CEN/TS 1099:2007

Plywood - Biological durability - Guidance for the assessment of plywood for use in different use classes

This document gives guidance on the selection of plywood for use in the different use classes as defined in EN 335 1.
The guidance given takes into account the natural durability classification for solid timber (see EN 350 2) together with other factors specific for plywood.
It does not consider durability against chemico-physical factors, such as weathering, nor does it consider the biological durability of the adhesive.
Guidance on precautionary measures for use is also given.

Sperrholz - Biologische Dauerhaftigkeit - Leitfaden zur Beurteilung von Sperrholz zur Verwendung in verschiedenen Gebrauchsklassen

Contreplaqué - Durabilité biologique - Guide d'utilisation dans les différentes classes d'emploi

Vezan les - Biološka trajnost - Navodilo za oceno uporabnosti vezanega lesa v različnih razredih uporabnosti

General Information

• Status: Published
• Publication Date: 07-Aug-2007
• ICS: 79.060.10 - Plywood
• Technical Committee: CEN/TC 112 - Woodbased panels
• Drafting Committee: CEN/TC 112/WG 2 - Plywood
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 13-Jan-2010
• Completion Date: 13-Jan-2010
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 89/106/EEC - Construction products
• Ref Project: SIST-TS CEN/TS 1099:2008 - Plywood - Biological durability - Guidance for the assessment of plywood for use in different use classes

Relations

• Replaces: ENV 1099:1997 - Plywood - Biological durability - Guidance for the assessment of plywood for use in different hazard classes
• Effective Date: 22-Dec-2008

Overview

CEN/TS 1099:2007 - "Plywood - Biological durability - Guidance for the assessment of plywood for use in different use classes" - is a CEN Technical Specification that helps manufacturers, specifiers and users select plywood according to the EN 335 defined use classes. The document aligns plywood selection with the natural durability classifications for solid timber (EN 350-2) while calling out plywood‑specific factors such as veneer lay‑up, adhesive effects and veneer thickness. It does not cover chemico‑physical weathering or the biological durability of adhesives.

Key topics and requirements

• Selection rules: Choose plywood for the most severe applicable EN 335 use class when end‑use exposure is uncertain or variable. Consider replaceability and consequence of failure when specifying higher durability.
• Use classes mapping: Practical guidance (tables) links natural durability classes of the constituent wood species to the five EN 335 use classes for risks from wood‑destroying fungi, insects and marine borers.
• Preservative treatment: When natural durability is insufficient, preservative treatment is recommended or required. The document warns about leaching risks with some preservatives and stresses protection during transport, construction and service.
• Installation and detailing: Advice on installation principles to avoid creating more severe in‑service conditions - e.g., allow wet plywood to dry before sealing, protect edges, ensure ventilation and avoid water retention.
• Plywood composition effects: Factors that influence biological durability:
  • Wood species (least durable species governs untreated panel performance)
  • Sapwood vs heartwood (sapwood less durable but more permeable)
  • Ply thickness and veneer thickness (thin plies often allow better glue penetration and improved durability; specific guidance for veneer >3 mm, 1.5–3 mm, ≤1.5 mm)
  • Adhesive content (some adhesives impart limited biocidal effect and glue lines can impede insect movement)
• Guidance tables: Table 1 (fungi) and Table 2 (insects/marine organisms) help assess when natural durability is sufficient or when treatment is advisable/necessary.

Applications and users

• Architects, structural and timber engineers specifying plywood for buildings and marine applications
• Plywood and wood‑based panel manufacturers developing product specifications
• Timber treatment and preservative suppliers evaluating treatment needs
• Product standards writers, testing laboratories and QA bodies assessing conformity to use class requirements
• Contractors and facility managers applying best practice installation and maintenance to maximize service life

Related standards

• EN 335-1 / EN 335-3 - Definitions and application of use/hazard classes
• EN 350-2 - Natural durability and treatability of solid wood
• EN 460 - Guidance on natural durability requirements
• EN 313-2 - Plywood terminology

