1、DRAFT FOR DEVELOPMENTDD CEN/TS 1099:2007Plywood Biological durability Guidance for the assessment of plywood for use in different use classesICS 79.060.10g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55
2、g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD CEN/TS 1099:2007This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 30 November 2007 BSI 2007ISBN 978 0 580 58041 3National forewordThis Draft for Development is the UK implementation
3、of CEN/TS 1099:2007. It supersedes DD ENV 1099:1998 which is withdrawn.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so that informati
4、on and experience of its practical application can be obtained.Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion to a European standard. A review of this publication will be init
5、iated not later than 3 years after its publication by the European organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards.According to the replies received by the end of t
6、he review period, the responsible BSI Committee will decide whether to support the conversion into a European Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards House,
7、 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to Technical Committee B/541, Wood-based panels.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessar
8、y provisions of a contract. Users are responsible for its correct application.Amendments issued since publicationAmd. No. Date CommentsTECHNICAL SPECIFICATIONSPCIFICATION TECHNIQUETECHNISCHE SPEZIFIKATIONCEN/TS 1099August 2007ICS 79.060.10 Supersedes ENV 1099:1997 English VersionPlywood - Biological
9、 durability - Guidance for the assessment ofplywood for use in different use classesContreplaqu - Durabilit biologique - Guide dutilisationdans les diffrentes classes demploiSperrholz - Biologische Dauerhaftigkeit - Leitfaden zurBeurteilung von Sperrholz zur Verwendung inverschiedenen Gebrauchsklass
10、enThis 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 theircomments, particularly on the question whether the CE
11、N/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 availablepromptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in paral
12、lel 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, Latvi
13、a, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2
14、007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. CEN/TS 1099:2007: E2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Precautionary measures for use4 4.1 Rules for selection.4 4.2 Use of treate
15、d plywood .4 4.3 Installation principles5 5 Influence of plywood composition on biological durability5 6 Use of plywood in different use classes .5 6.1 General5 6.2 Wood-destroying fungi .5 6.3 Insects and marine organisms.6 Annex A (informative) Specific factors related to the biological durability
16、 of plywood 8 Bibliography 9 CEN/TS 1099:20073 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
17、 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 stand
18、ards 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, Polan
19、d, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. CEN/TS 1099:20074 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 cl
20、assification 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 give
21、n. 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
22、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 u
23、se 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
24、 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
25、 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 With some preservative products, a
26、risk of excessive leaching exists1). 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 compromis
27、ed. CEN/TS 1099:20075 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 include building practice during
28、 construction, quality of maintenance, the type and integrity of surface coatings applied and the compatibility between treatments and coatings. 4.3 Installation principles Plywood should be installed and maintained in such a way that the conditions in-service are no more severe than those appropria
29、te to the specified material. The moisture content of plywood is influenced by the gradients of temperature and water vapour between the two faces and the permeability of any surface coatings applied to the faces. Where plywood intended for dry end use has become wet during installation, it should b
30、e allowed to dry thoroughly before the components or structures are sealed. In use classes 2 and 3 where there is a risk of wetting, but which can be minimised through design, it is important to incorporate in that design suitable detailing and adequate ventilation to ensure that a build-up and subs
31、equent retention of water does not occur. Special attention should be paid to protecting plywood edges, e.g. by applying a low permeability finish. 5 Influence of plywood composition on biological durability The characteristics of natural durability and treatability of solid wood are set out in EN 3
32、50-2 and EN 460. These can be used as guidance for estimating the durability and treatability performance of plywood. If the plywood contains more than one wood species, the species having the lowest natural durability should be used to indicate the expected durability level of the untreated plywood
