oSIST prEN 14081-1:2012

Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements

This European Standard specifies the requirements for visual and machine graded structural timber with rectangular cross-sections shaped by sawing, planing or other methods, and having deviations from the target sizes corresponding to EN 336.
This European Standard consists of provisions for test methods, evaluation of conformity (ITT and FPC) and marking of both grading types of structural timber.
NOTE   For the machine graded timber additional provisions for ITT are given in EN 14081-2 and for FPC in EN 14081-3.
This European Standard identifies as a minimum the characteristics for which limits shall be given in visual grading rules.
This European Standard covers structural rectangular timber, untreated or treated against biological attack.
This European Standard does not cover timber treated by fire retardant products to improve its fire performance.
Finger jointed timber made of rectangular cross-sections is not covered in this European Standard.

Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt - Teil 1: Allgemeine Anforderungen

Diese Europäische Norm legt die Anforderungen an visuell und maschinell sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt fest, das durch Sägen, Hobeln oder andere Verfahren geformt wurde und Mindestmaße nach EN 336 aufweist.
Die vorliegende Europäische Norm besteht aus Bestimmungen für Prüfverfahren, die Bewertung der Konformität (Erstprüfung und WPK) sowie die Kennzeichnung beider Sortierarten für Bauholz für tragende Zwecke.
ANMERKUNG   Für maschinell sortiertes Holz sind zusätzliche Bestimmungen für die Erstprüfung in der EN 14081 2 sowie für die WPK in EN 14081 3 angegeben.
Diese Europäische Norm legt als Mindest-Eigenschaften diejenigen fest, für die Grenzwerte in den visuellen Sortierregeln angegeben sind.
Diese Europäische Norm gilt für Bauholz für tragende Zwecke mit rechteckigem Querschnitt, das entweder unbehandelt ist oder gegen biologischen Befall behandelt wurde.
Bauholz, das mit Feuerschutzmitteln behandelt wurde, um sein Verhalten bei Brandeinwirkung zu verbessern, ist nicht Gegenstand dieser Europäischen Norm.
Keilgezinktes Bauholz mit rechteckigem Querschnitt ist nicht Gegenstand dieser Europäischen Norm.

Structures en bois - Bois de structure à section rectangulaire classé pour sa résistance - Partie 1: Exigences générales

La présente Norme européenne prescrit les exigences applicables au bois de structure à section rectangulaire classé visuellement et par machine, profilé par sciage, rabotage ou d’autres méthodes, et ayant des dimensions minimales conformes à l'EN 336.
La présente Norme européenne est constituée de dispositions relatives aux méthodes d'essai, à l'évaluation de la conformité (ITT et CPU) et au marquage pour les deux types de classement du bois de structure.
NOTE   Pour le bois classé par machine, des dispositions supplémentaires sont spécifiées dans l'EN 14081-2 pour les ITT et dans l'EN 14081-3 pour le CPU.
La présente Norme européenne identifie, au minimum, les caractéristiques pour lesquelles des limites sont établies dans les règles de classement visuel.
La présente Norme européenne couvre le bois de structure à section rectangulaire, non traité ou traité contre les attaques biologiques.
La présente Norme européenne ne couvre pas le bois traité par des produits ignifuges pour améliorer sa performance au feu.
Le bois avec aboutages à entures multiples constitué de sections rectangulaires n’est pas couvert par la présente Norme européenne.

Lesene konstrukcije - Razvrščanje konstrukcijskega lesa pravokotnega prečnega prereza po trdnosti - 1. del: Splošne zahteve

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Sep-2012
• ICS: 79.040 - Wood, sawlogs and sawn timber
• ICS: 91.080.20 - Timber structures
• Technical Committee: KON.005 - Timber structures
• Current Stage: 98 - Abandoned project (Adopted Project)
• Start Date: 07-Oct-2013
• Due Date: 12-Oct-2013
• Completion Date: 11-Oct-2013
• 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
• Mandate: M/112 - Mandate to CEN/CENELEC concerning the execution of standardization work for harmonized standards on structural timber products
• Ref Project: prEN 14081-1 rev - Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements

