Wood-based panels - Guidance on the use of load-bearing boards in floors, walls and roofs

This Technical Report gives guidance on the use of wood-based panels in structural applications as structural floor and roof decking on joists or structural wall sheathing on studs in accordance with EN 12871. It provides information on:
—   inspection at site;
—   transport and delivery;
—   handling;
—   stacking;
—   storage;
—   moisture content, conditioning and the effects of moisture;
—   cutting and machining;
—   selection;
—   installation.

Holzwerkstoffe - Leitfaden für die Verwendung von tragenden Platten in Böden, Wänden und Dächern

Panneaux à base de bois - Guide pour l'utilisation des panneaux structurels en planchers, murs et toitures

Lesne plošče - Napotki za talno, stensko in strešno uporabo nosilnih plošč

To tehnično poročilo podaja smernice o uporabi lesenih plošč pri gradbeni uporabi za konstrukcijska tla in strešne kritine na tramovih ali opaže konstrukcijskih zidov na zatičih v skladu s standardom EN 12871. Podaja informacije o:
– pregledovanju na mestu;
– transportu in dostavi;
– upravljanju;
– skladanju;
– shranjevanju;
– vsebnosti vlage, kondicioniranju in učinkih vlage;
– rezanju in obdelavi s stroji;
– izbiranju;
– instalaciji.

General Information

Status
Published
Publication Date
09-Dec-2014
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
10-Dec-2014
Due Date
27-Mar-2015
Completion Date
10-Dec-2014

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SLOVENSKI STANDARD
kSIST-TP FprCEN/TR 12872:2014
01-november-2014
/HVQHSORãþH1DSRWNL]DXSRUDERQRVLOQLKSORãþ]DSRGHVWHQHLQVWUHKH
Wood-based panels - Guidance on the use of load-bearing boards in floors, walls and
roofs
Holzwerkstoffe - Leitfaden für die Verwendung von tragenden Platten in Böden, Wänden
und Dächern
Panneaux à base de bois - Guide pour l'utilisation des panneaux structurels en
planchers, murs et toitures
Ta slovenski standard je istoveten z: FprCEN/TR 12872
ICS:
79.060.01 /HVQHSORãþHQDVSORãQR Wood-based panels in
general
kSIST-TP FprCEN/TR 12872:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST-TP FprCEN/TR 12872:2014

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kSIST-TP FprCEN/TR 12872:2014

TECHNICAL REPORT
FINAL DRAFT
FprCEN/TR 12872
RAPPORT TECHNIQUE

TECHNISCHER BERICHT

July 2014
ICS 79.060.01 Will supersede CEN/TS 12872:2007
English Version
Wood-based panels - Guidance on the use of load-bearing
boards in floors, walls and roofs
Panneaux à base de bois - Guide pour l'utilisation des Holzwerkstoffe - Leitfaden für die Verwendung von
panneaux structurels en planchers, murs et toitures tragenden Platten in Böden, Wänden und Dächern


This draft Technical Report is submitted to CEN members for Technical Committee Approval. It has been drawn up by the Technical
Committee CEN/TC 112.

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 Technical Report. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a Technical Report.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TR 12872:2014 E
worldwide for CEN national Members.