33、 and that being the most resistant to treatment should be used to indicate treatability. Choice of plywood for a particular application should be made with due consideration given to the characteristics of adhesive type, wood species and lay up and the required life expectancy. The behaviour of plyw
34、ood subjected to biological attack can differ from that of solid wood. The behaviour of plywood under different moisture regimes is affected by the wood species comprising the plies, and the nature and content of the adhesive used. The equilibrium moisture content of plywood made from a single wood
35、species can differ from that of solid wood of the same species under the same conditions. Specific factors for consideration are indicated in Annex A. 6 Use of plywood in different use classes 6.1 General In order to select suitable plywood, reference should be made to EN 350-2 to establish the natu
36、ral durability classification of the constituent wood species against the various biological organisms associated with the hazard class in which the plywood will be used. 6.2 Wood-destroying fungi Table 1 is based on EN 460 and gives guidance, where natural durability levels are insufficient, on the
37、 need for preservative treatment. CEN/TS 1099:20076 Table 1 Wood-destroying fungi Guidance on the application of natural durability classes of wood species to plywood used in various use classes Durability class of wood species used in the pliesaUse class for plywoodb1 2 3 4 5 1 O O O O O 2 O O O (O
38、) (O) 3 O O (O) (x) (x) 4 O (O) (x) x x 5 O (x) (x) x x aSapwood of all species is regarded as belonging to durability class 5. bThe use of plywood is only recommended in use class 4 and use class 5 if adequately modified (see EN 335-3:1995, Annex A and product standards). Key O natural durability s
39、ufficient (O) natural durability is normally sufficient but, under certain end uses, treatment can be advisable (see EN 460:1994, Annex A) (x) preservative treatment is normally advisable but, in certain end uses, natural durability can be sufficient (see EN 460:1994, Annex A) x preservative treatme
40、nt necessary 6.3 Insects and marine organisms Natural durability ratings for plywood against insect and marine borer attacks, based on the rating for constituent wood species given in EN 350-2, are given in Table 2. Wood destroying insects and marine organisms are universally present throughout Euro
41、pe. Specific end-use situations and local conditions should be taken into account when assessing this risk for selection of suitable plywood or the need for preservative treatment. CEN/TS 1099:20077 Table 2 Scheme for assigning natural durability rating of plywood for the various organisms Natural d
42、urability of wood species Organisms Durable Susceptible Hylotrupes DHySHy/SHHyAnobiumA A/SHALyctusL LDurable Moderately durable SusceptibleTermites DTMTSTMarine organisms DMa Ma MaExplanation of abbreviations: D durable M moderately durable S susceptible SH the heartwood is also known to be suscepti
43、ble Subcripts: A Anobium Hy Hylotrupes L Lyctus Ma Marine organisms T Termites Veneer thickness can result in a modification to the natural durability and thus affect the ratings which can be modified as follows: a) in case of veneer thicknesses 3 mm, Table 2 shall be used as shown; b) in case of ve
44、neer thicknesses 1,5 mm and 3 mm, change Table 2 as follows: SHY/SHHyto DHyc) in case of veneer thicknesses 1,5 mm: use b) but, due to the limited thickness of the veneer, risk by Hylotrupes bajulus need not to be taken into account, and change Table 2 as follows: SA/SHAto DASLto DLNOTE Table 2 is b
45、ased on Annex B of EN 350-2:1994. CEN/TS 1099:20078 Annex A (informative) Specific factors related to the biological durability of plywood A.1 Wood species The more durable the (solid) wood species used, the greater is the durability of the plywood. The durability of untreated plywood will be govern
46、ed by the least durable species. A.2 Sapwood and heartwood Sapwood is less durable than heartwood, but is often more permeable. The presence of sapwood in plywood can therefore result in the biological durability of plywood being less than that expected from the heartwood of the wood species used. T
47、he durability of these more permeable sapwood areas can be improved due to the penetration of glue, which may affect the spread of insect and fungal attack. The effect is influenced by the thickness of the plies. A.3 Thickness of plies Biological durability can be enhanced as a result of penetration
48、 of the plies by the glue. Thinner plies are more likely to be fully penetrated. Plywood made using thin plies of permeable wood can therefore have a greater biological durability than similar plywood made using thick plies of the same wood species. A.4 Adhesive content Certain adhesives are known t
49、o have biocidal and fungicidal properties. This can impart to the plywood a degree of adventitious protection. It is considered that this will be limited in effect and decreases with time but in some circumstances may obviate the need for preservative treatment. Additionally, the glue lines can act as a barrier preventing wood boring insects and their larvae crossing between plies. A.5 Preservative treatment As for solid wood, a suitable preservative treatment will confer enhanced biological durability to plywood, particularly if the wood s