Keywords: CEN/TS 1099, plywood biological durability, EN 335 use classes, EN 350-2, preservative treatment, veneer thickness, plywood selection, wood‑based panels.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2008
1DGRPHãþD
SIST ENV 1099:2000
9H]DQOHV%LRORãNDWUDMQRVW1DYRGLOR]DRFHQRXSRUDEQRVWLYH]DQHJDOHVDY
UD]OLþQLKUD]UHGLKXSRUDEQRVWL
Plywood - Biological durability - Guidance for the assessment of plywood for use in
different use classes
Sperrholz - Biologische Dauerhaftigkeit - Leitfaden zur Beurteilung von Sperrholz zur
Verwendung in verschiedenen Gebrauchsklassen
Contreplaqué - Durabilité biologique - Guide d'utilisation dans les différentes classes
d'emploi
Ta slovenski standard je istoveten z: CEN/TS 1099:2007
ICS:
79.060.10
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 1099
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
August 2007
ICS 79.060.10 Supersedes ENV 1099:1997
English Version
Plywood - Biological durability - Guidance for the assessment of
plywood for use in different use classes
Contreplaqué - Durabilité biologique - Guide d'utilisation Sperrholz - Biologische Dauerhaftigkeit - Leitfaden zur
dans les différentes classes d'emploi Beurteilung von Sperrholz zur Verwendung in
verschiedenen Gebrauchsklassen
This Technical Specification (CEN/TS) was approved by CEN on 14 July 2007 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 1099:2007: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Precautionary measures for use.4
4.1 Rules for selection.4
4.2 Use of treated plywood .4
4.3 Installation principles.5
5 Influence of plywood composition on biological durability.5
6 Use of plywood in different use classes .5
6.1 General.5
6.2 Wood-destroying fungi .5
6.3 Insects and marine organisms.6
Annex A (informative) Specific factors related to the biological durability of plywood .8
Bibliography .9

Foreword
This document (CEN/TS 1099:2007) has been prepared by Technical Committee CEN/TC 112 “Wood-based
panels”, the secretariat of which is held by DIN.
This document supersedes ENV 1099:1997.
Compared to ENV 1099:1997 the following changes have been made:
 “hazard class” has been replaced by “use class” in accordance with EN 335-1:2006;
 Clause 2 and the Bibliography have been updated;
 the deliverability has been changed from ENV to CEN/TS. No technical changes have been made.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

1 Scope
This document gives guidance on the selection of plywood for use in the different use classes as defined in
EN 335-1.
The guidance given takes into account the natural durability classification for solid timber (see EN 350-2)
together with other factors specific for plywood.
It does not consider durability against chemico-physical factors, such as weathering, nor does it consider the
biological durability of the adhesive.
Guidance on precautionary measures for use is also given.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 313-2:1999, Plywood — Classification and terminology — Part 2: Terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 313-2:1999 apply.
4 Precautionary measures for use
4.1 Rules for selection
Plywood should be selected according to the relevant use classes of its end use situation and taking into
account any risk from perceived hazards likely to occur.
Five use classes have been identified as being representative of the various conditions the material is likely to
meet. These five classes are defined in EN 335-1 and their applications for plywood in EN 335-3.
The risk of biological attack can differ for different end-uses within the same use class.
If the use class cannot be determined accurately or when different parts of the same plywood panel are
exposed to different use classes, selection should be made with regard to the most severe of the probable use
classes.
When a plywood component would be difficult to replace, or the consequences of its failure would be serious,
it is advisable to use more durable plywood than that normally appropriate for the use class of the end use
situation.
4.2 Use of treated plywood
1)
With some preservative products, a risk of excessive leaching exists . If the specified preservative product is
leachable, it is essential that the panel is covered, or otherwise protected, after treatment and during transport
and construction, as well as in service.

1) Leaching to a level where the conferred durability is compromised.
In addition to the natural biological durability of the plywood or durability conferred through preservative
treatment, other factors which can affect the performance of plywood and which should be considered during
development of specifications
...