SIST EN 16351:2021
(Main)Timber structures - Cross laminated timber - Requirements
Timber structures - Cross laminated timber - Requirements
This document sets out requirements regarding the performance of characteristics of the following types of cross laminated timber to be used in buildings and bridges:
- type 1: Straight or curved cross laminated timber comprising only timber layers but no large finger joints;
- type 2: Straight cross laminated timber comprising only timber layers and large finger joints;
- type 3: Straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints.
It also lays down procedures for assessment and verification of constancy of performance (AVPC) of characteristics and specifies marking and labelling of cross laminated timber.
This document covers cross laminated timber of all three types of cross laminated timber:
- manufactured according to this standard, which sets up provisions for:
- boundary conditions during manufacture of cross laminated timber;
- moisture content and temperature of timber to be bonded;
- production of finger joints and bonds between layers;
- to be used in service class 1 or 2 according to EN 1995 1 1;
- made of coniferous species and poplar listed in this standard;
- which may be made of layers made of different species having similar properties;
- bonded with phenolic or aminoplastic or moisture curing one-component polyurethane or emulsion polymer isocyanate adhesives of adhesive type I according to the respective standard;
- built up of at least three orthogonally bonded layers (at least two of them timber layers);
- which may have, depending on the number of layers, adjacent layers bonded parallel to the grain;
- made of timber layers which are made of strength graded timber according to EN 14081 1;
- made of timber layers having nominal thicknesses between 6 mm (including) and 60 mm (including) depending on the layup;
- made of timber layers
- which may comprise non-structural edge bonds; and
- have a mean gap width of less than or equal to 0,6 mm and a 90th percentile of the gap width of 2 mm;
- having nominal overall thicknesses up to 500 mm.
Additional provisions of this document apply for straight cross laminated timber comprising only timber layers and comprising large finger joints (type 2):
- made from cross laminated timber pieces having the same cross-section and layup;
- made from cross laminated timber pieces having nominal cross-sectional thicknesses from 51 mm (including) up to 345 mm (including) and nominal minimum thicknesses of the outer layers not less than 17 mm (including).
- made from cross laminated timber pieces solely comprising timber layers;
- made from plane cross laminated timber pieces;
- with parallel x-axes of the jointed components;
- with finger joints having a finger length of at least 45 mm and fingers which are visible at the two narrow sides of the components;
- bonded with phenolic or aminoplastic or moisture curing one-component polyurethane adhesives of adhesive type I according to the respective standard.
Additional provisions of this document apply for straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints (type 3):
- made of structural wood-based panels specified in this European standard;
- made of one panel per layer and;
- having thicknesses between 6 mm (including) and 45 mm (including);
This document applies to cross laminated timber untreated or treated against biological attack.
This document does not cover:
- cross laminated timber treated with fire retardants;
- cross laminated timber which is produced from re-used timber or wood-based panels comprising re-used timber.
Holzbauwerke - Brettsperrholz - Anforderungen
In diesem Dokument werden die Anforderungen an die Leistungsmerkmale der folgenden Arten von Brett-sperrholz festgelegt, die in Gebäuden und Brücken verwendet werden:
- Typ 1 ebenes oder gekrümmtes Brettsperrholz, das nur Brettlagen, aber keine Universal-Keilzinken-verbindungen umfasst;
- Typ 2: ebenes Brettsperrholz, das nur Brettlagen und Universal-Keilzinkenverbindungen umfasst;
- Typ 3: ebenes Brettsperrholz, das Bretter und Holzwerkstofflagen, aber keine Universal-Keilzinken-verbindungen umfasst.
Darüber hinaus legt die Norm auch Verfahren zur Bewertung und Überprüfung der Leistungsbeständigkeit (AVCP) von Merkmalen sowie die Kennzeichnung und Etikettierung von Brettsperrholz fest.
Dieses Dokument gilt für alle drei Arten von Brettsperrholz:
- das nach dieser Norm hergestellt wurde, die folgende Bestimmungen festlegt:
- Randbedingungen bei der Herstellung von Brettsperrholz;
- Feuchtegehalt und Temperatur der zu verklebenden Bretter;
- Herstellung von Keilzinkenverbindungen und Klebverbindungen zwischen Lagen;
- das in der Nutzungsklasse 1 oder 2 nach EN 1995 1 1 angewendet wird;
- das aus Pappel oder Nadelholzarten besteht, die in dieser Norm aufgeführt sind;
- das aus Lagen bestehen darf, die aus verschiedenen Holzarten mit ähnlichen Eigenschaften hergestellt sind;
- das mit Phenoplast und Aminoplast-Klebstoffen oder einem feuchtigkeitsvernetzenden Ein-komponenten-Klebstoff auf Polyurethanbasis oder Emulsion-Polymer-Isocyanat-Klebstoffen vom Typ I nach der jeweiligen Norm verklebt ist;
- das aus mindestens drei rechtwinklig zueinander verklebten Lagen (mindestens zwei Lagen sind Brettlagen) besteht;
- bei dem je nach Anzahl der Lagen aneinandergrenzende Lagen parallel zur Faser verklebt werden dürfen;
- das aus Lagen aus Vollholz (Bretter oder Bohlen, im Folgenden als Bretter bezeichnet) besteht, das entsprechend EN 14081 1 nach Festigkeit sortiert ist;
- das aus Brettlagen mit Nenndicken von 6 mm (einschließlich) bis 60 mm (einschließlich) besteht, je nach Aufbau;
- das aus Brettlagen besteht;
- das möglicherweise keine Schmalseitenverklebungen für tragende Zwecke enthält; und
das eine mittlere Spaltbreite von kleiner oder gleich 0,6 mm und ein 90. Perzentil der Spaltbreite von 2 mm aufweist;
- das Gesamt-Nenndicken von bis zu 500 mm hat.
