SIST EN 14081-1:2006
(Main)Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements
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 covers structural rectangular timber, untreated or treated against biological attack.
This European Standard does not cover timber treated by fire retardant products.
This European Standard identifies as a minimum the characteristics for which limits shall be given in visual grading rules.
Finger jointed timber 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 Anforderungen an visuell und maschinell sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt fest, welches durch Sägen, Hobeln oder andere Produktionsverfahren hergestellt wurde und die zulässigen Maßabweichungen nach EN 336 einhält.
Diese Europäische Norm gilt für Bauholz für tragende Zwecke mit rechteckigem Querschnitt, das entweder unbehandelt oder gegen biologischen Befall behandelt wurde.
Bauholz, das mit Feuerschutzmitteln behandelt wurde, ist nicht Gegenstand dieser Europäischen Norm.
Diese Europäische Norm legt diejenigen Merkmale, für die Grenzwerte in den visuellen Sortierregeln anzugeben sind, fest.
Keilgezinktes Bauholz ist nicht Gegenstand dieser Europäischen Norm.
Structures en bois - Bois de structure de section rectangulaire classé selon la résistance - Partie 1: Exigences générales
La présente Norme européenne prescrit les exigences applicables au bois de structure de sections rectangulaires classé visuellement et par machine, profilé par sciage, rabotage ou d’autres méthodes, et dont les dimensions s’écartent des dimensions cibles correspondant a l’EN 336.
La présente Norme européenne couvre le bois de structure rectangulaire, non traité ou traité contre les attaques biologiques.
La présente Norme européenne ne couvre pas le bois traité par des produits contre le feu.
La présente Norme européenne identifie les caractéristiques pour lesquelles, au minimum, doivent etre établies des limites dans les regles de classement visuel.
Le bois avec aboutages a entures multiples n’est pas couvert par la présente Norme européenne.
Lesene konstrukcije - Razvrščanje konstrukcijskega lesa s fazonskimi kosi po trdnosti - 1. del: Splošne zahteve
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirementsStructures en bois - Bois de structure de section rectangulaire classé selon la résistance - Partie 1: Exigences généralesHolzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt - Teil 1: Allgemeine AnforderungenTa slovenski standard je istoveten z:EN 14081-1:2005SIST EN 14081-1:2006en91.080.2079.040ICS:SIST EN 519:1996SIST EN 518:19961DGRPHãþDSLOVENSKI
STANDARDSIST EN 14081-1:200601-maj-2006
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14081-1November 2005ICS 79.040Supersedes EN 518:1995, EN 519:1995
English VersionTimber structures - Strength graded structural timber withrectangular cross section - Part 1: General requirementsStructures en bois - Bois de structure à sectionrectangulaire classé pour sa résistance - Partie 1:Exigences généralesHolzbauwerke - Nach Festigkeit sortiertes Bauholz fürtragende Zwecke mit rechteckigem Querschnitt - Teil 1:Allgemeine AnforderungenThis European Standard was approved by CEN on 26 August 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2005 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14081-1:2005: E
EN 14081-1:2005 (E) 2 Contents Page Foreword.3 Introduction.4 1 Scope.5 2 Normative references.5 3 Terms and definitions.6 4 Symbols.7 5 Requirements.7 5.1 Grading, general.7 5.2 Visual strength grading.8 5.3 Machine strength grading.8 5.4 Durability against biological attack.10 5.5 Reaction to fire.10 6 Evaluation of conformity.10 6.1 General.10 6.2 Initial type testing and assessment.10 6.3 Factory production control (FPC).12 7 Marking.13 7.1 General.13 7.2 Information on the product (except if omitted for aesthetic reasons).13 7.3 Information either on the product (except if omitted for aesthetic reasons) or in accompanying documentation.13 Annex A (normative)
Requirements for strength reducing characteristics for visual grading standards.16 A.1 Limitations for strength-reducing characteristics.16 A.2 Limitations for geometrical characteristics.17 A.3 Limitations for biological characteristics.18 A.4 Other characteristics.18 Annex B (informative)
Marking codes for single species.19 Annex C (normative)
Reaction to fire: Euroclass without the need for further testing.21 Annex ZA (informative)
Clauses of this European Standard addressing the provisions of the EU Construction Products Directive.22 ZA.1 Scope and relevant characteristics.22 ZA.2 Procedure for attestation of conformity of strength graded structural timber with rectangular cross section.23 ZA.3 Marking.26
EN 14081-1:2005 (E) 3 Foreword This European Standard (EN 14081-1:2005) has been prepared by Technical Committee CEN/TC 124 “Timber structures”, the secretariat of which is held by SFS. 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 May 2006, and conflicting national standards shall be withdrawn at the latest by August 2007. This European Standard 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(s). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this European Standard. This European Standard will supersede EN 518:1995 and EN 519:1995. Other parts of this European Standard 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, EN 14081-4 Timber structures - Strength graded structural timber with rectangular cross section - Part 4: Machine grading; grading machine settings for machine controlled systems. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EN 14081-1:2005 (E) 4 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 of around one working shift or more. 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. 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.