Relations

• Revised: SIST EN 14081-1:2006+A1:2011 - Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements
• Effective Date: 08-Jun-2022
• Revised: SIST EN 14081-1:2006+A1:2011 - Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements
• Effective Date: 29-Nov-2010
• Revised: SIST EN 14081-1:2006 - Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements
• Effective Date: 02-Oct-2010

Overview

The oSIST prEN 14081-1:2012 standard, developed by CEN, specifies the general requirements for strength graded structural timber with rectangular cross-section. It applies to both visual and machine-graded timber shaped by sawing, planing, or similar methods, compliant with size deviations per EN 336. This European Standard defines essential provisions for test methods, conformity evaluation-including Initial Type Testing (ITT) and Factory Production Control (FPC)-as well as marking and labeling of graded structural timber. It covers untreated timber as well as timber treated against biological attack but excludes fire-retardant treated or finger-jointed timber.

Key Topics

• Grading Methods: Two main grading methods are covered-visual grading and machine grading. Visual grading relies on established grading rules for strength-reducing characteristics, while machine grading involves technologically controlled output or machine systems requiring verification through visual inspection.
• Strength and Dimensional Requirements: Timber must comply with mechanical properties such as strength, modulus of elasticity, and density, and maintain dimensional stability in accordance with EN 336.
• Fire and Durability: The standard addresses the timber's fire resistance and biological durability, distinguishing untreated from preservative-treated timber. However, it excludes fire-retardant enhancement treatments.
• Evaluation of Conformity: Rigorous guidelines govern ITT and ongoing FPC to ensure consistent, reliable performance of structural timber in the market. ITT frameworks for machine grading defer to additional parts of the EN 14081 series.
• Marking and Labeling: Specific requirements mandate clear marking, labeling, and documentation either on the timber itself or its packaging to guarantee traceability and compliance.
• Visual Grading Limits: Defined limits for strength-reducing features such as knots, slope of grain, density fluctuations, fissures, wane, warp, and reaction wood are minimum requirements for visual grading rules.

Applications

• Timber Construction: oSIST prEN 14081-1:2012 underpins safe and reliable use of structural timber in buildings, bridges, and other engineered wooden structures across Europe.
• Quality Assurance: Manufacturers and suppliers leverage this standard to produce and deliver timber that meets consistent strength classes, ensuring structural integrity and durability.
• Machinery and Process Control: Timber processing facilities utilize the guidelines to integrate machine grading systems and maintain factory production control, improving efficiency and compliance.
• Regulatory Compliance: The standard supports adherence to the EU Construction Products Directive, facilitating CE marking and certification processes critical for market acceptance.

Related Standards

• EN 14081-2: Additional provisions for Initial Type Testing (ITT) of machine graded timber.
• EN 14081-3: Detailed requirements for Factory Production Control (FPC) in machine grading.
• EN 336: Specifies structural timber sizes and permitted deviations.
• EN 338: Defines strength classes of structural timber.
• EN 1995-1-2 (Eurocode 5): Structural fire design principles related to timber structures.
• EN 350 Series: Guidelines on wood durability and treatability against biological threats.
• EN 13501 Series: Fire classification of construction products including timber elements.

This comprehensive framework ensures the strength, safety, and traceability of structural timber products used in European construction, contributing to sustainable building practices and adherence to international quality standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2012
/HVHQHNRQVWUXNFLMH5D]YUãþDQMHNRQVWUXNFLMVNHJDOHVDSUDYRNRWQHJDSUHþQHJD
SUHUH]DSRWUGQRVWLGHO6SORãQH]DKWHYH
Timber structures - Strength graded structural timber with rectangular cross section -
Part 1: General requirements
Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende Zwecke mit
rechteckigem Querschnitt - Teil 1: Allgemeine Anforderungen
Structures en bois - Bois de structure à section rectangulaire classé pour sa résistance -
Partie 1: Exigences générales
Ta slovenski standard je istoveten z: prEN 14081-1 rev
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
91.080.20 Lesene konstrukcije Timber structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2012
ICS 79.040 Will supersede EN 14081-1:2005+A1:2011
English Version
Timber structures - Strength graded structural timber with
rectangular cross section - Part 1: General requirements
Structures en bois - Bois de structure à section Holzbauwerke - Nach Festigkeit sortiertes Bauholz für
rectangulaire classé pour sa résistance - Partie 1: tragende Zwecke mit rechteckigem Querschnitt - Teil 1:
Exigences générales Allgemeine Anforderungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 124.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14081-1 rev:2012: E
worldwide for CEN national Members.

