Bsi bs en 00635 3 1995 (1999)

BRITISH STANDARD

BS EN
635-3:1995
Incorporating
Amendment No. 1

Plywood —
Classification by
surface appearance —
Part 3: Softwood

The European Standard EN 635-3:1995 has the status of a
British Standard

ICS 79.060.10


BS EN 635-3:1995

Committees responsible for this
British Standard
The preparation of this British Standard was entrusted to Technical
Committee B/541, Wood based panels, upon which the following bodies were
represented:
APA/Engineered Wood Association
Association of British Plywood and Veneer Manufacturers
British Woodworking Federation
Council of the Forest Industries of British Columbia
Department of the Environment (Building Research Establishment)
Finnish Plywood International

Flat Roofing Contractors’ Advisory Board
Forestry Commission
Furniture Industry Research Association
Institution of Structural Engineers
Local Authority Organizations
Mineral Bonded Board Products Federation
National Federation of Roofing Contractors
National House-Building Council
National Panel Products Association
Royal Institute of British Architects
Structural Board Association
Timber Research and Development Association
Timber Trade Federation
Wood Panel Industries Federation
Zurich Municipal Building Guarantee
Co-opted members

This British Standard, having
been prepared under the
direction of the Sector Board
for Building and Civil
Engineering, was published
under the authority of the
Standards Board and
comes into effect on
15 December 1995
© BSI 07-1999
The following BSI references
relate to the work on this
standard:

Committee reference B/541
Draft for comment 92/11488 DC
ISBN 0 580 24772 4

Amendments issued since publication
Amd. No.

Date

Comments

9125

June 1996

Indicated by a sideline in the margin


BS EN 635-3:1995

Contents
Committees responsible
National foreword
Foreword
Text of EN 635-3
List of references

© BSI 07-1999

Page

Inside front cover
ii
2
3
Inside back cover

i


BS EN 635-3:1995

National foreword
This British Standard has been prepared by Technical Committee B/541 and is
the English language version of EN 635-3:1995, Plywood — Classification by
surface appearance — Part 3: Softwood, published by the European Committee
for Standardization (CEN). EN 635-3 was produced as a result of international
discussions in which the United Kingdom took an active part.
BS EN 635-1, BS EN 635-2 and BS EN 635-3 together supersede BS 6566-6:1985,
which will be withdrawn in accordance with CEN provisions within 6 months of
completion of the full package of standards covering plywood and related test
methods. These standards are:
EN 310

EN 325

EN 313-1

EN 635-1

EN 313-2

EN 635-2

EN 314-1

EN 635-3

EN 314-2

EN 636-1

EN 315

EN 636-2

EN 322

EN 636-3

EN 323

EN 1072

EN 324-1

EN 1084

EN 324-2
The method of classification used in BS EN 635-2 and BS EN 635-3 is similar to
that of BS 6566-6:1985. But although the appearance classes in BS EN 635-2 and

BS 635-3 are identified as E, I, II, III and IV, these classes do not correspond
exactly to the appearance classes E, I, II, III and IV of BS 6566-6. The BS EN 635
standards are thus not technically equivalent to BS 6566-6.
Cross-references
Publication referred to

Corresponding British Standard

EN 635-1:1994

BS EN 635 Plywood — Classification by surface
appearance
Part 1:1995 General

NOTE EN 635-3 makes informative references to EN 636-1, EN 636-2 and EN 636-3 which are
currently in preparation.

A British Standard does not purport to include all the necessary provisions of a
contract. Users of British Standards are responsible for their correct application.
Compliance with a British Standard does not of itself confer immunity
from legal obligations.

Summary of pages
This document comprises a front cover, an inside front cover, pages i and ii,
the EN title page, pages 2 to 8, an inside back cover and a back cover.
This standard has been updated (see copyright date) and may have had
amendments incorporated. This will be indicated in the amendment table on the
inside front cover.
ii

© BSI 07-1999


EUROPEAN STANDARD

EN 635-3

NORME EUROPÉENNE
May 1995

EUROPÄISCHE NORM
ICS 79.060.10

Descriptors: Wood board, plywood, coniferous timber, classifications, appearance, defects

English version

Plywood — Classification by surface appearance —
Part 3: Softwood

Contreplaqué — Classification selon l’aspect
des faces — Partie 3: Bois résineux

Sperrholz — Klassifizierung nach dem
Aussehen der Oberfläche — Teil 3: Nadelholz

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This European Standard was approved by CEN on 1995-04-14. CEN members
are bound to comply with the CEN/CENELEC Internal Regulations which

stipulate the conditions for giving this European Standard the status of a
national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any
CEN member.
This European Standard exists in three official versions (English, French,
German). A version in any other language made by translation under the
responsibility of a CEN member into its own language and notified to the
Central Secretariat has the same status as the official versions.
CEN members are the national bodies of Austria, Belgium, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.

