SIST-TS CEN/TS 15679:2008

Thermal Modified Timber - Definitions and characteristics

La présente Spécification technique donne les définitions et les caractéristiques relatives au bois modifié thermiquement. Le bois modifié thermiquement est utilisé dans des milieux intérieurs (secs, humides) et extérieurs. NOTE 1 Le bois modifié thermiquement est généralement un produit semi-fini dont les applications sont, par exemple, les planchers, les lambris, les bardages, les platelages, les fenêtres, les portes, le mobilier et autre menuiserie intérieure et extérieure. Les normes de produits spécifient les exigences et les méthodes d’essai devant être prises en compte. NOTE 2 Utilisation dans des applications porteuses – il convient de se référer aux normes EN pertinentes.

Thermisch modifiziertes Holz - Definitionen und Eigenschaften

Diese Technische Spezifikation legt die Definitionen und die Eigenschaften von thermisch modifiziertem Holz (en: Thermally Modified Timber, TMT)  fest. Thermisch modifiziertes Holz wird in Innenräumen (Trocken, Feuchtbereich) und im Außenbereich eingesetzt.
ANMERKUNG 1   Thermisch modifiziertes Holz ist üblicherweise ein Halbfertigprodukt, das für folgende Anwendungsfälle eingesetzt wird: z. B. Fußböden, Innenbekleidungen, Außenbekleidungen, Deckbeläge, Fenster, Türen, Möbel und andere Holzbauteile im Innen- und Außenbereich. Die entsprechenden Produktnormen enthalten Anforderungen und Prüf¬verfahren, die zu berücksichtigen sind.
ANMERKUNG 2   Für die Verwendung in last tragenden Konstruktionen sollte auf die zutreffenden EN Normen verwiesen werden.

Bois modifié thermiquement - Définitions et caractéristiques

La présente Spécification technique donne les définitions et les caractéristiques relatives au bois modifié thermiquement. Le bois modifié thermiquement est utilisé dans des milieux intérieurs (secs, humides) et extérieurs.
NOTE 1   Le bois modifié thermiquement est généralement un produit semi-fini dont les applications sont, par exemple, les planchers, les lambris, les bardages, les platelages, les fenêtres, les portes, le mobilier et autre menuiserie intérieure et extérieure. Les normes de produits spécifient les exigences et les méthodes d’essai devant être prises en compte.
NOTE 2   Utilisation dans des applications porteuses  il convient de se référer aux normes EN pertinentes.

Toplotno obdelan les - Definicije in lastnosti

General Information

• Status: Published
• Publication Date: 04-Mar-2008
• ICS: 01.040.79 - Wood technology (Vocabularies)
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: LES - Round and sawn timber
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 08-Jan-2008
• Due Date: 14-Mar-2008
• Completion Date: 05-Mar-2008
• Ref Project: CEN/TS 15679:2007 - Thermal Modified Timber - Definitions and characteristics

Overview

CEN/TS 15679:2007 - "Thermal Modified Timber - Definitions and characteristics" is a CEN Technical Specification that defines thermally modified timber (TMT) and describes the characteristic properties and test topics relevant to its use in interior (dry and humid) and exterior conditions. The document was approved provisionally by CEN (15 November 2007) and gives manufacturers, specifiers and testers a common vocabulary and a framework of characteristics to evaluate TMT products.

Key topics and technical requirements

The Technical Specification focuses on definitions and measurable characteristics rather than prescriptive product classes. Key technical topics covered include:

• Definition of TMT: wood altered by exposure above 160 °C under reduced oxygen so that cell‑wall composition and physical properties are permanently changed.
• Hygrothermal behaviour: reduced equilibrium moisture content (EMC) and related dimensional stability improvements.
• Durability: increased resistance to decay by wood‑destroying fungi (and sometimes increased insect resistance); reference to biological test methods (e.g., EN 113 and related standards).
• Mechanical properties: effects on bending strength, modulus of elasticity (MOE), impact strength, surface hardness, compression, and fastener performance.
• Other characteristics: density, thermal conductivity, adhesive bonding, coating adhesion, VOC emissions, reaction‑to‑fire behaviour and colour changes.
• Assessment and conformity: sampling, factory production control and marking requirements are addressed; normative references specify applicable test methods (e.g., EN 1995‑1‑1, EN 13183‑1, EN ISO 16000‑9, EN 13501‑1).