prEN 14081-1:2012 (E)
Contents Page
Foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols . 9
5 Requirements for structural timber . 9
5.1 Strengths, modulus of elasticity and density . 9
5.1.1 General on grading . 9
5.1.2 Visual strength grading . 9
5.1.3 Machine strength grading . 9
5.2 Dimensional stability . 11
5.3 Fire resistance R . 11
5.4 Reaction to fire . 11
5.5 Durability against biological attack . 12
5.5.1 Timber without preservative treatment . 12
5.5.2 Timber with preservative treatment . 12
6 Evaluation of conformity . 12
6.1 General . 12
6.2 Initial Type Testing – Type Testing . 12
6.2.1 General . 12
6.2.2 Test samples, testing and compliance criteria . 13
6.2.3 Test reports . 14
6.3 Factory production control (FPC) . 14
6.3.1 General . 14
6.3.2 Requirements . 14
6.3.3 Product specific requirements . 16
6.3.4 Initial inspection of factory and of FPC . 17
6.3.5 Continuous surveillance of FPC . 17
6.3.6 Procedure for modifications . 18
7 Marking, labelling and packaging . 18
7.1 General . 18
7.2 Information either on the timber (method A) or on its package (method B) . 18
7.3 Information in the documents accompanying either the timber or package of such
timber . 19
Annex A (normative) Requirements for strength reducing characteristics for visual grading
standards . 23
A.1 Limitations for strength-reducing characteristics . 23
A.1.1 Knots . 23
A.1.2 Slope of grain . 23
A.1.3 Density and rate of growth . 23
A.1.4 Fissures. 24
A.2 Limitations for geometrical characteristics . 24
A.2.1 Wane . 24
A.2.2 Warp . 24
A.3 Limitations for biological characteristics . 25
A.4 Other characteristics . 25
A.4.1 Reaction wood . 25
A.4.2 Other criteria . 25
prEN 14081-1:2012 (E)
Annex B (informative) Marking codes for single species . 26
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU
Construction Products Directive . 28
ZA.1 Scope and relevant characteristics . 28
ZA.2 Procedure for attestation of conformity of strength graded structural timber with
rectangular cross section . 30
ZA.2.1 Systems of attestation of conformity . 30
ZA.2.2 EC Certificate and Declaration of conformity . 31
ZA.3 CE marking and labelling . 32
ZA.3.1 General . 32
ZA.3.2 Simplified CE marking . 32
ZA.3.3 Complete CE marking . 33