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
Contents Page
1 Scope .5
2 Normative references .5
3 Terms and definitions .6
4 Information on product performance .7
5 Inspection at site.7
6 Transport and delivery .7
7 Handling .7
8 Stacking .8
9 Storage .9
10 Moisture content, conditioning and the effects of moisture .9
10.1 Moisture content .9
10.2 Dimensional movement . 10
10.3 Conditioning . 10
11 Cutting and machining . 11
11.1 General . 11
11.2 Cutting with hand tools . 11
11.3 Machining with power tools . 11
11.4 Drilling . 12
12 Fixing . 12
13 Floors — Selection and installation . 13
13.1 Selection (specification) . 13
13.2 Type of floor covering related to wood-based floor panels . 13
13.3 Installation . 14
13.3.1 Preparation of structure . 14
13.3.2 Edge profile . 14
13.3.3 Expansion gaps . 14
13.3.4 Gluing . 15
13.3.5 Laying of wood-based panels for flooring . 15
14 Walls — Selection and installation . 16
14.1 Selection (specification) . 16
14.2 Wall constructions using wood-based panels on studs . 16
14.3 Installation . 16
14.3.1 Preparation of structure . 16
14.3.2 Edge profile . 17
14.3.3 Expansion gaps . 17
14.3.4 Assembly of wood-based panels for walls on studs . 18
15 Roofs — Selection and installation. 19
15.1 Selection (specification) . 19
15.2 Type of roof covering related to wood-based roof panels . 19
15.3 Type of roofs . 19
15.3.1 Flat roofs: cold roofs — warm roofs . 19
15.3.2 Pitched roofs — principles . 20
15.4 Installation . 22
15.4.1 Preparation of structure . 22
2

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FprCEN/TR 12872:2014 (E)
15.4.2 Edge profile . 22
15.4.3 Expansion gaps . 23
15.4.4 Laying of wood-based panels in roof structures . 23
Bibliography . 25

3

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
Foreword
This document (FprCEN/TR 12872:2014) has been prepared by Technical Committee CEN/TC 112 “Wood-
based panels”, the secretariat of which is held by DIN.
This document is currently submitted to the Technical committee approval.
This document will supersede CEN/TS 12872:2007.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
Compared to CEN/TS 12872:2007 the following changes have been made:
a) deliverability changed from CEN/TS to CEN/TR;
b) references to requirements according to EN 12871 deleted after transformation of EN 12871 into a test
method standard;
c) in 10.2, Table 2, values of dimensional changes depending on moisture content for multilayer solid wood
panels added
d) presentation of wall and roof constructions in Clauses 14 and 15 indicated as basic examples;
e) recommended expansion gaps for walls and roofs in Clauses 14 and 15 reduced.
4

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
1 Scope
This Technical Report gives guidance on the use of wood-based panels in structural applications as structural
floor and roof decking on joists or structural wall sheathing on studs in accordance with EN 12871. It provides
information on:
— inspection at site;
— transport and delivery;
— handling;
— stacking;
— storage;
— moisture content, conditioning and the effects of moisture;
— cutting and machining;
— selection;
— installation.
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 300, Oriented Strand Boards (OSB) - Definitions, classification and specifications
EN 312, Particleboards - Specifications
EN 622-2, Fibreboards - Specifications - Part 2: Requirements for hardboards
EN 622-3, Fibreboards - Specifications - Part 3: Requirements for medium boards
EN 622-5, Fibreboards - Specifications - Part 5: Requirements for dry process boards (MDF)
EN 634-2, Cement-bonded particleboards - Specifications - Part 2: Requirements for OPC bonded
particleboards for use in dry, humid and external conditions
EN 636, Plywood - Specifications
EN 12871, Wood-based panels - Determination of performance characteristics for load bearing panels for use
in floors, roofs and walls
EN 13353, Solid wood panels (SWP) - Requirements
EN 1995-1-1:2004, Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for
buildings
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
5

