ISO/TR 17870-2:2015

TECHNICAL ISO/TR
REPORT 17870-2
First edition
2015-08-15
Ceramic tiles — Guidelines for
installation —
Part 2:
Installation of thin ceramic wall and
floor tiles and panels
Carreaux et dalles céramiques — Lignes directrices pour
l’installation —
Partie 2: Installation des carreaux et dalles céramiques minces au
sol et aux murs
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General . 2
3.2 Components of thin ceramic tiling . 2
3.3 Thin tiling techniques and operations . 3
3.4 Characteristics/aspects of thin ceramic tiling . 4
4 Exchange of information . 5
5 Materials . 5
5.1 General . 5
5.2 Basic materials . 5
5.3 Basic information . 6
6 Specification . 8
6.1 General . 8
6.2 The project data . 8
6.2.1 Installation location and working conditions . 8
6.2.2 Backgrounds . 9
6.3 Selection and specification of the materials .10
6.3.1 Criterion of performance .11
6.3.2 Criterion of compatibility .11
6.3.3 Criterion of safety.11
6.3.4 Adhesives . .11
6.4 Specification of the thin tiling .12
6.4.1 Thin tiling system .12
6.4.2 Thin tile joints .12
6.4.3 Movement joints .13
7 Installation .14
7.1 General .14
7.2 Analysis of the specification and planning of the work .14
7.3 Control of environmental conditions .15
7.4 Storage and control of the materials .15
7.5 Control and preparation of the background, preparation of the bedding material,
application of bedding and thin tiles and panels.16
7.6 Installation of movement joints .17
7.7 Cleaning and protection .17
8 Quality of thin ceramic tiling: characteristics and requirements .17
8.1 General characteristics of thin ceramic tiling .17
8.2 Guidelines for the specification of the requirements and their recommended tolerances 18
8.2.1 General.18
8.2.2 Regularity .18
8.2.3 Durability .20
8.2.4 Safety .20
9 Initial cleaning, protection, and maintenance .22
9.1 General .22
9.2 Initial cleaning .22
9.3 Protection .22
9.4 Treatment .22
9.4.1 Surface waterproofing treatments .22
9.4.2 Temporary thin ceramic tile or thin ceramic panel sealers .23
9.5 Maintenance .23
Bibliography .24
iv © ISO 2015 – All rights reserved

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 meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 189, Ceramic tile.
ISO/TR 17870 consists of the following parts, under the general title Ceramic tiles — Guidelines for
installation:
— Part 1: Installation of ceramic wall and floor tiles
— Part 2: Installation of thin ceramic wall and floor tiles and panels
Introduction
There are currently International Standards available for
— ceramic tiles, and
— adhesives and grouts for tiles.
NOTE ISO test methods for thin ceramic tiles and panels, as well as ISO 13007-5 dealing with liquid-applied
waterproofing membranes for use beneath ceramic tiling bonded with adhesives, are under preparation.
For these products to give satisfactory service, they need to be selected and installed competently, and
they have to receive appropriate initial treatment, protection, and maintenance.
Some countries have published standards and/or guides that specify the design and installation of
ceramic tiling. The purpose of ISO/TR 17870 is to foster good installation practices for thin ceramic
wall and floor tiles and panels, internationally.
vi © ISO 2015 – All rights reserved