Zusätzliche Bestimmungen dieses Dokuments gelten für ebenes Brettsperrholz, das nur Brettlagen und Universal-Keilzinkenverbindungen (Typ 2) enthält:
- das aus Brettsperrholzstücken mit gleichem Querschnitt und Aufbau besteht;
- das aus Brettsperrholzstücken mit Querschnitts-Nenndicken von 51 mm (einschließlich) bis 345 mm (einschließlich) besteht, wobei die Mindest-Nenndicken der äußeren Lagen mindestens 17 mm (einschließlich) betragen;
- das aus Brettsperrholzstücken besteht, die ausschließlich Brettlagen enthalten;
- das aus ebenen Brettsperrholzstücken besteht;
- mit parallelen x Achsen der verbundenen Bauteile;
- das Keilzinkenverbindungen mit einer Keilzinkenlänge von mindestens 45 mm enthält, wobei die Keilzinken an den beiden Schmalseiten der Komponenten sichtbar sind;
- das mit Phenoplast und Aminoplast-Klebstoffen oder einem feuchtigkeitsvernetzenden Ein-komponenten-Klebstoff auf Polyurethanbasis vom Typ I nach der jeweiligen Norm verklebt ist.
Zusätzliche Bestimmungen dieses Dokuments gelten für ebenes Brettsperrholz, das Bretter und Holz-werkstofflagen, aber keine Universal Keilzinkenverbindungen (Typ 3) enthält:
- das aus den in dieser Europäischen Norm festgelegten Holzwerkstoffen für tragende Zwecke besteht;
- das aus einer Platte je Lage besteht und;
- mit Dicken zwischen 6 mm (einschließlich) und 45 mm (einschließlich).
Dieses Dokument gilt für Brettsperrholz, das unbehandelt ist oder gegen biologischen Befall behandelt wurde.
...
Structures en bois - Bois lamellé croisé - Exigences
Le présent document établit les exigences relatives aux propriétés pour les types suivants de bois lamellé croisé devant être utilisés dans les bâtiments et les ponts :
- type 1 : Bois lamellé croisé, droit ou courbe, constitué uniquement de couches de bois et sans aboutage à entures multiples de grandes dimensions ;
- type 2 : Bois lamellé croisé droit, constitué uniquement de couches de bois et comprenant des aboutages à entures multiples de grandes dimensions ;
- type 3 : Bois lamellé croisé droit, constitué de couches de bois et de couches en panneaux à base de bois, sans aboutage à entures multiples de grandes dimensions.
Il établit également les procédures d'évaluation et de vérification de la constance des performances (EVCP) pour les caractéristiques et spécifie le marquage et l'étiquetage du bois lamellé croisé.
Le présent document couvre le bois lamellé croisé appartenant à l'ensemble des trois types de bois lamellé croisé :
- fabriqué conformément à la présente norme, qui établit les dispositions pour :
- les exigences minimales relatives à la fabrication du bois lamellé croisé ;
- la teneur en humidité et la température du bois à coller ;
- la production des aboutages à entures multiples et du collage entre les couches ;
- destiné à être utilisé en classe de service 1 ou 2 conformément à l'EN 1995 1 1 ;
- constitué des essences de bois de résineux et de peuplier énumérés dans la présente norme ;
- qui peut être constitué de couches provenant de différentes essences avec des propriétés similaires ;
- collé avec des adhésifs de nature phénolique ou aminoplaste, des adhésifs polyuréthane monocomposants durcissant à l'humidité ou des adhésifs à base d'isocyanate et de polymère en émulsion de type I conformément à la norme correspondante ;
- constitué d'au moins trois couches collées orthogonalement (au moins deux d'entre elles étant des couches de bois) ;
- pouvant comporter, en fonction du nombre de couches, des couches contigües collées parallèlement au fil ;
- comportant des couches de bois constituées de bois classé pour sa résistance mécanique conformément à l'EN 14081 1 ;
- constitué de couches de bois avec une épaisseur nominale comprise entre 6 mm et 60 mm selon la combinaison ;
- constitué de couches de bois :
- pouvant comporter des collages sur chant non structuraux ; et
- possédant une largeur de jeu moyenne inférieure ou égale à 0,6 mm et un 90e percentile pour la largeur de jeu de 2 mm ;
- ayant des épaisseurs totales nominales inférieures ou égales à 500 mm.
Des dispositions supplémentaires du présent document s'appliquent au bois lamellé croisé droit, constitué uniquement de couches de bois avec aboutages à entures multiples de grandes dimensions (type 2) :
- constitué de pièces de bois lamellé croisé ayant la même section transversale et la même combinaison ;
- constitué de pièces de bois lamellé croisé ayant des épaisseurs de section transversale nominales comprises entre 51 mm (inclus) et 345 mm (inclus), ainsi que des épaisseurs minimales nominales des couches extérieures supérieures ou égales à 17 mm ;
- constitué de pièces de bois lamellé croisé comprenant uniquement des couches de bois ;
- constitué de pièces de bois lamellé croisé planes ;
- avec des axes x parallèles pour les composants aboutés ;
- avec des aboutages à entures multiples ayant une longueur d'au moins 45 mm et des entures qui sont visibles au niveau des deux faces étroites des composants ;
- collé avec des adhésifs de nature phénolique ou aminoplaste, ou des adhésifs polyuréthane monocomposants durcissant à l'humidité de type I conformément à la norme correspondante.
