the bearers), the and bolts are used for fixing. While handling,
following load per square meter, in kg/m2, are scratching by screws, nuts and bolts or other metal
arrived at; the maximum load permitted is given fixtures should be avoided. This is particularly so in
provided that the face grain of the plywood is case of plywood with polymer coating or with
perpendicular to the length of bearers: suitable overlay.

Sl Centre Distance 9 mm 12 mm E-6 CONSTRUCTION

No. of Bearers (Span) Thickness Thickness
mm kg/m2 kg/m2 E-6.1 Concrete shuttering formers for columns,
(1) (2) (3) (4) piers, walls and other vertical surfaces are usually
i) 300 1 270 1 950 made from the plywood by fixing the same on to a
backing framework of timber or iron. The timber
ii) 400 540 850 frame members can be joined end to end by butt joint
iii) 450 320 640 or lap joint or mitred joint. The shuttering plywood
should be screwed or nailed to the framework.
iv) 600 170 360 When designing the formers, these shall be made in
the form of shooks to be joined side to side by
E-5.2.1 When the face grain of plywood is parallel suitable nuts and bolts spaced at suitable distances.
to the bearers, the permissible load may be as This would permit easy assembly and dismantling of
follows: the former and reassembling for second use. Steel
frameworks may be of angled iron or channel
Sl Centre Distance 9 mm 12 mm section suitably fabricated and braced to which
No. of Bearers (Span) Thickness Thickness shuttering plywood can be fixed either by nuts and
mm kg/m2 kg/m2 bolts or by screws, the latter driven from the steel
frame side. As an illustration, a concrete former box
(1) (2) (3) (4)
for a column is made in the form of four shooks or
i) 300 760 1 220 frames one for each side. The plywood is so fixed
ii) 400 320 540 on to the timber or steel framework that it gives a
iii) 450 195 390 flush surface on the inside. The four-side frames are
iv) 600 110 170 assembled into box form by use of nuts and bolts at
NOTES appropriate distances, where holes have been drilled
earlier. After the concrete is poured and kept for the
1 The above loads apply when the concrete is laid on
concrete shuttering plywood as in slabs and beams. The prescribed time, the former can be disassembled by
same thickness of concrete in a wall can be held without opening the nuts and bolts fixed on the sides and
excess deflection by thinner boards. reassembled or refixed for the second use with the
2 The maximum loads should be reduced to 75 percent, if same nuts and bolts.
wet boards are used.

12
 IS 4990 : 2024

E-6.2 Concrete formers for concrete walls or other E-6.7 Many users use thin sheets of plywood for
broad vertical surface works may be similarly made concrete shuttering as linings over conventional
in the form of wood or iron frames fixed with timber shuttering. The advantage gained by this is,
shuttering plywood panels. The two wide side primarily, a uniform, smooth surface on the concrete
surfaces on the two sides of a wall can be further work. Care should be taken in such cases that the
secured to avoid a sag at intermediate places by use level of timber battens is reasonably correct to take
of nut and bolts through the concrete. This would the maximum advantage of getting a uniform and
keep the former frames from spreading out. Such smooth surface finish of concrete work.
intermediate nuts and bolts may be removed after
48 h of concrete pouring and the hole in the wall E-6.8 When used for architectural concrete and
later on plugged with concrete. The bolts may also curved forms, the data given in E-5.3 should be
be left in and later on cut out at the protruding used to design the curved surfaces of the formers.
portions. An alternative method would be the
provision of well-designed additional supports and E-6.9 When removing concrete formers or sheets,
props outside. Formers, if required on one side only care should be taken to carry out the parting, sliding
of a wall as in underground tanks and sewers, should and lowering carefully to avoid damage.
be similarly made and suitably supported.
E-6.10 Plywood supplied with suitable overlay
E-6.3 In case of concrete slabs, the concrete requires handling with special care to avoid
shuttering plywood may be laid without any scratching of the surface as scratches on the surface
framework on suitable bearers and be assembled take away the advantage of surface overlay. The
side by side with suitable fixing cleats to avoid any sheets after each use shall be cleaned off of any
ridge formation in the concrete work at the joint. sticking sand or aggregate.
Dismantling may be done by carefully removing the
props and beams from one side. Some users prefer E-7 PRECAUTIONS
use of backing frame work even for horizontal slabs
and beams. Backing framework may be made of E-7.1 After work at one site is over, the plywood
wood or steel. used should be dried and sent to stores, or taken for
re-use elsewhere. If a builder has finished work
E-6.4 For concrete beams, box formers are made and does not want to store the plywood for long,
as in E-6.1 and then suitably supported by props. the same could be disposed off to another builder
for shuttering work or may be used as plywood of
E-6.5 Some users use steel framework into which non-decorative type for general purpose.
plywood may be slid just in the same way as pressed
steel shuttering sheets. The plywood for use as E-7.2 There is a tendency in builders to cut plywood
shuttering in such cases should be cut to the size of to shorter sizes for convenient handling. This should
the recess or to the required shape and rested into the be discouraged as the greatest advantage of plywood
position like shuttering steel sheets. for concrete shuttering is in its availability in large
sizes leading to smooth ridge-free concrete work,
E-6.6 The supporting structure for the plywood thus saving in the expenses of elaborate plastering.
shuttering should be adequately strong. The design
data given under E-5.2 provides some guidance to
design these supports.

