EN 1745:2020

SLOVENSKI STANDARD
01-december-2020
Nadomešča:
SIST EN 1745:2012
Zidovje in zidarski proizvodi - Metode za ugotavljanje toplotnih lastnosti
Masonry and masonry products - Methods for determining thermal properties
Mauerwerk und Mauerwerksprodukte - Verfahren zur Bestimmung von
wärmeschutztechnischen Eigenschaften
Maçonnerie et éléments de maçonnerie - Méthodes pour la détermination des propriétés
thermiques
Ta slovenski standard je istoveten z: EN 1745:2020
ICS:
91.080.30 Zidane konstrukcije Masonry
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 1745
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2020
EUROPÄISCHE NORM
ICS 91.080.30; 91.120.10 Supersedes EN 1745:2012
English Version
Masonry and masonry products - Methods for determining
thermal properties
Maçonnerie et éléments de maçonnerie - Méthodes Mauerwerk und Mauerwerksprodukte - Verfahren zur
pour la détermination des propriétés thermiques Bestimmung von wärmeschutztechnischen
Eigenschaften
This European Standard was approved by CEN on 17 May 2020.

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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1745:2020 E
worldwide for CEN national Members.

Contents Page
European foreword. 4
Introduction . 5
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and symbols . 9
3.1 Terms and definitions . 9
3.2 Symbols .10
4 Determination of λ10,dry, unit –values for solid masonry units and λ10,dry,mor –values
for mortars .11
4.1 General .11
4.2 λ –values for solid masonry units and mortars .12
10,dry, mat
4.2.1 Method S1. Determination of λ –values from tabulated λ /net dry
10,dry,unit 10,dry,mat
density relationship .12
4.2.2 Method S2. Determination of λ –values based on λ /net dry density
10,dry,unit 10,dry,mat
curve .12
4.2.3 Method S3. Determination of λ –values from determining the thermal
10,dry,unit
transmittance (U ) of masonry built from solid masonry units and mortar .14
mas
4.3 Test methods and numbers of samples to be taken .16
5 Determination of equivalent λ -values for masonry units with formed voids
10,dry,unit
and composite masonry units .16
5.1 General .16
5.2 Calculation methods.17
5.3 λ -values of masonry units with formed voids and composite units .17
10,dry,unit
5.3.1 Determination of λ -values from tabulated λ /λ relationship .17
10,dry,unit unit mat
5.3.2 Determination of λ -values based on calculation .18
10,dry,unit
5.3.3 Method P5. Determination of λ –values from determining the thermal
10,dry,unit
transmittance (U ) of masonry built from masonry units with formed voids or
mas
composite masonry units and mortar .18
5.4 Test methods and numbers of samples to be taken .21
6 Moisture conversion .22
6.1 General .22
6.2 Procedure A (for materials, mortar, solid masonry units and masonry): .22
6.3 Procedure B (for masonry units with formed voids): .23
6.4 Procedure C (for composite masonry units): .23
7 Determination of design thermal values (R or λ ) for masonry built
design,mas design,mas
from masonry units and mortar .23
7.1 General .23
7.2 R – or λ –values based on calculation .24
design,mas design,mas
7.2.1 R – or λ –values based on λ –values for the masonry units and
design,mas design,mas design
the mortar .24
7.2.2 R –or λ –values using a numerical calculation method based on the
design,mas design,mas
design thermal conductivity of the materials used – .24
7.3 R – or λ –values of masonry built from masonry units with formed
design,mas design,mas
voids and mortar based on tabulated values .24
7.3.1 Tabulated values .24
7.3.2 Application of Annex B .25
7.3.3 Alternative application of Annex B .25
7.4 Method S4/P6 R – or λ –values of masonry based on masonry
design,mas design,mas
testing . 26
8 Determination of the thermal transmittance of masonry . 26
9 Specific heat capacity . 27
10 Rounding rules for λ-values for masonry units and masonry . 27
Annex A (normative) Tabulated λ -values of materials used for masonry
10,dry,mat
products . 28
Annex B (informative) R - or λ -values of masonry built from a range of
dry,mas 10,dry,mas
masonry units containing formed voids. 38
Annex C (informative) Example of how to use the tables in Annex B . 78
Annex D (normative) Requirements for appropriate calculation procedures . 80
D.1 Capabilities of the program . 80
D.2 Input data and results . 80
D.3 Testing of the program accuracy. 81
D.4 Reference cases . 81
D.4.1 Case 1: Calculation of thermal resistance R and thermal conductivity λ of a
10,dry,unit
masonry unit (vertically perforated unit) . 81
D.4.2 Case 2: Calculation of thermal resistance R of masonry consisting of
dry,mas
vertically perforated masonry units, bed joints with mortar layers and internal/
external plaster layers . 83
D.4.3 CASE 3: Calculation of thermal resistance R of masonry consisting of masonry
t
units, horizontal mortar layers, vertical mortar pockets and additional external
insulation layer . 85
Annex E (informative) Assessment and verification of constancy of performance . 89
Annex F (informative) Alternative procedure for the moisture correction of units with
formed voids . 91
Annex G (informative) Simplified methodology for determining design moisture content
of composite masonry units . 92

European foreword
This document (EN 1745:2020) has been prepared by Technical Committee CEN/TC 125 “Masonry”,
the secretariat of which is held by BSI.
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 2021, and conflicting national standards shall
be withdrawn at the latest by January 2021.
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 1745:2012.
The following is a list of significant technical changes since the last edition EN 1745:2012:
— replacement of Figure 1 by Tables 1 a and 1 b;
— editorial improvement;
— changes in the definitions 3.1.5 and 3.1.10;
— correction of term in Annex A;
— amendment heading of column in Annex A;
— addition of Annex G.
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
This document provides methods for the determination of dry and design thermal conductivity and
thermal resistance values of masonry products and masonry.
The following types of masonry unit are covered by this document:
— solid masonry units;
— masonry units with formed voids;
— composite masonry units.
Methods are described for the determination of the dry thermal conductivity of solid masonry units
(λ10,dry,unit) and of mortar (λ10,dry,mor) and for the determination of equivalent dry thermal conductivity of
masonry units with formed voids and composite masonry units (λ ). Procedures are also
10,dry,unit
described for the determination of the design thermal values of masonry units and masonry. The
different methods are illustrated in Table 1.
The value in dry state is a characteristic of a masonry material, masonry unit or of masonry.
The determination of thermal values can be based on tabulated data, measurements, calculations or a
combination of these.
Design thermal values may be determined according to procedures given in this European standard
according to the intended application, environmental and climatic conditions, bearing in mind the
purpose of this determination, such as:
— ene
...