SIST EN 14951:2026

• Abstract:

  This document specifies characteristics of solid wood panelling and cladding with or without tongue and groove machined from hardwoods (wood of trees of the botanical group dicotyledons).; Products are intended for interior or exterior use.; This document covers treated, untreated and surface treated products, including those made of thermally and chemically modified wood, as well as finger jointed products.; This document does not cover processes for treatment, surface coating or modification.; NOTE Where further regulatory provisions (e.g. durability, reaction to fire, dangerous substances and generally CE-marking according to CPR) are required, harmonized EN 14915 applies.

• Status: Published
• Public Enquiry End Date: 16-Jul-2025
• Publication Date: 17-Aug-2026
• ICS: 79.060.99 - Other wood-based panels
• ICS: 79.080 - Semi-manufactures of timber
• Technical Committee: LLZ - Les, lesni izdelki in zaščita lesa
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-Jul-2026
• Due Date: 04-Oct-2026
• Completion Date: 18-Aug-2026
• Ref Project: EN 14951:2026 - Solid hardwood panelling and cladding - Machined profiles

• Refers: SIST EN 13183-3:2005 - Moisture content of a piece of sawn timber - Part 3: Estimation by capacitance method
• Effective Date: 02-Sep-2026
• Refers: SIST EN 13647:2021 - Wood flooring and wood panelling and cladding - Determination of geometrical characteristics
• Effective Date: 02-Sep-2026
• Refers: SIST EN 13183-2:2003 - Moisture content of a piece of sawn timber - Part 2: Estimation by electrical resistance method
• Effective Date: 02-Sep-2026
• Refers: SIST EN 13756:2018 - Wood flooring and parquet - Terminology
• Effective Date: 02-Sep-2026
• Refers: SIST EN 13183-1:2003 - Moisture content of a piece of sawn timber - Part 1: Determination by oven dry method
• Effective Date: 02-Sep-2026
• Refers: SIST EN 1309-3:2018 - Round and sawn timber - Methods of measurements - Part 3: Features and biological degradations
• Effective Date: 02-Sep-2026
• Refers: SIST EN 13307-1:2007 - Timber blanks and semi-finished profiles for non-structural uses - Part 1: Requirements
• Effective Date: 02-Sep-2026
• Refers: SIST EN 844:2019 - Round and sawn timber - Terminology
• Effective Date: 02-Sep-2026
• Referred By: SIST-TP CWA 17890:2022 - Guide to the implementation of cool surfaces for buildings’ envelope to mitigate the Urban Heat Island effects
• Effective Date: 28-Jan-2026
• Revises: SIST EN 14951:2006 - Solid hardwood panelling and cladding - Machined profiles elements
• Effective Date: 19-Jan-2023

Overview

SIST EN 14951:2026 defines the requirements for solid hardwood panelling and cladding with machined profiles, applicable to both interior and exterior use. This standard, developed by the Slovenian Institute for Standardization (SIST), covers panelling and cladding products produced from hardwoods belonging to the dicotyledons group. The scope includes products that are:

• Untreated, treated, or surface-treated
• Thermally or chemically modified
• Manufactured as finger jointed items

It sets out the key characteristics and grading classes for a broad range of hardwood species and specifies marking, grading, moisture content, and geometrical requirements. The document does not include the processes for wood treatment or modification. For CE-marking and extended regulatory requirements (durability, fire reaction, hazardous substances), the harmonized standard EN 14915 must be consulted.

Key Topics

• Hardwood Panelling and Cladding: Defines products suitable for internal and external installations, covering various hardwood species and manufactured profiles with or without tongue and groove.
• Grading Classes: Detailed criteria for visual grading (A and B, plus free grades) for oak, ash, beech, chestnut, maple, birch, aspen/poplar, alder, and other hardwoods. Grading covers aspects like knots, splits, checks, and color variation.
• Moisture Content: Requirements for production state - typically 15 ± 3% for exterior and 10 ± 3% for interior applications.
• Dimensional Tolerances & Surface Quality: Minimum and maximum allowable dimensions and tolerances for thickness, width, and length of profiles. Specifications for surface finish (planed, brushed, sawn, etc.) and machining precision.
• Product Marking and Labelling: Details the technical data and information to be provided on product labels or accompanying documentation, including wood species, grading, intended application, profile dimensions, and moisture content.
• Finger Jointed and Modified Products: Coverage includes finger jointed hardwood panels, as well as products made using thermal or chemical modification.

