ISO 17738-1:2017

INTERNATIONAL ISO
STANDARD 17738-1
First edition
2017-02
Thermal insulation products —
Exterior insulation and finish
systems —
Part 1:
Materials and systems
Produits isolants thermiques — Systèmes de finition et d’isolation
externe —
Partie 1: Materiaux et systèmes
Reference number
ISO 17738-1:2017(E)
©
ISO 2017

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ISO 17738-1:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 17738-1:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Requirements . 4
5 Testing . 5
6 Marking, packaging and labelling .14
Annex A (normative) Bond strength testing (reference: 5.3.3 and 5.4.3) .19
Annex B (normative) Water absorption coefficient of the LA-WRB (reference: 5.4.2) .22
Annex C (normative) Joint durability test (reference: 5.4.5) .27
Annex D (normative) Nail popping resistance test (reference: 5.4.6) .33
Annex E (normative) Assessing durability of EIFS under cyclic environmental conditions
(reference: 5.5.2) .38
Annex F (normative) Assessing drainage performance of EIFS (reference: 5.5.3) .49
Annex G (informative) Wind load testing (reference: 5.2.5 and Annex D) .57
Annex H (informative) Test specimen preparation for infrared analysis .61
Bibliography .62
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ISO 17738-1:2017(E)

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).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by 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.
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ISO 17738-1:2017(E)

Introduction
ISO 17738 comprises three parts: this document deals with the material performance of exterior
1)
1)
insulation and finish systems (EIFS), ISO 17738-2 provides guidance on installation and ISO 17738-3
gives guidance on the design of an EIFS system.
1) Under preparation.
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INTERNATIONAL STANDARD ISO 17738-1:2017(E)
Thermal insulation products — Exterior insulation and
finish systems —
Part 1:
Materials and systems
1 Scope
This document outlines requirements for exterior insulation and finish systems (EIFS), used in
combination with a drained air space as an exterior wall cladding system. It also outlines the
requirements for water resistive barrier systems that are to be used with EIFS.
The EIFS wall cladding system is comprised of liquid-applied water resistive barrier, an adhesive for
attachment of the thermal insulation boards to the substrate, rigid thermal insulation boards, a glass fibre
reinforcing mesh embedded in a base coat on the face of the thermal insulation boards and a finish coat.
The use of mechanical fasteners is outside the scope of this document, but is acceptable as a complement
and/or as an alternate to adhesive for attachment where the substrate will not support adhesive
attachment of the EIFS.
In EIFS, the thermal insulation boards support the base coat with integral glass fibre reinforcing mesh.
Systems where the reinforcement is the supporting element of the rendering, e.g. conventional stucco,
are not covered by this document.
This document does not purport to address all the health and safety aspects associated with its use.
Anyone using this document has the responsibility to consult the appropriate authorities and to establish
health and safety practices, in conjunction with any existing applicable regulatory requirements, prior
to its use.
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 846, Plastics — Evaluation of the action of microorganisms
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 1663:2007, Rigid cellular plastics — Determination of water vapour transmission properties
ISO 1926, Rigid cellular plastics — Determination of tensile properties
ISO 3451-1, Plastics — Determination of ash — Part 1: General methods
ISO 4606, Textile glass — Woven fabric — Determination of tensile breaking force and elongation at break
by the strip method
ISO 4611, Plastics — Determination of the effects of exposure to damp heat, water spray, and salt mist
ISO 4628:2016, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 4: Assessment of degree of
cracking
ISO 4650, Rubber — Identification — Infrared spectrometric methods
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ISO 17738-1:2017(E)

ISO 4898, Rigid cellular plastics — Thermal insulation products for buildings — Specifications
ISO 8145, Thermal insulation — Mineral wool board for overdeck insulation of roofs — Specification
ISO 15148, Hygrothermal performance of building materials and products — Determination of water
absorption coefficient by partial immersion
ISO 15821, Doorsets and windows — Water-tightness test under dynamic pressure — Cyclonic aspects
ISO 16474-3, Paints and varnishes — Methods of exposure to laboratory light sources — Part 3: Fluorescent
UV lamps