CEN
European Committee for Standardization
Comité Européen de Normalisation
Europäisches Komitee für Normung
Central Secretariat: rue de Stassart 36, B-1050 Brussels
© 1995 All rights of reproduction and communication in any form and by any means reserved in all
countries to CEN and its members
Ref. No. EN 635-3:1995 E


EN 635-3:1995

Foreword
This European Standard has been prepared by the
Technical Committee CEN/TC 112, Wood-based
panels, of which the secretariat is held by DIN.
This standard is one of a series of standards for the

classification of plywood by surface appearance. The
other Parts of this series are listed in clause 2
and Annex A.
This European Standard shall be given the status of
a national standard, either by publication of an
identical text or by endorsement, at the latest by
November 1995, and conflicting national standards
shall be withdrawn at the latest by November 1995.
According to the CEN/CENELEC Internal
Regulations, the following countries are bound to
implement this European Standard: Austria,
Belgium, Denmark, Finland, France, Germany,
Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden,
Switzerland and United Kingdom.

Contents
Foreword
1 Scope
2 Normative references
3 Classification by surface appearance
3.1 Appearance classes
3.2 Permissible characteristics and defects
Annex A (informative) Bibliography
Table 1 — Classification according to
characteristics inherent in wood
Table 2 — Classification according to
manufacturing defects

Page

2
3
3
3
3
3
7
4
6

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2

© BSI 07-1999


EN 635-3:1995

1 Scope

3 Classification by surface appearance

This European Standard specifies the nature and
limits of characteristics inherent in wood and
manufacturing defects enabling the visual
assessment of the plywood for allocation to an
appearance class. This classification is a
contribution to assessing the finishing suitability of
plywood.

This Part of EN 635 applies to plywood, the surface
veneers of which are made from softwood species. It
does not apply to overlaid panels.

3.1 Appearance classes

2 Normative references
This European Standard incorporates by dated or
undated reference, provisions from other
publications. These normative references are cited
at the appropriate places in the text and the
publications are listed hereafter. For dated
references, subsequent amendments to or revisions
of any of these publications apply to this European
Standard only when incorporated in it by
amendment or revision. For undated references the
latest edition of the publication referred to applies.
EN 635-1, Plywood — Classification by surface
appearance — Part 1: General.

Assessment of characteristics and defects for
determination of appearance class shall be carried
out in accordance with EN 635-1. Surface
classification shall be based on the permissible
characteristics and defects within each of the
appearance classes as specified in 3.2.
NOTE Guidance on selection of finishing for each appearance
class is given in ENV 635-4.

3.2 Permissible characteristics and defects

Each surface shall be individually assigned to one of
the appearance classes E, I, II, III, IV, as defined by
the permissible characteristics and defects
indicated in Table 1 and Table 2.

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© BSI 07-1999

3


Table 1 — Classification according to characteristics inherent in wood
Categories of characteristics

Appearance class
E

3.2.1.1 Pin knots

a

3.2 1.2 Sound intergrown knots

Practically
absent

I

3/m2

II

III

IV

Permitted

Permitted up to an individual diameter of:
15 mm provided their
50 mm
60 mm
cumulative diameter does not
exceed 30 mm/m2
Such knots may have splits provided they are
very slight
slight
3.2.1.3 Unsound or non-adhering knots
Permitted up to an individual diameter of:
and knot holes
6 mm if filled and up to a
5 mm if unrepaired, 40 mm
number of 2/m2
25 mm if filled and up
to a number of 6/m2
3.2.1.4 Splits
Open
Permitted if less than:
1/10