Applications

Products specified in SIST EN 14951:2026 are highly relevant for:

• Interior Wall Panelling: Enhancing aesthetics and acoustics in residential, commercial, or public interiors using hardwood profiles finished to a high standard.
• Exterior Wood Cladding: Improving building envelopes for durability, weather resistance, and architectural appeal, using hardwood elements graded for outdoor exposure.
• Construction and Fit-Out Projects: Applicable to renovation, new building, and sustainable construction where natural hardwood materials are specified.
• Products with Special Treatments: Design flexibility for designers and manufacturers to supply surface or structurally enhanced hardwood cladding panels, including thermally modified or finger jointed products.
• Regulatory and Trade Conformity: Ensures that products meet established European quality and grading standards, supporting CE-marking and facilitating market acceptance.

Related Standards

For comprehensive compliance and best practices, consider the following related standards:

• EN 14915: Solid wood panelling and cladding - product standard for regulatory requirements including CE-marking and fire reaction.
• EN 13307-1: Timber blanks and semi-finished profiles for non-structural uses - Part 1: Requirements.
• EN 13647: Determination of geometrical characteristics for wood flooring, panelling, and cladding.
• EN 13756: Terminology for wood flooring and parquet.
• EN 13183 Series: Determination of moisture content in sawn timber.
• EN 844: Terminology for round and sawn timber.
• CEN/TS 12169: Criteria for lot conformity assessment in sawn timber.

SIST EN 14951:2026 is a valuable reference for manufacturers, architects, builders, and specifiers aiming to ensure quality, durability, and market compliance in hardwood panelling and cladding. By following this standard, stakeholders support sustainable timber use and consistent product performance across projects.

SLOVENSKI STANDARD
01-september-2026
Notranje in zunanje obloge (opaž) iz masivnega lesa listavcev - Profili
Solid hardwood panelling and cladding - Machined profiles
Innen- und Außenbekleidungen aus massivem Laubholz - Profilholz
Lambris et bardages en bois massif feuillus - Lames profilées usinées
Ta slovenski standard je istoveten z: EN 14951:2026
ICS:
79.080 Polizdelki iz lesa Semi-manufactures of timber
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 14951
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2026
EUROPÄISCHE NORM
ICS 79.080 Supersedes EN 14951:2006
English Version
Solid hardwood panelling and cladding - Machined profiles
Lambris et bardages en bois massif feuillus - Lames Innen- und Außenbekleidungen aus massivem
profilées usinées Laubholz - Profilholz
This European Standard was approved by CEN on 4 June 2026.

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, Türkiye 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14951:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Symbols and abbreviations . 5
5 Requirements . 5
5.1 General. 5
5.2 Grading . 5
5.2.1 General. 5
5.2.2 Grading classes . 6
5.2.3 Free grade . 14
5.3 Moisture content . 14
5.4 Geometrical characteristics . 15
5.4.1 General. 15
5.4.2 Profiles . 15
5.4.3 Dimensions and tolerances . 15
5.4.4 Machining . 18
6 Sampling . 19
7 Technical specifications and marking . 19
Annex A (normative) Requirements for the classification of a free class . 20
Bibliography . 21

