EN 1995-1-2:2025

SLOVENSKI STANDARD
oSIST prEN 1995-1-2:2023
01-december-2023
Nadomešča:
SIST EN 1995-1-2:2005
Evrokod 5: Projektiranje lesenih konstrukcij - 1-2. del: Projektiranje požarnovarnih
konstrukcij
Eurocode 5 - Design of timber structures - Part 1-2: Structural fire design
Eurocode 5 - Bemessung und Konstruktion von Holzbauten - Teil 1-2:
Tragwerksbemessung für den Brandfall
Eurocode 5 - Calcul des structures en bois - Part 1-2: Calcul du comportement au feu
Ta slovenski standard je istoveten z: prEN 1995-1-2
ICS:
13.220.50 Požarna odpornost Fire-resistance of building
gradbenih materialov in materials and elements
elementov
91.010.30 Tehnični vidiki Technical aspects
91.080.20 Lesene konstrukcije Timber structures
oSIST prEN 1995-1-2:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 1995-1-2:2023
oSIST prEN 1995-1-2:2023
DRAFT
EUROPEAN STANDARD
prEN 1995-1-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2023
ICS 13.220.50; 91.080.20; 91.010.30 Will supersede EN 1995-1-2:2004
English Version
Eurocode 5 - Design of timber structures - Part 1-2:
Structural fire design
Eurocode 5 - Calcul des structures en bois - Part 1-2: Eurocode 5 - Bemessung und Konstruktion von
Calcul du comportement au feu Holzbauten - Teil 1-2: Tragwerksbemessung für den
Brandfall
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 250.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1995-1-2:2023 E
worldwide for CEN national Members.

oSIST prEN 1995-1-2:2023
prEN 1995-1-2:2023 (E)
Contents Page
European foreword . 6
0 Introduction . 7
1 Scope . 10
1.1 Scope of EN 1995-1-2 . 10
1.2 Assumptions . 10
2 Normative references . 10
3 Terms, definitions and symbols . 12
3.1 Terms and definitions . 12
3.2 Symbols and abbreviations . 15
3.2.1 Latin upper case letters . 15
3.2.2 Latin lower case letters . 16
3.2.3 Greek upper case letters . 20
3.2.4 Greek lower case letters . 21
4 Basis of design . 22
4.1 General. 22
4.2 Nominal fire exposure . 22
4.3 Physically based fire exposure . 23
4.4 Actions . 23
4.5 Design values of material properties . 23
4.6 Verification methods . 24
4.7 Member analysis . 25
4.8 Analysis of parts of the structure . 25
4.9 Global structural analysis . 25
5 Material properties . 26
5.1 General. 26
5.2 Thermal properties . 29
5.3 Mechanical properties . 29
5.4 Charring . 29
5.4.1 General. 29
5.4.2 The European charring model . 30
5.5 Adhesives . 40
5.5.1 General. 40
5.5.2 Bond line integrity of face bonds . 41
6 Tabulated design data . 41
6.1 General. 41
6.2 Time limits for charring phases . 41
6.3 Initially protected timber members . 44
6.4 Plane timber members made of CLT . 46
6.4.1 General. 46
6.4.2 CLT with bond line integrity maintained . 46
6.4.3 CLT with bond line integrity not maintained . 47
7 Simplified design methods . 49
7.1 General. 49
7.1.1 Materials and products covered . 49
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7.1.2 Timber members . 50
7.1.3 Mechanically jointed members . 51
7.2 Effective cross-section method . 51
7.2.1 General . 51
7.2.2 Design of linear timber members . 53
7.2.3 Design of plane timber members . 56
7.2.4 Design of timber frame assemblies . 60
7.2.5 Design of timber-concrete-composite members . 69
7.3 Separating function method . 70
7.3.1 General . 70
7.3.2 Protection time . 72
7.3.3 Insulation time . 75
7.3.4 Position coefficients . 76
7.3.5 Joint coefficients. 79
7.3.6 Correction times . 80
8 Advanced design methods . 83
8.1 General . 83
8.2 Thermal analysis . 83
8.3 Mechanical analysis . 83
8.4 Validation of advanced design methods . 84
8.5 Thermal properties. 84
8.5.1 General . 84
8.5.2 Timber and wood-based materials . 85
8.5.3 Gypsum plasterboard and gypsum fibreboard . 88
8.5.4 Insulation materials . 89
8.6 Mechanical properties . 90
9 Connections . 92
9.1 General . 92
9.2 Initially unprotected connections with timber side members . 92
9.2.1 General . 92
9.2.2 Minimum fire resistance . 93
9.2.3 Geometric requirements for a specific fire resistance . 93
9.2.4 Exponential reduction method for connections with dowels or bolts . 102
9.2.5 Exponential reduction method for connections with nails or screws . 105
9.3 Connections with axially loaded mechanical fasteners . 107
