EN 14081-1:2016
(Main)Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements
General Information
- Abstract
This European Standard specifies requirements for strength graded structural timber with rectangular cross-sections either visual or machine graded, shaped by sawing, planning or other methods and with cross-sectional dimensions complying with EN 336 (referred to as structural timber in the following clauses).
This European Standard includes provisions for test methods, Assessment and Verification of Constancy of Performance and marking of structural timber.
NOTE 1 For machine strength graded timber additional provisions for type testing (TT) are given in EN 14081-2 and for factory production control (FPC) in EN 14081-3.
NOTE 2 An acceptance procedure for verification of a lot is given in EN 14358 which may be used for a delivery of structural timber.
This European Standard identifies characteristics for which limits have to be given in visual grading standards.
This European Standard covers structural timber, untreated or treated against biological attack.
This European Standard does not cover:
- timber treated by fire retardant products to improve its fire performance;
- thermally and/or chemically modified timber;
- structural finger jointed timber.
- Status
- Withdrawn
- Publication Date
- 09-Feb-2016
- Withdrawal Date
- 16-Sep-2026
- Technical Committee
- CEN/TC 124 - Timber structures
- Drafting Committee
- CEN/TC 124/WG 2 - Solid timber
- Current Stage
- 9960 - Withdrawal effective - Withdrawal
- Start Date
- 14-Aug-2019
- Completion Date
- 17-Sep-2026
Relations
- Effective Date
- 17-Feb-2016
- Effective Date
- 17-Feb-2016
- Effective Date
- 05-Jun-2019
- Effective Date
- 05-Aug-2026
- Effective Date
- 22-Jul-2026
- Effective Date
- 22-Jul-2026
- Effective Date
- 15-Apr-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Refers
EN 15228:2009 - Structural timber - Structural timber preservative treated against biological attack - Effective Date
- 28-Jan-2026
- Refers
EN 1995-1-2:2025 - Eurocode 5 - Design of timber structures - Part 1-2: Structural fire design - Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
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Frequently Asked Questions
EN 14081-1:2016 is a standard published by the European Committee for Standardization (CEN). Its full title is "Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements". This standard covers: This European Standard specifies requirements for strength graded structural timber with rectangular cross-sections either visual or machine graded, shaped by sawing, planning or other methods and with cross-sectional dimensions complying with EN 336 (referred to as structural timber in the following clauses). This European Standard includes provisions for test methods, Assessment and Verification of Constancy of Performance and marking of structural timber. NOTE 1 For machine strength graded timber additional provisions for type testing (TT) are given in EN 14081-2 and for factory production control (FPC) in EN 14081-3. NOTE 2 An acceptance procedure for verification of a lot is given in EN 14358 which may be used for a delivery of structural timber. This European Standard identifies characteristics for which limits have to be given in visual grading standards. This European Standard covers structural timber, untreated or treated against biological attack. This European Standard does not cover: - timber treated by fire retardant products to improve its fire performance; - thermally and/or chemically modified timber; - structural finger jointed timber.
This European Standard specifies requirements for strength graded structural timber with rectangular cross-sections either visual or machine graded, shaped by sawing, planning or other methods and with cross-sectional dimensions complying with EN 336 (referred to as structural timber in the following clauses). This European Standard includes provisions for test methods, Assessment and Verification of Constancy of Performance and marking of structural timber. NOTE 1 For machine strength graded timber additional provisions for type testing (TT) are given in EN 14081-2 and for factory production control (FPC) in EN 14081-3. NOTE 2 An acceptance procedure for verification of a lot is given in EN 14358 which may be used for a delivery of structural timber. This European Standard identifies characteristics for which limits have to be given in visual grading standards. This European Standard covers structural timber, untreated or treated against biological attack. This European Standard does not cover: - timber treated by fire retardant products to improve its fire performance; - thermally and/or chemically modified timber; - structural finger jointed timber.