prEN 14081-1:2012 (E)
Foreword
This document (prEN 14081-1:2012) has been prepared by Technical Committee CEN/TC 124 “Timber
Structures”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 14081-1:2005+A1:2011.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive.
For relationship with EU Directive, see informative Annex ZA, which is an integral part of this document.
Other parts of the series of EN 14081 are:
EN 14081-2, Timber structures - Strength graded structural timber with rectangular cross section - Part 2:
Machine grading; additional requirements for initial type testing,
EN 14081-3, Timber structures - Strength graded structural timber with rectangular cross section - Part 3:
Machine grading; additional requirements for factory production control,
prEN 14081-1:2012 (E)
Introduction
There are basically two methods of strength grading: visual grading and machine grading.
Machine grading is in common use in a number of countries. The countries use two basic systems, referred
to as 'output controlled' and 'machine controlled'. Both systems require a visual override inspection to cater
for strength-reducing characteristics that are not automatically sensed by the machine. The output-
controlled system is suitable for use where the grading machines are situated in sawmills grading limited
sizes, species and grades in repeated production runs. This enables the system to be controlled by testing
timber specimens from the daily output. These tests together with statistical procedures are used to monitor
and adjust the machine settings to maintain the required strength properties for each strength class. With
this system it is permissible for machine approval requirements to be less demanding and for machines of
the same type to have non-identical performance.
The machine controlled system was developed in Europe. Because of the large number of sizes, species
and grades used it was not possible to carry out quality-control tests on timber specimens drawn from
production. The system relies therefore, on the machines being strictly assessed and controlled, and on
considerable research effort to derive the machines settings, which remain constant for all machines of the
same type.
Visual grading is also in common use in a number of countries. There are many different visual strength
grading rules for timber in use in Europe. These have come into existence to allow for:
 different species or groups of species;
 geographic origin;
 different dimensional requirements;
 varying requirements for different uses;
 quality of material available;
 historic influences or traditions.
Because of the diversity of existing visual grading rules in use in different countries, it is currently impossible
to lay down a single set of acceptable rules for all Member States.
The requirements given in this European Standard on visual strength grading rules therefore give basic
principles, which should be followed when drawing up requirements for limits for some of the
characteristics.
The accepted assignments to strength classes are based on approved grading reports (AGR).
In most cases, the AGR's have been evaluated by CEN/TC124/WG2/TG1, which is the basis for the attestation
of conformity by the Notified Body conducting the certification of the producer’s factory production control
(FPC) needed for the CE marking.
prEN 14081-1:2012 (E)
1 Scope
This European Standard specifies the requirements for visual and machine graded structural timber with
rectangular cross-sections shaped by sawing, planning or other methods, and having minimum dimensions
complying with EN 336.
This European Standard consists of provisions for test methods, evaluation of conformity (ITT and FPC)
and marking of both grading types of structural timber.
NOTE For the machine graded timber additional provisions for ITT are given in EN 14081-2 and for FPC in EN
14081-3.
This European Standard identifies as a minimum the characteristics for which limits are given in visual
grading rules.
This European Standard covers structural rectangular timber, untreated or treated against biological attack.
This European Standard does not cover timber treated by fire retardant products to improve its fire
performance.
Finger jointed timber made of rectangular cross-sections is not covered in this European Standard.
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 335-1, Durability of wood and wood-based products — Definition of use classes — Part 1: General
EN 335-2, Durability of wood and wood-based products — Definition of use classes — Part 2: Application to
solid wood
EN 336, Structural timber — Sizes, permitted deviations
EN 338, Structural timber — Strength classes
EN 350-1, Durability of wood and wood-based products — Natural durability of solid wood — Part 1: Guide
to the principles of testing and classification of the natural durability of wood
EN 350-2, Durability of wood and wood-based products — Natural durability of solid wood — Part 2: Guide
to natural durability and treatability of selected wood species of importance in Europe
EN 384, Structural timber — Determination of characteristic values of mechanical properties and density
EN 844-7, Round and sawn timber — Terminology — Part 7: Terms relating to anatomical structure of
timber
EN 844-9, Round and sawn timber — Terminology — Part 9: Terms relating to features of sawn timber
EN 844-10, Round and sawn timber — Terminology — Part 10: Terms relating to stain and fungal attack
EN 1310:1997, Round and sawn timber — Method of measurement of features
EN 1912:2004+A4:2010, Structural timber — Strength classes — Assignment of visual grades and species
EN 1995-1-2, Eurocode 5 –Design of timber structures – Part 1-2: General – Structural fire design
prEN 14081-1:2012 (E)
EN 13183-2, Moisture content 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
EN 13238, Reaction to fire tests for building products — Conditioning procedures and general rules for
selection of substrates
EN 13501-1:2007+A1:2009, Fire classification of construction products and building elements — Part 1:
Classification using test data from reaction to fire tests
EN 13501-2:2007+A1:2009, Fire classification of construction products and building elements — Part
2:Classification using data from fire resistance tests, excluding ventilation services
EN 13556, Round and sawn timber — Nomenclature of timbers used in Europe
EN 13823, Reaction to fire tests for building products — Building products excluding floorings exposed to
the thermal attack by a single burning item
EN 14081-2, Timber structures — Strength graded structural timber with rectangular cross section — Part 2:
Machine grading; additional requirements for initial type testing
EN 14081-3, Timber structures — Strength graded structural timber with rectangular cross section — Part 3:
Machine grading; additional requirements for factory production control
EN 15228:2009, Structural timber — Structural timber preservative treated against biological attack
EN ISO 3166-1, Codes for the representation of names of countries and their subdivisions — Part 1:
Country codes (ISO 3166-1)
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
batch
timber of one species, species combination, population and size graded in one working shift. In the case of
machine graded timber, the timber should also be graded by one machine.
3.2
characteristic strength
population 5-percentile value obtained from the results of tests with a duration of (300 ± 120) s using test
pieces at an equilibrium moisture content resulting from a temperature of 20 °C and a relative humidity of 65