13
IS 4990 : 2024

ANNEX F
(Foreword)
COMMITTEE COMPOSITION
Wood and Other Lignocellulosic Products Sectional Committee, CED 20

Organization Representative(s)

Institute of Wood Science & Technology, Bengaluru DR M. P. SINGH (Chairperson)

Balaji Action Buildwell, New Delhi SHRI RAJESHWAR NAIR

SHRI VIVEK JAIN (Alternate)

Bamboo Society of India, Bengaluru SHRI PUNATI SRIDHAR

DR S. R. SHUKLA (Alternate I)
DR JAGADISH VENGALA (Alternate II)

Central Building Research Institute, Roorkee SHRIMATI HEMALATA

DR JEESHAN KHAN (Alternate I)
SHRI PRASANTA KAR (Alternate II)

Central Institute of Coir Technology, Bengaluru DR O. L. SHANMUGASUNDARAM

SHRIMATI SUMY SEBASTIAN (Alternate)

Central Public Works Department, New Delhi CHIEF ENGINEER (CSQ)

SUPERINTENDENT ENGINEER (TAS) (Alternate)

Century Plyboard India Ltd, Kolkata SHRI AJAY BALDAWA

SHRI JAGANNATH DAS (Alternate)

CSIR - Advance Materials and Processes Research DR ASOKAN PAPPU

Institute (AMPRI), Bhopal

Federation of Indian Plywood & Panel Industry, DR C. N. PANDEY

New Delhi SHRI JAYDEEP CHITLANGIA (Alternate)

Greenpanel Industries Limited, Tirupati SHRI SUBHASH KUMAR AGARWAL

DR PURSHOTTAM (Alternate)

Greenply Industries Ltd, Kolkata SHRI ARABINDA SAHA

Institute of Wood Science & Technology, Bengaluru SHRI ANAND NANDANWAR

MS SUJATHA D. (Alternate)

Mutha Industries, Agartala SHRI NEERAJ MUTHA

SHRI ANIL MUTHA (Alternate)

National Test House, Kolkata DR SOMIT NEOGI

SHRI S. PANERIA (Alternate)

The South Indian Plywood Manufacturers SHRI MOIZ VAGH

Association, Chennai

The Western India Plywood Limited, Kannur SHRI P. K. MAYAN MOHAMED

DR E. SREENIVASAN (Alternate)

Timpack Private Limited, Byrnihat SHRI INDER PAL SINGH BHUSRI

SHRI ANGAD SINGH BHUSRI (Alternate)

14
 IS 4990 : 2024

Organization Representative(s)

Wood Technology Association, Yamuna Nagar SHRI S. C. JOLLY

BIS Directorate General SHRI ARUNKUMAR S., SCIENTIST ‘E’/DIRECTOR AND

HEAD (CIVIL ENGINEERING) [ REPRESENTING
DIRECTOR GENERAL (EX-officio)]

Member Secretary
SHRI PRADEEP SINGH SHEKHAWAT
SCIENTIST ‘D’/JOINT DIRECTOR
(CIVIL ENGINEERING), BIS

Plywood, Veneers and Adhesives for Wood Products Subcommittee, CED 20:1

Organization Representative(s)

Institute of Wood Science and Technology, MS SUJATHA D. (Convener)

Bengaluru

Allied Resins and Chemicals Limited, Kolkata SHRI RAJESH MUNDRA

SHRI ASHIM KUMAR DAS (Alternate)

Central Public Works Department, New Delhi CHIEF ENGINEER (CSQ)

SUPERINTENDENT ENGINEER (TAS) (Alternate)

Defence R&D Organization, Kanpur DR D. N. TRIPATHY

Directorate of Standardisation, Ministry of SHRI V. K. CHHABRA

Defence, DTE of Standardization Government, SHRI S. K. SAXENA (Alternate)
New Delhi

Federation of Indian Plywood and Panel Industry, SHRI C. N. PANDEY

New Delhi SHRI JAYDEEP CHITLANGIA (Alternate)

Forest Research Institute (FRI), Dehradun DIRECTOR

Greenply Industries Limited, Kolkata SHRI ARABINDA SAHA

Hunsur Plywood Works Private Limited, Hunsur SHRI MOIZ VAGH

Institute of Wood Science and Technology, DR NARSIMHAMURTHY

Bengaluru

Kanara Wood & Plywoods Industries Limited, SHRI P. H. G. REDDY

Mangaluru SHRI Y. MOHAMMED FARHAAD (Alternate)

National Test House, Kolkata SHRI SOMIT NEOGI

SHRI S. PANERIA (Alternate)

Nuchem Limited, New Delhi SHRI SUDEV BARAR

SHRI ARUSH BARAR (Alternate)

Sarda Plywood Industries Limited, Kolkata SHRI SUNDEEP CHITLANGIA

SHRI S. L. YADAV (Alternate)

15
IS 4990 : 2024

Organization Representative(s)

The South Indian Plywood Manufacturers SHRI MOIZ VAGH

Association, Mysuru

The Western India Plywood Limited, Kannur SHRI P. K. MAYAN MOHAMED

DR E. SREENIVASAN (Alternate)

In Personal Capacity (S-9, Sangath Alarcity Flats, DR R. N. KUMAR

M.G.R. Nagar, Second Main Road, Velachery,
Chennai)

In Personal Capacity (House No. 12, HIG, 1st Stage, SHRI S. S. ZOOLAGUD
K.H.B. Colony, Basaveswara Nagar,
Bangaluru)

16
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