SIST EN 16818:2018

SLOVENSKI STANDARD
01-december-2018
Odpornost lesa in lesnih izdelkov - Dinamika vlaženja lesa in lesnih izdelkov
Durability of wood and wood-based products - Moisture dynamics of wood and wood-
based products
Dauerhaftigkeit von Holz und Holzprodukten - Feuchte-Dynamik von Holz und
Holzprodukten
Durabilité du bois et des matériaux à base de bois - Cinétique d'humidification du bois et
des produits à base de bois
Ta slovenski standard je istoveten z: CEN/TS 16818:2018
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
79.080 Polizdelki iz lesa Semi-manufactures of timber
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 16818
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
August 2018
TECHNISCHE SPEZIFIKATION
ICS 79.080
English Version
Durability of wood and wood-based products - Moisture
dynamics of wood and wood-based products
Durabilité du bois et des matériaux à base de bois - Dauerhaftigkeit von Holz und Holzprodukten -
Cinétique d'humidification du bois et des produits à Feuchte-Dynamik von Holz und Holzprodukten
base de bois
This Technical Specification (CEN/TS) was approved by CEN on 2 March 2018 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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.
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. CEN/TS 16818:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 6
5 Test specimens . 6
5.1 Quality . 6
5.2 Provision of the test specimens (Annex A) . 6
5.3 Dimensions of each test specimen . 6
5.3.1 Floating test . 6
5.3.2 Submersion test . 6
5.4 Number of test specimens . 6
5.5 Products and reagents . 6
5.5.1 Water . 6
5.5.2 End sealer . 7
5.6 Apparatus . 7
6 Procedure. 7
6.1 Treatment of the wood test specimens . 7
6.1.1 Sealing of the end grain and edges . 7
6.1.2 Conditioning of test specimens . 7
6.2 Absorption cycle . 7
6.2.1 Floating test . 7
6.2.2 Submersion test . 8
6.3 Desorption cycle . 8
6.4 Additional short-term absorption cycle . 8
6.5 Oven dry mass . 9
7 Calculation and reporting results . 9
7.1 Absorption coefficient . 9
7.2 Residual moisture . 10
8 Test report . 12
Annex A (informative) Production of treatment blocks . 13
Annex B (informative) Example of a test report . 14
Bibliography . 15

European foreword
This document (CEN/TS 16818:2018) has been prepared by Technical Committee CEN/TC 38 “Durability
of wood and wood-based products”, the secretariat of which is held by AFNOR.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to announce this Technical Specification: 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 the United Kingdom.
Introduction
Moisture has a significant influence on the mechanical and physical properties and on the biological
durability of wood and wood-based materials. The test method described in this Technical Specification
is a laboratory method in which small samples are exposed to water. It provides a basis for assessment
of the moisture dynamics of wood and wood-based materials in service. The method permits the
determination of the water uptake and moisture release which may provide important information on
the susceptibility to the onset of fungal attack in certain end uses.
It is recommended that the results of this test should be supplemented by further suitable tests and
especially by practical experience.
1 Scope
This document details a method for determining the water uptake and the effectiveness of the drying
process on solid wood, wood-based materials or coated wood by means of water absorption and water
vapour desorption. This document lays down a method to assess the moisture dynamics of wooden
products which can be a contributing factor to the susceptibility to wood decay.
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 ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696)
EN 13183-1, Moisture content of a piece of sawn timber — Part 1: Determination by oven dry method
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:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
supplier
sponsor of the test (person or company providing the samples or wood-based products to be tested)
3.2
residue
moisture content left in the test specimen after desorption as a percentage of the absorbed moisture
3.3
residual moisture content
increase in moisture content in the test specimen after desorption
3.4
absorption coefficient
slope of the fitted line for a plot of the water uptake per square metre against the square root of the
elapsed time
3.5
treatment block
wood or wood-based product that is subsequently edge and end grain sealed to create the test specimen
4 Principle
Test specimens prepared from the wood or wood-based product under test are exposed to water by
means of floating or submersion. During a prescribed wetting and drying period under defined conditions
the mass of the specimens is registered. The mass gain and mass loss is used to estimate the residual
moisture and thus the potential to reach and remain at a moisture content at which fungal decay can
occur.
5 Test specimens
5.1 Quality
The wood and wooden products shall be free from cracks, stain, decay, insect damage or other defect. In
case of timber, it shall be quarter sawn for provision of test specimens.
5.2 Provision of the test specimens (Annex A)
Condition the wood and wooden products at (65 ± 5) % and (20 ± 2) °C to constant mass (mass variation
in consecutive measurements ± 0,01 g). Prepare planed strips having a cross section of (50 ± 0,5) mm and
(25 ± 0,5) mm. The longitudinal faces of the wood samples shall be parallel to the direction of the grain.
The annual rings shall not be parallel to the faces (contact angle > 10°) but otherwise can run in any other
direction. Make transverse cuts, neatly to give sharp edges and a fine-sawn finish to the end grain
surfaces, to give test specimens a length of (50 ± 0,5) mm for the floating test method or a length of
(150 ± 0,5) mm long for the submersion test method.
The test specimens shall originate from a minimum of three planks or panels.
5.3 Dimensions of each test specimen
5.3.1 Floating test
The dimension of each test specimen at conditioned mass shall be (50 ± 0,5) mm × (50 ± 0,5) mm ×
(25 ± 0,5) mm or the thickness of the panel under test.
5.3.2 Submersion test
The dimension of each test specimen at conditioned mass shall be (150 ± 0,5) mm × (50 ± 0,5) mm ×
(25 ± 0,5) mm or the thickness of the panel under test.
5.4 Number of test specimens
Use at least three test specimens per plank or panel. This results in a minimum total of 9 test specimens.
5.5 Products and reagents
5.5.1 Water
Complying with grade 3 of EN ISO 3696.
5.5.2 End sealer
The end sealer is necessary to prevent water penetrating along th
...