The specification also notes that property changes depend on wood species, modification technology and process parameters (principally treatment temperature and oxygen reduction method: heated air/steam, nitrogen, or oil bath).

Applications and users

Typical semi‑finished and finished applications for TMT include:

• Flooring, parquet and decking
• External cladding and panelling
• Windows, doors and joinery
• Furniture and interior panelling

Primary users of CEN/TS 15679:2007:

• Timber product manufacturers and process engineers
• Product testers and certification bodies
• Architects, specifiers and engineers evaluating TMT for building use
• Standards writers and conformity assessment organizations

For load‑bearing or structural use, the specification recommends referencing relevant EN standards (for example Eurocode 5 / EN 1995‑1‑1).

Related standards (examples)

Relevant normative references cited by the specification include: EN 113 (fungal durability), EN 1995‑1‑1 (design of timber structures), EN 13183‑1 (moisture content), EN ISO 16000‑9 (VOC emissions) and EN 13501‑1 (reaction to fire). These standards define specific test methods and requirements to be applied when assessing TMT products.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2008
Toplotno obdelan les - Definicije in lastnosti
Thermal Modified Timber - Definitions and characteristics
Thermisch modifiziertes Holz - Definitionen und Eigenschaften
Bois modifié thermiquement - Définitions et caractéristiques
Ta slovenski standard je istoveten z: CEN/TS 15679:2007
ICS:
01.040.79
79.040
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 15679
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
November 2007
ICS 01.040.79; 79.040
English Version
Thermal Modified Timber - Definitions and characteristics
Bois Modifié Thermiquement - Définitions et Thermisch modifiziertes Holz - Definitionen und
caractéristiques Eigenschaften
This Technical Specification (CEN/TS) was approved by CEN on 15 November 2007 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, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15679:2007: E
worldwide for CEN national Members.

Contents Page
Foreword.3
Introduction .4
1 Scope.5
2 Normative references.5
3 Terms and definitions .7
4 Symbols and abbreviations .8
5 Characteristics.8
5.1 General.8
5.2 Equilibrium moisture content.10
5.3 Dimensional stability.10
5.4 Durability : resistance to attack by fungi .10
5.5 Density.11
5.6 Mechanical properties.11
5.6.1 Bending strength and modulus of elasticity.11
5.6.2 Impact strength.11
5.6.3 Surface hardness.11
5.6.4 Tension perpendicular to grain.11
5.6.5 Compression strength.12
5.6.6 Strength of mechanical fasteners.12
5.7 Thermal conductivity.12
5.8 Adhesive bonding of TMT.12
5.9 Adhesion of coating to TMT .12
5.10 Emissions.12
5.11 Reaction to fire.12
5.12 Durability : resistance to attack by insects.12
5.13 Colour.12
6 Assessment of characteristics.13
6.1 General.13
6.2 Sampling.13
6.3 Factory production control.13
6.3.1 General.13
6.3.2 Characteristics of the TMT product to be controlled.14
7 Marking.15
Annex A (informative) Examples of characteristics .16
A.1 Equilibrium moisture content.16
A.2 Dimensional stability.16
A.3 Biological durability.17
Bibliography .18

