SIST EN 14734:2022

Durability of wood and wood-based products - Determination of treatability of timber species to be impregnated with wood preservatives - Laboratory method

This document specifies a laboratory method for the determination of the treatability of wood in order to determine the likely reaction of different wood species to impregnation with wood preservatives. It is also applicable to investigate variation between samples of the same species but of different origin.

Dauerhaftigkeit von Holz und Holzprodukten - Bestimmung der Tränkbarkeit von Holzarten zur Tränkung mit Holzschutzmitteln - Laborverfahren

Dieses Dokument legt ein Laborverfahren zur Bestimmung der Tränkbarkeit von Holz fest, um die wahrscheinliche Reaktion unterschiedlicher Holzarten auf die Imprägnierung mit Holzschutzmitteln zu bestimmen. Es ist auch dazu anzuwenden, Abweichungen zwischen Proben derselben Holzart, jedoch unterschiedlicher Herkunft, zu untersuchen.

Durabilité du bois et des matériaux dérivés du bois - Détermination de l'imprégnabilité d'essences de bois par des produits de préservation - Méthode de laboratoire

Le présent document spécifie une méthode de laboratoire permettant de déterminer l'imprégnabilité du bois, afin de prévoir la réaction probable de différentes essences de bois à une imprégnation par des produits de préservation. Il peut aussi être appliqué pour vérifier les variations entre les échantillons de la même essence mais d'une origine différente.

Trajnost lesa in lesnih proizvodov - Ugotavljanje možnosti za impregnacijo lesnih vrst z biocidnimi proizvodi za zaščito lesa - Laboratorijska metoda

Ta dokument opisuje laboratorijsko metodo za določanje možnosti impregnacije lesa, da se opredeli verjetna reakcija različnih vrst lesa na impregnacijo s sredstvi za zaščito lesa. Uporablja se lahko tudi za proučevanje razlik med vzorci iste vrste, vendar različnega izvora.

General Information

• Status: Published
• Public Enquiry End Date: 24-Feb-2021
• Publication Date: 23-Aug-2022
• ICS: 71.100.50 - Wood-protecting chemicals
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: LLZ - Les, lesni izdelki in zaščita lesa
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 04-Aug-2022
• Due Date: 09-Oct-2022
• Completion Date: 24-Aug-2022
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Ref Project: EN 14734:2022 - Durability of wood and wood-based products - Determination of treatability of timber species to be impregnated with wood preservatives - Laboratory method

Relations

• Corrected By: SIST EN 14734:2022/AC:2023 - Durability of wood and wood-based products - Determination of treatability of timber species to be impregnated with wood preservatives - Laboratory method
• Effective Date: 26-Oct-2022
• Revised: SIST-TP CEN/TR 14734:2005 - Durability of wood and wood-based products - Determination of treatability of timber species to be impregnated with wood preservatives - Laboratory method
• Effective Date: 01-Sep-2022

Overview

EN 14734:2022 - Durability of wood and wood-based products - Determination of treatability of timber species to be impregnated with wood preservatives - Laboratory method - is a CEN laboratory procedure to objectively evaluate how different timber species (and samples of the same species from different origins) respond to preservative impregnation. The method produces penetration and treatability data used to inform treatment specifications and compliance (for example in EN 351-1).

Key topics and technical requirements

• Purpose: Determine likely reaction of sapwood or heartwood to impregnation with wood preservatives and quantify penetration.
• Test specimens: Minimum ten specimens (recommended 20 to capture variability), each from a different plank; typical cross-section (40 ± 0.3) mm × (40 ± 0.3) mm and length ~750 mm; moisture content at test between 13 % and 18 %.
• Reagents: Standard aqueous indicator system using copper sulfate pentahydrate (50 g/kg solution) and an indicator such as chrome azurol S (0.5 g + 5 g sodium acetate / 100 ml) to visualise penetration.
• Apparatus & conditions: Ordinary lab equipment plus a treatment vessel with vacuum and pressure capability. The procedure applies a vacuum (document specifies (1,0 ± 0,5) kPa) for 45 minutes, followed by filling with solution and a pressure phase (document specifies a pressure period of 120 minutes).
• Procedure steps: moisture and density determination (oven-dry), vacuum-pressure impregnation with copper sulfate solution, drying below fibre saturation point, splitting specimens, application of indicator to cross-sections and longitudinal surfaces, and measurement of axial and lateral penetration (minimum and average values).
• Data handling: Assign treatability classes for individual samples and sets; the method supports objective classification used by EN 351-1 and complements subjective classifications such as EN 350.
• Reporting: Test report requirements and sampling guidance are provided (Annex A and B give sampling and report examples).