...
Lesene konstrukcije - Križno lamelirani les - Zahteve
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 16351:2021
01-julij-2021
Nadomešča:
SIST EN 16351:2015
Lesene konstrukcije - Križno lamelirani les - Zahteve
Timber structures - Cross laminated timber - Requirements
Holzbauwerke - Brettsperrholz - Anforderungen
Structures en bois - Bois lamellé croisé - Exigences
Ta slovenski standard je istoveten z: EN 16351:2021
ICS:
79.060.10 Vezan les Plywood
91.080.20 Lesene konstrukcije Timber structures
SIST EN 16351:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 16351:2021
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SIST EN 16351:2021
EN 16351
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 79.060.10 Supersedes EN 16351:2015
English Version
Timber structures - Cross laminated timber -
Requirements
Structures en bois - Bois lamellé croisé - Exigences Holzbauwerke - Brettsperrholz - Anforderungen
This European Standard was approved by CEN on 4 January 2021.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16351:2021 E
worldwide for CEN national Members.
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SIST EN 16351:2021
EN 16351:2021 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 7
2 Normative references . 8
3 Terms, definitions and symbols .10
3.1 Terms and definitions .10
3.2 Symbols .16
3.2.1 Main symbols .16
3.2.2 Subscripts .17
4 Characteristics .19
4.1 Modulus of elasticity, bending strength, compressive strength, tensile strength and
shear strength .19
4.1.1 General .19
4.1.2 Geometrical data of cross laminated timber .21
4.1.3 Strength, stiffness and density properties of layers .22
4.1.4 Bending strength of large finger joints .24
4.1.5 Rolling shear strength, compression strength perpendicular to grain and density of
cross laminated timber .24
4.2 Bonding strength .25
4.2.1 General .25
4.2.2 Bonding strength of glue lines between layers .25
4.2.3 Bonding strength of structural edge bonds .26
4.2.4 Bonding strength of large finger joints .26
4.3 Resistance to fire .26
4.4 Reaction to fire .27
4.4.1 General .27
4.4.2 Classification without further testing .27
4.4.3 Classification based on testing .29
4.5 Dimensional stability .30
4.6 Emission of formaldehyde .30
4.7 Durability .31
4.7.1 Durability of bonding strength .31
4.7.2 Durability of other characteristics .32
5 Assessment and Verification of Constancy of Performance (AVCP) .33
5.1 General .33
5.2 Type testing .33
5.2.1 General .33
5.2.2 Test samples, testing and compliance criteria .34
5.2.3 Test reports .41
5.3 Factory production control (FPC) .41
5.3.1 General .41
5.3.2 Provisions .41
5.3.3 Initial inspection of factory and of FPC .51
5.3.4 Continuous surveillance of FPC .51
5.3.5 Procedure for modifications .51
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SIST EN 16351:2021
EN 16351:2021 (E)
Annex A (normative) Delamination test of glue lines between layers . 52
Annex B (normative) Tests with laminations with or without finger joints . 56
Annex C (normative) Determination of strength, stiffness and density characteristics of
cross laminated timber . 59
Annex D (normative) Measurement of moisture content . 76
Annex E (normative) Adhesive application for finger joints in laminations. 77
Annex F (normative) Minimum production provisions . 78
Annex G (normative) Shear tests. 92
Annex H (normative) Additional test methods and requirements for adhesives of subclass
FJ for use in structural edge bonds . 95
Bibliography . 96
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SIST EN 16351:2021
EN 16351:2021 (E)
European foreword
This document (EN 16351:2021) has been prepared by Technical Committee CEN/TC 124 “Timber
structures”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2021, and conflicting national standards shall
be withdrawn at the latest by December 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 16351:2015.
The following changes have been made:
— the standard has been adjusted to the latest versions of standards for adhesives;
— the provisions for reaction and resistance to fire have been modified;
— the provisions for gap widths and ratios of lamination width by thickness have been modified;
— missing provisions for factory production control have been added;
— the provisions for determination of strength, stiffness and density characteristics of cross laminated
timber have been modified;
— the standard has been adjusted to the latest templates;
— Annex ZA has been deleted.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
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SIST EN 16351:2021
EN 16351:2021 (E)
Introduction
Figure 1 shows the relation of some European Standards on structural timber products.
Key
1 boards 6 glued laminated timber (glulam)
2 is a component for 7 glulam with large finger joints
3 structural finger jointed timber 8 block glued glulam
4 glued laminated products 9 cross laminated timber
5 glued solid timber 10 cross laminated timber with large finger joints
Figure 1 — Relation of some European Standards on structural timber products
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SIST EN 16351:2021
EN 16351:2021 (E)
Cross laminated timber in accordance with this document and multilayer solid wood panels in
accordance with EN 13353 may have the same layup, but for cross laminated timber the timber is
strength graded according to EN 14081-1 and the adhesives are tested according to the provisions of this
document.
The following standards mentioned in Clause 2, EN 13986, EN 14080, EN 14081-1, EN 14374 and
EN 15497, are harmonized product standards. The applicable version cited in the Official Journal of the
EU are not necessarily the latest published by CEN.
