BRITISH STANDARD BS EN 314-2:1993

Plywood — Bonding quality —

Part 2: Requirements

The European Standard EN 314-2:1993 has the status of a British Standard

UDC 674.03-419.3:621.792:620.176

BS EN 314-2:1993

This British Standard, having been prepared under the direction of the Technical Sector Board for Building and Civil Engineering (B/-), was published under the authority of the Standards Board and comes into effect on15 April 1993

© BSI 09-1999

The following BSI references relate to the work on this standard:Committee reference B/541Draft for comment 90/15588 DC

ISBN 0 580 21036 7

Cooperating organizations

The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries:

Austria Oesterreichisches NormungsinstitutBelgium Institut belge de normalisationDenmark Dansk StandardiseringsraadFinland Suomen Standardisoimisliito, r.y.France Association française de normalisationGermany Deutsches Institut für Normung e.V.Greece Hellenic Organization for StandardizationIceland Technological Institute of IcelandIreland National Standards Authority of IrelandItaly Ente Nazionale Italiano di UnificazioneLuxembourg Inspection du Travail et des MinesNetherlands Nederlands Normalisatie-instituutNorway Norges StandardiseringsforbundPortugal Instituto Portuguès da QualidadeSpain Asociación Española de Normalización y CertificaciónSweden Standardiseringskommissionen i SverigeSwitzerland Association suisse de normalisationUnited Kingdom British Standards Institution

Amendments issued since publication

Amd. No. Date Comments

BS EN 314-2:1993

© BSI 09-1999 i

Contents

PageCooperating organizations Inside front coverNational foreword iiForeword 2Text of EN 314-2 3National annex NA (informative) Committees responsible Inside back coverNational annex NB (informative) Cross-reference Inside back cover

BS EN 314-2:1993

ii © BSI 09-1999

National foreword

This British Standard has been prepared under the direction of the Technical Sector Board for Building and Civil Engineering and is the English language version of EN 314-2:1993 Plywood — Bonding quality — Part 2: Requirements, published by the European Committee for Standardization (CEN).EN 314-2 was produced as a result of international discussion in which the UK took an active part.EN 314-2 supersedes clauses 1, 2 and 3 of BS 6566-8:1985 Plywood — Part 8 Specification for bond performance of veneer plywood, which will be withdrawn in due course.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 pagesThis document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 6, 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.

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 314-2

February 1993

UDC 674.03-419.3:621.792:620.176

Descriptors: Wooden boards, plywood, gluing, quality, specifications, classification, shear strength

English version

Plywood — Bonding quality —

Part 2: Requirements

Contreplaqué — Qualité du collage — Partie 2: Exigences

Sperrholz — Qualität der Verklebung — Teil 2: Anforderungen

This European Standard was approved by CEN on 1992-12-15. CEN membersare bound to comply with the CEN/CENELEC Internal Regulations whichstipulate the conditions for giving this European Standard the status of anational standard without any alteration.Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to anyCEN member.This European Standard exists in three official versions (English, French,German). A version in any other language made by translation under theresponsibility of a CEN member into its own language and notified to theCentral Secretariat has the same status as the official versions.CEN members are the national standards bodies of Austria, Belgium,Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUnited Kingdom.

CEN

European Committee for StandardizationComité Européen de NormalisationEuropäisches Komitee für Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

© 1993 Copyright reserved to CEN membersRef. No. EN 314-2:1993 E

EN 314-2:1993

© BSI 09-19992

Foreword

This European Standard was prepared by Working Group 2 “Plywood” (Secretariat: France) of Technical Committee CEN/TC 112 “Wood-based panels” (Secretariat: Germany).This standard is one of a series of standards specifying requirements and test methods for plywood.No existing European Standard is superseded.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 August 1993, and conflicting national standards shall be withdrawn at the latest by December 1994.In accordance with 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, United Kingdom.

Contents

PageForeword 21 Scope 32 Normative references 33 Bonding classes 34 Requirements 35 Determination of the bonding class 3Annex A (informative) Bibliography 5Figure 1 — Relationship between the mean percentage of apparent cohesive wood failure and the mean shear strength 4Table 1 — Pretreatments for the three bonding classes 3Table 2 — Requirements 3

EN 314-2:1993

© BSI 09-1999 3

1 ScopeThis European Standard specifies requirements for bonding classes of veneer plywood according to their end uses.The appropriate test methods are specified in EN 314-1.

