1、BSI Standards PublicationBS EN 336:2013Structural timber Sizes,permitted deviationsBS EN 336:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 336:2013. Itsupersedes BS EN 336:2003 which is withdrawn.The UK participation in its preparation was entrusted to Te
2、chnicalCommittee B/518, Structural timber.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards I
3、nstitution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 77771 4ICS 79.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments i
4、ssued since publicationDate Text affectedBS EN 336:2013EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 336 October 2013 ICS 79.040 Supersedes EN 336:2003English Version Structural timber - Sizes, permitted deviations Bois de structure - Dimensions, carts admissibles Bauholz fr tragende Zwecke -
5、 Mae, zulssige Abweichungen This European Standard was approved by CEN on 24 August 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 li
6、sts 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 unde
7、r 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 Y
8、ugoslav 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 COMIT EURO
9、PEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 336:2013: EBS EN 336:2013EN 336:2013 (E) 2 Contents Page Foreword . 3 Int
10、roduction 4 1 Scope 5 2 Normative references . 5 3 Terms and definitions 5 4 Sizes for structural timber . 5 4.1 General . 5 4.2 Changes in size due to changes in moisture content 6 4.3 Permitted cross-sectional deviations 6 4.4 Permitted length deviations . 6 5 Moisture content measurement . 6 Bibl
11、iography 7 BS EN 336:2013EN 336:2013 (E) 3 Foreword This document (EN 336:2013) has been prepared by Technical Committee CEN/TC 124 “Timber structures”, 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 ide
12、ntical text or by endorsement, at the latest by April 2014, and conflicting national standards shall be withdrawn at the latest by April 2014. 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 re
13、sponsible for identifying any or all such patent rights. This document will supersede EN 336:2003. Compared to EN 336:2003, the following modifications have been made: a) in the scope, the limit to 300 mm is deleted so the standard is available for large cross section; b) minimum size changed from 2
14、2 mm to 6 mm; c) in subclause 4.2, the changes in size due to changes in moisture content are given for hardwoods; d) in subclause 4.3, the permitted cross sectional deviations are given for thicknesses and widths above 300 mm; e) in Clause 5, moisture content measurement in accordance with the thre
15、e parts of EN 13183. According to the CEN-CENELEC Internal Regulations, the national standards organizations 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 M
16、acedonia, 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. BS EN 336:2013EN 336:2013 (E) 4 Introduction Target size is the ba
17、sis for the standard. A method of calculating sizes at other moisture levels is provided. The standard also stipulates a method for the measurement of moisture content. BS EN 336:2013EN 336:2013 (E) 5 1 Scope This European Standard specifies two classes of permitted deviations from target sizes for
18、structural timber of softwood and hardwood species. It also specifies the moisture content to be used as a reference point for the measurement of sizes, and gives average values for changes in size due to changes in moisture content. It is applicable to sawn and prepared square-edged structural timb
19、er with parallel edges having sawn thicknesses or widths greater than 6 mm. 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 re
20、ferences, the latest edition of the referenced document (including any amendments) applies. EN 1309-1, Round and sawn timber Method of measurement of dimensions Part 1: Sawn timber EN 13183-1, Moisture content of a piece of sawn timber Part 1: Determination by oven dry method EN 13183-2, Moisture co
21、ntent of a piece of sawn timber Part 2: Estimation by electrical resistance method EN 13183-3, Moisture content of a piece of sawn timber Part 3: Estimation by capacitance method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 target size siz
22、e specified (at the reference moisture content), and to which the deviations, which would ideally be zero, are to be related 3.2 deviation difference between actual size and the corresponding target size, making allowance for the difference in size due to difference in moisture content (see Clause 5
23、) 3.3 moisture content amount of water present in timber, expressed as a percentage of the oven-dry mass 4 Sizes for structural timber 4.1 General Sizes shall be measured in accordance with EN 1309-1. For the purposes of this European Standard, the reference moisture content is 20 %. NOTE The refere
24、nce moisture content is the moisture content at which sizes are given. It is different from target moisture contents which are defined in EN 14298. BS EN 336:2013EN 336:2013 (E) 6 4.2 Changes in size due to changes in moisture content Unless there is evidence to the contrary, it shall be assumed tha
25、t: for softwoods and poplar, the thickness and width of a piece of timber increase by 0,25 % for every 1,0 % of moisture content higher than 20 % up to 30 %, and decrease by 0,25 % for every 1,0 % of moisture content lower than 20 %; for hardwoods, the thickness and width of a piece of timber increa
26、se by 0,35 % for every 1,0 % of moisture content higher than 20 % up to 30 %, and decrease by 0,35 % for every 1,0 % of moisture content lower than 20 %. The above values are typical, without regard to species. 4.3 Permitted cross-sectional deviations In any cross section of each piece of timber, th
27、e actual thickness and actual width (corrected for changes due to changes in moisture content) may not deviate from the target size by more than the values given in Table 1 for tolerance class 1 or in Table 2 for tolerance class 2: a) Tolerance class 1 Table 1 Values for tolerance class 1 For thickn
28、esses and widths 100 mm: (-1 +3) mm For thicknesses and widths 100 mm and 300 mm: (-2 +4) mm For thicknesses and widths 300 mm (-3 +5) mm b) Tolerance class 2 Table 2 Values for tolerance class 2 For thicknesses and widths 100 mm: (-1 +1) mm For thicknesses and widths 100 mm and 300 mm: (-1,5 +1,5)
29、mm For thicknesses and widths 300 mm (-2,0 +2,0) mm For large cross sections, deviations from squareness may be given as part of the specifications. The average actual thickness and the average actual width of square-edged timber shall not be less than the target sizes, making allowance for changes
30、in size due to changes in moisture content. 4.4 Permitted length deviations Negative deviations are not permitted. If overlength is likely to be a problem, a limit should be placed in the contract at the time of purchase. 5 Moisture content measurement Moisture content shall be measured in accordanc
31、e with EN 13183 (part 1 or 2 or 3). BS EN 336:2013EN 336:2013 (E) 7 Bibliography 1 EN 14298, Sawn timber Assessment of drying quality This page deliberately left blankThis page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related pub
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