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SIST EN 16351:2021
EN 16351:2021 (E)
1 Scope
This document sets out provisions regarding the performance of characteristics of the following Types of
cross laminated timber for use in buildings and bridges:
— Type 1: Straight or curved cross laminated timber comprising only timber layers but no large finger
joints;
— Type 2: Straight cross laminated timber comprising only timber layers and large finger joints;
— Type 3: Straight cross laminated timber comprising timber and wood-based panel layers but no large
finger joints.
This document covers cross laminated timber of all three Types of cross laminated timber:
— manufactured according to this document, which sets up provisions for:
— boundary conditions during manufacture of cross laminated timber;
— moisture content and temperature of timber to be bonded;
— production of finger joints and bonds between layers;
— to be used in service class 1 or 2 according to EN 1995-1-1;
— made of coniferous species and poplar listed in this document;
— which may be made of layers made of different species;
— bonded with phenolic or aminoplastic or moisture curing one-component polyurethane or emulsion
polymer isocyanate adhesives of adhesive Type I according to the respective standard;
— made of timber laminations having a nominal width between 40 mm (including) and 300 mm
(including);
— built up of at least three orthogonally bonded layers (at least two of them timber layers);
— which may have, depending on the number of layers, adjacent layers bonded parallel to the grain;
— made of timber layers which are made of strength graded timber according to EN 14081-1;
— made of timber layers having nominal thicknesses between 6 mm (including) and 47 mm (including);
— made of timber layers which may comprise edge bonds;
— having nominal overall thicknesses up to 500 mm.
Additional provisions of this document apply for straight cross laminated timber comprising only timber
layers and comprising large finger joints (Type 2):
— made from cross laminated timber pieces having the same cross-section and layup;
— made from cross laminated timber pieces having nominal cross-sectional thicknesses from 51 mm
(including) up to 345 mm (including) and nominal minimum thicknesses of the outer layers not less
than 17 mm (including);
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SIST EN 16351:2021
EN 16351:2021 (E)
— made from cross laminated timber pieces solely comprising timber layers;
— made from plane cross laminated timber pieces;
— with parallel x-axes of the jointed components;
— with large finger joints having a finger length of at least 45 mm and fingers which are visible at the
two narrow sides of the components;
— having large finger joints bonded with phenolic or aminoplastic or moisture curing one-component
polyurethane adhesives of adhesive Type I according to the respective standard.
Additional provisions of this document apply for straight cross laminated timber comprising timber and
wood-based panel layers but no large finger joints (Type 3):
— made of structural wood-based panels specified in this document;
— made of one panel per layer and;
— having thicknesses between 6 mm (including) and 45 mm (including).
This document applies to cross laminated timber untreated or treated against biological attack.
This document does not cover:
— cross laminated timber treated with fire retardants;
— cross laminated timber which is produced from re-used timber or wood-based panels comprising re-
used timber.
It also lays down procedures for assessment and verification of constancy of performance (AVPC) of cross
laminated timber.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 301:2017, Adhesives, phenolic and aminoplastic, for load-bearing timber structures - Classification and
performance requirements
EN 302-1, Adhesives for load-bearing timber structures - Test methods - Part 1: Determination of
longitudinal tensile shear strength
EN 302-2, Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of resistance
to delamination
EN 338, Structural timber - Strength classes
EN 335, Durability of wood and wood-based products - Use classes: definitions, application to solid wood
and wood-based products
EN 350, Durability of wood and wood-based products - Testing and classification of the durability to
biological agents of wood and wood-based materials
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SIST EN 16351:2021
EN 16351:2021 (E)
EN 351-1, Durability of wood and wood-based products - Preservative-treated solid wood - Part 1:
Classification of preservative penetration and retention
EN 408:2010+A1:2012, Timber structures - Structural timber and glued laminated timber - Determination
of some physical and mechanical properties
EN 717-1, Wood-based panels - Determination of formaldehyde release - Part 1: Formaldehyde emission by
the chamber method
EN 789, Timber structures - Test methods - Determination of mechanical properties of wood based panels
EN 1995-1-1, Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for
buildings
EN 1995-1-2, Eurocode 5: Design of timber structures - Part 1-2: General - Structural fire design
EN 12369-2, Wood-based panels - Characteristic values for structural design - Part 2: Plywood
EN 12369-3, Wood-based panels - Characteristic values for structural design - Part 3: Solid-wood panels
EN 13183-1, Moisture content of a piece of sawn timber - Part 1: Determination by oven dry method
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 by capacitance 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
data from reaction to fire tests
EN 13501-2, Fire classification of construction products and building elements - Part 2: Classification using
data from fire resistance tests, excluding ventilation services
EN 13823, Reaction to fire tests for building products - Building products excluding floorings exposed to the
thermal attack by a single burning item
EN 13986, Wood-based panels for use in construction - Characteristics, evaluation of conformity and
marking
EN 14081-1, Timber structures - Strength graded structural timber with rectangular cross-section - Part 1:
General requirements
EN 14358, Timber structures - Calculation and verification of characteristic values
EN 14374, Timber structures - Structural laminated veneer lumber - Requirements
EN 15228:2009, Structural timber - Structural timber preservative treated against biological attack
EN 15425:2017, Adhesives - One component polyurethane (PUR) for load-bearing timber structures -
Classification and performance requirements
EN 16254:2013+A1:2016, Adhesives - Emulsion polymerized isocyanate (EPI) for load bearing timber
structures - Classification and performance requirements
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EN 16351:2021 (E)
EN ISO 9239-1, Reaction to fire tests for floorings - Part 1: Determination of the burning behaviour using a
radiant heat source (ISO 9239-1)
EN ISO 11925-2:2020, Reaction to fire tests - Ignitability of products subjected to direct impingement of
flame - Part 2: Single-flame source test (ISO 11925-2)
3 Terms, definitions and symbols
For the purposes of this document, the following terms, definitions and symbols apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 Terms and definitions
3.1.1
actual size
measured size of a cross laminated timber at a given moisture content
[SOURCE: EN 14080:2013, 3.1 - modified]
3.1.2
bonding strength
structural effectiveness of adhesives between timber pieces when subjected to stresses
[SOURCE: EN 14080:2013, 3.2]
3.1.3
contact-free application
application without contact between timber and application unit
3.1.4
corrected size
size of a cross laminated timber corrected by calculation from its actual size to its size at the reference
moisture content
[SOURCE: EN 14080:2013, 3.6 - modified]
3.1.5
cross laminated timber
structural timber member composed by at least three face-bonded layers which comprise solid timber
laminations and may comprise wood-based panels, at least one layer orthogonally oriented to the two
adjacent layers
Note 1 to entry: See also Figure 2.