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
3.1
service classes
3.1.1
service class 1
is characterised by a moisture content in the materials corresponding to a temperature of 20 °C and the
relative humidity of the surrounding air only exceeding 65 % for a few weeks per year
[SOURCE: EN 1995-1-1:2004, 2.3.1.3]
3.1.2
service class 2
is characterised by a moisture content in the materials corresponding to a temperature of 20 °C and the
relative humidity of the surrounding air only exceeding 85 % for a few weeks per year
[SOURCE: EN 1995-1-1:2004, 2.3.1.3]
3.1.3
service class 3
climatic conditions leading to higher moisture contents than in service class 2
[SOURCE: EN 1995-1-1:2004, 2.3.1.3]
3.2
structural floor decking
assembly of wood-based panels supported on joists over which the decking spans
Note 1 to entry: The characteristic of the decking is that it is supported by joists and, when subjected to load, is free to
deflect between the joists.
3.3
structural wall sheathing
wood-based panel capable of providing mechanical resistance to a wall structure
3.4
structural roof decking
assembly of wood-based panels supported on joists over which the roof decking spans
Note 1 to entry: The characteristic of the decking is that it is supported by joists and, when subjected to load, is free to
deflect between the joists.
3.5
warm roof
roof design in which the panels supported on joists are placed below the insulation
Note 1 to entry: The panels are considered to be under conditions corresponding to service class 1.
3.6
cold roof
roof design in which the panels and some of the supporting joists are placed above the insulation
Note 1 to entry: The panels are considered to be under conditions corresponding to service class 2.
3.7
sub floor
structural panel meant to be covered by overlays
6

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
4 Information on product performance
Information on product performance based on EN 13986 will be made available by the manufacturer or
supplier.
5 Inspection at site
The following should be checked based on the marking of the panel and/or the manufacturer's documentation
and/or the designers specification:
— grade or class according to EN specification standard;
— thickness;
— service class;
— suitability for biological durability use class;
— surface (sanded or un-sanded);
— edges (tongue and groove or other type of profile);
— joist or stud spacing;
— load category;
— main load-bearing direction for OSB, plywood and solid wood panels only.
6 Transport and delivery
Panels should be adequately protected by a waterproof covering during transportation. Edges should be well
protected from rain or traffic spray. Edge protection should also be provided to avoid damage by ropes, straps
or other banding. This applies particularly to profiled panels such as tongued and grooved panels.
Panels should be stacked properly to avoid sagging or other distortion, see Clause 8.
If packing includes banding or strapping this should be removed as soon as possible after delivery to prevent
any permanent deformation of the panels. When packs are delivered with edge or face protection panels,
these should be left in place until the pack is required for use.
7 Handling
When lifting, moving and stacking panels, edge protection should also be provided to avoid damage by lifting
ropes and/or forklifts.
When handling pre-finished panels, it is essential to avoid damage or dirt on the finished surfaces.
Pre-finished panels should always be lifted from a stack and never slid.
8 Stacking
Panels should be stacked flat on a level surface with all four edges flush. The ideal base is a close boarded or
slatted pallet.
If this is not possible the panels should be carefully stacked on battens of equal thickness at centres not
exceeding 600 mm as shown in Figure 1.
7

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
Intermediate battens are recommended every 15 to 20 panels to allow through ventilation, they shall be
placed directly above those below. The battens should be placed parallel to the short edges across the full
width. Overhang of the panels at the ends of the stack should not exceed 150 mm. Where stacks are placed
on top of one another, the bearers should line up vertically to prevent distortion.
The top of the stack should be covered.
Stacking on edge should be avoided whenever possible. Where space will only permit edge stacking then the
edges should not be permitted to come into direct contact with the floor to avoid possible moisture pick-up or
damage to the edges. Panels should not be leant against walls but supported by a braced, purpose made rack
using thick (>18 mm) base and back panels (see Figure 2).
In case of tongued and grooved panels, edge stacking on the tongue should be avoided.
Dimensions in millimetres

