SIST EN 16818:2018

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Trajnost lesa in lesnih izdelkov - Dinamika vlaženja lesa in lesnih izdelkovDauerhaftigkeit von Holz und Holzprodukten - Feuchte-Dynamik von Holz und HolzproduktenDurabilité du bois et des matériaux à base de bois - Cinétique d'humidification du bois et des produits à base de boisDurability of wood and wood-based products - Moisture dynamics of wood and wood-based products79.080Polizdelki iz lesaSemi-manufactures of timber79.040Les, hlodovina in žagan lesWood, sawlogs and sawn timberICS:Ta slovenski standard je istoveten z:CEN/TS 16818:2018SIST EN 16818:2018en,fr,de01-december-2018SIST EN 16818:2018SLOVENSKI
STANDARD



SIST EN 16818:2018



TECHNICAL SPECIFICATION SPÉCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION
CEN/TS 16818
August
t r s z ICS
y {ä r z r English Version
Durability of wood and woodæbased products æ Moisture dynamics of wood and woodæbased products Durabilité du bois et des matériaux à base de bois æ Cinétique d 5humidification du bois et des produits à base de bois
Dauerhaftigkeit von Holz und Holzprodukten æ FeuchteæDynamik von Holz und Holzprodukten March
t r s z for provisional applicationä
hree yearsä After two years the members of CEN will be requested to
available promptly at national level in an appropriate formä It is permissible to keep conflicting national standards in force CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Rue de la Science 23,
B-1040 Brussels
9
t r s z CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä SIST EN 16818:2018



CEN/TS 16818:2018 (E) 2 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
SIST EN 16818:2018



CEN/TS 16818:2018 (E) 3 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. SIST EN 16818:2018



CEN/TS 16818:2018 (E) 4 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. SIST EN 16818:2018



CEN/TS 16818:2018 (E) 5 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 SIST EN 16818:2018



CEN/TS 16818:2018 (E) 6 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. SIST EN 16818:2018



CEN/TS 16818:2018 (E) 7 5.5.2 End sealer The end sealer is necessary to prevent water penetrating along the end grain. A two pack polyurethane finish (e.g. Si
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