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345 and ISO 9229 and the
following 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
adhesive
product for adhering the thermal insulation board (3.21) to the water resistive barrier system (3.23)
3.2
base coat
polymer-based coating, either factory-blended (3.10) or field-mixed (3.11), applied directly to the thermal
insulation board (3.21), fully embedding the reinforcing mesh (3.17) providing the primary barrier to
water penetration
3.3
cure
develop the ultimate properties of an initial wet state material by a chemical process
3.4
drainage cavity
space between the WRB and thermal insulation board (3.21) that allows for the free drainage of water
that penetrates the EIFS (3.9)
3.5
dry
develop the ultimate properties of an initial wet state material solely by evaporation of volatile
ingredients
3.6
durability
ability of a building or any of its components to perform its required functions in its service environment
over a period of time without unforeseen cost for maintenance or repair
3.7
EIFS manufacturer
producer of the materials and components forming a proprietary EIFS (3.9)
3.8
embed
press into and encapsulate the reinforcing mesh (3.17) in the wet base coat (3.2)
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3.9
exterior insulation and finish system
EIFS
non-load-bearing wall cladding system comprised of LA-WRB (3.15), an adhesive (3.1) for attachment
of the thermal insulation board (3.21) to the LA-WRB, rigid thermal insulation board, a glass fibre
reinforcing mesh (3.17) embedded in a base coat (3.2) on the face of the thermal insulation board and a
finish coat (3.12)
3.10
factory-blended
material that arrives from the manufacturer requiring no additions apart from water to produce the
wet state material
3.11
field-mixed
materials that are mixed in the field by combining two or more materials, other than, or in addition
to water
3.12
finish coat
outermost coat applied over the base coat (3.2), which gives the wall its colour and texture, exclusive of
sealers and paints
3.13
geometrically defined drainage cavity
GDDC
path created between the WRB and thermal insulation board (3.21) through the use of thermal
insulation board that has a pattern cut into its back
3.14
lamina
composite of base coat (3.2), reinforcing mesh (3.17) and finish coat (3.12)
3.15
liquid applied water resistive barrier
LA-WRB
fluid material applied by spray, roller or trowel, that dries to a membrane possessing low water
absorption properties becoming a component of the water resistive barrier system (3.23)
3.16
manufacturer’s installation instructions
written installation instructions provided by the EIFS manufacturer (3.7) that include information that
will assist in the correct use and installation of the materials and components that comprise their system
3.17
reinforcing mesh
woven or non-woven glass fibre fabric component of the EIFS (3.9) encapsulated in the base coat (3.2) to
strengthen the system
3.18
substrate
structural component supporting the EIFS (3.9), which is resistant to deterioration caused by water or
is protected by a water resistive barrier system (3.23)
3.19
test sample
prepared materials or systems from which test specimens (3.20) are taken
3.20
test specimen
portion of a test sample (3.19) taken for measurement of a given property or characteristic
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3.21
thermal insulation board
component that functions to reduce heat flow through the wall and serves as the surface to receive the
base coat (3.2)
3.22
water absorption coefficient
mass of water absorbed by a test specimen (3.20) under specified time and pressure, per unit area and
per square root of time
3.23
water resistive barrier system
WRB
material(s) possessing low water absorption properties that are applied over substrates (3.18)
susceptible to water absorption to create a continuous surface that prevents water penetration into the
wall assembly
3.24
water retention ratio
weight of water retained in the test specimen (3.20) following the drainage capacity test divided by the
projected area of wetted wall
3.25
wrap
protect the exposed edges of thermal insulation board (3.21) by back-wrapping or edge-wrapping
4 Requirements
4.1 EIFS constituent products
4.1.1 The constituent products of EIFS shall meet the technical requirements listed in Table 1.
4.1.2 Rigid cellular plastic thermal insulation board shall meet the requirements of ISO 4898.
4.1.3 Semi-rigid mineral fibre thermal insulation board shall meet the requirements of ISO 8145.
4.2 LA-WRB
The LA-WRB shall meet the technical requirements listed in Table 2. Where the LA-WRB is not intended
by the EIFS manufacturer for application to a wood substrate, the LA-WRB does not have to meet the
requirements for the following:
a) joint durability test;
b) nail popping resistance test.
