EN 335:2013

Durability of wood and wood-based products - Use classes: definitions, application to solid wood and wood-based products

This European Standard is applicable to solid wood and wood-based products.
This European Standard defines five use classes that represent different service situations to which wood and wood-based products can be exposed. This standard also indicates the biological agents relevant to each situation.
A use class is not a performance class and does not give guidance for how long wood and wood-based product will last in service.

Dauerhaftigkeit von Holz und Holzprodukten - Gebrauchsklassen: Definitionen, Anwendung bei Vollholz und Holzprodukten

Diese Europäische Norm gilt für Vollholz und Holzprodukte.
Diese Europäische Norm legt fünf Gebrauchsklassen fest, die die verschiedenen Nutzungssituationen repräsentieren, denen Holz und Holzprodukte ausgesetzt sein können. Diese Norm enthält zudem Aussagen, welche Organismen unter den jeweiligen Bedingungen von Bedeutung sind.
Eine Gebrauchsklasse ist keine Leistungsklasse und beschreibt nicht die zu erwartende Gebrauchsdauer des Holzes und der Holzprodukte.

Durabilité du bois et des matériaux à base de bois - Classes d'emploi: définitions, application au bois massif et aux matériaux à base de bois

Cette Norme européenne est applicable aux produits en bois et à base de bois.
Cette Norme européenne définit cinq classes d’emploi qui correspondent aux différentes situations en service auxquelles peuvent être exposés le bois et les matériaux à base de bois. Cette Norme indique également les agents biologiques correspondant à chaque situation.
Une classe d’emploi n’est pas une classe de performance et ne donne pas d’indication concernant la durée de vie du bois en service des produits en bois et à base de bois.

Trajnost lesa in lesnih proizvodov - Razredi uporabe: definicije, uporaba pri masivnem lesu in lesnih ploščah

Ta evropski standard se uporablja za masivni les in lesne proizvode. Ta evropski standard določa pet razredov uporabe, ki ustrezajo različnim razmeram, kjer se lahko uporabljajo les in lesni proizvodi. V standardu so opisani tudi biološki dejavniki, značilni za posamezen razred uporabe. Razred uporabe ni razred učinkovitosti in ne podaja smernic glede življenjske dobe lesa in lesnih proizvodov na določenem mestu uporabe.

General Information

• Status: Published
• Publication Date: 19-Mar-2013
• Withdrawal Date: 29-Sep-2013
• ICS: 71.100.50 - Wood-protecting chemicals
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: CEN/TC 38 - Durability of wood and derived materials
• Drafting Committee: CEN/TC 38/WG 21 - Durability - Classification ( Use classes-natural durability)
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 21-Nov-2024
• Completion Date: 14-Apr-2025
• 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 EN 335:2013 - Durability of wood and wood- based products - Use classes: definitions, application to solid wood and wood based panels

Relations

• Replaces: EN 335-3:1995 - Durability of wood and wood-based products - Definition of hazard classes of biological attack - Part 3: Application to wood-based panels
• Effective Date: 27-Mar-2013
• Replaces: EN 335-2:2006 - Durability of wood and wood-based products - Definition of use classes - Part 2: Application to solid wood
• Effective Date: 27-Mar-2013
• Replaces: EN 335-1:2006 - Durability of wood and wood- based products - Definition of use classes - Part 1: General
• Effective Date: 22-Dec-2008

Overview

EN 335:2013 - a CEN European Standard - defines five use classes for the exposure of solid wood and wood‑based products to different service situations. Applicable to solid timber and wood‑based panels (LVL, plywood, OSB, particleboard, fibreboard, modified wood, etc.), the standard describes the exposure conditions and the biological agents (fungi, beetles, termites, marine borers) relevant to each situation. EN 335 clarifies that a use class is a classification of exposure, not a performance or service‑life rating.

Key topics

• Scope and definitions: Terminology aligned with EN 1001‑2:2005; applies to solid wood and wood‑based products.
• Five use classes (UC):
  • UC 1 - Interior, dry: not exposed to weather or wetting; biological attack insignificant.
  • UC 2 - Interior or under cover with occasional wetting/condensation.
  • UC 3 - Exterior, above ground, exposed to weather; subdivided into:
    • UC 3.1 - Limited wetting (dries quickly).
    • UC 3.2 - Prolonged wetting (water may accumulate).
  • UC 4 - In contact with ground and/or fresh water.
  • UC 5 - Permanently or regularly submerged in salt (marine) water.
• Biological agents: Indicates relevant risks - wood‑destroying and disfiguring fungi, wood‑boring insects (Coleoptera), termites (Isoptera), marine borers - and notes geographic variability in insect risk.
• Annexes and guidance:
  • Annex A: relationship to EN 1995‑1‑1 (Eurocode 5) service classes.
  • Annex B: assignment advice for borderline or complex cases.
  • Annex C: detailed information on biological agents.
• Key limitations: Use classes do not prescribe protective measures or expected durability durations.

Applications

EN 335:2013 is used to classify exposure conditions during design, specification, production and procurement. Typical users:

• Architects and structural timber designers - to assess appropriate exposure class and coordinate with Eurocode 5 service classes.
• Manufacturers of timber and wood‑based products - for product labeling and selection of preservative treatments or design measures.
• Specifiers, contractors and building owners - to determine appropriate materials, coatings and installation details based on exposure risk.
• Certification bodies and regulators - for standardised exposure classification in test reports and standards compliance.

Practical value: use classes guide material selection, treatment decisions and maintenance planning by describing the likely service situation and relevant biological risks.