European foreword
This document (EN 14951:2026) has been prepared by Technical Committee CEN/TC 175 “Round and
sawn timber”, 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 January 2027, and conflicting national standards shall
be withdrawn at the latest by January 2027.
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 EN 14951:2006.
In comparison with the previous edition, the following technical modifications have been made:
— alignment of the series of product standards: EN 14519, EN 15146 and EN 14951;
— scope, normative references and terms and definitions updated;
— ranges of moisture content for panelling and cladding were specified more precisely
— CEN/TS 12169 was referenced for sampling methods instead of Annex B;
— clauses “Technical specifications” and “Marking” were merged and aligned;
— Annex B deleted.
This document is one of a series of standards concerning solid wood panelling and cladding and wood
flooring (including parquet).
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, Türkiye and the United
Kingdom.
1 Scope
This document specifies characteristics of solid wood panelling and cladding with or without tongue and
groove machined from hardwoods (wood of trees of the botanical group dicotyledons).
Products are intended for interior or exterior use.
This document covers treated, untreated and surface treated products, including those made of thermally
and chemically modified wood, as well as finger jointed products.
This document does not cover processes for treatment, surface coating or modification.
NOTE Where further regulatory provisions (e.g. durability, reaction to fire, dangerous substances and
generally CE-marking according to CPR) are required, harmonized EN 14915 applies.
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 844, Round and sawn timber — Terminology
EN 1309-3, Round and sawn timber — Methods of measurements — Part 3: Features and biological
degradations
EN 13183-1, Moisture content of a piece of sawn timber — Part 1: Determination by oven dry method
EN 13183-2, Moisture content of a piece of sawn timber — Part 2: Estimation by electrical resistance
method
EN 13183-3, Moisture content of a piece of sawn timber — Part 3: Estimation by capacitance method
EN 13307-1, Timber blanks and semi-finished profiles for non-structural uses — Part 1: Requirements
EN 13647, Wood flooring and wood panelling and cladding — Determination of geometrical characteristics
EN 13756, Wood flooring and parquet — Terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13756, EN 844, and the
following apply.
ISO and IEC maintain terminology 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/
3.1
panelling
elements of solid wood mainly for interior use which have been machined on the face and have been
regularised on the back
3.2
cladding
elements of solid wood mainly for exterior use which have been machined on the face and have been
regularised on the back
3.3
face
visible surfaces of an element when installed
Note 1 to entry: This includes edges and chamfers.
3.4
regularised
feature of the surface of an element where some areas of a face remain untouched during
the planning process
3.5
tongue and groove
elements with groove on one edge and a corresponding tongue on the opposite edge (or similar
interlocking profiles)
3.6
end matching
profile at the end of the panelling or cladding including tongue and/or groove
4 Symbols and abbreviations
Symbols and abbreviations used in this document are given in Figure 1 and Figure 2 and in Table 10 and
Table 11.
5 Requirements
5.1 General
The hardwood species shall be selected with regard to the appearance expected, the suitability for the
intended purpose and the general characteristics of the species itself. All requirements apply at the time
of production, unless otherwise specified.
Finger jointing according to EN 13307-1 is permitted if agreed upon and specified e.g. by the
manufacturer.
NOTE Regarding the bonding and glue type other standards and regulations can apply.
5.2 Grading
5.2.1 General
Grading applies to the face only, unless otherwise specified. Machining requirements are covered in 5.4.4
and apply to all grades of all species.
The measurement of features shall be in accordance with EN 1309-3.
The elements may be finished with surface coating. The grading shall be done before coating.
Additionally, to the grading classes given in 5.2.2 different grading classes and quality criteria for
panelling and cladding exist on national and company levels in Europe. Hence, free grades according to
5.2.3 may also be used
5.2.2 Grading classes
Grading classes and the features for hardwoods are given in Tables 1 to 9.
A combined grading class, e.g. A/B, is permitted if agreed upon and specified e.g. by the manufacturer.
