ISO 22390:2020

INTERNATIONAL ISO
STANDARD 22390
Second edition
2020-03
Timber structures — Laminated
veneer lumber — Structural
properties
Structures en bois — Lamibois — Propriétés structurelles
Reference number
ISO 22390:2020(E)
©
ISO 2020

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ISO 22390:2020(E)

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© ISO 2020
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ISO 22390:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 3
4.1 Veneers . 3
4.2 Bonding quality . 3
4.3 Specimen dimension measurement accuracy . 4
5 Test methods . 4
5.1 General . 4
5.2 Edgewise bending strength . 5
5.3 Flatwise bending strength . 5
5.4 Tension strength parallel to the grain . 5
5.5 Compression strength parallel to the grain . . 6
5.6 Shear strength (edge) related to edgewise bending . 6
5.7 Shear strength (flat) related to flatwise bending . 6
5.8 Compression strength perpendicular to the grain . 6
6 Stiffness . 7
6.1 General . 7
6.2 Modulus of elasticity in edgewise bending . 7
6.3 Modulus of elasticity in flatwise bending . 7
6.4 Modulus of elasticity in tension parallel to the grain . 7
6.5 Modulus of elasticity in compression parallel to the grain . 8
7 Other physical characteristics . 8
7.1 Density . 8
7.2 Moisture content . 8
7.3 Species equivalency for connection properties . 8
7.4 Creep and duration of load effects . 8
Bibliography . 9
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ISO 22390:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 165, Timber structures.
This second edition cancels and replaces the first edition (ISO 22390:2010), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the specimen dimension measurement accuracy in 4.3 and
— routine update of the standard.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 22390:2020(E)

Introduction
Laminated veneer lumber (LVL) is being produced in many countries under different national standards
and these products are being exported from one country to another. While the national standards have
many similarities, there are also many areas of dissimilarity. Thus, there is a need for the development
of this International Standard to establish consistency between these standards in order to ensure the
suitability of LVL for structural end-use applications, regardless of the country of manufacture or end
use. It is valuable for the industry, consumers, governments and distributors.
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INTERNATIONAL STANDARD ISO 22390:2020(E)
Timber structures — Laminated veneer lumber —
Structural properties
1 Scope
This document specifies requirements for establishing the characteristic properties of structural
laminated veneer lumber (LVL), including 5th percentile strength values, stiffness characteristics and
other performance characteristics, related to its end use as a structural product for dry use (service
class 1). It is applicable to members used in flatwise or edgewise bending orientations.
It does not cover the assessment of formaldehyde requirements, biological durability, fire performance
or manufacturing, such as quality control and marking.
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.
ISO 10033-1, Laminated Veneer Lumber (LVL) — Bonding quality — Part 1: Test methods
ISO 10033-2, Laminated Veneer Lumber (LVL) — Bonding quality — Part 2: Requirements
ISO 13910, Timber structures — Strength graded timber — Test methods for structural properties
ISO 16572, Timber structures — Wood-based panels — Test methods for structural properties
ISO 16979, Wood-based panels — Determination of moisture content
EN 408, Timber structures — Structural timber and glued laminated timber — Determination of some
physical and mechanical properties
ASTM D143, Standard Test Methods for Small Clear Specimens of Timber
ASTM D198, Standard Test Methods of Static Tests of Lumber in Structural Sizes
ASTM D4761, Standard Test Methods for Mechanical Properties of Lumber and Wood-Base Structural
Material
ASTM D5456, Standard Specification for Evaluation of Structural Composite Lumber Products
ASTM D6815, Standard Specification for Evaluation of Duration of Load and Creep Effects of Wood and
Wood-Based Products
Notification No MAFF 701 (Revised 2016), Japanese Agricultural Standard for Laminated Veneer Lumber
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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/
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ISO 22390:2020(E)

3.1
laminated veneer lumber
LVL
composite of wood veneer sheet elements manufactured from one or more species, either separately or
mixed, with wood fibres primarily oriented along the length of the member
Note 1 to entry: This does not exclude laminated veneer lumber with cross-laminated veneers.
3.2
characteristic value for strength
estimate of the 5th percentile values based on a statistical distribution obtained from results of tests
on the defined properties with the test duration between 60 s and 300 s
Note 1 to entry: The characteristic values used for 3.2 are an estimate of the 5th percentile value of the sample as
determined from ISO 12122-1 and ISO 12122-4.
Note 2 to entry: The defined properties are in accordance with Clauses 5 and 6.
3.3
characteristic value for stiffness
estimate of the mean property from results of tests on the defined properties with the test duration
between 60 s and 300 s
Note 1 to entry: The characteristic values used for 3.3 are an estimate of the mean value of the sample as
determined from ISO 12122-1 and ISO 12122-4.
Note 2 to entry: The defined properties are in accordance with Clauses 5 and 6.
3.4
test specimen
specimen cut from random locations within the pieces of the LVL samples
3.5
thickness
t
dimension of a cross-section, which is perpendicular to the plane of the veneers, and measured in the
Y-direction
Note 1 to entry: See Figure 1.
3.6
width
b
dimension of a cross-section, which is perpendicular to the thickness (or parallel to the plane of the
veneers) and measured in the X-direction
Note 1 to entry: See Figure 1.
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ISO 22390:2020(E)

a)  Cross-section related to edgewise (Joist) b) Cross-section related to flatwise (Plank)
bending bending
Key
F applied load
t thickness of the LVL
b width of the LVL
Figure 1 — Cross-section of laminated veneer lumber
4 Requirements
4.1 Veneers
The minimum number of veneers in the cross-section shall be five. The maximum thickness of each
veneer shall be 6 mm.
4.2 Bonding quality
The LVL shall utilize a structural adhesive suitable for dry service (service class 1) and the bonding
quality and adhesive qualification shall be determined in accordance with ISO 10033-1 and ISO 10033-2.
NOTE 1 Attention is drawn to national standards which can be applicable.
NOTE 2 Examples of applicable national standards include EN 314-1, ASTM D5456 and MAFF Notification
No. 701.
NOTE 3 Additional testing to cover more severe bonding service conditions (service classes 2 and 3) can be
considered as a manufacturer's option and can be required by some nationa
...