9.4 Protected connections . 109
9.5 Connections with external steel plates . 110
9.5.1 Unprotected connections . 110
9.5.2 Protected connections . 111
9.6 Carpentry connections. 111
10 Detailing . 111
10.1 General . 111
10.2 Panels . 112
10.2.1 Dimensions and spacings. 112
10.2.2 Fixing and joints of panels . 113
10.3 Insulation . 116
10.4 Joints in and between elements and to other adjacent components . 118
10.5 Penetrations and openings . 120
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Annex A (informative) Design of timber structures exposed to physically based design fires . 123
A.1 Use of this Annex . 123
A.2 Scope and field of application . 123
A.3 Structural fire load by the timber members . 123
A.4 Design models . 124
Annex B (normative) Assessment of the bond line integrity in fire . 132
B.1 Use of this Annex . 132
B.2 Scope and field of application . 132
B.3 Bond line integrity of face bonds . 132
B.4 Bond line integrity of finger joints in I-shaped timber members . 137
Annex C (normative) Determination of the basic charring rate . 141
C.1 Use of this Annex . 141
C.2 Scope and field of application . 141
C.3 Test equipment . 141
C.4 Test conditions . 141
C.5 Test specimen . 141
C.6 Installation of the test specimen . 143
C.7 Application of instrumentation . 143
C.8 Test procedure . 145
C.9 Test results . 146
C.10 Assessment . 146
C.11 Application range of results . 148
Annex D (normative) Assessment of Protection Level (PL) of the cavity insulation . 149
D.1 Use of this Annex . 149
D.2 Scope and field of application . 149
D.3 Test equipment . 149
D.4 Test conditions . 149
D.5 Test specimen . 149
D.6 Installation of the test specimen . 151
D.7 Application of instrumentation . 151
D.8 Test procedure . 152
D.9 Test results . 152
D.10 Assessment . 152
Annex E (informative) Assessment of external flaming . 153
E.1 Use of this annex . 153
E.2 Scope and field of application . 153
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E.3 External flaming . 153
Annex F (informative) Assessment of the failure time of fire protection systems . 155
F.1 Use of this annex . 155
F.2 Scope and field of application . 155
F.3 Failure times . 155
Annex G (normative) Implementation rules for the Separating Function Method . 157
G.1 Use of this Annex . 157
G.2 Scope and field of application . 157
G.3 General . 157
G.4 Fire testing . 157
G.5 Determination of the design equations . 159
G.6 Determination of the design equations . 160
G.7 Verification of the developed design equations . 163
Annex I (normative) Design model for timber frame assemblies with I-shaped linear timber
members . 164
I.1 Use of this annex . 164
I.2 Scope and field of application . 165
I.3 Design model . 166
Annex M (normative) Material and product properties for the design with EN 1995-1-2 . 176
M.1 Use of this Annex . 176
M.2 Timber members . 176
M.3 Panels . 176
M.4 Cavity insulation . 176
Annex T (informative) Determination of temperature in timber members . 177
T.1 Use of this Annex . 177
T.2 Temperature determination . 177
Bibliography . 179

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European foreword
This document (prEN 1995-1-2:2023) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all
Structural Eurocodes and has been assigned responsibility for structural and geotechnical design matters
by CEN.
This document is currently submitted to the CEN Enquiry.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognise the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
The main changes compared to the previous edition are listed below:
— improvement of the charring model (Clause 5.4);
— introduction of tabulated design data (Clause 6);
— improvement of the Effective cross-section method (Clause 7.2);
— addition of design rules for cross-laminated timber (Clause 7.2.3);
— improvement of design rules for timber frame assemblies (Clause 7.2.4);
— addition of design rules for timber-concrete composite members (Clause 7.2.5);
— introduction of the Separating function method (Clause 7.2.3);
— improvement of design rules for connections (Clause 9);
— improvement of rules for detailing (Clause 10);
— addition of normative and informative annexes.
