SIST EN 1745:2020

SLOVENSKI STANDARD
oSIST prEN 1745:2019
01-september-2019
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: prEN 1745
ICS:
91.080.30 Zidane konstrukcije Masonry
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
oSIST prEN 1745:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 1745:2019

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oSIST prEN 1745:2019


DRAFT
EUROPEAN STANDARD
prEN 1745
NORME EUROPÉENNE

EUROPÄISCHE NORM

May 2019
ICS 91.080.30; 91.120.10 Will supersede 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 draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 125.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1745:2019 E
worldwide for CEN national Members.

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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 λ –values for solid masonry units and λ –values
10,dry, unit 10,dry,mor
for mortars .11
4.1 General .11
4.2 λ –values for solid masonry units and mortars .11
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 .11
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 (Umas) of masonry built from solid masonry units and mortar .15
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 (Umas) of masonry built from masonry units with formed voids or
composite masonry units and mortar .18
5.4 Test methods and numbers of samples to be taken .22
6 Moisture conversion .22
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 .23
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 .23
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 .24
7.3.3 Alternative application of Annex B .25
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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 . 26
10 Rounding rules for λ-values for masonry units and masonry . 26
Annex A (normative) Tabulated λ -values of materials used for masonry
10,dry,mat
products . 27
Annex B (informative) R - or λ -values of masonry built from a range of
dry,mas 10,dry,mas
masonry units containing formed voids. 36
Annex C (informative) Example of how to use the tables in Annex B . 77
Annex D (normative) Requirements for appropriate calculation procedures . 79
D.1 Capabilities of the program . 79
D.2 Input data and results . 79
D.3 Testing of the program accuracy. 80
D.4 Reference cases . 80
D.4.1 Case 1: Calculation of thermal resistance R and thermal conductivity λ of a
10,dry,unit
masonry unit (vertically perforated unit) . 80
D.4.2 Case 2: Calculation of thermal resistance R of masonry consisting of
dry,mas
vertically perforated masonry units and internal/ external plaster layers . 82
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 . 83
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 . 93

3

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European foreword
This document (prEN 1745:2019) has been prepared by Technical Committee CEN/TC 125 “Masonry”,
the secretariat of which is held by BSI.
This document supersedes EN 1745:2012.
This document has been prepared under a mandate given to CEN by the European Commission and
the European Free Trade Association.
The following is a list of significant technical changes since the last edition:
— replacement of Figure 1 by Table 1;
— editorial improvement;
— changes in the definition 3.1.5;
— correction of term in Annex A;
— amendment heading of column in Annex A;
— addition of Annex G.

4

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Introduction
This European standard 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 European standard:
— 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 dry value 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 are determined according to the procedure given in this European standard
according to the intended application, environmental and climatic conditions, bearing in mind the
purpose of this determination, such as:
— energy consumption;
— design of heating and cooling equipment;
— surface temperature determination;
— compliance with national building regulations;
— consideration of non-steady-state thermal conditions in buildings.
Table 1 — Determination of thermal properties of masonry units and masonry
Overview of methods to determine λ
10,dry,unit
Method Masonry
a b
Determination of λ  Required parameters
10,dry,unit
(Clause) units
using tabulated value from Annex A
S1 Net dry density of
Solid units for the λ / net dry density
10,dry,mat
a
(4.2.1) unit/material
relationship
based on determination of dry
Net dry density and thermal
S2 thermal conductivity by
Solid units conductivity of
(4.2.2) measurement and of the masonry
a
unit/material
unit material / dry density curve
5