1/3
1/2
of panel length
up to an individual width of:
3 mm
10 mm
15 mm
and up to a number of:
3/m
3/m
3/m
of panel width
if properly filled
All splits greater
than 2 mm in width to
be filled
Closed
Permitted
3.2.1.5 Anomalies due to insects, marine Not permitted Not permitted
Marks of parasitic plants not permitted.
borers, and parasitic plants
Insects and marine borer holes permitted
up to a:
diameter of 3 mm
width up
vertically to the plane to 15 mm and a
of the panel up to a
length of 60 mm
number of 10/m2
up to a number

of 3/m2

EN 635-3:1995

4

3.2.1 Classification according to characteristics inherent in wood

Permitted but
see note

Permitted but
see note
Length
unlimited

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25 mm

unlimited

Permitted but
see note

© BSI 07-1999


© BSI 07-1999

Table 1 — Classification according to characteristics inherent in wood

Categories of characteristics

Appearance class
E

3.2.1.6

Resin pockets and inbark

Not permitted Not permitted

Resin streaks
3.2.1.7 Irregularities in the structure of
the wood

I

Not permitted
Practically
absent

3.2.1.8 Discoloration which is not wood
destroying

II

Permitted up to a width of:
6 mm if properly filled

40 mm

Permitted is slight

Permitted

Permitted
if very slight

Not permitted Not permitted

3.2.1.10 Other characteristics

Practically
absent

IV

Permitted but
see note

Permitted
if slight

Permitted if low contrast

3.2.1.9 Fungal decay, wood destroying

III

Permitted

To be considered under the category which they most closely resemble

NOTE Characteristics inherent to the wood are permitted provided that they do not impair the serviceability of the panel.
a
Pin knots: sound intergrown knots of no more than 3 mm diameter.

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EN 635-3:1995

5


Table 2 — Classification according to manufacturing defects
Categories of defects

Appearance class
E

3.2.2.1

Open joints

Not permitted

I

Not permitted

3.2.2.2

Over laps

Not permitted

3.2.2.3
3.2.2.4
3.2.2.5
3.2.2.6

Blisters
Hollows, imprints and bumps
Roughness
Sanding through

Not permitted
Not permitted
Not permitted
Not permitted

3.2.2.7

Glue penetration

II

III

Permitted up to a width of:

3 mm
10 mm
and up to a number of:
1/m
2/m
of panel width with joints
filled if more
unfilled
than 1 mm in width
Permitted up to a
Permitted up to a
2
number of 1/m and
number of 2/m2
up to 100 mm length

IV

25 mm
unlimited
unfilled
Permitted but
see note

Permitted if slight
Permitted if slight

Permitted
Permitted
Permitted up to an extent of:

1%
5%
(but see note)
of panel surface
Not permitted Permitted
Permitted but
see note
if slight and
up to an extent
occasional
of 5 % of the
panel surface
Not permitted Not permitted Ferrous particles not permitted
Practically
Permitted if properly made and tightly filled up to a number of:
without defects 5/m2
unlimited

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Foreign particles
Repairs
a) Patches
b) Shims
Not permitted Not permitted Permitted with limits of the category it
Unlimited
most
closely
resembles
c) Synthetic fillers

3.2.2.10 Defects at the edges of the panel due to Practically
Permitted up to:
Permitted but
sanding or sawing
without defects 2 mm
see note
5 mm
5 mm
from the edge
3.2.2.11 Other defects
To be considered under the category which they most closely resemble
3.2.2.8
3.2.2.9

© BSI 07-1999

NOTE

EN 635-3:1995

6

3.2.2 Classification according to manufacturing defects

Manufacturing defects are permitted provided that they do not impair the serviceability of the panel.


EN 635-3:1995

Annex A (informative)

Bibliography
EN 313-1, Plywood — Classification and terminology — Part 1: Classification.
EN 313-2, Plywood — Classification and terminology — Part 2: Terminology.
EN 635-1, Plywood — Classification by surface appearance — Part 1: General.
EN 635-2, Plywood — Classification by surface appearance — Part 2: Hardwood.
ENV 635-4, Guideline — Plywood — Classification by surface appearance — Part 4: Parameters of ability
for finishing1).
EN 636-1, Plywood — Specifications —
Part 1: Requirements for plywood for use in dry conditions.
EN 636-2, Plywood — Specifications — Part 2: Requirements for plywood for use in humid conditions.
EN 636-3, Plywood — Specifications — Part 3: Requirements for plywood for use in exterior conditions.

1)

At present at the draft stage.

© BSI 07-1999

7


8

blank


BS EN 635-3:1995

List of references
See national foreword.

© BSI 07-1999


BS EN
635-3:1995

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