EN 14081-1:2005 (E) 5 1 Scope 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 covers structural rectangular timber, untreated or treated against biological attack. This European Standard does not cover timber treated by fire retardant products. This European Standard identifies as a minimum the characteristics for which limits shall be given in visual grading rules. Finger jointed timber is not covered in this European Standard. 2 Normative references The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. 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 408, Timber structures — Structural timber and glued laminated timber — Determination of some physical and mechanical properties 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, Structural timber — Strength classes — Assignment of visual grades and species EN 13183-2, Moisture content of a piece of sawn timber — Part 2: Estimation by electrical resistance method EN 13238, Reaction to fire tests for building products — Conditioning procedures and general rules for selection of substrates EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification using test data from reaction to fire tests EN 13556, Round and sawn timber — Nomenclature of timbers used in Europe
EN 14081-1:2005 (E) 6 EN 13823, Reaction to fire tests for building products — Building products excluding floorings exposed to the thermal attack by a single burning item EN 14081-2:2005, Timber structures
— Strength graded structural timber with rectangular cross section — Part 2: Machine grading; additional requirements for initial type testing EN 14081-3:2005, Timber structures — Strength graded structural timber with rectangular cross section — Part 3: Machine grading; additional requirements for factory production control EN 14081-4:2005, Timber structures — Strength graded structural timber with rectangular cross section — Part 4: Machine grading; grading machine settings for machine controlled systemsprEN 15228, 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 3166-1:1997) EN ISO 11925-2, Reaction to fire tests — Ignitability of building products subjected to direct impingement of flame — Part 2: Single-flame source test (ISO 11925-2:2002) 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 batch timber of one species 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 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 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 producer legal entity responsible for the conformity of the product to the requirements of this European Standard
EN 14081-1:2005 (E) 7 3.8 settings values associated with the variable controls of a grading machine which determine the acceptance to each grade of timber graded by the machine 3.9 species 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 3.10 strength-reducing characteristic property or feature of a piece of timber that reduces its load carrying capacity NOTE 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. 3.11 strength class result of the classification of timber based on particular values of mechanical properties and density 3.12 timber size sawn or processed dimensions with respect to the permitted deviations given in EN 336 3.13 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 Electronic or mechanical instruments can be used to assist the visual grader in this process. 3.14 width greater dimension perpendicular to the longitudinal axis of a piece of timber 4 Symbols None. 5 Requirements 5.1 Grading, general 5.1.1 Timber shall be either visually graded according to 5.2 or machine graded according to 5.3, and have characteristic values for the bending strength, tension strength, compression strength, shear strength, modulus of elasticity and density according to the method given in the appropriate subclause in 5.2 or 5.3. 5.1.2 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.