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Overview of methods to determine λ
10,dry,unit
Method Masonry
a b
Determination of λ  Required parameters
10,dry,unit
(Clause) units
based on determination of the Net dry density and
S3 thermal transmittance (U ) of percentage area of units;
mas
Solid units
(4.2.3) masonry, then adjusting for the thermal conductivity and
influence of the mortar percentage area of mortar
Net dry density and thermal
Units with based on determination of dry
P1 conductivity of
formed thermal conductivity of the masonry
(5.3.1.3) unit/material and
voids unit material, then using Annex B
configuration of the units
Units with Net dry density of
P2 using tabulated values from Annex A,
formed unit/material and
(5.3.1.4) then using Annex B
voids configuration of the units
Units with
formed by calculation according to 5.2, using Net dry density and thermal
P3 voids dry thermal conductivity by conductivity of unit/infill
(5.3.2.2) and measurement of the masonry unit material and configuration
composite material and any infill of the units
units
Units with by calculation according to 5.2 using
Net dry density and thermal
formed tabulated thermal conductivity of the
P4 conductivity of unit/infill
voids and masonry unit material from Annex A
(5.3.2.3) material and configuration
composite and thermal conductivity of any infill
of the units
units material
Units with
based on determination of the Gross dry density and
formed
P5 thermal transmittance (U ) of percentage area of units,
mas
voids and
(5.3.3) masonry, then adjusting for the thermal conductivity and
composite
influence of the mortar percentage area of mortar
units
a
Methods S1 and S2 are also applicable for the determination of λ .
10,dry,mor
b
If necessary, moisture correction according to Clause 6.

a b
Overview of methods to determine λ and λ
design,unit design,mas
a b a
λ (Clause) Masonry Determination of λ / Required
design design,unit
b
units λ parameters
design,mas
λ Solid, by applying moisture Thermal conductivity
design,unit
(6) with formed correction according to in dry state and
voids and Clause 6 upon λ moisture conversion
10,dry,unit
composite factor of unit
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a b
Overview of methods to determine λ and λ
design,unit design,mas
a b a
λ (Clause) Masonry Determination of λ / Required
design design,unit
b
units λ parameters
design,mas
λ Solid, by using a simplified Design thermal
design,mas
(7.2.1) with formed calculation based conductivity of unit
voids and on λ and λ and mortar and
design,unit design,mor
composite percentage area of
mortar joints
λ Solid, by numerical calculation based Design thermal
design,mas
(7.2.2) with formed on λ conductivity of
design,mat
voids and materials and
composite configuration
λ with formed using of Annex B and Net dry density and
design,mas
(7.3) voids application of the correction thermal conductivity
according to Clause 6 of unit/material and
respective moisture
conversion factors
S4/P6 Solid, by applying moisture Thermal
with formed correction according to transmission of
λ
design,mas
voids and Clause 6 onto the thermal masonry and
(7.4)
composite transmittance (U ) of moisture conversion
mas
masonry factor
a
Or alternatively the design thermal resistance of the unit Rdesign,unit .
b
Or alternatively the design thermal resistance of the masonry Rdesign,mas .