Applications and users

• Who uses it: Independent testing laboratories, timber processors, wood-preservative manufacturers, researchers, certification bodies and specifiers involved in wood durability and preservation.
• Practical uses:
  • Assessing whether a species or batch is suitable for pressure impregnation treatments.
  • Supporting treatment specifications and quality control for preservative penetration and retention.
  • Providing objective data for regulatory compliance and product standards (e.g., selection of treatability class for EN 351-1).

Related standards

• EN 351-1 (treatment specification based on penetration/retention)
• EN 350 (subjective treatability and natural durability guidance)
• Supersedes CEN/TR 14734:2004; prepared by CEN/TC 38.

Keywords: EN 14734:2022, treatability, timber impregnation, wood preservatives, laboratory method, copper sulfate, penetration measurement, treatability classes, wood durability.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2022
Trajnost lesa in lesnih proizvodov - Ugotavljanje možnosti za impregnacijo lesnih
vrst z biocidnimi proizvodi za zaščito lesa - Laboratorijska metoda
Durability of wood and wood-based products - Determination of treatability of timber
species to be impregnated with wood preservatives - Laboratory method
Dauerhaftigkeit von Holz und Holzprodukten - Bestimmung der Tränkbarkeit von
Holzarten zur Tränkung mit Holzschutzmitteln - Laborverfahren
Durabilité du bois et des matériaux dérivés du bois - Détermination de l'imprégnabilité
d'essences de bois par des produits de préservation - Méthode de laboratoire
Ta slovenski standard je istoveten z: EN 14734:2022
ICS:
71.100.50 Kemikalije za zaščito lesa Wood-protecting chemicals
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 14734
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2022
EUROPÄISCHE NORM
ICS 79.040 Supersedes CEN/TR 14734:2004
English Version
Durability of wood and wood-based products -
Determination of treatability of timber species to be
impregnated with wood preservatives - Laboratory
method
Durabilité du bois et des matériaux dérivés du bois - Dauerhaftigkeit von Holz und Holzprodukten -
Détermination de l'imprégnabilité d'essences de bois Bestimmung der Tränkbarkeit von Holzarten zur
par des produits de préservation - Méthode de Tränkung mit Holzschutzmitteln - Laborverfahren
laboratoire
This European Standard was approved by CEN on 20 April 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, 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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14734:2022 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 . 5
5 Reagents . 5
5.1 Copper sulfate pentahydrate, at least 98 % pure, solution of 50 g/kg. . 5
5.2 Indicator solution. 5
5.3 Sealing compound . 5
6 Apparatus . 6
7 Preparation of test specimens . 7
8 Procedure. 7
8.1 Moisture content and density determination . 7
8.2 Impregnation of test specimens (standard procedure) . 7
8.3 Measurement of penetration . 8
9 Data handling. 9
9.1 Treatability classes for individual test samples . 9
9.2 Differentiation between treatability classes 3 and 4 . 10
9.3 Assignation of a treatability class to a set of specimens . 10
10 Test report . 11
Annex A (informative) Guidance on sampling . 12
A.1 General . 12
A.2 Origin of the material . 12
A.3 Homogeneity of the sample . 12
A.4 Heartwood . 12
A.5 Saw pattern . 13
A.6 Seasoning . 13
A.7 Grading . 13
Annex B (informative) Example of a test report . 14
Bibliography . 16
European foreword
This document (EN 14734:2022) has been prepared by Technical Committee CEN/TC 38 “Durability of
wood and wood-based products”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2022, and conflicting national standards shall
be withdrawn at the latest by December 2022.
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.
This document supersedes CEN/TR 14734:2004.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Introduction
The basis for this document was prepared as being part of the work for SMT project MAT-CT 94061
project number 3307: Improvement of CEN standards by short term methods for testing the natural
durability and treatability of solid wood and wood based panel products.
It provides the means whereby the treatability of sapwood or heartwood of different wood species can
be determined in order to determine likely reaction to impregnation with wood preservatives. Such an
assessment provides data for use in EN 351-1 which establishes a system for specifying the treatment of
wood with wood preservatives based upon the penetration and retention of preservatives achieved by
the treatment process. EN 351-1 recognizes that different wood species respond to treatment differently
depending on their ability to absorb preservative, and requires a different level of compliance depending
on the treatability of the wood concerned. While EN 350 includes a subjective classification of the
treatability of different wood species using a four class system, the method described in this document
provides the means to determine the treatability objectively.
Although the method described uses an aqueous solution as the impregnating liquid, the method can be
modified using other preservative types, e.g. organic solvent or emulsion preparations, if the response of
the wood to a specific preservative is required. However, the method does not take account of
preservative formulations where the active ingredients are selectively adsorbed on to the wood substrate
resulting in the solvent penetrating more deeply than the biocides.
1 Scope
This document specifies a laboratory method for the determination of the treatability of wood in order
to determine the likely reaction of different wood species to impregnation with wood preservatives. It is
also applicable to investigate variation between samples of the same species but of different origin.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
After moisture and density determination of each of the test specimens, a set of test specimens is
impregnated with copper sulfate solution in accordance with a standard test procedure. After application
of an indicator solution to the exposed cross-section and to one of the exposed longitudinal surfaces of
each of test specimens, the lateral and axial penetration is measured and the treatability class is
evaluated.
5 Reagents
5.1 Copper sulfate pentahydrate, at least 98 % pure, solution of 50 g/kg
Dissolve 50 g of copper sulfate pentahydrate (CuSO • 5H O) in 950 g water, preferably deionized.
4 2
NOTE The volume of copper sulfate solution required will depend on the capacity of the impregnation
apparatus.
5.2 Indicator solution
For the indication of the penetration an indicator solution, e.g. chrome azurol S, can be used. Dissolve
0,5 g chrome azurol S and 5 g sodium acetate in 100 ml water.
Other indicators can be used but should have at least the same sensitivity to copper as chrome azurol S.
5.3 Sealing compound
A sealing compound which is inert to the copper sulfate solution (5.1) and unaffected by the test
conditions.
6 Apparatus
Ordinary laboratory apparatus and:
6.1 Balance, capable of weighing with maximum permissible error of 0,01 g.
6.2 Conditioning chamber, well ventilated and controlled at (20 ± 2) °C and (65 ± 5) % relative
humidity.
6.3 Measuring devices, capable of measuring the dimensions of test sample size of up to 40 mm and
1000 mm, respectively, and to a maximum uncertainty of measurement of 0,1 mm.
6.4 Drying oven, capable of being controlled at (103 ± 2) °C.
6.5 Desiccator, with efficient desiccant (silica gel for example).
6.6 Treatment vessel, consisting of a chamber and header tank with ancillary vacuum and pressure
pumps capable of exerting a vacuum of (1 ± 0,5) kPa and a pressure of (10 ± 1) × 10 kPa. The pipe work
between the treatment vessel and the pumps shall be designed so that adding or draining treatment
solutions can be achieved while maintaining the existing pressure in the vessel. A typical treatment vessel
with connected pumps and storage tank is shown in Figure 1.

