kSIST FprEN 14374:2019
(Main)Timber structures - Laminated veneer lumber (LVL) - Requirements
Timber structures - Laminated veneer lumber (LVL) - Requirements
This European Standard sets out provisions regarding the performance characteristics of structural laminated veneer lumber (LVL) for use in buildings and bridges and non-structural laminated veneer lumber for internal and external applications in construction.
It also lays down procedures for Assessment and Verification of Constancy of Performance of laminated veneer lumber.
This European Standard covers laminated veneer lumber
— made of at least five veneers having a maximum veneer thickness of 6 mm;
— which may comprise crossband veneers;
— which may comprise veneers made from different species;
— being preservative treated or untreated against biological attack or treated to improve the reaction to fire.
This European Standard defines provisions for bonding strength and durability of bonding strength in dry, humid and exterior conditions. It covers structural LVL to be used in all conditions and non-structural LVL to be used in the respective conditions for which bonding strength tests have been performed.
This European Standard defines strength classes for structural laminated veneer lumber.
Holzbauwerke - Furnierschichtholz (LVL) - Anforderungen
Diese Europäische Norm legt Bestimmungen bezüglich der Leistungsmerkmale von Furnierschichtholz für tragende Zwecke (LVL), zur Verwendung in Gebäuden und Brücken, und von Furnierschichtholz für nicht tragende Zwecke, für Innen- und Außenanwendungen im Bau, fest.
Sie legt ebenfalls Verfahren fest, für Bewertung und Überprüfung der Leistungsbeständigkeit von Furnierschichtholz.
Diese Europäische Norm deckt Furnierschichtholz ab,
— das aus mindestens fünf Furnieren, mit einer maximalen Furnierdicke von 6 mm, hergestellt ist;
— welches Absperrfurniere enthalten kann;
— welches Furniere aus unterschiedlichen Holzarten enthalten kann;
— der gegen biologischen Befall mit Holzschutzmittel behandelt oder unbehandelt oder zur Verbesserung des Brandverhaltens behandelt ist.
Diese Europäische Norm legt Bestimmungen für Haftfestigkeit und Beständigkeit von Haftfestigkeit, unter trockenen, feuchten und Außenbedingungen, fest. Sie deckt LVL für tragende Zwecke, zur Verwendung unter allen Bedingungen und LVL für nicht tragende Zwecke, zur Verwendung unter den jeweiligen Bedingungen, für die Haftfestigkeitsprüfungen ausgeführt wurden, ab.
Diese Europäische Norm legt Festigkeitsklassen für Furnierschichtholz für tragende Zwecke fest.
Structures en bois - Lamibois (LVL) - Exigences
Le présent document définit les exigences relatives aux caractéristiques de performance des types suivants de lamibois (LVL) :
- type 1 : LVL pour les applications structurelles dans les immeubles et ponts en milieu sec, humide et extérieur ;
- type 2 : LVL contrecollé pour les applications structurelles dans les immeubles et ponts en milieu sec, humide et extérieur ;
- type 3 : LVL non structurel dans des applications de construction intérieures et extérieures.
Le présent document traite du lamibois de tous types :
- constitué d’au moins cinq plis et présentant une épaisseur de pli maximale de 6 mm ;
- pouvant comprendre des plis d’essences différentes ;
- fait uniquement de plis parallèles ou placés symétriquement avec au moins deux plis croisés.
Le présent document traite également du LVL contrecollé (Type 2) qui est produit par collage des faces de plusieurs panneaux conformément à la présente norme.
Le présent document traite du lamibois de tout type qu’il ait ou non subi un traitement de préservation contre les attaques biologiques ou qu’il soit traité pour améliorer la performance de réaction au feu.
Le présent document établit également des modes opératoires d’évaluation et de vérification de la constance des performances (EVCP) et spécifie le marquage et l’étiquetage du lamibois.
Le présent document ne traite pas du lamibois qui est produit à partir de bois recyclé.
Lesene konstrukcije - Slojnat furnirni les (LVL) - Zahteve
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 14374:2016
01-julij-2016
Lesene konstrukcije - Slojnat furnirni les (LVL) - Zahteve
Timber structures - Laminated veneer lumber (LVL) - Requirements
Holzbauwerke - Furnierschichtholz (LVL) - Anforderungen
Structures en bois - Lamibois (LVL) - Exigences
Ta slovenski standard je istoveten z: prEN 14374
ICS:
79.080 Polizdelki iz lesa Semi-manufactures of timber
91.080.20 Lesene konstrukcije Timber structures
oSIST prEN 14374:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 14374:2016
DRAFT
EUROPEAN STANDARD
prEN 14374
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2016
ICS 79.080; 91.080.20 Will supersede EN 14279:2004+A1:2009,
EN 14374:2004
English Version
Timber structures - Laminated veneer lumber (LVL) -
Requirements
Structures en bois - Lamibois (LVL) - Exigences Holzbauwerke - Furnierschichtholz (LVL) -
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, 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 NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14374:2016 E
worldwide for CEN national Members.