7

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1 Scope
This document specifies methods for the determination of thermal properties of masonry and masonry
products.
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 772-3, Methods of test for masonry units — Part 3: Determination of net volume and percentage of
voids of clay masonry units by hydrostatic weighing
EN 772-4, Methods of test for masonry units — Part 4: Determination of real and bulk density and of total
and open porosity for natural stone masonry units
EN 772-13, Methods of test for masonry units — Part 13: Determination of net and gross dry density of
masonry units (except for natural stone)
EN 772-16, Methods of test for masonry units — Part 16: Determination of dimensions
EN 1015-10, Methods of test for mortar for masonry — Part 10: Determination of dry bulk density of
hardened mortar
EN 1934, Thermal performance of buildings — Determination of thermal resistance by hot box method
using heat flow meter — Masonry
EN 1936, Natural stone test methods — Determination of real density and apparent density, and of total
and open porosity
EN 12664, Thermal performances 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 12667, Thermal performance of building materials and products- Determination of thermal
resistance by means of guarded hot plate and heat flow meter methods – Products of high and medium
thermal resistance
EN ISO 6946, Building components and building elements — Thermal resistance and thermal
transmittance — Calculation methods (ISO 6946)
EN ISO 7345, Thermal performance of buildings and building components — Physical quantities and
definitions (ISO 7345)
EN ISO 10211, Thermal bridges in building construction — Heat flows and surface temperatures —
Detailed calculations (ISO 10211)
EN ISO 10456, Building materials and products — Hygrothermal properties — Tabulated design values
and procedures for determining declared and design thermal values (ISO 10456)
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3 Terms, definitions and symbols
For the purposes of this document, the following terms, definitions and symbols and those given in
EN ISO 7345 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
masonry
assemblage of masonry units laid in a specified pattern and joined together with masonry mortar
3.1.2
masonry product
masonry units, masonry mortars, rendering and plastering mortars
3.1.3
solid masonry unit
masonry unit containing no perforations except external indentations such as grip holes, grooves, etc.
3.1.4
masonry unit with formed voids
masonry unit with a system of intentionally formed voids
3.1.5
composite masonry unit
masonry unit incorporating additional material
3.1.6
thermal value
2
common term for either the thermal conductivity (W/(m K)) or the thermal resistance (m ·K/W)
3.1.7
dry state
state after drying under conditions stated in the relevant standards
3.1.8
dry thermal value
value of a thermal property of a building material or product in a dry state determined according to
this European Standard as a basis for the calculation of design thermal values
Note 1 to entry: The dry thermal value can be expressed as thermal conductivity or thermal resistance.
3.1.9
design thermal value
value of a thermal property of a building material or product under specific external and internal
conditions which can be considered as typical of the performance of that material or product when
incorporated in a building component or building
9

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3.1.10
masonry thermal conductivity
value which is derived by dividing the thickness of a given masonry element by its thermal resistance
excluding surface resistance
3.1.11
reference conditions
set of conditions identifying a state of equilibrium selected as the base to which the thermal values of
building materials and products are referred
3.1.12
equivalent thermal conductivity
value derived by dividing the width of a masonry unit with formed voids or a composite masonry unit
or masonry by its thermal resistance excluding surface resistance
3.2 Symbols
The order of the indices for thermal values is temperature, condition and subject.
Symbol Quantity Unit
λ thermal conductivity at an average temperature of 10 °C in dry state W/(m·K)
10,dry,mat
for a masonry unit material and/or infill material
λ thermal conductivity at an average temperature of 10 °C in dry state W/(m·K)
10,dry,mas
for the masonry
λ thermal conductivity at an average temperature of 10 °C in dry state W/(m·K)
10,dry,mor
for the mortar
λ thermal conductivity at an average temperature of 10 °C in dry state W/(m·K)
10,dry,unit
for the unit. For solid units the λ10,dry, unit is the same as λ10,dry, mat and
for units with formed voids and composite units the λ is the
10,dry, unit
equivalent thermal conductivity.
λ design thermal conductivity for the masonry W/(m·K)
design,mas
λ design thermal conductivity for the mortar W/(m·K)
design,mor
λ design thermal conductivity for the unit W/(m·K)
design,unit
λ individual determined thermal conductivity W/(m·K)
i
2
R individual measured thermal resistance m ·K/W
i
2
R thermal resistance of masonry m ·K/W
dry,mas
2
R design thermal resistance of masonry m ·K/W
design,mas
2
Rsi, Rse internal and external surface resistance m ·K/W
a percentage area of mortar joint in the measured masonry %
mor
a percentage area of units in the measured masonry %
unit
d thickness of the masonry m
T Temperature K
μ water vapour resistance factor
c specific heat capacity J/(kg·K)
p
10

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l length of a masonry unit mm
w width of a masonry unit mm
h height of a masonry unit mm
unit
h thickness of a mortar joint mm
mor
F moisture conversion factor
m
f moisture conversion coefficient by mass kg/kg
u
3 3
f moisture conversion coefficient by volume m /m
ψ
u moisture content mass by mass kg/kg
3 3
ψ moisture content volume by volume m /m
2
U thermal transmittance of the masonry in dry state W/(m ·K)
10,dry,mas
2
U thermal transmittance of the masonry W/(m ·K)
mas
2
U thermal transmittance of the mortar W/(m ·K)
mor
2
U thermal transmittance of the units W/(m ·K)
unit
P fractile of population %
3
ρ gross dry density kg/m
g,dry
3
ρ net dry density kg/m
n,dry
v percentage of voids %