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0 Introduction
0.1 Introduction to the Eurocodes
The Structural Eurocodes comprise the following standards generally consisting of a number of Parts:
— EN 1990 Eurocode: Basis of structural and geotechnical design
— EN 1991 Eurocode 1: Actions on structures
— EN 1992 Eurocode 2: Design of concrete structures
— EN 1993 Eurocode 3: Design of steel structures
— EN 1994 Eurocode 4: Design of composite steel and concrete structures
— EN 1995 Eurocode 5: Design of timber structures
— EN 1996 Eurocode 6: Design of masonry structures
— EN 1997 Eurocode 7: Geotechnical design
— EN 1998 Eurocode 8: Design of structures for earthquake resistance
— EN 1999 Eurocode 9: Design of aluminium structures
— New parts are under development, e.g. Eurocode for design of structural glass.
The Eurocodes are intended for use by designers, clients, manufacturers, constructors, relevant
authorities (in exercising their duties in accordance with national or international regulations),
educators, software developers, and committees drafting standards for related product, testing and
execution standards.
NOTE Some aspects of design are most appropriately specified by relevant authorities or, where not specified,
can be agreed on a project-specific basis between relevant parties such as designers and clients. The Eurocodes
identify such aspects making explicit reference to relevant authorities and relevant parties.
0.2 Introduction to EN 1995 (all parts)
(1) EN 1995 (all parts) applies to the design of buildings and civil engineering works in timber (solid
timber, sawn, planed or in pole form, structural finger jointed timber, glued solid timber, glued laminated
timber, cross laminated timber and structural laminated veneer lumber), wood-based panels and
softboards as sheeting of timber frame members jointed together with adhesives or mechanical fasteners.
The design rules given in the standard are valid for softwoods and hardwoods of all species. Special
limitations are given in relevant Clauses. It complies with the principles and requirements for the safety
and serviceability of structures and the basis of their design and verification given in EN 1990 – Basis of
structural and geotechnical design.
(2) EN 1995 (all parts) is only concerned with requirements for resistance, serviceability, durability and
fire resistance of timber structures. Other requirements, e.g. concerning thermal or sound insulation, are
not considered.
EN 1995 is intended to be used in conjunction with:
— EN 1990 “Basis of structural and geotechnical design”
— EN 1991 “Actions on structures”
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— ENs for construction products relevant to timber structures
— EN 1998 “Design of structures for earthquake resistance”, when timber structures are built in seismic
regions
(3) EN 1995 is subdivided in various parts:
— EN 1995-1 Design of timber structures — Part 1: General rules and rules for buildings
— EN 1995-2 Design of timber structures — Part 2: Bridges
— EN 1995-3 Design of timber structures — Part 3: Execution
EN 1995-1 in itself does not exist as a physical document, but comprises the following 3 separate parts:
— EN 1995-1-1 Design of timber structures — Part 1-1 General rules and rules for buildings
— EN 1995-1-2 Design of timber structures — Part 1-2: Structural fire design
— CEN/TS 19103 Eurocode 5 — Design of Timber Structures — Structural design of timber-concrete
composite structures — Common rules and rules for buildings
EN 1995-2 “Bridges” refers to the common rules in EN 1995-1-1 and supplements, modifies or supersedes
them, where relevant.
EN 1995-3 “Execution” refers to the common rules in EN 1995-1-1 and supplements, modifies or
supersedes them, where relevant.
0.3 Introduction to EN 1995-1-2
This document provides rules for the structural fire design of timber structures and civil engineering
timber works.
0.4 Verbal forms used in the Eurocodes
The verb “shall" expresses a requirement strictly to be followed and from which no deviation is permitted
in order to comply with the Eurocodes.
The verb “should” expresses a highly recommended choice or course of action. Subject to national
regulation and/or any relevant contractual provisions, alternative approaches could be used/adopted
where technically justified.
The verb “may" expresses a course of action permissible within the limits of the Eurocodes.