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EN 16351:2021 (E)
Key
1 plane of the element 2 wide face 3 narrow faces 4 outer layers
5 inner layers 6 laminations 7 finger joints in lamination 8 large finger joint
9 usually the length 10 usually the width b of a plate or height h of a beam
CL CL
Figure 2 — Cross laminated timber
3.1.6
delamination length
sum of the lengths of delaminations in one glue line measured around the circumference of a test piece
[SOURCE: EN 14080:2013, 3.8 - modified]
3.1.7
edge bond
bond between adjacent laminations within a timber layer
3.1.8
finger angle
inclination α of each side of the fingers of a finger joint
[SOURCE: EN 14080:2013, 3.10]
Note 1 to entry: See Figure 3.
3.1.9
finger joint
interlocking end joint formed by machining a number of similar, tapered, symmetrical fingers in the ends
of timber components using a finger joint cutter and then bonded together
[SOURCE: EN 14080:2013, 3.11]
Note 1 to entry: In this document, the term finger joint is used for finger joints in laminations whereas finger
joints between cross laminated timber are defined as large finger joints (see 3.1.13).
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Key
b tip width of the cutter b tip width l finger length l slot base p pitch
cut t j t
α finger angle 1 tip base 2 fingertip 3 finger flank
Figure 3 — Typical profile of a finger joint
3.1.10
finger length
distance l between the finger base and the tip of the finger, measured along the centre line of the finger
j
[SOURCE: EN 14080:2013, 3.12]
Note 1 to entry: See Figure 3.
3.1.11
finished thickness
thickness after machining
[SOURCE: EN 14080:2013, 3.13]
3.1.12
lamination
part of a structural glued timber product consisting of one board or two or more finger-jointed boards
[SOURCE: EN 14080:2013, 3.19 - modified]
3.1.13
large finger joint
finger joint through the full cross-sectional area of two cross laminated timber components
[SOURCE: EN 14080:2013, 3.20 - modified]
Note 1 to entry: See Figure 4.
Figure 4 — Cross laminated timber with large finger joint
3.1.14
layer
courses lying over or under another
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3.1.15
layup
cross-sectional arrangement of timber layers which may be assigned to different strength classes
according to EN 338 or different sets of individual values of strength, stiffness and density characteristics
or wood-based panel layers which may be assigned to different strength classes according to EN 12369-2
or EN 12369-3 or different sets of individual values of strength, stiffness and density characteristics
[SOURCE: EN 14080:2013, 3.21 - modified]
3.1.16
maximum delamination length
largest delamination length in any single glue line
[SOURCE: EN 14080:2013, 3.24 - modified]
3.1.17
mean moisture content
mean value of the moisture content of cross laminated timber calculated from at least two measurements
[SOURCE: EN 14080:2013, 3.25 - modified]
Note 1 to entry: See D.2.
3.1.18
minimum mean density
required mean density at reference moisture content, estimated as the weighted mean of the mean
densities of the layers, if necessary
[SOURCE: EN 14080:2013, 3.26]
Note 1 to entry: Minimum mean density is used for the classification of the reaction to fire.
3.1.19
nominal size
size specified at the reference moisture content to which deviations are related
3.1.20
pitch
distance between centres of adjacent fingertips
[SOURCE: EN 14080:2013, 3.27]
Note 1 to entry: See Figure 3.
3.1.21
ratio of resin to hardener
proportion of resin to hardener by mass with the resin set at 100 parts
[SOURCE: EN 14080:2013, 3.28]
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3.1.22
reduction factor
ratio ν between tip width b and pitch p
t
[SOURCE: EN 14080:2013, 3.29 - modified]
Note 1 to entry: See Figure 3.
3.1.23
reference moisture content
moisture content of 12 % at which nominal sizes are established
[SOURCE: EN 14080:2013, 3.30]
3.1.24
relative tip gap
ratio e between tip gap l and finger length l
t j
[SOURCE: EN 14080:2013, 3.31 - modified]
Note 1 to entry: See Figure 3.
3.1.25
re-used timber
timber product made from timber which has been used before
3.1.26
rolling shear
shear stress for which both complementary stress components are perpendicular to the grain
3.1.27
solid wood failure
wood failure which is invariably more than two cell layers away from the adhesive layer
3.1.28
straight cross laminated timber
cross laminated timber having a precamber of up to 1 % of the respective span
3.1.29
timber layer
layer made of timber laminations with or without edge bonds
3.1.30
tip gap
distance l between fingertip and slot base in a bonded finger joint
t
[SOURCE: EN 15497:2014, 3.11]
Note 1 to entry: See Figure 3.