%
3.3
control plank
object that simulates the characteristics of timber that are being sensed by the measuring devices in a
grading machine, which, when passed through the machine, is able to check the calibration of the machine
dynamically
3.4
dry-graded timber
timber that is part of a batch that has intentionally been graded at a mean moisture content of 20 % or less,
without any measurement exceeding 24 %
3.5
grade
strength grade or strength class
prEN 14081-1:2012 (E)
3.6
machine strength grading
process by which a piece of timber can be sorted by a machine sensing, non-destructively, one or more
properties of the timber, with any necessary visual overriding inspection, into grades to which characteristic
values of strength, stiffness and density may be allocated. There are two methods of control, machine
control and output control (see Introduction)
3.7
package
timber
- of one grade,
- of one species or species combination,
- of one cross section size or of multiple sizes where the timber is to be used for one structure,
- graded in one working shift
- to be delivered to one customer
3.8
producer
legal entity responsible for the conformity of the product to the requirements of this European Standard
3.9
settings
values associated with the variable controls of a grading machine which determine the acceptance to each
grade of timber graded by the machine
3.10
strength class
result of the classification of structural timber based on particular values of its mechanical properties and
density
3.11
strength-reducing characteristic
property or feature of a piece of timber that reduces its load bearing capacity
Note 1 to entry: Can result from natural growth of the tree (e.g. knots, slope of grain), changes in moisture content
(e.g. fissures), conversion of the log (e.g. the inclusion of wane), attack from fungi, insects or mechanical damage.
3.12
timber population
timber from an identifiable source and of a species or species combination that is, or is intended to be,
strength graded and marketed as a commercially defined product
3.13
timber size
sawn or processed dimensions with respect to the permitted deviations given in EN 336
3.14
visual strength grading
process by which a piece of timber can be sorted, by means of visual inspection, into a grade to which
characteristic values of strength, stiffness and density may be allocated
Note 1 to entry: Electronic or mechanical instruments can be used to assist the visual grader in this process.
3.15
width
greater dimension perpendicular to the longitudinal axis of a piece of timber
prEN 14081-1:2012 (E)
4 Symbols
None.
5 Requirements for structural timber
5.1 Strengths, modulus of elasticity and density
5.1.1 General on grading
Structural timber, shall be either visually graded according to 5.1.2 or machine graded according to 5.1.3,
and have characteristic values for the edgewise bending strength, tension strength, compression strength,
shear strength, modulus of elasticity and density according to the method given in 5.1.2 or 5.1.3.
If the grading has been carried out before processing, provided that the processing reduction is not greater
than 5 mm for dimensions less than or equal to 100 mm, or not greater than 10 mm for dimensions greater
than 100 mm, the grade shall be considered not to have changed. If the reduction is greater, the timber
shall be re-graded.
Moisture content shall be determined in accordance with EN 13183-2 or EN 13183-3. The accuracy of
moisture meter shall be ± 2 %.
If the grading method restricts the timber to a special use, e.g. flatwise bending or compression, the timber
shall be marked accordingly.
5.1.2 Visual strength grading
Timber shall be graded visually in accordance to a national grading standard that meets the requirements
given in Annex A.
If the grade and species have been assigned to a strength class by EN 1912, the characteristic values for
the properties shall be those given for the assigned strength class in EN 338; otherwise they shall be
determined in accordance with EN 384.
If there are any restrictions or additional criteria related to the strength or constructional use of timber,
resulting from the method of grading or species of timber, they shall be stated in the grading standard.
5.1.3 Machine strength grading
If the timber is machine graded to a strength class from EN 338, the characteristic values for the properties
shall be those given for the strength class in EN 338; otherwise they shall be determined in accordance with
EN 384.
For a grade and species (or species combination) graded by a machine controlled system, the settings shall
be derived for the total growth area from which the timber will be graded within one or more countries.
Grading machines shall use settings determined in accordance with EN 14081-2. Grading machines and
settings used in machine controlled system shall be evaluated by CEN/TC124. Accepted settings shall be
documented in Approved Grading Reports (AGR).
NOTE Approved Grading Reports are intended to give basic documentation for the certification by a Notified Body
of a producer's factory production control (FPC) needed for the CE marking. An updated list of AGRs may be obtained
through CEN/TC124.
The visual characteristics of each piece of machine graded timber shall meet the requirements given in
Table 1.
prEN 14081-1:2012 (E)
Table 1 — Visual override inspection requirements for machine strength graded structural timber
Strength class acc. to EN 338 C18 and below Above C18
Fissures not Fissures less than half the thickness may be ignored e
going through
Not greater than 1,5 m or ½ the length Not greater than 1 m or ¼ the
the thickness
of the piece, whichever is the lesser length of the piece, whichever
Max. length
a is the lesser
of fissures
Fissures going Not greater than 1 m or ¼ the length of Only permitted at the ends with
through the the piece, whichever is the lesser. If at a length not greater than the
thickness the ends, a length not greater than two width of the piece
times the width of the piece
Bow 20 mm 10 mm
b
Max. warp
Spring 12 mm 8 mm
in mm over
Twist 2 mm/25 mm width 1 mm/25 mm width
2 m of length
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 Soft rot shall not be permitted. Soft rot shall not be permitted.
c
dote (see
Dote is permitted Dote shall not be permitted
EN 844-10)
Insect Active infestation shall not be permitted. Wood wasp holes shall not be
damage permitted and worm and pin holes shall be assessed as other defects
Other Where the reduction in strength caused by the other defect is obviously less
defects 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 The length of fissures is linked with moisture content and therefore the limits given apply only at the time of grading.
As a consequence of this, the moisture content at the time of grading should be appropriate to the end-use.
Permitted limits for both the depth and length of fissures refer to the sum of fissures in one plane in a piece of timber.
b Warp is influenced by moisture content, so the limits apply only at the time of grading. As a consequence of this ,
the moisture content at the time of grading should be appropriate to the end-use. Longitudinal curvature in square
section pieces may be assessed using the limits for bow.
c Stain is not a structural defect and is acceptable without limitation.
d Other defects include for example mechanical damage, top rupture, included bark
e A 0.2 mm feeler gauge is a suitable device for measuring fissure depth