EN 14081-1:2016 is classified under the following ICS (International Classification for Standards) categories: 79.040 - Wood, sawlogs and sawn timber. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 14081-1:2016 has the following relationships with other standards: It is inter standard links to EN 14081-1:2005+A1:2011, EN 14081-4:2009, EN 14081-1:2016+A1:2019, EN 13238:2026, EN 13183-2:2002, EN 13183-3:2005, EN 16485:2026, EN 1310:1997, EN 16485:2014, EN 14081-2:2018+A1:2022, EN 13556:2003, EN 1912:2024, EN 15228:2009, EN 1995-1-2:2025, EN 844:2019. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 14081-1:2016 is associated with the following European legislation: EU Directives/Regulations: 305/2011; Standardization Mandates: M/112_Am1. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN 14081-1:2016 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.DYRNRWQHJDHolzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende zwecke mit rechteckigem Querschnitt - Teil 1: Allgemeine AnforderungenStructures en bois - Bois de structure à section rectangulaire classé pour sa résistance - Partie 1 : Exigences généralesTimber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements91.080.20Lesene konstrukcijeTimber structures79.040Les, hlodovina in žagan lesWood, sawlogs and sawn timberICS:Ta slovenski standard je istoveten z:EN 14081-1:2016SIST EN 14081-1:2016en,fr,de01-april-2016SIST EN 14081-1:2016SLOVENSKI
STANDARDSIST EN 14081-4:2009SIST EN 14081-1:2006+A1:20111DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14081-1
February
t r s x ICS
y {ä r v r Supersedes EN
s v r z sæ sã t r r w ªA sã t r s sá EN
s v r z sæ vã t r r {English Version
Timber structures æ Strength graded structural timber with rectangular cross section æ Part
sã General requirements Structures en bois æ Bois de structure à section rectangulaire classé pour sa résistance æ Partie
s ã Exigences générales
Holzbauwerke æ Nach Festigkeit sortiertes Bauholz für tragende zwecke mit rechteckigem Querschnitt æ Teil
sã Allgemeine Anforderungen This European Standard was approved by CEN on
s u February
t r s xä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v r z sæ sã t r s x ESIST EN 14081-1:2016
Requirements for strength reducing characteristics for visual grading standards . 24 A.1 Limitations for strength-reducing characteristics . 24 A.1.1 Knots . 24 A.1.2 Slope of grain . 24 SIST EN 14081-1:2016
Marking codes for species . 27 B.1 Marking codes for single species . 27 B.2 Marking codes for species combination . 28 Annex C (normative)
Measurement of moisture content . 30 C.1 General . 30 C.2 Measurement of moisture content of timber during production. 30 Annex ZA (informative)
Clauses of this European Standard addressing the provisions of the EU Construction Products Regulation . 31 ZA.1 Scope and relevant characteristics . 31 ZA.2 Procedure for Assessment and Verification of the Constancy of Performance (AVCP) of strength graded structural timber with rectangular cross section . 33 ZA.2.1 System(s) of AVCP . 33 ZA.2.2 Declaration of performance (DoP) . 34 ZA.2.2.1 General . 34 ZA.2.2.2 Content . 35 ZA.2.2.3 Example of DoP . 35 ZA.3 CE marking and labelling . 36 ZA.3.1 General . 36 ZA.3.2 CE marking . 36 ZA.3.3 Marking on the product or on a label attached to the package . 39 Bibliography . 41
Above C18, D18, T11 Max. length of fissures b Fissures not going through the thickness Fissures less than half the thickness may be ignored f Not greater than 1,5 m or 1/2 the length of the piece, whichever is the lesser Not greater than 1 m or 1/4 the length of the piece, whichever is the lesser Fissures going through the thickness Not greater than 1 m or 1/4 the length of the piece, whichever is the lesser. If at the ends, a length not greater than two times the width of the piece Only permitted at the ends with a length not greater than the width of the piece Max. warp c in mm over
2 m of length Bow 20 mm 10 mm Spring 12 mm 8 mm Twist 2 mm/25 mm width 2 mm/25 mm width Cup Unrestricted Unrestricted Wane Wane shall not be greater than one third of the full edge and/or face dimensions of the piece Soft rot and dote d (see
EN 844–10) Soft rot shall not be permitted Dote is permitted Soft rot shall not be permitted Dote shall not be permitted Insect damage Active infestation shall not be permitted. Insect holes above 2 mm diameter shall not be permitted. Smaller holes shall be assessed as other defects Other defects e Where the reduction in strength caused by another defect is obviously less than caused by defects permitted by this table, the piece may be accepted provided the defect is of a type that will not increase after conversion and drying a For alternative strength classes, visual overrides are checked with corresponding strength value limits b The length of fissures is linked with moisture content and therefore the limits given apply only at the time of grading. Permitted limits for both the depth and length of fissures refer to the sum of fissures in one plane in a piece of timber. c Warp is influenced by moisture content, so the limits apply only at the time of grading. Longitudinal curvature in square section pieces may be assessed using the limits for bow. d Stain is not a structural defect and is acceptable without limitation. e Other defects include for example mechanical damage, top rupture, and included bark. f A 0,2 mm feeler gauge is a suitable device for measuring fissure depth. Where a machine does not grade completely to the ends of each piece of structural timber (as in bending type machines) the ungraded portions shall be visually inspected and assessed. SIST EN 14081-1:2016
Strength class according to EN 338 a
C18, D18, T11 and below Above C18, D18, T11 Knot diameter on face up to 1/2 x width of piece up to 1/4 x width of piece Knot diameter on edge up to 3/4 x thickness of piece up to 1/2 x thickness of piece Slope of grain 1 in 6 1 in 10 a For alternative strength classes, visual overrides are checked with corresponding strength value limits NOTE 1 These limits are applicable only where the size of knots and slope of grain in the non-fully graded portion exceeds the size of similar characteristics in the fully graded portion of the same piece. NOTE 2 The knot diameter is measured perpendicular to the longitudinal axis of the piece of timber. For arris knots the above limits apply to the portion of the knot visible on the particular face or edge being considered. 5.2 Fire resistance (charring rate) Where required, the fire resistance performance of the structural timber whether treated against biological attack or not, shall be tested and declared according to EN 13501-2 or determined by calculation according to EN 1995-1-2. When calculating the fire resistance, the charring rate shall be evaluated on the basis of the species and characteristic density. 5.3 Reaction to fire The class of reaction to fire performance of the structural timber (including the additional classification on smoke production and flaming droplets/particles, if any), shall be determined and declared according to EN 13501-1: a) either without the need for further testing (CWFT), as given in Table 3 1), if the structural timber is proved to meet the requirements of the class also given therein; b) or based on testing of the timber according to the standards, referred to in EN 13501-1, when the timber does not meet the requirements of Table 3 or where a higher classification than the one in a) is sought.