The type of wood substrate can have an effect on the adhesion of the LA-WRB to the substrate. Given
its nature of manufacture, oriented strand board (OSB) is deemed to represent a worst-case scenario in
this regard. Therefore, any LA-WRB that passes the tests required in 5.4, when applied to OSB, shall be
deemed suitable for use on plywood.
4.3 EIFS
The EIFS shall be tested as an assembly as required in 5.5; the associated technical requirements for
the system are listed in Table 3.
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4.4 Special applications
Special applications may require properties other than, or in addition to, those specified in this
document. These properties, when agreed upon by the interested parties, may be added to the
requirements of this document.
5 Testing
5.1 Sampling
Random sampling, of a minimum number of material components, as required to complete the necessary
testing, shall be carried out by an organization determining compliance with this document. A random
selection of materials is to be obtained from the production or main storage facility for identification
before they are sent to the testing laboratory. The identified samples are then to be forwarded directly
to the testing laboratory.
5.2 Preparation of sample panels
5.2.1 As a minimum, the following test sample panels shall be prepared.
5.2.1.1 One nominal 610 mm × 610 mm panel consisting of 25 mm thick thermal insulation board and
base coat, including reinforcing mesh shall be prepared. The base coat and reinforcing mesh shall be
applied at the thickness stipulated by the EIFS manufacturer, determined for the purpose of confirmation
as a mass per unit area, as per 5.2.5. This test sample panel shall be used for preparation of the test
specimens for the following tests:
a) bond strength test of the base coat;
b) base coat water impermeability test;
c) water absorption of the base coat test.
5.2.1.2 Five nominal 610 mm × 610 mm panels consisting of 25 mm thick thermal insulation board
and base coat, including reinforcing mesh, and finish coat. The edges of four of the panels shall be
wrapped with base coat, reinforcing mesh and finish coat. The base coat shall be allowed to cure for a
minimum of 24 h prior to application of the finish coat. The base coat and reinforcing mesh and finish
coat shall be applied at the thicknesses stipulated by the EIFS manufacturer, determined for the purpose
of confirmation as a mass per unit area, as per 5.2.5. This test sample panel shall be used for preparation
of the test specimens for the following tests:
a) bond strength test of the finish coat;
b) water vapour permeance of the lamina test;
c) lamina salt spray resistance test;
d) lamina ultraviolet resistance test;
e) EIFS impact resistance test (the wrapped panels).
5.2.1.3 One nominal 610 mm × 1 220 mm vertical wood frame to which is attached 19 mm thick
OSB sheathing meeting the requirements of ISO 16894 and having a water absorption coefficient of
2 1/2
(0,002 ± 0,001) kg/m s . The OSB sheathing shall include a joint with a width of 3,2 mm, as shown in
Figure 1. The OSB shall be free of any dirt, dust or other deleterious substances that may affect the adhesion
of the LA-WRB. The LA-WRB shall be applied to the OSB in strict accordance with the manufacturer’s
installation instructions and at the minimum thickness recommended by the manufacturer, determined
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ISO 17738-1:2017(E)

for the purpose of confirmation as a weight per unit area, as per 5.2.5. This test sample panel shall be
used for preparation of the test specimens for the following tests:
a) bond strength test of the LA-WRB;
b) water absorption coefficient of the LA-WRB test;
c) joint durability test;
d) accelerated weathering resistance test of the LA-WRB.
5.2.1.4 One nominal 610 mm × 610 mm panel consisting of LA-WRB applied to nominally 13 mm
thick glass mat gypsum sheathing. The LA-WRB shall be applied in accordance with the manufacturers
installation instructions and at the thickness stipulated by the EIFS manufacturer, determined for the
purpose of confirmation as a mass per unit area, as per 5.2.5. This test sample panel shall be used for
preparation of the test specimens to test the water vapour permeance of the LA-WRB.
5.2.2 The test sample panels shall be prepared in a vertical orientation to simulate installation in
the field.
2)
5.2.3 For the installation requirements of EIFS and LA-WRB, see ISO 17738-2 .
5.2.4 The test sample panels shall be conditioned at (23 ± 2) °C and (50 ± 5) % relative humidity for a
minimum of 14 d.