Foreword
This document (CEN/TS 15679:2007) has been prepared by Technical Committee CEN/TC 175 “Round and
sawn timber”, 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 [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Introduction
The principal changes on thermal modification of timber - compared with untreated wood – are improved
dimensional stability and increased resistance to decay by wood destroying fungi, and in some cases changed
colours.
Due to the treatment, equilibrium moisture content of thermally modified timber is reduced.
Because of altered strength properties comparing to untreated wood, for the use of TMT, it is essential that
the relevant requirements of European and national Standards be taken into consideration.
Thermal modification may have an influence on reaction to fire properties of timber.
The properties of thermally modified timber and the degree that the property changes is dependent of the
wood species, the type of technology and the process parameters, particularly the treatment temperature
level.
The altering of acoustic properties can be of interest particularly for musical instruments.
Some tests have shown an increased resistance of TMT against some insects. Improved resistance against
termites has not been proved. Requirements on resistance against termites in some EU member states are to
be taken into consideration.
The technologies for manufacturing thermally modified timber are mainly characterized by the way they
reduce the oxygen concentration during treatment. The currently applied, industrial scale processes are using
atmospheres of heated air and or steam or heated nitrogen or in a bath of heated oil.
1 Scope
This Technical Specification gives definitions and characteristics for Thermally Modified Timber. TMT is used
in interior (dry, humid) and exterior conditions.
NOTE 1 TMT is usually a semi-finished product; applications are e.g. flooring, panelling, cladding, decking, windows,
doors, furniture and other internal and external joinery. Where product standard exist, the given requirements and test
methods are to be taken into consideration.

NOTE 2 Use in load bearing applications – reference to relevant EN standards should be made.

2 Normative references
The following referenced documents are indispensable for the application 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 20-2, Wood preservative – Determination of the protective effectiveness against Lyctus brunneus
(Stephens) – Part 2: Application by impregnation (Laboratory method)
EN 47, Wood preservatives – Determination of the toxic values against larvae of Hylotrupes bajulus
(Linnaeus) – (Laboratory method)
EN 84, Wood preservatives – Accelerated ageing of treated wood prior to biological testing – Leaching
procedure
EN 113, Wood preservatives – Test method for determining the protective effectiveness against wood
destroying basidiomycetes – Determination of the toxic values
EN 117, Wood preservatives – Determination of toxic values against Reticulitermes species (European
termites) (Laboratory method)
EN 204, Classification of thermoplastic wood adhesives for non-structural applications
EN 252, Field test method for determining the relative protective effectiveness of a wood preservative in
ground contact
EN 275, Wood preservatives – Determination of the protective effectiveness against marine borers
EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures – Classification and
performance requirements
EN 335-1, Durability of wood and wood-based products – Definition of use classes – Part 1: General

EN 335-2, Durability of wood and wood-based products – Definition of use classes – Part 2 : Application to
solid wood,
EN 350-1, Durability of wood and wood-based products – Natural durability of solid wood – Part 1: Guide to
the principles of testing and classification of the natural durability of wood
EN 383, Timber Structures – Test methods – Determination of embedment strength and foundation values for
dowel type fasteners
EN 408, Timber structures – Structural timber and glued laminated timber – Determination of some physical
and mechanical properties
EN 460, Durability of wood and wood-based products – Natural durability of solid wood – Guide to the
durability requirements for wood to be used in hazard classes
ENV 807, Wood preservatives – Determination of the effectiveness against soft rotting micro-fungi and other
soil inhabiting micro-organisms
prCEN/TS 839, Wood preservatives – Determination of the protective effectiveness against wood destroying
basidiomycetes - Application by surface treatment.
EN 844-1, Round and sawn timber – Terminology – Part 1 : General terms common to round timber and sawn
timber
EN 844-2, Round and sawn timber – Terminology – Part 2 : General terms relating to round timber
EN 844-3, Round and sawn timber – Terminology – Part 3 : General terms relating to sawn timber
EN 844-4, Round and sawn timber – Terminology – Part 4 : Terms relating to moisture content
EN 844-5, Round and sawn timber – Terminology – Part 5 : Terms relating to dimensions of round timber
EN 844-6, Round and sawn timber – Terminology – Part 6 : Terms relating to dimensions of sawn timber
EN 844-7 Round and sawn timber – Terminology – Part 7: Terms relating to anatomical structure of timber
EN 844-8, Round and sawn timber – Terminology – Part 8 : Terms relating to features of round timber
EN 844-9, Round and sawn timber – Terminology – Part 9 : Terms relating to features of sawn timber
EN 844-10, Round and sawn timber – Terminology – Part 10 : Terms relating to stain and fungal attack
EN 844-11, Round and sawn timber – Terminology – Part 11 : Terms relating to degrade by insects
EN 844-12, Round and sawn timber – Terminology – Part 12 : Additional terms and general index
EN 927-6, Paints and varnishes - Coating materials and coating systems for exterior wood – Part 6 : Exposure
of wood coatings to artificial weathering using fluoresdent UV lamps and water
EN 1001-2, Durability of wood and wood based products – Terminology - Part 2: Vocabulary
EN 1380, Timber structures – Test methods – Load bearing nailed joints
EN 1382, Timber structures – Test methods – Withdrawal capacity of timber fasteners