The verb “can" expresses possibility and capability; it is used for statements of fact and clarification of
concepts.
0.5 National Annex for EN 1995-1-2
National choice is allowed in this document where explicitly stated within notes. National choice includes
the selection of values for Nationally Determined Parameters (NDPs).
The national standard implementing EN 1995-1-2 can have a National Annex containing all national
choices to be used for the design of buildings and civil engineering works to be constructed in the relevant
country.
When no national choice is given, the default choice given in this document is to be used.
When no national choice is made and no default is given in this document, the choice can be specified by
a relevant authority or, where not specified, agreed for a specific project by appropriate parties.
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National choice is allowed in prEN 1995-1-2 through notes to the following clauses:
4.5(1) 6.1(3) 9.2.3(1)
National choice is allowed in prEN 1995-1-2 on the application of the following Informative annexes:
Annex A Annex E Annex F Annex T
The National Annex can contain, directly or by reference, non-contradictory complementary information
for ease of implementation, provided it does not alter any provisions of the Eurocodes.
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1 Scope
1.1 Scope of EN 1995-1-2
(1) This document deals with the design of timber structures for the accidental situation of fire exposure
and it is intended to be used in conjunction with prEN 1995-1-1 and prEN 1991-1-2.
This document only identifies differences from, or supplements to, normal temperature design.
(2) This document applies to timber structures required to fulfil a loadbearing function, separating
function or both.
(3) This document gives principles and application rules for the design of structures for specified
requirements in respect of the aforementioned functions and the levels of performance.
(4) This document applies to structures, or parts of structures, that are within the scope of prEN 1995-1-1
and are designed accordingly.
(5) The methods given in this document are applicable to all products covered by harmonized technical
specifications made reference to in this document.
1.2 Assumptions
(1) In addition to the general assumptions of EN 1990, the following assumptions apply:
— the choice of the relevant design fire scenario is made by appropriate qualified and experienced
personnel, or is given by the relevant national regulation;
— any fire protection measure taken into account in the design will be adequately maintained.
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.
NOTE See the Bibliography for a list of other documents cited that are not normative references, including those
referenced as recommendations (i.e. in ‘should’ clauses), permissions (‘may’ clauses), possibilities ('can' clauses),
and in notes.
EN 300, Oriented strand boards (OSB) — Definitions, classification and specifications
EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures — Classification and
performance requirements
EN 312, Particleboards — Specifications
EN 520, Gypsum plasterboards — Definitions, requirements and test methods
EN 622-2, Fibreboards — Specifications — Part 2: Requirements for hardboards
EN 622-3, Fibreboards — Specifications — Part 3: Requirements for medium boards
EN 622-4, Fibreboards — Specifications — Part 4: Requirements for softboards
EN 622-5, Fibreboards — Specifications — Part 5: Requirements for dry process boards (MDF)
EN 636, Plywood — Specifications
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EN 998-1, Specification for mortar for masonry — Part 1: Rendering and plastering mortar
EN 1363-1, Fire resistance tests — Part 1: General requirements
EN 1990:2023, Eurocode — Basis of structural and geotechnical design
EN 1991 (all parts), Eurocode 1 — Actions on structures
prEN 1991-1-2:2021, Eurocode 1 — Actions on structures — Part 1-2: Actions on structures exposed to fire
FprEN 1992-1-2, Eurocode 2 — Design of concrete structures — Part 1-2: Structural fire design
prEN 1993-1-2, Eurocode 3 — Design of steel structures — Part 1-2: Structural fire design
prEN 1995-1-1:2023, Eurocode 5 — Design of timber structures — Part 1-1: General rules and rules for
buildings
ISO 5660-1, Reaction-to-fire tests — Heat release, smoke production and mass loss rate — Part 1: Heat
release rate (cone calorimeter method) and smoke production rate (dynamic measurement)
EN 13162, Thermal insulation products for buildings — Factory made mineral wool (MW) products —
Specification
EN 13171, Thermal insulation products for buildings — Factory made wood fibre (WF) products.
