Träteknik

Ämnesområden: Plywood
Kommittébeteckning: SIS/TK 182 (Trä)
Källa: CEN
Svarsdatum: den 13 jan 2019
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This document sets out requirements regarding the performance of characteristics of the following types of cross laminated timber to be used in buildings and bridges:

— type 1: Straight or curved cross laminated timber comprising only timber layers but no large finger joints;

— type 2: Straight cross laminated timber comprising only timber layers and large finger joints;

— type 3: Straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints.

It also lays down procedures for assessment and verification of constancy of performance (AVPC) of characteristics and specifies marking and labelling of cross laminated timber.

This document covers cross laminated timber of all three types of cross laminated timber:

— manufactured according to this standard, which sets up provisions for:

— boundary conditions during manufacture of cross laminated timber;

— moisture content and temperature of timber to be bonded;

— production of finger joints and bonds between layers;

— to be used in service class 1 or 2 according to EN 1995-1-1;

— made of coniferous species and poplar listed in this standard;

— which may be made of layers made of different species having similar properties;

— bonded with phenolic or aminoplastic or moisture curing one-component polyurethane or emulsion polymer isocyanate adhesives of adhesive type I according to the respective standard;

— built up of at least three orthogonally bonded layers (at least two of them timber layers);

— which may have, depending on the number of layers, adjacent layers bonded parallel to the grain;

— made of timber layers which are made of strength graded timber according to EN 14081-1;

— made of timber layers having nominal thicknesses between 6 mm (including) and 60 mm (including) depending on the layup;

— made of timber layers

— which may comprise non-structural edge bonds; and

— have a mean gap width of less than or equal to 0,6 mm and a 90th percentile of the gap width of 2 mm;

— having nominal overall thicknesses up to 500 mm.

Additional provisions of this document apply for straight cross laminated timber comprising only timber layers and comprising large finger joints (type 2):

— made from cross laminated timber pieces having the same cross-section and layup;

— made from cross laminated timber pieces having nominal cross-sectional thicknesses from 51 mm (including) up to 345 mm (including) and nominal minimum thicknesses of the outer layers not less than 17 mm (including).

— made from cross laminated timber pieces solely comprising timber layers;

— made from plane cross laminated timber pieces;

— with parallel x-axes of the jointed components;

— with finger joints having a finger length of at least 45 mm and fingers which are visible at the two narrow sides of the components;

— bonded with phenolic or aminoplastic or moisture curing one-component polyurethane adhesives of adhesive type I according to the respective standard.

Additional provisions of this document apply for straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints (type 3):

— made of structural wood-based panels specified in this European standard;

— made of one panel per layer and;

— having thicknesses between 6 mm (including) and 45 mm (including);

This document applies to cross laminated timber untreated or treated against biological attack.

This document does not cover:

— cross laminated timber treated with fire retardants;

— cross laminated timber which is produced from re-used timber or wood-based panels comprising re-used timber.

Kommittébeteckning: SIS/TK 182 (Trä)
Källa: CEN
Svarsdatum: den 5 feb 2019
Se merSe mindre
 

This document gives guidance on the selection of wood species based on their biological durability and selection of wood materials based on their specific enhanced resistance (wood preservative treatment, wood modification and other non-biocidal methods) to attack by wood-destroying organisms for use as solid wood, as engineered wood products (e.g. glulam) and as wood based composites (e.g. plywood, wood polymer composites) in the use classes defined in EN 335.

This standard does not consider:

i) the durability characteristics of the glue used in engineered wood products or wood-based composites;

ii) the aesthetic function of wood products (discoloration, surface weathering, mould);

iii) the strategy for protection of products as it will be different based on priorities of the user and client and the type of product e.g. glulam compared to plywood.