4 Determination of λ –values for solid masonry units and λ –
10,dry, unit 10,dry,mor
values for mortars
4.1 General
λ –values for solid masonry units and λ –values for mortars are identical to the λ –
10,dry,unit 10,dry,mor 10,dry,mat
values. The λ –values of solid masonry units and of mortars can be determined from tests
10,dry,mat
carried out on samples of the material or from tables or graphs which relate λ to density or from
10,dry,mat
determining the thermal transmittance (U ) of masonry built from masonry units and mortar. In all
mas
cases the λ –value is to be representative of the material.
10,dry,mat
NOTE For the determination of the λ -value, λ -value and λ -value, with fractile X and
10,dry,unit 10,dry,mor 10,dry,mat
confidence level Y, the basis is the corresponding gross dry density or net dry density and configuration.
4.2 λ –values for solid masonry units and mortars
10,dry, mat
4.2.1 Method S1. Determination of λ –values from tabulated λ /net dry density
10,dry,unit 10,dry,mat
relationship
Tabulated λ –values for different materials used for masonry products are given in Annex A,
10,dry,mat
differentiated by material and dry density. This annex also contains values for the water vapour
resistance factor, the specific heat capacity and the moisture conversion coefficient.
These tabulated values are valid for materials where there is factory production control of the net dry
density but no directly determined λ -values. λ –values are given as 50 % and 90 % fractiles (P).
10,dry,mat
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4.2.2 Method S2. Determination of λ –values based on λ /net dry density curve
10,dry,unit 10,dry,mat
4.2.2.1 General
To determine a λ –value from a λ /net dry density relationship the following procedure
10,dry,mat 10,dry,mat
shall be used:
4.2.2.2 Test specimens
Test specimens shall be in accordance with the requirements of EN 12664. Care should be taken that
the test specimens are representative of the masonry product itself.
NOTE An appropriate way to ensure this is to cut specimens from masonry units.
4.2.2.3 Conditioning of specimens
Normally masonry materials are tested in a dry condition. It is also possible to carry out tests in a moist
condition (e.g. conditioned to constant mass in an environment of (23 ± 2) °C and 50 % ± 5 % relative
humidity), in which case the measured value has to be converted to the dry state following one of the
procedures given in Clause 6.
4.2.2.4 Test measurement
The reference test method is given in EN 12664. The test shall be carried out at a mean temperature
of 10 °C.
Alternative test methods, which may require different test specimens and different conditioning
methods, may be used, if the correlation between the reference test method and the alternative method
can be given.
4.2.2.5 Establishing a product related λ /net dry density-curve
10,dry,mat
Three items of information are necessary for this determination procedure:
1) the tabulated λ /net dry density-correlation for the given material (see Annex A);
10,dry,mat
2) the product net dry density range, which can be derived either from the production history or
from the net dry density tolerances which are given in the relevant product standards;
3) at least three individual test measurements of the net dry density and λ , on material which is
i
representative for the current material produced. The measurements of net dry density and λ shall
be carried out on the same specimens. The three tests have to be carried out on specimens from
different production batches to represent the manufactured product net dry density range. These
three measurements are used to determine the distance of the individual λ /net dry density-
10,dry,mat
curve, for a defined production, from the tabulated λ /net dry density curve.
10,dry,mat
Determine the λ –value as described in 4.2.2.1 to 4.2.2.3 and calculate the arithmetic mean value of the
I
3 λ –results.
i
Measure the net dry density of each of the three samples following the procedure described in
EN 772-4 or EN 772-13 or EN 1015-10 and calculate the arithmetic mean value of the 3 results.
Then use the following procedure.
Through the point A representing mean thermal conductivity and mean net dry density draw a λ/net
dry density-curve parallel to the general λ /net dry density-curve obtained from plotting the
10,dry,mat
tabulated λ— and ne
...