ISO 17738-2:2019

INTERNATIONAL ISO
STANDARD 17738-2
First edition
2019-08
Thermal insulation products —
Exterior insulation and finish systems
(EIFS) —
Part 2:
Installation
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 3
5 Materials storage and handling . 4
6 Substrate . 4
7 Mixing. 5
8 Installation of the liquid-applied water resistive barrier system . 5
8.1 General . 5
8.2 Transition membrane . 6
9 Thermal insulation boards . 6
9.1 General . 6
9.2 Attachment of the thermal insulation boards . 7
9.2.1 General. 7
9.2.2 Clearances (spacing). 8
9.2.3 Rasping and surface preparation . 8
9.3 Aesthetic reveals . 9
10 Installation of the base coat and glass fibre reinforcing mesh . 9
10.1 Attachment of the glass fibre reinforcing mesh . 9
10.2 Terminations and aesthetic reveals .12
10.2.1 General.12
10.2.2 Wrapped terminations.12
10.3 Base coat surface .17
11 Installation of the finish material .18
11.1 General .18
11.2 Execution.18
Annex A (informative) Mechanical fasteners .19
Annex B (informative) Site quality assurance programme (SQAP) .20
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
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expressions related to conformity assessment, as well as information about ISO's adherence to the
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use
in the built environment, Subcommittee SC 3, Thermal insulation products.
A list of all parts in the ISO 17738 series can be found on the ISO website.
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 © ISO 2019 – All rights reserved

Introduction
This document provides minimum installation requirements for an exterior insulation and finish
system where the materials meet the requirements of ISO 17738-1, and where the installation meets
the requirements for design in accordance with ISO 17738-3.
Exterior insulation and finish systems (EIFS) are a unique insulated cladding that consists of a water
resistive barrier system (WRB) over the substrate, a drained cavity and an insulated cladding that is
bonded adhesively to the WRB, covered with a base coat, mesh and a finish material.
A risk management process may recommend additional requirements for the establishment of a site
quality assurance programme (SQAP). Additional information related to a SQAP is included in Annex B.
INTERNATIONAL STANDARD ISO 17738-2:2019(E)
Thermal insulation products — Exterior insulation and
finish systems (EIFS) —
Part 2:
Installation
1 Scope
This document specifies requirements for the installation of exterior insulation and finish systems
(EIFS) for wall applications using material which meet the materials requirements of ISO 17738-1 and
the design requirements of ISO 17738-3. This document further includes installation requirements for
the EIFS materials that include a water resistive barrier (WRB) and decorative projections as part of
the cladding system for walls.
This document does not include requirements for the structural design of the substrate/building
structural members or for the integrity of the substrate/building structural members to which the EIFS
is to be attached, nor the requirements for installation or repair of the substrate/building structural
members before installation commences.
This document does not include requirements for the competence that an EIFS installer needs for
installation of the system.
The installation of EIFS on horizontal surfaces exposed to direct precipitation is outside the scope of
this document.
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 7345, Thermal performance of buildings and building components — Physical quantities and definitions
ISO 4624, Paints and varnishes — Pull-off test for adhesion
ISO 8873-1, Rigid cellular plastics — Spray-applied polyurethane foam for thermal insulation — Part 1:
Material specifications
ISO 8873-2, Rigid cellular plastics — Spray-applied polyurethane foam for thermal insulation — Part 2:
Application
ISO 9229, Thermal Insulation — Vocabulary
ISO 17738-1, Thermal insulation products — Exterior insulation and finish systems — Part 1: Materials
and systems
ISO 17738-3, Thermal insulation products — Exterior insulation and finish systems — Part 3: Design
requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345, ISO 9229 and
ISO 17738-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
aesthetic reveal
groove cut into the thermal insulation board for decorative purposes only
3.2
back-wrap
encapsulate the exposed edge of the thermal insulation board by securing a strip of glass fibre
reinforcing mesh (3.9) to the substrate and embedding it in base coat around the board edge onto the
face of the insulation
3.3
edge-wrap
encapsulate the edge of thermal insulation board by embedding a strip of glass fibre reinforcing mesh
(3.9) in base coat and lapping it onto the face of the insulation board and onto the edge of an opening
3.4
EIFS contractor
legal entity (corporate or personal) responsible for the site installation of EIFS
3.5
EIFS moulding
insulation profile that is mounted on or incorporated into the thermal insulation boards, covered by the
lamina integrated into EIFS
3.6
expansion joint
joint designed to permit movement due to expansion and contraction of any part of the system
Note 1 to entry: See ISO 9229.
3.7
flashing
continuous material(s) that stops the vertical flow of water within a wall assembly or system and
directs the water, via gravity, to the exterior of the cladding
3.8
pot-life
period of time that a material maintains its workable properties after it has been mixed
3.9
glass fibre reinforcing mesh
woven or non-woven glass fibre fabric material of EIFS that is encapsulated in the base coat to
strengthen EIFS
3.10
pre-wrap
encapsulate the exposed edge of the thermal insulation board with base coat and mesh, lapping onto
the front and back of the insulation board before installation
3.11
transition membrane
component of the WRBA (3.12) that maintains continuity of the WRB at joints and openings in the
substrate that cannot be bridged with the LA-WRB
2 © ISO 2019 – All rights reserved

3.12
water resistive barrier assembly
WRBA
materials possessing water resistant properties that are install
...