This table is the same as given in the Decision of the Commission 2003/43/EC of 2003-01-17 (see OJEU L13 of 2003-01-18), as amended firstly by 2003/593/EC of 2003-08-07 (see OJEU L201 of 2003-08-08),
(kg/m3) Minimum overall thickness (mm) Class b
(excluding floorings) Structural timber Visual and machine graded structural timber with rectangular cross-sections shaped by sawing, planing or other methods or with round cross-sections 350 22 D-s2, d0 a Applies to all species covered by the product standards. b Class as provided for in Table 1 of the Annex to Decision 2000/147/EC. c Conditioned according to EN 13238. NOTE The minimum mean density is the minimum value of the mean density for which the table applies. This density may be taken from tables as in EN 338. When tested according to EN 13823 under option b), the structural timber shall be mounted and fixed in accordance with the following: a) the whole area of both wings in the SBI apparatus shall be covered with timber pieces mounted edge to edge (butt jointed), without jointing or bonding and orientated horizontally or vertically, supported by; b) timber battens, minimum (40 × 40) mm, fixed to the test backing boards at 400 mm to 600 mm centres horizontally or vertically (perpendicular to the orientation of the timber pieces). In the case of preservative treated timber, it may be necessary to take into account additional provisions set by EN 15228. 5.4 Release of dangerous substances National Regulations on dangerous substances may require verification and declaration on release /content of dangerous substances when construction products covered by this standard are placed on those markets. NOTE 1 This only concerns treated timber. In the absence of European harmonized test methods, verification and declaration on release/content on dangerous substances should be done taking into account national provisions in the place of use. NOTE 2 An informative database covering European and national provisions on dangerous substances is available at the Construction website on EUROPA accessed through: http://ec.europa.eu/enterprise/construction/cpd-ds 5.5 Biological durability 5.5.1 Structural timber without preservative treatment The natural durability in accordance with EN 350-2 shall be declared with specific reference being made to sapwood if the producer makes no special provision for its exclusion. For species and origins not listed in EN 350-2, the natural durability shall be assessed according to EN 350-1. SIST EN 14081-1:2016
General All performances related to essential characteristics included in this standard (see characteristics written in bold letters in Table 4) shall be determined when the manufacturer intends to declare the respective performances unless the standard gives provisions for declaring them without performing tests (e.g. use of previously existing data, Classification Without Further Testing (CWFT) and conventionally accepted performance). For machine strength graded timber, product-type determination shall be carried out in accordance with EN 14081-2. Assessment previously performed in accordance with the provisions of this standard, may be taken into account provided that this was made to the same or a more rigorous test method, under the same AVCP system on the same product type, such that the results are applicable to the product type in question. For the purposes of assessment, the manufacturer's products may be grouped into families, where it is considered that the results for one or more characteristics from any one product within the family are representative for that same characteristics for all products within that same family. NOTE
Products may be grouped in different families for different essential characteristics. Reference to the assessment method standards (e.g. EN 384 in general, and EN 14081–2 for machine graded timber) should be made to allow the selection of a suitable representative sample. SIST EN 14081-1:2016
EN 13501–1 Classes according to EN 13501–1 Durability of all characteristics expressed as durability against biological attack Without preservative treatment 5.5.1 For species listed in EN 350–2 (assessment) For species and origins not listed in EN 350–2, assessed according to EN 350–1 – Natural durability in accordance with EN 350–2 SIST EN 14081-1:2016
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