Table 1 — Grading classes for oak (Quercus spp.)
Face of the element
Grade
b c
Features
A B
a
Sound sapwood Not permitted for exterior use, Not permitted for exterior
permitted for interior use use, permitted for interior
use
d
Knots Permitted if: Permitted if:
≤ 20 % of the width of the ≤ 50 % of the width of the
Sound and intergrown
element element
Unsound knots (if not in clusters) diameter ≤ 2 mm diameter ≤ 10 mm
Checks Total length ≤ one width of the Total length ≤ 2 width of
element per meter. the element per meter.
Split Not permitted Total length ≤ one width of
the element per meter.
End shakes (going through the element) for Not permitted Total length ≤ 1/2 width of
end-matched elements the element
End shakes (going through the element) for Total length ≤ 1/2 width of the Total length ≤ one width of
non end-matched elements element the element
Bark pockets Not permitted All features permitted
without limit to size or
Slope of grain Permitted
quantity if these do not
impair the use
Colour variation Slight variation permitted
Medullary ray Permitted
Biological alteration (Fungal attack, insect Not permitted Not permitted, except blue
damage) stain and black holes
Non-visible parts
All features permitted without limit to size or quantity if these do not impair the use.
In the case of class A sound sapwood is permitted from the back up to the upper part of the tongue (for elements
with tongue) and up to 3 mm for elements without tongue and groove.
a
Grading applies to the face (see 3.3) only, unless otherwise specified (see 5.2.1).
b
Not more than 5 % of the quantity of the consignment is allowed to be of lower grade.
c
The classification for appearance does not take into account features which may impair the element when installed.
d
Cat paws allowed.
Table 2 — Grading classes for ash (Fraxinus excelsior)
Face of the element
Grade
b c
Features
A B
a
Sound sapwood Normally not distinguishable from heartwood
Knots Permitted if: Permitted if:
Sound and intergrown ≤ 20 % of the width of the element ≤ 50 % of the width of the element
Unsound knots diameter ≤ 2 mm diameter ≤ 10 mm
Checks Total length ≤ one width of the Total length ≤ 2 width of the element
element per m. per m.
Split Not permitted Total length ≤ one width of the
element per m.
End shakes (going through Not permitted Total length ≤ 1/2 width of the
the element) for end-matched
element
elements
End shakes (going through Total length ≤ 1/2 width of the Total length ≤ one width of the
the element) for non end- element element
matched elements
Bark pockets Not permitted All features permitted without limit
to size or quantity if these do not
Slope of grain Permitted
impair the use
Colour variation Natural colour variation accepted
Stick marks Not permitted
Biological alteration (Fungal Not permitted Not permitted, except blue stain and
attack, insect damage) black holes
Non-visible parts
All features permitted without limit to size or quantity if these do not impair the use.
a
See Clause 5.2.1.
b
Not more than 5 % of the quantity of the consignment is allowed to be of lower grade.
c
The classification for appearance does not take into account features which may impair the element when installed.
Table 3 — Grading classes for beech (Fagus sylvatica)
Face of the element
Grade
c d
Features
A B
b
Sound sapwood Normally not distinguishable from heartwood
Knots Permitted if: Permitted if:
Sound and intergrown ≤ 20 % of the width of the element ≤ 50 % of the width of the element
Unsound knots diameter ≤ 2 mm diameter ≤ 10 mm
Checks Total length ≤ one width of the Total length ≤ 2 width of the element
element per m. per m.
Split Not permitted Total length ≤ one width of the
element per m.
End shakes (going through Not permitted Total length ≤ 1/2 width of the
the element) for end-matched element
elements
End shakes (going through Total length ≤ 1/2 width of the Total length ≤ one width of the
the element) for non end- element element
matched elements
Slope of grain Permitted All features permitted without limit
to size or quantity if these do not
a
Colour variation Slight variation permitted . Slight
impair the use
traces of natural discoloration
permitted.
Red heart Not permitted
Sticks marks Not permitted Permitted
Medullary ray Permitted Permitted
Biological alteration (Fungal Not permitted Not permitted, except blue stain and
attack, insect damage) black holes
Non-visible parts
All features permitted without limit to size or quantity if these do not impair the use.
a
Only permitted for steamed beech.
b
See Clause 5.2.1.
c
Not more than 5 % of the quantity of the consignment is allowed to be of lower grade.
d
The classification for appearance does not take into account features which may impair the element when installed.
...