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Contents Page
European foreword . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 Symbols . 10
4.1 Main symbols . 10
4.2 Subscripts . 11
5 Classification. 11
6 Material characteristics and testing, assessment and sampling methods . 12
6.1 Modulus of elasticity, bending, compressive, tensile and shear strength of structural
LVL . 12
6.2 Strength and stiffness under point load of structural LVL (punching shear) . 12
6.3 Racking resistance of structural LVL . 12
6.4 Impact resistance of structural LVL . 13
6.5 Embedment strength of fasteners in structural LVL . 13
6.6 Mechanical durability (i.e. duration of load and creep) of structural LVL . 13
6.7 Bonding strength and durability of bonding strength (also covering moisture
resistance) of structural and non-structural LVL . 13
6.8 Dimensional stability of structural and non-structural LVL (also covering durability-
swelling in thickness) . 14
6.9 Durability of other characteristics against biological attack of structural and non-
structural LVL . 15
6.10 Resistance to fire of structural LVL . 16
6.11 Reaction to fire of structural and non-structural LVL . 16
6.12 Fire protection ability . 19
6.13 Release of formaldehyde of structural and non-structural LVL . 19
6.14 Release/content of other dangerous substances (also covering release/content of
pentachlorphenol (PCP)) of structural and non-structural LVL . 20
6.15 Water vapour permeability of structural and non-structural LVL . 20
6.16 Airborne sound insulation (surface mass) of structural and non-structural LVL . 20
6.17 Sound adsorption of structural and non-structural LVL . 21
6.18 Thermal conductivity of structural and non-structural LVL . 21
6.19 Air permeability of structural and non-structural LVL . 21
6.20 Supplementary properties of structural and non-structural LVL . 21
7 Assessment and Verification of Constancy of Performance (AVCP) . 21
7.1 General. 21
7.2 Type testing . 22
7.3 Factory production control (FPC) . 30
8 Marking and labelling . 42
Annex A (normative) Testing of strength, stiffness and density properties of laminated
veneer lumber . 43
A.1 General. 43
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A.2 Edgewise bending strength and edgewise modulus of elasticity in bending parallel to
the grain of the face veneers . 45
A.3 Edgewise bending strength, edgewise modulus of elasticity and edgewise shear
strength in bending perpendicular to the grain of the face veneers . 45
A.4 Flatwise bending strength and flatwise modulus of elasticity in bending parallel to
the grain of the face veneers . 46
A.5 Flatwise bending strength and flatwise modulus of elasticity in bending
perpendicular to the grain of the face veneers . 46
A.6 Tension strength and modulus of elasticity in tension parallel to the grain of the face
veneers . 46
A.7 Edgewise tension strength in plane of the veneers and perpendicular to the grain of
the face veneers . 46
A.8 Compression strength and modulus of elasticity in compression parallel to the grain
of the face veneers . 47
A.9 Edgewise compression strength and edgewise modulus of elasticity in compression
in plane of the veneers and perpendicular to the grain of the face veneers . 47
A.10 Flatwise compression strength and flatwise modulus of elasticity perpendicular to
the plane of the veneers . 47
A.11 Edgewise shear strength and edgewise shear modulus parallel to the grain of the
face veneers . 47
A.12 Flatwise shear strength and flatwise shear modulus parallel to the grain of the face
veneers . 47
A.13 Flatwise shear strength and flatwise shear modulus perpendicular to the grain of
the face veneers . 48
A.14 Density . 48
A.15 Moisture content . 48
Annex B (normative) Strength classes for structural laminated veneer lumber . 49
B.1 General . 49
B.2 LVL without cross-band veneers . 49
B.3 LVL with crossband veneers . 51
Annex C (normative) Layup factors for laminated veneer lumber with cross-band veneers . 53
C.1 General . 53
C.2 Determination of layup factors for LVL made from one species. 54
C.3 Layup factors for LVL made of different species. 55
Annex D (normative) Testing of bonding quality for structural LVL . 56
D.1 Specimens . 56
D.2 Tests . 56
D.3 Report . 56
Annex E (normative) Testing of bonding strength for non-structural LVL . 57
E.1 General . 57
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E.2 Test pieces . 57
E.3 Apparatus . 64
E.4 Procedure . 64
E.5 Evaluation of test results . 64
Annex F (normative) Release of formaldehyde . 65
F.1 General. 65
F.2 Classification. 65
F.3 Test procedure and test report . 65
Annex G (informative) Supplementary characteristics . 66
G.1 General. 66
Annex H (informative) Supplementary design rules . 67
H.1 General. 67
H.2 Deformation factors k . 67
def
H.3 Provisions for compression perpendicular to the grain . 67
H.4 Charring rate . 68
Annex ZA (informative) Relationship of this European Standard with Regulation (EU) No.