5.2.5 The applied material thickness shall be verified as a mass per unit area, as follows. In determining
the area of the test sample panel, its linear dimensions shall be measured to an accuracy of 1 mm.
5.2.6 Using the thickness stipulated by the EIFS manufacturer, and the density of the material as
provided by the EIFS manufacturer, the required mass of material to be applied to the test sample panel
shall be determined as follows:
3 2 -6
Mass (g) = Density (kg/m ) × area of test sample panel (mm ) × thickness (mm) × 10 .
The initial mass of the material including its storage container shall be measured to an accuracy of
1/1 00 of the mass.
Material shall be removed from the storage container and applied uniformly to the test sample panel
until the mass of material removed is equal to the mass determined. The mass of material removed
shall be determined by measuring the mass of the remaining material, including its storage container,
until the difference between the initial mass and the final mass is equal to the mass determined to an
accuracy of 1/1 00 of the mass.
Care shall be taken in removing material from the storage container and in its application that all
material is applied to the test sample panel. If any material is lost (i.e. dropped before it reaches the
test sample panel), its mass shall be determined and taken into consideration when determining the
amount of material applied to the test sample panel.
5.2.7 Test specimens, unless otherwise specified in the test methods, shall be obtained from the
conditioned test sample panels described in 5.2.1.1 through 5.2.1.4. Care and caution shall be exercised
when cutting the test specimens from the test sample panels so that the bond between materials is not
affected. The speed of the saw blade, the number of teeth per inch and other cutting variables shall be
considered in test specimen preparation in order to avoid excess vibrations or heat build-up.
2) Under preparation.
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5.3 EIFS constituent material tests
5.3.1 Ash content
5.3.1.1 This test shall be conducted only if deemed necessary by the testing agency as a means of
identification of the test sample materials submitted.
5.3.1.2 When conducted, test specimens shall be prepared and the ash content of the base coat and
finish coat material shall be determined in accordance with ISO 3451-1 and the results shall be expressed
as a percentage of the initial weight of the dry test specimen.
5.3.2 Infrared analysis
5.3.2.1 This test shall be conducted only if deemed necessary by the testing agency as a means of
identification of the test sample materials submitted.
5.3.2.2 Test specimens shall be prepared and the absorption spectrum of the organic fraction of the
binder used in the formulation of the base coat and finish coat shall be determined in accordance with
ISO 4650 and the results shall be recorded on a plot of percent transmittance vs. wavelength.
Test specimen preparation for infrared analysis is provided in Annex H.
5.3.3 Bond strength tests
5.3.3.1 Test specimen preparation and testing of the bond strength of the adhesive, base coat and finish
coat shall be according to Annex A.
5.3.3.2 The average of the results of the bond strength test shall be reported in Pa for each state tested
(initial, wet and dry).
5.3.4 Water vapour permeance of the lamina
5.3.4.1 Three test specimens of a size suitable for the test equipment to be used shall be cut from the
test sample panel specified in 5.2.1.2 and the lamina carefully removed from the thermal insulation
board. The dry thickness of the lamina shall be measured in at least five locations on each test specimen
and the average thickness reported.
5.3.4.2 The water vapour permeance of the lamina shall be determined according to ISO 1663 with the
face coat of the lamina exposed to the test chamber.
2
5.3.4.3 The average water vapour permeance of the lamina shall be reported in ng/(Pa·s·m ).
5.3.5 Base coat water impermeability test
5.3.5.1 Three test specimens measuring 200 mm × 200 mm shall be cut from the test sample panel
described in 5.2.1.1. The edges of each test specimen shall be sealed with wax or other suitable vapour
impermeable material.
NOTE A wax meeting the requirements of ISO 1663:2007, 5.8, “sealant wax”, would be a suitable material to
use for sealing the edges of the test specimens.
5.3.5.2 Over a surface area of 100 mm × 100 mm in the centre of the test specimens, the thermal
insulation board shall be removed, by scraping, down to the back of the base coat. Methyl Violet 2B
powder shall be brushed onto the back of the base coat.