a) CORRECT

b) INCORRECT
Figure 1 — Panel storage

Figure 2 — Correct method of edge stacking
8

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
9 Storage
Wood based panels can be susceptible to damage from high levels of moisture and measures should be
taken to prevent such elevated levels of moisture during transport and subsequent storage, in particular
protect from rain or standing water.
Panels should preferably be stored in an enclosed dry building. Where temporary storage outside cannot be
avoided, then stacks should be covered with waterproof but vapour permeable sheeting, keeping all panels on
raised bearers to prevent contact with the ground, water or vegetation. Any protective wrapping should be
kept in place as long as possible prior to conditioning for use.
10 Moisture content, conditioning and the effects of moisture
10.1 Moisture content
Moisture content of wood-based panel products varies in accordance with the moisture condition of the
surrounding environment, and is affected primarily by the relative humidity (rh) of the surrounding air. It moves
towards and maintains an equilibrium moisture content (emc) i.e. one that is in equilibrium with the
surrounding air. This means that moisture contents in wood-based panel products will vary depending on the
situation of use and with time as temperature and humidity conditions change.
Although it is not possible to give precise levels, the figures in Table 1 give a general indication of the range of
moisture contents in wood-based panels in various conditions.
Table 1 — Equilibrium moisture content and conditions of use
Normal range of
Service Approximate equilibrium
relative humidity (rh) Conditions of use
class moisture content (emc)
at 20 °C
1 30 % to 65 % 4 % ≤ emc ≤ 11 % Dry installations, no risk of wetting
in service
2 65 % to 85 % 11 % ≤ emc ≤ 17 % Risk of wetting during installation
and risk of occasional wetting in
service
3 > 85 % emc > 17 % Risk of regular wetting in service
The moisture content of panels when they leave the factory can be as low as 2 % depending on the type of
panel.
NOTE The allowable moisture content range is stated in the respective product standard.
This indicates that unconditioned newly manufactured panels can increase in moisture content when installed
in a building under construction and subsequently change in moisture content as the building is occupied,
heated and dries out, with the consequence of dimensional changes, see ranges given in 10.2.
10.2 Dimensional movement
Timber and wood-based panels expand on taking up moisture from the surrounding air, and shrink on losing
moisture. Excessive changes in moisture content may therefore lead to unacceptable dimensional changes
which may result in bowing, buckling or open joints between panels.
Panels should be protected from rain, dampness and accidental wetting and prior to fixing be conditioned to
the moisture content corresponding to the moisture conditions of end use.
Problems which may occur if insufficient care is taken with protection or conditioning include edge swelling
due to moisture ingress at unprotected edges, localized swelling due to moisture pick-up from adjacent
9

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kSIST-TP FprCEN/TR 12872:2014
FprCEN/TR 12872:2014 (E)
materials which have a higher moisture content, e.g. timber joists, and general expansion causing bowing
between supports or restraints. Any increase in moisture content will cause slight expansion in the panel.
For guidance purposes it may be assumed that a 1 % change in panel moisture content will cause a
dimensional change in panel width, length and thickness as given in Table 2.
The dimensional movement of specific products can differ from those given in Table 2 and reference should
be made to the manufacturers, where this is critical.
Table 2 — Dimensional change for a 1 % change in panel moisture content
Dimensional change at 1 % change
...

SLOVENSKI STANDARD
SIST-TP CEN/TR 12872:2015
01-marec-2015
1DGRPHãþD
SIST-TS CEN/TS 12872:2008
/HVQHSORãþH1DSRWNL]DWDOQRVWHQVNRLQVWUHãQRXSRUDERQRVLOQLKSORãþ
Wood-based panels - Guidance on the use of load-bearing boards in floors, walls and
roofs
Holzwerkstoffe - Leitfaden für die Verwendung von tragenden Platten in Böden, Wänden
und Dächern
Panneaux à base de bois - Guide pour l'utilisation des panneaux structurels en
planchers, murs et toitures
Ta slovenski standard je istoveten z: CEN/TR 12872:2014
ICS:
79.060.01 /HVQHSORãþHQDVSORãQR Wood-based panels in
general
SIST-TP CEN/TR 12872:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST-TP CEN/TR 12872:2015

---------------------- Page: 2 ----------------------

SIST-TP CEN/TR 12872:2015

TECHNICAL REPORT
CEN/TR 12872

RAPPORT TECHNIQUE

TECHNISCHER BERICHT
December 2014
ICS 79.060.01 Supersedes CEN/TS 12872:2007
English Version
Wood-based panels - Guidance on the use of load-bearing
boards in floors, walls and roofs
Panneaux à base de bois - Guide pour l'utilisation des Holzwerkstoffe - Leitfaden für die Verwendung von
panneaux structurels en planchers, murs et toitures tragenden Platten in Böden, Wänden und Dächern


This Technical Report was approved by CEN on 11 November 2014. It has been drawn up by the Technical Committee CEN/TC 112.