TECHNICAL REPORT ISO/TR 17870-2:2015(E)
Ceramic tiles — Guidelines for installation —
Part 2:
Installation of thin ceramic wall and floor tiles and panels
1 Scope
This part of ISO/TR 17870 defines the quality of thin ceramic tiling and provides guidance for materials
selection, installation, and use, to achieve required levels of quality and performance.
It considers aspects related to the specification and installation of the tiling project, in terms of:
— manufacture and distribution of the materials (thin ceramic tiles and panels, adhesives, grouts, etc.),
— specification of the thin tiling, and
— installation of the tiling (thin tile fixing operations).
It is applicable to internal and external thin ceramic floor and wall tiling, installed by adhesive methods.
NOTE The quality of thin ceramic tiling depends on the following general characteristics:
— regularity;
— durability;
— safety.
The durability of the thin tiling can depend on its use and management.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 13006, Ceramic tiles — Definitions, classification, characteristics and marking
ISO 13007-1, Ceramic tiles — Grouts and adhesives — Part 1: Terms, definitions and specifications for
adhesives
ISO 13007-3, Ceramic tiles — Grouts and adhesives — Part 3: Terms, definitions and specifications for grouts
1)
ISO 13007-5 , Ceramic tiles — Grouts and adhesives — Part 5: Liquid applied waterproofing membranes for
use beneath ceramic tiling bonded with adhesives — Requirements, test methods, evaluation of conformity,
classification and designation
3 Terms and definitions
For the purposes of this document, the terms and definitions given ISO 13006, ISO 13007-1, ISO 13007-3,
ISO 13007-5, and the following apply.
1) To be published.
3.1 General
3.1.1
thin ceramic tile
ceramic tile with thickness ≤5,5 mm, surface area ≤3 600 cm , and no tile edge > 600 mm or a ceramic
tile declared as a thin ceramic tile by its manufacturer or having properties meeting an international or
national standard for thin ceramic tiles
3.1.2
thin ceramic large format tile
ceramic tile with thickness ≤5,5 mm, surface area >3 600 cm , and no tile edge >1 200 mm or a ceramic
tile declared as a thin ceramic large format tile by its manufacturer or having properties meeting an
international or national standard for thin ceramic large format tiles
3.1.3
thin ceramic panel
ceramic panel with thickness ≤5,5 mm, surface area >1 m , and any tile edge > 1 200 mm or a ceramic
tile declared as a thin ceramic panel by its manufacturer or having properties meeting an international
or national standard for thin ceramic panels
3.1.4
thin ceramic tiling
thin ceramic tiles and panels installed, together with its associated bedding and jointing
3.1.5
design (of thin ceramic tiling)
specification (of thin ceramic tiling)
selection of thin ceramic tiles and panels, backgrounds, fixing methods, and fixing and jointing materials
as appropriate for the structure and intended use
3.1.6
installation (of thin ceramic tiling)
thin tile fixing
application of thin ceramic tiling in accordance with the specification
3.2 Components of thin ceramic tiling
3.2.1
background
any material system used as a base over which the thin ceramic tile or panel is to be fixed
3.2.2
filling out layer
separate application of material to achieve the required vertical flatness (walls)
EXAMPLE Plaster, render, proprietary tile backer boards.
3.2.3
fixing surface
plane rigid surface upon which the thin tile or panel is fixed
3.2.4
insulating layer
layer included to obtain sound or thermal insulation
3.2.5
intermediate joint
movement joint to divide large areas of tiling into smaller, approximately square areas
2 © ISO 2015 – All rights reserved