Related standards

• EN 1995‑1‑1 (Eurocode 5) - Service classes for timber design (see Annex A for alignment guidance).
• EN 1001‑2:2005 - Durability terminology and vocabulary.

Keywords: EN 335:2013, use classes, durability of wood, wood‑based products, solid wood, biological agents, timber exposure, Eurocode 5.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2013
1DGRPHãþD
SIST EN 335-1:2006
SIST EN 335-2:2006
SIST EN 335-3:2002
7UDMQRVWOHVDLQOHVQLKSURL]YRGRY5D]UHGLXSRUDEHGHILQLFLMHXSRUDEDSUL
PDVLYQHPOHVXLQOHVQLKSORãþDK
Durability of wood and wood- based products - Use classes: definitions, application to
solid wood and wood based panels
Dauerhaftigkeit von Holz und Holzprodukten - Gebrauchsklassen: Definitionen,
Anwendung bei Vollholz und Holzwerkstoffen
Durabilité du bois et des matériaux à base de bois - Classes d'emploi: définitions,
application au bois massif et aux panneaux à base de bois
Ta slovenski standard je istoveten z: EN 335:2013
ICS:
71.100.50 .HPLNDOLMH]D]DãþLWROHVD Wood-protecting chemicals
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
79.060.01 /HVQHSORãþHQDVSORãQR Wood-based panels in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 335
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2013
ICS 71.100.50; 79.040 Supersedes EN 335-1:2006, EN 335-2:2006, EN 335-
3:1995
English Version
Durability of wood and wood-based products - Use classes:
definitions, application to solid wood and wood-based products
Durabilité du bois et des matériaux à base de bois - Dauerhaftigkeit von Holz und Holzprodukten -
Classes d'emploi: définitions, application au bois massif et Gebrauchsklassen: Definitionen, Anwendung bei Vollholz
aux matériaux à base de bois und Holzprodukten
This European Standard was approved by CEN on 5 February 2013.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 335:2013: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Use classes: application to wood and wood-based products .5
4.1 General .5
4.2 Use class 1 (UC 1) .5
4.3 Use class 2 (UC 2) .6
4.4 Use class 3 (UC 3) .6
4.4.1 General .6
4.4.2 Sub-class 3.1 (UC 3.1) .6
4.4.3 Sub-class 3.2 (UC 3.2) .6
4.5 Use class 4 (UC 4) .6
4.6 Use class 5 (UC 5) .7
4.7 Summary of use classes for wood and wood-based products .8
Annex A (informative) Service classes according to EN 1995-1-1 .9
Annex B (informative) Additional information for the assignment of use classes . 10
Annex C (informative) Information on biological agents . 11
C.1 General . 11
C.2 Fungi . 11
C.2.1 General . 11
C.2.2 Wood-destroying fungi . 11
C.2.3 Wood-disfiguring fungi . 11
C.3 Insects . 12
C.3.1 Coleoptera (beetles) . 12
C.3.2 Isoptera (termites). 12
C.4 Marine borers . 13
Bibliography . 14

Foreword
This document (EN 335:2013) has been prepared by Technical Committee CEN/TC 38 “Durability of wood
and wood-based products”, the secretariat of which is held by AFNOR.
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 September 2013, and conflicting national standards shall be
withdrawn at the latest by September 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 335-3:1995, EN 335-1:2006 and EN 335-2:2006.
Compared to EN 335, parts 1 to 3, the main modifications are as follows:
1) the former three parts of EN 335 have been combined;
2) the subclasses 3.1 and 3.2 have been redefined;
3) the subdivision of use class 4 has been omitted.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Introduction
This standard gives general definitions of use classes for different service situations and is relevant to solid
wood and wood-based products.
This standard gives information on the biological agents that can attack wood and wood-based products in
defined situations.
The possibility of alignment between the three service classes of Eurocode 5 (EN 1995-1-1) and the five use
classes of EN 335 has been carefully studied. It is important to note that the two systems use different criteria
to achieve different results.
Annex A gives guidance on relationships between use classes and service classes.
Annex B gives additional information for the assignment of use classes.
Annex C gives information on biological agents.
1 Scope
This European Standard is applicable to solid wood and wood-based products.
This European Standard defines five use classes that represent different service situations to which wood and
wood-based products can be exposed. This standard also indicates the biological agents relevant to each
situation.
A use class is not a performance class and does not give guidance for how long wood and wood-based
product will last in service.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 1001-2:2005, Durability of wood and wood-based products — Terminology — Part 2:Vocabulary
EN 1995-1-1, Eurocode 5 — Design of timber structures — Part 1-1: General — Common rules and rules for
buildings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1001-2:2005 and the following apply.
3.1
service situation
situation of exposure of the wood element in use
3.2
wood-based product
any products containing wood
Note 1 to entry: For instance solid wood panel, laminated veneer lumber (LVL), plywood, oriented strand board (OSB),
resin-bonded particleboard, cement-bonded particleboard or fibreboard, modified wood are wood-based products.
4 Use classes: application to wood and wood-based products
4.1 General
The differences between the use classes are based on differences in environment exposures that can make
the wood or wood-based products susceptible to biological deterioration.
NOTE Border line and extreme cases of use of wood and wood-based products exist. This can cause the assignment
of a use class that differs from that defined in this standard (see Annex B).
4.2 Use class 1 (UC 1)
Situations in which the wood or wood-based product is inside a construction, not exposed to the weather and
wetting.
The attack by disfiguring fungi or wood-destroying fungi is in
...