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.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 12872:2014 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
Contents Page
Foreword .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Information on product performance .7
5 Inspection at site.7
6 Transport and delivery .7
7 Handling .7
8 Stacking .7
9 Storage .9
10 Moisture content, conditioning and the effects of moisture .9
10.1 Moisture content .9
10.2 Dimensional movement .9
10.3 Conditioning . 10
11 Cutting and machining . 11
11.1 General . 11
11.2 Cutting with hand tools . 11
11.3 Machining with power tools . 11
11.4 Drilling . 12
12 Fixing . 12
13 Floors — Selection and installation . 13
13.1 Selection (specification) . 13
13.2 Type of floor covering related to wood-based floor panels . 13
13.3 Installation . 14
13.3.1 Preparation of structure . 14
13.3.2 Edge profile . 14
13.3.3 Expansion gaps . 14
13.3.4 Gluing . 15
13.3.5 Laying of wood-based panels for flooring . 15
14 Walls — Selection and installation . 16
14.1 Selection (specification) . 16
14.2 Wall constructions using wood-based panels on studs . 16
14.3 Installation . 16
14.3.1 Preparation of structure . 16
14.3.2 Edge profile . 17
14.3.3 Expansion gaps . 17
14.3.4 Assembly of wood-based panels for walls on studs . 18
15 Roofs — Selection and installation. 19
15.1 Selection (specification) . 19
15.2 Type of roof covering related to wood-based roof panels . 19
15.3 Type of roofs . 19
15.3.1 Flat roofs: cold roofs — warm roofs . 19
15.3.2 Pitched roofs — principles . 20
15.4 Installation . 21
2

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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
15.4.1 Preparation of structure . 21
15.4.2 Edge profile . 21
15.4.3 Expansion gaps . 22
15.4.4 Laying of wood-based panels in roof structures . 22
Bibliography . 24

3

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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
Foreword
This document (CEN/TR 12872:2014) has been prepared by Technical Committee CEN/TC 112 “Wood-based
panels”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TS 12872:2007.
Compared to CEN/TS 12872:2007 the following changes have been made:
a) deliverability changed from CEN/TS to CEN/TR;
b) references to requirements according to EN 12871 deleted after transformation of EN 12871 into a test
method standard;
c) in 10.2, Table 2, values of dimensional changes depending on moisture content for multilayer solid wood
panels added;
d) presentation of wall and roof constructions in Clauses 14 and 15 indicated as basic examples;
e) recommended expansion gaps for walls and roofs in Clauses 14 and 15 reduced.
4

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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
1 Scope
This Technical Report gives guidance on the use of wood-based panels in structural applications as structural
floor and roof decking on joists or structural wall sheathing on studs in accordance with EN 12871. It provides
information on:
— inspection at site;
— transport and delivery;
— handling;
— stacking;
— storage;
— moisture content, conditioning and the effects of moisture;
— cutting and machining;
— selection;
— installation.
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 300, Oriented Strand Boards (OSB) - Definitions, classification and specifications
EN 312, Particleboards - Specifications
EN 622-2, Fibreboards - Specifications - Part 2: Requirements for hardboards
EN 622-3, Fibreboards - Specifications - Part 3: Requirements for medium boards
EN 622-5, Fibreboards - Specifications - Part 5: Requirements for dry process boards (MDF)
EN 634-2, Cement-bonded particleboards - Specifications - Part 2: Requirements for OPC bonded
particleboards for use in dry, humid and external conditions
EN 636, Plywood - Specifications
EN 12871, Wood-based panels - Determination of performance characteristics for load bearing panels for use
in floors, roofs and walls
EN 13353, Solid wood panels (SWP) - Requirements
EN 1995-1-1:2004, Eurocode 5 — Design of timber structures — Part 1-1: General — Common rules and
rules for buildings
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
5