305/2011 . 69
ZA.1 Scope and relevant characteristics . 69
ZA.2 System of Assessment and Verification of Constancy of Performance (AVCP) . 73
ZA.3 Assignment of AVPC tasks . 73
Bibliography . 76
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European foreword
This document (prEN 14374:2016) 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, 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
document.
This document will supersede EN 14374:2004 and EN 14279:2004+A1:2009.
Compared to EN 14374:2004 and EN 14279: 2004+A1:2009, the following changes have been made:
— both standards have been merged and completely revised;
— the merged standard has been written according to the latest CEN-Template, i.e. each mandated
characteristic is addressed in a separate subclause;
— a universal classification for structural and non-structural LVL has been introduced;
— specific rules for LVL with crossband veneers are given;
— layup factors for LVL with crossband veneers for the determination of properties from tests are
given;
— more strength and stiffness properties are defined and the respective test methods have been
introduced;
— strength classes for structural LVL have been introduced;
— tolerances have been modified;
— provisions regarding resistance to fire and fire protection ability have been introduced.
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1 Scope
This European Standard sets out provisions regarding the performance characteristics of structural
laminated veneer lumber (LVL) for use in buildings and bridges and non-structural laminated veneer
lumber for internal and external applications in construction.
It also lays down procedures for Assessment and Verification of Constancy of Performance of laminated
veneer lumber.
This European Standard covers laminated veneer lumber
— made of at least five veneers having a maximum veneer thickness of 6 mm;
— which may comprise crossband veneers;
— which may comprise veneers made from different species;
— being preservative treated or untreated against biological attack or treated to improve the reaction
to fire.
This European Standard defines provisions for bonding strength and durability of bonding strength in
dry, humid and exterior conditions. It covers structural LVL to be used in all conditions and non-
structural LVL to be used in the respective conditions for which bonding strength tests have been
performed.
This European Standard defines strength classes for structural laminated veneer lumber.
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 310, Wood-based panels - Determination of modulus of elasticity in bending and of bending strength
EN 314-1, Plywood - Bonding quality - Part 1: Test methods
EN 314-2, Plywood - Bonding quality - Part 2: Requirements
EN 318, Wood based panels - Determination of dimensional changes associated with changes in relative
humidity
EN 322, Wood-based panels - Determination of moisture content
EN 323, Wood-based panels - Determination of density
EN 324-1, Wood-based panels - Determination of dimensions of boards - Part 1: Determination of
thickness, width and length
EN 326-1, Wood-based panels - Sampling, cutting and inspection - Part 1: Sampling and cutting of test
pieces and expression of test results
EN 335, Durability of wood and wood-based products - Use classes: definitions, application to solid wood
and wood-based products
EN 351-1, Durability of wood and wood-based products - Preservative-treated solid wood - Part 1:
Classification of preservative penetration and retention
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EN 351-2, Durability of wood and wood-based products - Preservative-treated solid wood - Part 2:
Guidance on sampling for the analysis of preservative-treated wood
EN 383, Timber Structures - Test methods - Determination of embedment strength and foundation values
for dowel type fasteners
EN 408, Timber structures — Structural timber and glued laminated timber - Determination of some
physical and mechanical properties
EN 594, Timber structures - Test methods - Racking strength and stiffness of timber frame wall panels
EN 596, Timber structures - Test methods - Soft body impact test of timber framed walls
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 1156,Wood-based panels - Determination of duration of load and creep factors
EN 1995-1-1, Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for
buildings
EN 12114, Thermal performance of buildings - Air permeability of building components and building
elements - Laboratory test method
EN 12664, Thermal performance of building materials and products - Determination of thermal resistance
by means of guarded hot plate and heat flow meter methods - Dry and moist products of medium and low
thermal resistance
EN 12871, Wood-based panels - Determination of performance characteristics for load bearing panels for
use in floors, roofs and walls
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 13501-2, Fire classification of construction products and building elements - Part 2: Classification
using data from Resistance to fire 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 14358, Timber structures - Calculation of characteristic 5-percentile values and acceptance criteria for
a sample
CEN/TS 16516, Construction products - Assessment of release of dangerous substances - Determination of