EN 1534, Wood and parquet flooring – Determination of resistance to indentation (Brinell) – Test method

EN 1910, Wood and parquet flooring and wood panelling and cladding – Determination of dimensional stability

EN 1995-1-1, Eurocode 5: Design of timber structures – Part 1-1: General – Common rules and rules for
buildings
CEN/TS 12037, Wood preservatives – Field test method for determining the relative protective effectiveness
of a wood preservative exposed out of ground contact – Horizontal lap-joint method
ENV 12169, Criteria for the assessment of conformity of a lot of sawn timber

EN 12524, Building materials and products – Hygrothermal properties – Tabulated design values
EN 12664, Thermal performance of building materials and products - Determination of thermal resistance by
means of guarded hot plate and heat flow meter methods - Dry and moist products of medium and low
thermal resistance
EN 13183-1, Moisture content of a piece of sawn timber - Part 1: Determination by oven dry method
EN 13501-1, Fire classification of construction products and building elements - Part 1: Classification using
data from reaction to fire tests
EN 13823, Reaction to fire tests for building products - Building products excluding floorings exposed to the
thermal attack by a single burning item
EN 14762, Wood flooring, Sampling procedures for evaluation of conformity
prCEN/TS 15397, Wood preservatives – Method for natural preconditioning out of ground contact of treated
wood specimens prior to biological laboratory test
EN 20105-A03, Textiles - Tests for colour fastness - Part A03: Grey scale for assessing staining (ISO 105-
A03:1993)
EN ISO 179-1, Plastics - Determination of Charpy impact properties - Part 1: Non-instrumented impact test
(ISO 179- 1:2000)
EN ISO 2409, Paints and varnishes - Cross-cut test (ISO 2409:1992)
EN ISO 4624, Paints and varnishes – Pulloff test for ahesion (ISO 4624: 2002)
EN ISO 9239-1, Reaction to fire tests for floorings – Part 1 : Determination of the burning behaviour using a
radiant heat source (ISO 9239-1:2002)
EN ISO 16000-9, Indoor air – Part 9 : Determination of the emission of volatile organic compounds from
building products and furnishing – Emission test chamber method (ISO 16000-9:2006)
ISO 7724-1, Paints and varnishes -- Colorimetry -- Part 1: Principles
ISO 7724-2, Paints and varnishes -- Colorimetry – Part 2 : Colour measurement
ISO 7724-3, Paints and varnishes -- Colorimetry – Part 3 : Calculation of colour differences
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 844 part 1 to part 12 and in EN
1001-2:2005 and the following apply.
3.1
thermally modified timber
Wood at which the composition of the cell wall material and its physical properties are modified by the
exposure of temperature higher than 160 ºC and conditions of reduced oxygen availability. The wood is
altered in such way that at least some of the wood properties are permanently affected through the cross
section of the timber
3.2
dry conditi
...