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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
3.1 Service classes
3.1.1
service class 1
is characterised by a moisture content in the materials corresponding to a temperature of 20 °C and the
relative humidity of the surrounding air only exceeding 65 % for a few weeks per year
[EN 1995-1-1:2004, 2.3.1.3]
3.1.2
service class 2
is characterised by a moisture content in the materials corresponding to a temperature of 20 °C and the
relative humidity of the surrounding air only exceeding 85 % for a few weeks per year
[EN 1995-1-1:2004, 2.3.1.3]
3.1.3
service class 3
climatic conditions leading to higher moisture contents than in service class 2
[EN 1995-1-1:2004, 2.3.1.3]
3.2
structural floor decking
assembly of wood-based panels supported on joists over which the decking spans
Note 1 to entry: The characteristic of the floor decking is that it is supported by joists and, when subjected to load, is
free to deflect between the joists.
3.3
structural wall sheathing
wood-based panel capable of providing mechanical resistance to a wall structure
3.4
structural roof decking
assembly of wood-based panels supported on joists over which the roof decking spans
Note 1 to entry: The characteristic of the decking is that it is supported by joists and, when subjected to load, is free to
deflect between the joists.
3.5
warm roof
roof design in which the panels supported on joists are placed below the insulation
Note 1 to entry: The panels are considered to be under conditions corresponding to service class 1.
3.6
cold roof
roof design in which the panels and some of the supporting joists are placed above the insulation
Note 1 to entry: The panels are considered to be under conditions corresponding to service class 2.
3.7
sub floor
structural panel meant to be covered by overlays
6

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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
4 Information on product performance
Information on product performance based on EN 13986 will be made available by the manufacturer or
supplier.
5 Inspection at site
The following should be checked based on the marking of the panel and/or the manufacturer's documentation
and/or the designers specification:
— grade or class according to EN specification standard;
— thickness;
— service class;
— suitability for biological durability use class;
— surface (sanded or un-sanded);
— edges (tongue and groove or other type of profile);
— joist or stud spacing;
— load category;
— main load-bearing direction for OSB, plywood and solid wood panels only.
6 Transport and delivery
Panels should be adequately protected by a waterproof covering during transportation. Edges should be well
protected from rain or traffic spray. Edge protection should also be provided to avoid damage by ropes, straps
or other banding. This applies particularly to profiled panels such as tongued and grooved panels.
Panels should be stacked properly to avoid sagging or other distortion, see Clause 8.
If packing includes banding or strapping this should be removed as soon as possible after delivery to prevent
any permanent deformation of the panels. When packs are delivered with edge or face protection panels,
these should be left in place until the pack is required for use.
7 Handling
When lifting, moving and stacking panels, edge protection should also be provided to avoid damage by lifting
ropes and/or forklifts.
When handling pre-finished panels, it is essential to avoid damage or dirt on the finished surfaces.
Pre-finished panels should always be lifted from a stack and never slid.
8 Stacking
Panels should be stacked flat on a level surface with all four edges flush. The ideal base is a close boarded or
slatted pallet.
If this is not possible the panels should be carefully stacked on battens of equal thickness at centres not
exceeding 600 mm as shown in Figure 1.
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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
Intermediate battens are recommended every 15 to 20 panels to allow through ventilation, they shall be
placed directly above those below. The battens should be placed parallel to the short edges across the full
width. Overhang of the panels at the ends of the stack should not exceed 150 mm. Where stacks are placed
on top of one another, the bearers should line up vertically to prevent distortion.
The top of the stack should be covered.
Stacking on edge should be avoided whenever possible. Where space will only permit edge stacking then the
edges should not be permitted to come into direct contact with the floor to avoid possible moisture pick-up or
damage to the edges. Panels should not be leant against walls but supported by a braced, purpose made rack
using thick (> 18 mm) base and back panels (see Figure 2).
In case of tongued and grooved panels, edge stacking on the tongue should be avoided.
Dimensions in millimetres