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3.1.31
tip width
distance b between finger flanks, measured at the tip of the finger
t
[SOURCE: EN 14080:2013, 3.35 - modified]
Note 1 to entry: See Figure 3.
3.1.32
total delamination length
sum of delamination lengths of all glue lines
[SOURCE: EN 14080:2013, 3.36 - modified]
3.1.33
wood-based panels
structural plywood and structural solid wood panels according to EN 13986
and structural LVL according to EN 14374
3.1.34
wood-based panel layer
layer made of one piece of wood-based panel
3.1.35
wood failure percentage
percentage of the solid wood failure area after splitting in relation to the glued area before splitting
[SOURCE: EN 14080:2013, 3.38 - modified]
3.1.36
x-axis
axis parallel to grain of the timber layers or outer layers or veneers of wood-based panel layers
Note 1 to entry: See Figure 2.
3.1.37
z-axis
axis perpendicular to the layers
Note 1 to entry: See Figure 2.
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3.2 Symbols
3.2.1 Main symbols
2
A area, in mm ;
2
A area of wane, in mm (see Figure F.1);
w
A* net sehar area,
a size or distance between support and load introduction or excess length in mm;
a length of the diagonals of wane, in mm (see Figure F.1);
w
a maximum length of the diagonal of wane, in mm (see Figure F.2);
w,max
b width, in mm;
b tip width of the cutter (see Figure 3);
cut
b tip width, in mm (see Figure 3);
t
b gap width, in mm;
gap
d diameter, in mm;
d distance, in mm (see Figure 6);
Delam maximum delamination, in %;
max
Delam total delamination, in %;
tot
e relative tip gap;
2
E modulus of elasticity, in N/mm ;
2
E modulus of elasticity related to I , in N/mm ;
local CL,net
2
(EI) appereant bending stiffnes
...
SLOVENSKI STANDARD
oSIST prEN 16351:2019
01-januar-2019
Lesene konstrukcije - Križno lamelirani les - Zahteve
Timber structures - Cross laminated timber - Requirements
Holzbauwerke - Brettsperrholz - Anforderungen
Structures en bois - Bois lamellé croisé - Exigences
Ta slovenski standard je istoveten z: prEN 16351
ICS:
79.060.10 Vezan les Plywood
91.080.20 Lesene konstrukcije Timber structures
oSIST prEN 16351:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 16351:2019
DRAFT
EUROPEAN STANDARD
prEN 16351
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2018
ICS 79.060.10 Will supersede EN 16351:2015
English Version
Timber structures - Cross laminated timber -
Requirements
Structures en bois - Bois lamellé croisé - Exigences Holzbauwerke - Brettsperrholz - 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, 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
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16351:2018 E
worldwide for CEN national Members.
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Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions .10
4 Symbols .14
4.1 Main symbols .14
4.2 Subscripts .15
5 Designation.16
6 Components and product characteristics .16
6.1 Component characteristics .16
6.1.1 Timber .16
6.1.2 Timber laminations .16
6.1.3 Timber layers .17
6.1.4 Wood-based panel layers .17
6.1.5 Species .17
6.1.6 Adhesives .18
6.2 Product characteristics .18
6.2.1 General .18
6.2.2 Modulus of elasticity, bending strength, compressive strength, tensile strength and
shear strength .19
6.2.3 Bonding strength .22
6.2.4 Resistance to fire .23
6.2.5 Reaction to fire .23
6.2.6 Dimensional stability .26
6.2.7 Emission of formaldehyde .26
6.2.8 Durability .27
7 Assessment and Verification of Constancy of Performance (AVCP) .28
7.1 General .28
7.2 Type testing .28
7.2.1 General .28
7.2.2 Test samples, testing and compliance criteria .29
7.2.3 Test reports .36
7.2.4 Shared other party results .36
7.2.5 Cascading determination of the product type results .36
7.3 Factory production control (FPC) .37
7.3.1 General .37
7.3.2 Requirements .38
7.3.3 Product specific requirements .47
7.3.4 Initial inspection of factory and of FPC .48
7.3.5 Continuous surveillance of FPC .48
7.3.6 Procedure for modifications .48
8 Marking and labelling .49
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Annex A (normative) Delamination test of glue lines between layers . 50
A.1 Principle . 50
A.2 Apparatus . 50
A.3 Sampling and preparation of test pieces . 50
A.4 Procedures . 50
A.5 Results . 52
A.6 Test report . 53
Annex B (normative) Tests with laminations with or without finger joints (including
compliance criteria) . 54
B.1 Sampling . 54
B.2 Testing . 54
B.3 Compliance criteria of finger joints in laminations . 55
B.4 Report of tests with finger joints in laminations . 55
B.5 Tests with laminations without finger joints . 56
Annex C (normative) Determination of strength, stiffness and density properties of cross
laminated timber . 57
C.1 General . 57
C.2 Characteristics determined by tests with out of plane loads. 61
C.3 Characteristics determined by tests with in-plane loads . 65
Annex D (normative) Measurement of moisture content . 70
D.1 General . 70
D.2 Measurement of moisture content of boards during production . 70
D.3 Mean moisture content of cross laminated timber made from timber laminations . 70
Annex E (normative) Separation tests with finger joints in laminations produced with
contact-free application of adhesive . 71
Annex F (normative) Minimum production requirements . 72
F.1 Personnel . 72
F.2 Production and storage facilities . 72
F.3 Equipment . 72
F.4 Finger joints in laminations . 73
F.5 Grooving of laminations . 77
F.6 Gaps between laminations . 77
F.7 Bonding of layers . 78
F.8 Layup . 79
F.9 Cross laminated timber with large finger joints . 81
F.10 Corrected sizes and moisture deformation factor . 83
3
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Annex ZA (informative) Relationship between this European Standard and
Regulation (EU) No. 305/2011 .84
ZA.1 Scope and relevant characteristics .84
ZA.2 System of Assessment and Verification of Constancy of Performance (AVCP) .88
ZA.3 Assignment of AVCP tasks .88
Bibliography .92
4
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European foreword
This document (prEN 16351:2018) 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 has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
For the relationship with Regulation No. 305/2011, see informative Annex ZA, which is an integral part
of this document.