EN 14081-1:2005 (E) 8 5.1.3 Moisture content shall be determined in accordance with EN 13183-2. NOTE A third part of EN 13183 is being drafted for determining moisture content using capacitance meters. 5.1.4 If the grading method restricts the timber to a special use, e.g. flatwise bending or compression, the timber shall be marked accordingly. 5.2 Visual strength grading 5.2.1
Timber shall be visual graded to a grading standard that meets the requirements given in Annex A. 5.2.2 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 are determined in accordance with EN 384. 5.2.3 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. 5.3 Machine strength grading 5.3.1 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. 5.3.2 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. Timber from a lesser area e.g. sub-division of the growth area, i.e. region within a country, shall be machine graded using the output controlled system. 5.3.3 Grading machines operating in a machine controlled system shall use settings determined in accordance with Clause 6 in EN 14081-2:2005 and listed in EN 14081-4:2005. Machines operating in an output controlled system shall use settings determined in accordance with Clause 7 of EN 14081-2:2005. 5.3.4 The visual characteristics of each piece of machine graded timber shall meet the requirements of the grade, which shall as a maximum be those given in Table 1. Fissures, warp and slope of grain shall be measured in accordance with EN 1310. 5.3.5 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 in the fully graded portion of the same piece of timber, and exceeds the limits given in Table 2, then the piece shall be rejected. 5.3.6 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 species population caused by the previous grading. NOTE The number of grades that can be graded in one pass through the machine will depend upon the accuracy and capabilities of the machine and the settings available.
EN 14081-1:2005 (E) 9 Table 1 – Visual override requirements (see 5.3.4) Strength class according to EN 338 C18 and below Above C18
Fissures less than half the thickness may be ignored Fissures not going through the thickness Not greater than 1,5 m or ½ the length of the piece, whichever is the lesser Not greater than 1 m or ¼ the length of the piece, whichever is the lesser
Max. permitted length of fissures a Fissures going through the thickness Not greater than 1 m or ¼ 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 Bow 20 mm 10 mm Spring 12 mm 8 mm Twist 2 mm/25 mm width 1 mm/25 mm width
Max. warp b in mm over 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 dote c (see EN 844-10)
Soft rot is not permitted. Dote is permitted Soft rot is not permitted. Dote is not permitted Insect damage
No active infestation is permitted. Wood wasp holes are not permitted and worm and pin holes shall be assessed as abnormal defects Abnormal defects
Where the reduction in strength caused by the abnormal defect is obviously less than caused by other 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. Limitations on fissures for special grades for specific components may be disregarded if research confirms that they have no effect on strength. Permitted limits for both the depth and length of fissures refer to the cumulative sum of fissures in one plane in a piece of timber. b Because warp is influenced by moisture content, the limits apply only at the time of grading. Limits of warp will be less if required by the method of operation of the grading machine. Longitudinal curvature in square section pieces shall be assessed using the limits for bow. c Sapstain is not a structural defect and is acceptable without limitation.
EN 14081-1:2005 (E) 10 Table 2 – Visual override requirements for non-fully machine graded portions (see 5.3.5)
Strength class according to EN 338
C18 and below Above C18 Knot diameter on face ½ x width of piece ¼ x width of piece Knot diameter on edge ¾ x thickness of piece ½ x thickness of piece Slope of grain 1 in 6 1 in 10 NOTE 1 These maximum limits are only applicable 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.
5.4 Durability against biological attack 5.4.1 Natural durability If listed in EN 350-2, the natural durability shall be as given therein; otherwise it shall be assessed in accordance with EN 350-1. 5.4.2 Timber treated against biological attack Timber treated against biological attack shall meet the requirements of prEN 15228. 5.5 Reaction to fire Where the manufacturer wishes to claim performance (e.g. when the product is subject to regulatory requirements) reaction to fire shall be tested and classified according to EN 13501-1, except for products covered by Annex C, which are classified without the need for further testing. 6 Evaluation of conformity 6.1 General Compliance with the requirements of this European Standard shall be demonstrated by: initial type testing or initial assessment; factory production control by the producer. All records shall be kept for at least ten years. 6.2 Initial type testing and assessment 6.2.1 Initial type testing or assessment shall be performed to demonstrate conformity with this European Standard and when a change occurs, e.g. in raw materials, which could significantly change one or more of the characteristics. Where testing has previously been performed according to the requirements of this European Standard, such testing may be taken into account for the purpose of initial type testing.