CORRECT

INCORRECT
Figure 1 — Panel storage

Figure 2 — Correct method of edge stacking
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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
9 Storage
Wood based panels can be susceptible to damage from high levels of moisture and measures should be
taken to prevent such elevated levels of moisture during transport and subsequent storage, in particular
protect from rain or standing water.
Panels should preferably be stored in an enclosed dry building. Where temporary storage outside cannot be
avoided, then stacks should be covered with waterproof but vapour permeable sheeting, keeping all panels on
raised bearers to prevent contact with the ground, water or vegetation. Any protective wrapping should be
kept in place as long as possible prior to conditioning for use.
10 Moisture content, conditioning and the effects of moisture
10.1 Moisture content
Moisture content of wood-based panel products varies in accordance with the moisture condition of the
surrounding environment, and is affected primarily by the relative humidity (rh) of the surrounding air. It moves
towards and maintains an equilibrium moisture content (emc) i.e. one that is in equilibrium with the
surrounding air. This means that moisture contents in wood-based panel products will vary depending on the
situation of use and with time as temperature and humidity conditions change.
Although it is not possible to give precise levels, the figures in Table 1 give a general indication of the range of
moisture contents in wood-based panels in various conditions.
Table 1 — Equilibrium moisture content and conditions of use
Normal range of
Service Approximate equilibrium
relative humidity (rh) Conditions of use
class moisture content (emc)
at 20 °C
1 30 % to 65 % 4 % ≤ emc ≤ 11 % Dry installations, no risk of wetting
in service
2 65 % to 85 % 11 % ≤ emc ≤ 17 % Risk of wetting during installation
and risk of occasional wetting in
service
3 > 85 % emc > 17 % Risk of regular wetting in service
The moisture content of panels when they leave the factory can be as low as 2 % depending on the type of
panel.
NOTE The allowable moisture content range is stated in the respective product standard.
This indicates that unconditioned newly manufactured panels can increase in moisture content when installed
in a building under construction and subsequently change in moisture content as the building is occupied,
heated and dries out, with the consequence of dimensional changes, see ranges given in 10.2.
10.2 Dimensional movement
Timber and wood-based panels expand on taking up moisture from the surrounding air, and shrink on losing
moisture. Excessive changes in moisture content may therefore lead to unacceptable dimensional changes
which may result in bowing, buckling or open joints between panels.
Panels should be protected from rain, dampness and accidental wetting and prior to fixing be conditioned to
the moisture content corresponding to the moisture conditions of end use.
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SIST-TP CEN/TR 12872:2015
CEN/TR 12872:2014 (E)
Problems which may occur if insufficient care is taken with protection or conditioning include edge swelling
due to moisture ingress at unprotected edges, localised swelling due to moisture pick-up from adjacent
materials which have a higher moisture content, e.g. timber joists, and general expansion causing bowing
between supports or restraints. Any increase in moisture content will cause slight expansion in the panel.
For guidance purposes it may be assumed that a 1 % change in panel moisture content will cause a
dimensional change in panel width, length and thickness as given in Table 2.
The dimensional movement of specific products can differ from those given in Table 2 and reference should
be made to the manufacturers, where this is critical.
Table 2 — Dimensional change for a 1 % change in panel moisture content
Dimensional change at 1 % change in
panel moisture content
Type of panel
...

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