Key
1 storage tank
2 pump
3 vacuum pump
4 treatment vessel (chamber)
PI pressure gauge
Figure 1 — Typical treatment vessel (with connected pumps and storage tank)
7 Preparation of test specimens
Prepare a minimum of ten test specimens, each from a different plank of the wood species under test (see
also 8.2). The test specimens shall be characterized and marked appropriately so that a distinguishment
between heartwood and sapwood zones are made. The wood shall be sound, straight-grained and
without knots and the visible features of the wood shall be given for example: resin pockets, cross-grain,
widths of annual rings and proportion of latewood. At the time of test, the moisture content of the test
specimens shall be between 13 % and 18 %.
NOTE It is important that the timber tested is representative of the population from which it comes. Guidance
on the sampling of timber is provided in Annex A.
20 test specimens should be used to take into account variability between specimens.
From each plank, prepare a strip having a length of at least 800 mm and a cross-section of
(40 ± 0,3) mm × (40 ± 0,3) mm. When the sapwood zone is less than 40 mm wide it can be necessary to
limit the cross-section of each strip. The lateral surfaces shall be planed and shall be true radial and
tangential surfaces. Cross cut 15 mm to 20 mm from one end and discard. Cross cut a (10 ± 0,1) mm long
sample from the same end, for moisture content and density determination (see 8.1). Trim the other end
of the remaining length to give a test specimen (750 ± 1) mm long for impregnation. Number both test
specimens so as to retain the identity of the plank. Apply the sealing compound (5.3) to one cross-section
end of each test specimen for impregnation and allow to set. Inspect the end seal to ensure that it
completely covers the end grain and apply a second coat if required.
It is recommended that neither dimension of the cross-section is less than 20
...