EN 14081-1:2005 (E) 11 6.2.2 For machine graded timber, initial type testing shall be carried out in accordance with
EN 14081-2. 6.2.3 Where control planks are required to be used to calibrate a grading machine, they shall meet the requirements of Annex C in EN 14081-2:2005. 6.2.4 The testing and assessment methods shall be in accordance with Table 3. Table 3 – Sampling plan and compliance criteria for initial and further testing Property Requirement Method Number of specimens Compliance criteria Characteristic strength - bending - compressive - tensile - shear - density
See EN 408 or for machine grading see EN 14081-2 See EN 384 or for machine grading see EN 14081-2 Characteristic values estimated according to EN 384 shall not be less than declared values. For machine grading see EN 14081-2 Modulus of elasticity
See EN 408 or for machine grading see EN 14081-2 See EN 384 or for machine grading see EN 14081-2 Characteristic values estimated according to EN 384 shall not be less than declared values. For machine grading see EN 14081-2 Natural durability Fungi: Class 1-5 Termites, wood boring insects and marine organisms: Class D,M,S Beetles: Class D,S,SH EN 350-1 EN 350-2
Natural durability shall be taken as given in EN 350-2. If the species is not given it shall be tested in accordance with EN 350-1 Timber treated against biological attacks See 5.4.2
Reaction to fire Class C − E
EN 13823 EN ISO 11925-2 See EN 13501-1a The requirements of the declared class shall be fulfilled a CWFT products (see Annex C) do not require direct testing of reaction to fire.
EN 14081-1:2005 (E) 12 6.3 Factory production control (FPC) 6.3.1 The producer shall establish document and maintain a production control system to ensure that the products placed on the market conform with the stated characteristics. The control system shall consist of procedures, regular inspections and test and/or assessment, and the use of the results to control raw materials, equipment, the process and the product. 6.3.2 In addition to the other requirements given in this clause for the factory production control of machine graded timber, the requirements of EN 14081-3 apply. 6.3.3 Where it is required to use control planks to calibrate a grading machine, the procedures given in Annex B of EN 14081-3:2005 shall be followed. 6.3.4 The results of inspections, tests or assessments requiring action shall be recorded, as shall any action taken. The action to be taken when control values or criteria are not met shall be recorded. 6.3.5 The following shall be controlled once per shift: timber source and species (or species combination); deviations from target size; grading; moisture content, if dry-graded timber; marking. 6.3.6 The following shall be controlled at least annually: competence of the personnel, including the assessment of graded material; calibration of moisture meter. 6.3.7 The following records shall be kept for each batch of graded timber: a) job or order number and customer's name, if known; b) timber species population; c) grades and grading standard (where appropriate); d) timber size and surface finish (planed or sawn); e) for timber that is dry-graded, the moisture content; f) date and working shift; g) grader's or machine operator's name. 6.3.8 In addition to 6.3.7 the following records shall be kept for each batch of machine graded timber: a) number of pieces in each grade and the number of pieces rejected by the machine; b) all machine settings.
EN 14081-1:2005 (E) 13 7 Marking 7.1 General Each piece of graded timber shall be clearly and indelibly marked to provide the information given in 7.2. If the end use of the timber requires marking to be omitted for aesthetic reasons, each batch of timber shall be accompanied by a commercial document bearing all the information given in 7.2 and 7.3. 7.2 Information on the product (except if omitted for aesthetic reasons) a)
Name or identifying mark of producer. b)
Either the information required in 7.3 or a reference number that identifies the documentation containing the information required in
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.