ISO 7729:2026

International
Standard
ISO 7729
Second edition
Typical vertical joints between two
2026-04
prefabricated ordinary concrete
external wall components —
Properties, characteristics and
classification criteria
Assemblages verticaux courants entre deux composants de façade
en béton ordinaire — Propriétés, caractéristiques et éléments de
la classification
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Properties of joints and agents to which they are exposed . 2
4.1 Properties .2
4.2 Agents to which joints are exposed .3
5 Characteristics of joints . 4
5.1 General .4
5.2 Thermal transmission between internal and external environments .4
5.3 Influence of joint on acoustical insulation of the floor .4
5.4 Air permeability of joints (between external and internal environments) .4
5.5 Water tightness .4
5.5.1 Families of joint (solutions given by way of examples) .4
5.5.2 Supplementary arrangements.7
5.6 Water vapour condensation .7
5.6.1 On the internal face of the wall and/or floor in the vicinity of the joint .7
5.6.2 Inside the joints .8
5.7 Transmission of forces .8
5.7.1 Bracing wall .8
5.7.2 Supported external wall .8
5.8 Fire resistance .8
5.9 Emission of gases or toxic fumes in the event of fire.8
5.10 Internal and external appearance .9
5.11 Durability .9
6 Other indications to be given . 9
6.1 Maintenance of jointing materials .9
6.2 Replacement of degradable jointing materials .9
6.3 Dismantling and reassembling components .9
7 Dimensional coordination . 9
8 Classification criteria . 10
Bibliography .11

iii
Foreword
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in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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This document was prepared by Technical Committee ISO/TC 59, Buildings and civil engineering works,
Subcommittee SC 19, Prefabricated building.
This second edition cancels and replaces the first edition (ISO 7729:1985), which has been technically
revised.
The main changes are as follows:
— update of reference documents;
— addition of Tables 1 and 2, integrating 4.1 and Clause 8;
— redrafting of Figure 1, integrating 5.4.1.1;
— redrafting of Figure 2 and Figure 3, integrating 5.4.1.2;
— addition of μ value calculation reference in 5.5.1;
— addition of joint fillers determines the condensation coefficient inside, fire resistance, and emission of
gases or toxic smoke in 5.5.1, 5.7 and 5.8;
— addition of explain of heterogeneity coefficient, Q, in 5.9;
— redrafting the text describing durability in 5.10;
— addition of description of maintenance of jointing materials in 6.1.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document outlines a convention for designers about jointing two prefabricated ordinary concrete
external wall components.
This convention refers to standardized methods for the determining the properties of the joint. However, the
methods for some of these properties are not elaborated. Given the importance of these properties, solutions
are proposed and both experience and laboratory studies have shown to be satisfactory under the usual
conditions. It should be noted that these solutions are not the only viable option.

v
International Standard ISO 7729:2026(en)
Typical vertical joints between two prefabricated ordinary
concrete external wall components — Properties,
characteristics and classification criteria
1 Scope
This document specifies the properties and characteristics of typical vertical joints between two
prefabricated concrete external wall components irrespective of whether these joints coincide with joints
between the external wall and an internal wall or column.
However, the characteristics of joints which are involved in the structural behaviour of buildings are not
specified in this document.
This document is applicable to all public or private buildings, used as dwellings, offices, educational or
hospital premises.
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.
ISO 6707-1, Joints in building - Vocabulary
ISO 6589, Joints in building — Laboratory method of test for air permeability of joints
ISO 717-1, Acoustics — Rating of sound insulation in buildings and of building elements — Part 1: Airborne
sound insulation
ISO 16283-1, Acoustics — Field measurement of sound insulation in buildings and of building elements — Part 1:
Airborne sound insulation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6707-1 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
watertightness system with tongue and grooves
assembly made of two grooves and a tongue the shapes of which are such that the tongue can be inserted
longitudinally into the grooves through a slot in these grooves but cannot move transversely out of the
grooves without a significant effort

4 Properties of joints and agents to which they are exposed
4.1 Properties
For joints, the necessary properties listed in Table 1 shall be considered. The optional properties listed in
Table 2 should be considered.
Table 1 — Necessary properties of joints
Necessary properties
No. Property name Description Application environ-
ment
a Thermal conduc- To limit thermal losses (between the internal and external envi- Various climatic con-
tivity ronments). ditions
b Soundproofing To limit sound transmission (between the spaces separated by the Various indoor envi-
interior wall, if any). ronments
c Air-tightness To provide satisfactory resistance to air penetration. Various climatic con-
ditions
d Water and Snow To ensure water and snow tightness between the exterior and Various climatic con-
Tightness interior wall, and for water and other liquids, between the spaces ditions
separated by the floor.
e Light Blocking To prevent the passage of light (between spaces separated by the Various lighting con-
interior wall, if any). ditions
f Non-toxic and The joints should be non-toxic and not emit odours (odours emitted Various indoor envi-
odour-free by jointing products). ronments
g Anti-condensation Condensation of water vapour should not occur opposite the joints Various climatic con-
and in the joints on the internal face of the wall. ditions
h Stress resistance To resist stresses in one or more directions due to the transmis- Various force condi-
sion of static or dynamic forces in the wall (forces inherent to the tions
function, if any, of the external wall in the stability of the construc-
tion), by impacts and vibrations of various origins, by dimensional
variations and deformations of materials, components and parts of
the construction (shrinkage or expansion, creep, thermal dilation
or contraction, etc.).
i Fire resistance To prevent the passage of flames, smoke and gases, between the Fire environments
spaces separated by the interior wall, if any.
j Non-toxic fumes The joints should not generate gases and toxic fumes in the event of Fire environments
under combus- fire (for the part of the junctions in contact with or in the vicinity
tion/high temper- o
...