This document will supersede EN 16351:2015.
Compared to EN 16351:2015 the following changes have been made:
— the scope is limited to cross laminated timber with or without non-structural edge-bonds produced
according to the provisions given in this standard;
— provisions for designation codes have been added;
— the standard has been adjusted to the latest versions of standards for adhesives;
— the provisions for reaction and resistance to fire have been modified;
— the provisions for gap widths and ratios of lamination width by thickness have been modified;
— missing provisions for factory production control have been added;
— the provisions for determination of strength, stiffness and density properties of cross laminated
timber have been modified;
— the standard has been adjusted to the latest templates.
5
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Introduction
Figure 1 shows the relation of some harmonized European Standards on structural timber products.
Key
1 boards 6 glued laminated timber (glulam)
2 is a component for 7 glulam with large finger joints
3 structural finger jointed timber 8 block glued glulam
4 glued laminated products 9 cross laminated timber
5 glued solid timber 10 cross laminated timber with large finger joints
Figure 1 — Relation of some harmonized European Standards on structural timber products
Cross laminated timber in accordance to this European Standard and multilayer solid wood panels in
accordance with EN 13353 may have the same layup, but for cross laminated timber the timber is
strength graded according to EN 14081-1 and the adhesives are tested according to the provisions of this
European Standard.
6
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1 Scope
This document sets out requirements regarding the performance of characteristics of the following types
of cross laminated timber to be used in buildings and bridges:
— type 1: Straight or curved cross laminated timber comprising only timber layers but no large finger
joints;
— type 2: Straight cross laminated timber comprising only timber layers and large finger joints;
— type 3: Straight cross laminated timber comprising timber and wood-based panel layers but no large
finger joints.
It also lays down procedures for assessment and verification of constancy of performance (AVPC) of
characteristics and specifies marking and labelling of cross laminated timber.
This document covers cross laminated timber of all three types of cross laminated timber:
— manufactured according to this standard, which sets up provisions for:
— boundary conditions during manufacture of cross laminated timber;
— moisture content and temperature of timber to be bonded;
— production of finger joints and bonds between layers;
— to be used in service class 1 or 2 according to EN 1995-1-1;
— made of coniferous species and poplar listed in this standard;
— which may be made of layers made of different species having similar properties;
— bonded with phenolic or aminoplastic or moisture curing one-component polyurethane or emulsion
polymer isocyanate adhesives of adhesive type I according to the respective standard;
— built up of at least three orthogonally bonded layers (at least two of them timber layers);
— which may have, depending on the number of layers, adjacent layers bonded parallel to the grain;
— made of timber layers which are made of strength graded timber according to EN 14081-1;
— made of timber layers having nominal thicknesses between 6 mm (including) and 60 mm (including)
depending on the layup;
— made of timber layers
— which may comprise non-structural edge bonds; and
th
— have a mean gap width of less than or equal to 0,6 mm and a 90 percentile of the gap width of
2 mm;
— having nominal overall thicknesses up to 500 mm.
Additional provisions of this document apply for straight cross laminated timber comprising only timber
layers and comprising large finger joints (type 2):
— made from cross laminated timber pieces having the same cross-section and layup;
7
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— made from cross laminated timber pieces having nominal cross-sectional thicknesses from 51 mm
(including) up to 345 mm (including) and nominal minimum thicknesses of the outer layers not less
than 17 mm (including).
— made from cross laminated timber pieces solely comprising timber layers;
— made from plane cross laminated timber pieces;
— with parallel x-axes of the jointed components;
— with finger joints having a finger length of at least 45 mm and fingers which are visible at the two
narrow sides of the components;
— bonded with phenolic or aminoplastic or moisture curing one-component polyurethane adhesives of
adhesive type I according to the respective standard.
Additional provisions of this document apply for straight cross laminated timber comprising timber and
wood-based panel layers but no large finger joints (type 3):
— made of structural wood-based panels specified in this European standard;
— made of one panel per layer and;
— having thicknesses between 6 mm (including) and 45 mm (including);
This document applies to cross laminated timber untreated or treated against biological attack.