Where a machine does not fully grade to the ends of each piece of timber (as in bending type machines)
these non-fully graded portions shall be visually examined. If the diameter of knots and slope of grain in the
non-fully graded portions exceeds the size of such defects exceeds the limits given in Table 2, then the
piece of timber shall be rejected. Knots and slope of grain shall be measured in accordance with EN 1310.
Timber that has previously been graded shall not be re-graded to the same or different grades unless the
method of determining settings has made allowances for such changes to the timber population caused by
the previous grading.
prEN 14081-1:2012 (E)
Table 2 — Visual override inspection requirements for non-fully machine graded portions
Strength class according to EN 338
C18 and below Above C18
Knot diameter on face up to ½ x width of piece up to ¼ x width of piece
Knot diameter on edge up to ¾ x thickness of piece up to ½ x thickness of piece
Slope of grain 1 in 6 1 in 10
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 Dimensional stability
Dimensional stability shall be considered as swelling and shrinkage of structural timber due to changes of
its moisture content.
Swelling and shrinkage values can be regarded as constant values in the perpendicular to grain directions
of timber, as given in EN 336,. These values are negligible along the grain.
5.3 Fire resistance R
Where required, the fire resistance performance R of the structural timber either treated against biological
attack or not, shall be declared according to EN 13501-2.
For this purpose the timber cross section sizes, determined according to EN 336, and the species shall be
declared enabling so that this performance can be calculated later according to EN 1995-1-2 for the specific
end-use situation.
5.4 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:
1)
a) either without the need for further testing (CWFT), as given in Table 3 , if the 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.
Table 3 — Structural timber considered as classified without the need for further testing (CWFT)
Minimum Minimum
a b
Product Product detail Class
mean overall
c (excluding
density thickness
3 floorings)
(kg/m ) (mm)
Structural Visual and machine graded structural timber
timber with rectangular cross-sections shaped by 350 22 D-s2, d0
sawing, planning or other methods or with