2 Normative referencesThis 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 636-1, Plywood — Specifications — Part 1: Requirements for plywood for use in dry conditions1). EN 636-2, Plywood — Specifications — Part 2: Requirements for plywood for use in humid conditions1). EN 636-3, Plywood — Specifications — Part 3: Requirements for plywood for use in exterior conditions1). EN 314-1, Plywood — Bonding quality — Part 1: Test methods.

3 Bonding classesBonding quality is divided into three classes, according to EN 636-1, EN 636-2 and EN 636-3, based upon moisture resistance as follows.

— Class 1: dry conditionsThis bonding class is appropriate for normal interior climate.— Class 2: humid conditionsThis bonding class is appropriate for protected external applications (e.g. behind cladding or under roof coverings), but is capable of resisting weather exposure for short periods (e.g. when exposed during the construction). It is also suitable for interior situations where the service moisture condition is raised above the class 1 level.— Class 3: exterior conditionsThis bonding class is designed for exposure to weather over sustained periods.

NOTE The durability of plywood depends not only upon the bonding performance level, but also upon other factors.

4 RequirementsFor each pretreatment both the mean shear strength and the mean apparent cohesive wood failure for a minimum of 10 test pieces per glueline, shall satisfy the criteria given in Table 2 for all three bonding classes.The pretreatments are related to the bonding classes as given in Table 1.Each pretreatment is carried out on a separate set of ten pieces for each glueline.

Table 1 — Pretreatments for the three bonding classes

For all three bonding classes, each glueline shall satisfy two criteria: the mean shear strength and the mean apparent cohesive wood failure, as combined in the following table.

Table 2 — Requirements

The relationship between the mean percentage of apparent cohesive wood failure and the mean shear strength given in Table 2 is illustrated in Table 1.

5 Determination of the bonding classThe comparison of results obtained according to EN 314-1 and requirements defined in this Standard, allows determination of the bonding class to which the tested panel belongs.

1) At present at the draft stage.

Pretreatments(according to EN 314-1)

5.1.1 5.1.2 5.1.3a 5.1.4

Class 1: dry interior X

Class 2: covered exterior

X X

Class 3: non covered exterior

X X X

a When full phenolic glues are used, pretreatment 5.1.3 can be used provided pretreatment 5.1.4 is occasionally used as a test of confirmation.

Mean shear strength fvMean apparent cohesive

wood failure w

N/mm2 %

0,2 k fv < 0,4 U 80

0,4 k fv < 0,6 U 60

0,6 k fv < 1,0 U 40

1,0 k fv no requirement

EN 314-2:1993

4 © BSI 09-1999

Figure 1 — Relationship between the mean percentage of apparent cohesive wood failure and the mean shear strength

EN 314-2:1993

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Annex A (informative) BibliographyEN 313-1, Plywood — Classification and terminology — Part 1: Classification.EN 313-2, Plywood — Classification and terminology — Part 2: Terminology.

6 blank

BS EN 314-2:1993

© BSI 09-1999

National annex NA (informative) Committees responsibleThe United Kingdom participation in the preparation of this European Standard was entrusted by the Technical Sector Board for Building and Civil Engineering (B/-) to Technical Committee B/541, upon which the following bodies were represented:

American Plywood AssociationAssociation of British Plywood and Veneer ManufacturersBritish Woodworking FederationChartered Institute of BuildingCo-ordinator for Timber and Timber ProductsCouncil of the Forest Industries of British ColumbiaDepartment of the Environment (Construction Directorate)Fibre Building Board Organisation (FIDOR)Finnish Plywood InternationalFlat Roofing Contractors’ Advisory BoardForestry CommissionFurniture Industry Research AssociationInstitution of Structural EngineersNational Federation of Roofing ContractorsNational House-building CouncilNational Panel Products AssociationRoyal Institute of British ArchitectsTimber Research and Development AssociationTimber Trade FederationUnited Kingdom and Ireland Particleboard AssociationCoopted member

National annex NB (informative) Cross-reference

Publication referred to Corresponding British Standard

EN 314-1:1993 BS EN 314 Plywood — Bonding qualityPart 1:1993 Test methods

BS EN 314-2:1993

BSI389 Chiswick High RoadLondonW4 4AL

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