This document does not cover:
— cross laminated timber treated with fire retardants;
— cross laminated timber which is produced from re-used timber or wood-based panels comprising re-
used timber.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 301:2017, Adhesives, phenolic and aminoplastic, for load-bearing timber structures - Classification and
performance requirements
EN 302-2, Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of resistance
to delamination
EN 302-6, Adhesives for load-bearing timber structures - Test methods - Part 6: Determination of the
minimum pressing time under referenced conditions
EN 335, Durability of wood and wood-based products - Use classes: definitions, application to solid wood
and wood-based products
EN 350, Durability of wood and wood-based products - Testing and classification of the durability to
biological agents of wood and wood-based materials
EN 351-1, Durability of wood and wood-based products - Preservative-treated solid wood - Part 1:
Classification of preservative penetration and retention
8
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EN 408:2010+A1:2012, Timber structures - Structural timber and glued laminated timber - Determination
of some physical and mechanical properties
EN 717-1, Wood-based panels - Determination of formaldehyde release - Part 1: Formaldehyde emission by
the chamber method
EN 789, Timber structures - Test methods - Determination of mechanical properties of wood based panels
EN 1995-1-1, Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for
buildings
EN 12369-2, Wood-based panels - Characteristic values for structural design - Part 2: Plywood
EN 13183-1, Moisture content of a piece of sawn timber - Part 1: Determination by oven dry method
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 13353, Solid wood panels (SWP) - Requirements
EN 13501-1, Fire classification of construction products and building elements - Part 1: Classification using
data from reaction to fire tests
EN 13501-2, Fire classification of construction products and building elements - Part 2: Classification using
data from fire resistance tests, excluding ventilation services
EN 13823, Reaction to fire tests for building products - Building products excluding floorings exposed to the
thermal attack by a single burning item
EN 13986, Wood-based panels for use in construction - Characteristics, evaluation of conformity and
marking
EN 14080:2013, Timber structures - Glued laminated timber and glued solid timber - Requirements
EN 14081-1, Timber structures - Strength graded structural timber with rectangular cross section - Part 1:
General requirements
EN 14358, Timber structures - Calculation and verification of characteristic values
EN 14374, Timber structures - Structural laminated veneer lumber - Requirements
EN 15228:2009, Structural timber - Structural timber preservative treated against biological attack
EN 15416-5, Adhesives for load bearing timber structures other than phenolic and aminoplastic - Test
methods - Part 5: Determination of minimum pressing time under referenced conditions
EN 15425:2017, Adhesives - One component polyurethane (PUR) for load-bearing timber structures -
Classification and performance requirements
EN 16254:2013+A1:2016, Emulsion polymerized isocyanate (EPI) for load bearing timber structures -
Classification and performance provisions
9
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EN ISO 9239-1, Reaction to fire tests for floorings - Part 1: Determination of the burning behaviour using a
radiant heat source (ISO 9239-1)
EN ISO 11925-2, Reaction to fire tests - Ignitability of products subjected to direct impingement of flame -
Part 2: Single-flame source test (ISO 11925-2)
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
actual size
measured size of a cross laminated timber at a related measured/estimated moisture content
3.2
bonding strength
structural effectiveness of adhesives between timber pieces when subjected to stresses
3.3
corrected size
size of a cross laminated timber corrected by calculation from its actual size to its size at the reference
moisture content
3.4
cross laminated timber
structural timber consisting of at least three face-bonded layers which comprise solid timber laminations
and may comprise wood-based panels, at least one layer orthogonally oriented to the two adjacent layers
Note 1 to entry: See also Figure 2.
Key
1 plane of the element 2 wide face 3 narrow face 4 outer layer
10
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5 inner layer 6 lamination 7 finger joint in lamination 8 large finger joint
9 usually the length 10 usually the width b of a plate or height h of a beam
CL CL
Figure 2 — Cross laminated timber
3.5
curved cross laminated timber
cross laminated timber having a precamber greater than 1% of the respective span
3.6
edge bonds
non-structural bonds between adjacent laminations within a timber layer
3.7
finger angle
inclination α of each side of the fingers of a finger joint
Note1 to entry: See Figure 3.
3.8
finger joint
interlocking end joint formed by machining a number of similar, tapered, symmetrical fingers in the ends
of timber components using a finger joint cutter and then bonded together
Note 1 to entry: In this European Standard, the term finger joint is used for finger joints in laminations whereas
finger joints between cross laminated timber are defined as large finger joints (see 3.12).
Key
b tip width of the cutter
cut
b tip width
t
lj finger length
lt tip gap
p pitch
α finger angle
1 tip base
Figure 3 — Typical profile of a finger joint
3.9
finger length
distance l between the finger base and the tip of the finger, measured along the centre line of the finger
j
11
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Note 1 to entry: See Figure 3.
3.10
finished thickness
thickness after planing
3.11
laminations
part of a structural glued timber product consisting of one board or two or more finger-jointed boards
3.12
large finger joint
finger joint through the full cross-sectional area of two cross laminated timber components
Note 1 to entry: See Figure 4.
Figure 4 — Cross laminated timber with large finger joints
3.13
layup
cross-sectional arrangement of timber layers or wood-based panel layers in which layers may be made
of different species and may be assigned to different strength classes or technical classes
3.14
maximum delamination length
largest delamination length in any single glue line measured around the circumference of the test piece
3.15
mean moisture content
mean value of the moisture content of cross laminated timber calculated from at least two measurements
Note 1 to entry: See D.3.
3.16
minimum mean density
required mean density at reference moisture content, estimated as the weighted mean of the mean
densities of the layers, if necessary
Note 1 to entry: Minimum mean density is used for the classification of the reaction to fire.
3.17
nominal size
size specified at the reference moisture content to which deviations are related
3.18
pitch
distance between centres of adjacent finger tips
Note 1 to entry: See Figure 3.
12
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3.19
ratio of resin to hardener
proportion of resin to hardener by mass with the resin set at 100 parts
3.20
reduction factor
ratioν between tip width and pitch
Note 1 to entry:
...
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