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), secondly by 2006/673/EC of 2006-10-05 (see OJEU
L276 of 2006-10-07) and thirdly by 2007/348/EC of 2007-05-15 (see OJEU L131 of 2007-05-23),
prEN 14081-1:2012 (E)
round cross-sections
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.
When tested as SBI according to EN 13823 under option b), the 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).
5.5 Durability against biological attack
5.5.1 Timber without preservative treatment
The natural durability in accordance with EN 350-2 shall be declared.
5.5.2 Timber with preservative treatment
If a preservative treatment is used, information in accordance with EN 15228 shall be declared.
6 Evaluation of conformity
6.1 General
The compliance of structural timber with the requirements of this standard and with the declared values
(including strength grades or strength classes) shall be demonstrated by:
 Initial Type Testing;
 factory production control by the manufacturer, including product assessment.
The manufacturer shall always retain the overall control and shall have the necessary means to take
responsibility for the product.
6.2 Initial Type Testing – Type Testing
6.2.1 General
Initial Type Testing and Type Testing shall be performed to demonstrate compliance with this European
standard.
All essential characteristics, for which the manufacturer declares performances, are subject to Initial Type
Testing. In addition, the need to perform Type Tests applies to all other characteristics included in a
standard when the manufacturer claims compliance, unless the standard gives provisions (e.g. use of
previously existing data, CWFT and conventionally accepted performance) for declaring performances
without performing tests.
For machine strength graded timber, initial type testing shall be carried out in accordance with
EN 14081-2.
prEN 14081-1:2012 (E)
Control planks shall meet the requirements given in EN 14081-3
Tests previously performed in accordance with the provisions of this standard, may be taken into account
provided that they were made to the same or a more rigorous test method, under the same system of
attestation of conformity on the same product or products of similar design, construction and functionality,
such that the results are applicable to the product in question.
For the purposes of testing, the manufacturer's products may be grouped into families, where it is shown
that the results for one or more characteristics from any one product within the family are representative for
that same characteristic for all products within that same family (a product may be in different families for
different characteristics).
NOTE Reference to the test method standards should be made to allow the selection of a suitable representative
sample.
In addition, Type Tests or Initial Type Testing shall be performed for all characteristics included in the
standard for which the manufacturer declares performances:
 at the beginning of the production of a new or modified structural timber (unless a member of the same
family), or
 at the beginning of a new or modified method of production (where this may affect the stated
properties); or
they shall be repeated for the appropriate characteristic(s), whenever a change occurs, in the raw material,
or in the production process (subject to the definition of a family), which would affect significantly one or
more of the characteristics.
Products marked in accordance with appropriate harmonised European specifications may be presumed to
have the performances stated with that marking,
6.2.2 Test samples, testing and compliance criteria
The number of samples of structural timber to be tested/assessed shall be in accordance with Table 4
Table 4 — Sampling plan, test methods and compliance criteria for initial type testing