emissions into indoor air
EN ISO 354, Acoustics - Measurement of sound absorption in a reverberation room (ISO 354)
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EN ISO 717-1, Acoustics - Rating of sound insulation in buildings and of building elements - Part 1:
Airborne sound insulation (ISO 717-1)
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 10140-2, Acoustics - Laboratory measurement of sound insulation of building elements - Part 2:
Measurement of airborne sound insulation (ISO 10140-2)
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)
EN ISO 12460-3, Wood-based panels - Determination of formaldehyde release - Part 3: Gas analysis
method (ISO 12460-3)
EN ISO 12572, Hygrothermal performance of building materials and products - Determination of water
vapour transmission properties (ISO 12572)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
crossband veneer
veneer whose fibres are oriented perpendicular to the fibres of the face veneers
3.2
dry conditions
conditions corresponding to service class 1 of EN 1995-1-1 which is characterised by a moisture
content in the material corresponding to a temperature of 20 °C and a relative humidity of the
surrounding air only exceeding 65 % for a few weeks per year
3.3
exterior conditions
conditions corresponding to service class 3 of EN 1995-1-1 which is characterised by climatic
conditions leading to higher moisture contents than in service class 2
3.4
humid conditions
conditions corresponding to service class 2 of EN 1995-1-1 which is characterised by a moisture
content in the material corresponding to a temperature of 20°C and a relative humidity of the
surrounding air only exceeding 85 % for a few weeks per year
3.5
laminated veneer lumber
LVL
wood based composite consisting of veneers, glued together predominantly parallel to the direction of
the grain in adjacent layers which may have crossband veneers
Note 1 to entry: See Figure 1.
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a) LVL without crossband veneers b) LVL with crossband veneers
Key
b width
l length
t thickness
Figure 1 — Laminated veneer lumber without and with crossband veneers
3.6
layup
cross sectional arrangement of veneers
3.7
length
the dimension parallel to the plane of the veneers and parallel to the direction of the fibres of the face
veneers
Note 1 to entry: See Figure 1.
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3.8
nominal size
size specified at a reference moisture content to which deviations are to be related
3.9
product type
product defined by layup, thickness range, species or species combination, adhesive, bonding and
strength characteristic
3.10
reference moisture content
equilibrium moisture content at a temperature of 20 °C and a relative humidity of 65 %
3.11
thickness
the cross sectional dimension perpendicular to the plane of the veneers
Note 1 to entry: See Figure 1.
3.12
width
the cross sectional dimension parallel to the plane of the veneers and perpendicular to the direction of
the fibres of the face veneers
Note 1 to entry: See Figure 1.
4 Symbols
4.1 Main symbols
b width, in mm;
2
f strength, in N/mm ;
2
E modulus of elasticity, in N/mm ;
2
G shear modulus, in N/mm ;
k factor;
l length, in mm;
m effective number of veneers;
N number of single layers;
P number of pretreatments;
q number of test pieces;
R airborne sound insulation, in dB;
s size effect parameter;
t thickness, in mm;
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u moisture content, in %;
V coefficient of variation, in %;
X characteristic value for layup i;
i
o
α deviation from the right angle, in ;
α sound absorption factor;
α , γ , δ layup factors for layup i;
i i i
λ thermal conductivity, in W/mK;
d
µ water vapour resistance factor;
3
ρ density, in kg/m .
4.2 Subscripts
c compression;
cor corrected;
edge loaded parallel to the glue lines between the veneers;
flat loaded perpendicular to the glue lines between the veneers;
k characteristic;
lay layer;
m bending;
mean mean value;
t tension;
v shear;
0 parallel to the grain of the face veneers;
90 perpendicular to the grain of the face veneers.
5 Classification
Laminated veneer lumber shall be classified as follows:
— the abbreviation ”LVL” shall be given;
— the abbreviation “S” for structural LVL and “NS” for non-structural LVL shall be given;
— crossband veneers shall be indicated by “cross";
— for structural LVL assigned to a class according to Annex B the class name shall be given. The class
name comprises the abbreviations “LVL”, “S” and “cross” (if relevant) and also indicates the
2
characteristic value for flatwise bending parallel to the grain of the face veneer in N/mm shall be
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given. For structural LVL not assigned to a class according to Annex B and for non-structural LVL no
characteristic value shall be given as part of the designation.
NOTE For structural LVL not assigned to a class according to Annex B, all strength, stiffness and density
values are declared within the markings, see Clause 8 and Annex ZA.
The classification mentioned above may be combined with a manufacturer specific brand-name, if, in
the case of structural LVL, that brand-name cannot be mixed up with the denomination of strength
cla
...
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