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5.3.5.3 The test specimens, with the coatings facing downward, shall be placed in a tank of water to a
depth of (5 ± 0,25) mm for at least 2 h.
5.3.5.4 After two hours, the area of dampness on the test specimen as determined by a colour change
in the Methyl Violet 2B powder shall be recorded as a percentage of the total exposed base coat area. Any
observation of liquid water shall be recorded.
5.3.6 Water absorption of the base coat
5.3.6.1 Two test specimens measuring 100 mm × 100 mm shall be cut from the test sample panel
described in 5.2.1.1 and the thermal insulation board shall be detached from each of them.
5.3.6.2 The test specimens shall be dried in a well-ventilated oven for 24 h at a temperature of
(105 ± 2) °C. After cooling at room temperature for 15 min, the dry weight of the test specimens shall be
measured and reported to the nearest 0,01 g.
5.3.6.3 Each test specimen shall then be immersed flat, 5 mm below the surface of distilled (20 ± 5) °C
water for a period of 48 h.
5.3.6.4 After 48 h immersion, the weight of each test specimen shall be measured to the nearest 0,01 g.
The water absorption shall be determined by the increase in mass in relation to the dry weight of the
specimen expressed as a percentage of the dry weight of the test specimen. The average percentage
water absorption of the two test specimens shall be reported.
5.3.7 Finish coat fungus resistance test
5.3.7.1 One test specimen shall be prepared by applying finish coat onto a clean 50 mm × 50 mm glass
slide. The finish coat shall be applied according to manufacturer’s installation instructions.
5.3.7.2 The fungus resistance test shall be conducted according to ISO 846. The test specimen shall be
incubated for a minimum of 28 d.
5.3.7.3 At the end of the test period, the test specimen shall be examined for fungal growth on the
finish coat material and the observations recorded according to the requirements of ISO 846.
5.3.8 Lamina salt resistance test
5.3.8.1 Three test specimens measuring 100 mm × 300 mm shall be cut from the test sample panel
described in 5.2.1.2. The edges of each test specimen shall be sealed with wax.
5.3.8.2 The test specimens shall be tested according to ISO 4611 for 300 h.
5.3.8.3 The test specimens shall be visually examined without magnification.
5.3.8.4 Any deleterious effects, such as cracking or flaking, shall be recorded.
5.3.9 Lamina ultraviolet resistance test
5.3.9.1 Three test specimens measuring 100 mm × 300 mm shall be cut from the test sample panel
described in 5.2.1.2. The edges of each test specimen shall be sealed with wax.
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5.3.9.2 The test specimens shall be tested according to ISO 16474-3. The xenon arc device shall be
used with a borosilicate inner filter and a borosilicate outer filter. The parameters of testing shall be as
follows:
a) 102 minutes of light exposure with no water spray [black panel temperature of (63 ± 2) °C and
(50 % ± 5 %) RH];
b) 18 min of light exposure with water spray [water temperature at (16 ± 3) °C];
c) the above cycle (A and B) is repeated for 18 h;
d) 6 h of darkness, no water spray [black panel temperature of (24 ± 2) °C and (95 ± 5) % RH];
e) the above cycle (A through D) represents 24 h or 1 d exposure. The cycle is repeated for a total of at
least 1 998 h of light exposure (2 664 h or 111 d total).
5.3.9.3 At the end of the testing, the test specimens shall be visually examined without magnification.
5.3.9.4 Any deleterious effects, such as cracking or flaking, shall be recorded.
5.3.10 Reinforcing mesh strength and alkalinity resistance
5.3.10.1 A minimum of 20 test specimens, each measuring 50 mm wide and 300 mm long, shall be
prepared from the lightest weight of mesh used with a proprietary system. At least 10 test specimens
shall have the long dimension in the direction of the weft and 10 test specimens shall have the long
dimension in the direction of the warp. At least five of each type of test specimen shall be exposed to an
alkaline solution for 28 d and then allowed to dry for 7 d in accordance with ISO 4606.
5.3.10.2 The clamps of the testing machine shall be covered with a suitable rubber surface and be
sufficiently rigid to resist deformation during the test. The clamps shall hold the whole width of the test
specimens.
The results of test specimens that slip in the jaws of the testing m
...