Characteristics Requirement Sampling Compliance criteria
clause and testing
method
5.1.1 and 5.1.2 EN 384 Characteristic values determined according to
• Strength:
for visual EN 384 shall not be less than declared values.
- bending,
grading
- tension
- compression,
5.1.1 and 5.1.3 EN 14081-2 Characteristic values shall be in accordance
- shear; and
for machine with EN 14081-2.
• Modulus of elasticity
grading
• Density
Dimensional stability 5.2 - Swelling & shrinkage value in the perpendicular
to grain directions of timber, as given in EN 336

Fire resistance R 5.3 - Timber cross section sizes, determined acc. to
a)
EN 336, and the species declared .
b)
Reaction to fire - Class given in Table 3 for CWFT, or
5.4.a)
Class A1 to F determined after testing done in
5.4.b)
EN 13501-1 accordance with EN 13501-1
Durability: 5.5.1 EN 350-1 For known species: taken as given in EN 350-2;
Natural durability EN 350-2 otherwise tested in accordance with EN 350-1
prEN 14081-1:2012 (E)
Durability: 5.5.2 EN 15228 To be declared according to EN 15228:
Timber treated against
biological attacks
a) This will enable that this performance, expressed acc. to EN 13501-2, can be calculated later according to EN 1995-1-2 for
the specific end-use situation.
b) In this case the requirements are met for timber assigned to strength classes according EN 338 and having
dimensions according to EN 336.
6.2.3 Test reports
All Type Tests, and/or Initial Type Tests and their results shall be documented in test reports. All test
reports and Approved Grading Reports (where applicable) shall be retained by the manufacturer for at least
10 years after the last date of production of the structural timber to which they relate.
6.3 Factory production control (FPC)
6.3.1 General
The manufacturer shall establish, document and maintain an FPC system to ensure that the products
placed on the market comply with the declared performance of the characteristics.
The FPC system shall consist of procedures, regular inspections and tests and/or assessments and the use
of the results to control raw materials, equipment, the production process and the product. All the elements,
requirements and provisions adopted by the manufacturer shall be documented in a systematic manner in
the form of written policies and procedures.
This production control system documentation shall ensure a common understanding of conformity
evaluation and enable the achievement of the required product characteristics and the effective operation of
the production control system to be checked. FPC therefore brings together operational techniques and all
measures allowing maintenance and control of the compliance of the product with this European standard.
In addition to the other requirements given in this clause for the FPC of machine graded timber, the
requirements of EN 14081-3 shall apply.
6.3.2 Requirements
6.3.2.1 General
The manufacturer is responsible for organizing the effective implementation of the FPC system. Tasks and
responsibilities in the production control organization shall be documented and this documentation shall be
kept up-to-date.
The responsibility, authority and the relationship between personnel that manages, performs or verifies
work affecting product conformity, shall be defined. This applies in particular to personnel that need to
initiate actions preventing product non-conformities from occurring, actions in case of non-conformities and
to identify and register product conformity problems. Personnel performing work affecting product
conformity shall be competent on the basis of appropriate education, training, skills and experience for
which records shall be maintained.
Competence of the personnel involved in the grading process shall be checked at least annually. The check
shall include the assessment of graded timber.
In each factory the manufacturer may delegate the action to a person having the necessary authority to:
 identify procedures to demonstrate conformity of the product at appropriate stages;
 identify and record any instance of non-conformity;
 identify procedures to correct instances of non-conformity.
prEN 14081-1:2012 (E)
The manufacturer shall draw up and keep up-to-date documents defining the FPC. The manufacturer's
documentation and procedures should be appropriate to the product and manufacturing process. The FPC
system should achieve an appropriate level of confidence in the conformity of the product. This involves:
a) the preparation of documented procedures and instructions relating to FPC operations, in accordance
with the requirements of the technical specification to which reference is made;
b) the effective implementation of these procedures and instructions;
c) the recording of these operations and their results;
d) the use of these results to correct any deviations, repair the effects of such deviations, treat any
resulting instances of non-conformity and, if necessary, revise the FPC to rectify the cause of non-
conformity.
NOTE Manufacturers having an FPC system, which complies with EN ISO 9000 series standard and which
addresses the requirements of this European standard are recognized as satisfying the FPC requirements of the
Council Directive 89/106/EEC.
6.3.2.2 Equipment
6.3.2.2.1 Testing
All weighing, measuring and testing equipment shall be calibrated and regularly inspected according to
documented procedures, frequencies and criteria.
Manufacturer’s records with regard to suitability, set-up, calibration, service and maintenance of the grading
machine, and the derivation and use of settings, as required in EN 14081-2 and EN 14081-3, shall be
checked and monitored.
6.3.2.2.2 Manufacturing
All equipment used in the manufacturing process shall be regularly inspected and maintained to ensure
use, wear or failure does not cause inconsistency in the manufacturing process. Inspections and
maintenance shall be carried out and recorded in accordance with the manufacturer’s written procedures
and the records retained for the period defined in the manufacturer's FPC procedures.
6.3.2.3 Raw materials
The specifications of all incoming raw materials shall be documented, as shall the inspection scheme for
ensuring their compliance.
6.3.2.4 Traceability and marking
Individual product batches or packages shall be identifiable and traceable with regard to their production
origin. The manufacturer shall have written procedures ensuring that processes related to affixing
traceability codes and/or markings are inspected regularly.
6.3.2.5 Controls during manufacturing process
The manufacturer shall plan and carry out production under controlled conditions.
6.3.2.6 Product testing and evaluation
The manufacturer shall establish procedures to ensure that the stated values of the characteristics he
declares are maintained.
The following shall be controlled at least once per shift:
prEN 14081-1:2012 (E)
a) timber source, species
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