Specification
EN 13353, Solid wood panels (SWP) — Requirements
EN 13914-2, Design, preparation and application of external rendering and internal plastering — Part 2:
Internal plastering
EN 13986, Wood-based panels for use in construction — Characteristics, evaluation of conformity and
marking
EN 14080, Timber structures — Glued laminated timber and glued solid timber — Requirements
EN 14081-1, Timber structures — Strength graded structural timber with rectangular cross section —
Part 1: General requirements
EN 14279, Laminated Veneer Lumber (LVL) — Definitions, classification and specifications
EN 14374, Timber structures — Structural laminated veneer lumber — Requirements
EN 14915, Solid wood panelling and cladding — Characteristics, requirements and marking
EN 15101-1, Thermal insulation products for buildings — In-situ formed loose fill cellulose (LFCI) products
— Part 1: Specification for the products before installation
EN 15283-2, Gypsum boards with fibrous reinforcement — Definitions, requirements and test methods —
Part 2: Gypsum fibre boards
EN 15425, Adhesives — One component polyurethane (PUR) for load-bearing timber structures —
Classification and performance requirements
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EN 15497, Structural finger jointed solid timber — Performance requirements and minimum production
requirements
EN 16351, Timber structures — Cross laminated timber — Requirements
3 Terms, definitions and symbols
3.1 Terms and definitions
(1) For the purposes of this document, the terms and definitions given in EN 1990, prEN 1991-1-2 and
prEN 1995-1-1 and the following apply.
3.1.1
assembly
composition of elements
[SOURCE: prEN 1995-1-1]
3.1.2
basic design charring rate
charring rate of wood species of initially unprotected members or charring rate of initially unprotected
panels exposed to fire from one side without considering effects of gaps (3.1.16), joints, etc.
3.1.3
bond line integrity in fire
ability of the bond line for face bonds to provide stickability between layers in the fire situation
3.1.4
char-line
border-line between char layer and the residual cross-section (3.1.25), assumed to be equal with the
position of the 300 °C isotherm
3.1.5
charring depth
distance from the original surface of the timber member to the char-line (3.1.4)
3.1.6
charring phase
initially unprotected, protected, post-protected or consolidated phase within the European charring
model, defined as a time period
3.1.7
cladding
lining
external or internal covering formed by panels
3.1.8
coating
surface treatment applied on timber member
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3.1.9
component
part of an assembly (3.1.1) or element
[SOURCE: prEN 1995-1-1]
3.1.10
effective cross-section
cross-section of the original timber member reduced by the charring depth (3.1.5) and the zero-strength
layer at heated sides of the timber member
3.1.11
failure time of fire protection system
time at which the fall-off of the fire protection system occurs
3.1.12
fire protection material
material applied for the purpose of increasing fire resistance
3.1.13
fire protection system
kit of fire protection material(s) (3.1.12) together with a defined method of fixing and mounting
3.1.14
foil
thin layer applied on and in an assembly (3.1.1) or element for example a vapour barrier
3.1.15
fully developed char layer
layer of charred material insulating the substrate
3.1.16
gap
distance between or within adjacent assemblies, elements or components (3.1.9) in a joint
3.1.17
I-shaped member
glued thin-webbed beam or stud consisting of wood-based flanges and symmetrically placed thin web
between the flanges, for example I-joist or I-stud
3.1.18
insulation time
time from the start of fire to reach the temperature rise of 140 K on the unexposed side of the assembly
(3.1.1) used for the separating function method
3.1.19
notional charring depth
charring depth (3.1.5) considering notional design charring rates (3.1.20) for all relevant charring phases
(3.1.6)
3.1.20
notional design charring rate
charring rate within one charring phase (3.1.6) considering effects of dimensions, gaps (3.1.16), joints,
etc. according to the European charring model
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3.1.21
normal temperature design
design for ambient temperature according to Part 1-1 of EN 1992 to EN 1996 or EN 1999
3.1.22
protected member
member with applied fire protection systems
3.1.23
protection time
time to reach the charring of entire thickness or temperature rise of 250 K behind the considered material
or product
3.1.24
protection level
PL
level describing the ability of cavity insulation to protect timber members in case of fire
3.1.25
residual cross-section
cross-section of the original timber member reduced by the charring depth (3.1.5) at heated sides of the
timber member
3.1.26
start time of charring
time at the beginning of the fire exposure for initially unprotected sides of timber members, or time when
the surface temperature for initially protected sides of timber members reaches
...