3.2.6
levelling layer
layer applied to compensate for unevenness and differences in height of the base or to accommodate
services (floors)
3.2.7
movement joint
joint in thin tiles or panels, backgrounds or substrates, designed to accommodate movement
Note 1 to entry: Types of movement joints: structural joint, perimeter joint, intermediate joint.
3.2.8
perimeter joint
movement joint to isolate the thin ceramic tiling from adjacent building elements
3.2.9
primer
fluid material, used separately or mixed with binder to form a slurry, applied as a thin layer to improve
adhesion of the bedding to the background, or to isolate the bedding material from the background surface
3.2.10
separating layer
material which separates layers within the thin tiling system (floors)
3.2.11
structural joint
movement joint in thin ceramic tiling to correspond with structural movement joint in the background
3.2.12
tile bed
bedding
layer of specified materials in which the thin tile or panel is set and which bonds the thin tiles or panels
to the background
3.2.13
tile joint
space between adjacent thin tiles or panels
3.2.14
waterproofing membrane
continuous layer of impervious material to resist the passage of water
3.3 Thin tiling techniques and operations
3.3.1
bonded method
floor tiling laid with a system where the bedding is bonded to the background
3.3.2
buttering method
adhesive applied to the back of the thin tile or panel, just before the tile or panel is placed
3.3.3
contact area
proportion of the thin tile or panel back and/or background support that is in contact with the bedding
after the thin tile or panel has been fixed into position
3.3.4
direct bedding
thin tile or panel fixing directly onto a structural background
3.3.5
floating method
adhesive applied to the fixing surface, just before the thin tile or panel is placed
3.3.6
floating and buttering method
adhesive applied to the fixing surface and to the back of the thin tile or panel, just before the thin tile or
panel is placed
3.3.7
grouting
operation of filling the joint space between thin tiles or panels other than at movement joints
3.3.8
maintenance (of thin ceramic tiling)
all aspects of the cleaning, treatment, and periodic repair of damage to the thin ceramic tiling
3.3.9
plastering
application of a gypsum plaster to a vertical background
3.3.10
rendering
application of a cement mortar to a vertical background
3.3.11
screeding
application of a screed on a floor background
3.3.12
tanking
application of an impermeable layer beneath thin tiling and bedding to prevent water penetration into
the background
3.3.13
unbonded method
any method of laying floors which provides separation of the thin tiling system from the background
3.4 Characteristics/aspects of thin ceramic tiling
3.4.1
durability
quality of thin tiling which maintains its characteristics over time
3.4.2
flatness
conformity of the surface of the thin tiling to a theoretical plane within an allowable tolerance
3.4.3
levelness
conformity of the surface of thin floor tiling to a fixed horizontal level within an allowable tolerance
3.4.4
lipping
deviation between thin tile surfaces either side of a joint (including movement joints)
3.4.5
plumbness
conformity of the surface of thin wall tiling, designed to be vertical, to a fixed plane within an
allowable tolerance
4 © ISO 2015 – All rights reserved

3.4.6
slip resistance
ability of a thin floor tile to provide sufficient friction to resist slipping by pedestrians
4 Exchange of information
In order for the correct floor/wall covering to be installed in appropriate conditions, at the right time,
etc., it is essential that all parties have a clear understanding of the requirements of the project. To
ensure that this is achieved, it is essential that there is wide consultation between all the parties
involved in the project, including client, sub-contractors, and materials suppliers.
As each project will be unique, it is impossible to give a definitive list of the information to be exchanged,
but the following are common examples.
a) Specification: the information required (see Clause 6).
b) Special attendances: access, unloading, hoisting and storage facilities, heat, light and power, and
any additional items considered necessary to expedite the work.
c) Materials: technical specification and instructions for transport, storage, use.
d) Backgrounds: type and age of construction; location within the building; type, characteristics
(mechanical strength, deformation, etc.), and regularity of background (see Clause 6); and any need
for an intermediate substrate or for movement joints.
e) Associated work: services embedded in or passing through the backgrounds and junctions with
other adjacent finishes
f) Finishes: type, size, and colour of thin tiles or panels and layout requirements.
g) Installation: type and technique (see Clause 7).
h) Programme: a time schedule for the progress of the work taking into consideration drying and
curing periods of backgrounds and thin tiling until completion
5 Materials
5.1 General
This clause identifies and lists the materials that can be involved in a thin ceramic tiling installation
using thin ceramic tiles or thin ceramic panels, and defines the main information and rules that apply
to these materials.
The identification and selection of materials suitable for any given application are aspects of the
specification. The relative criteria are therefore set out in 6.3.
5.2 Basic materials
The basic materials for “thin” tiling can be the following:
— finishing layer:
— thin ceramic tiles or thin ceramic panels;
— cementitious grouts;
— reaction resin grouts;
— pre-prepared or proprietary grouts;
— bedding:
— adhesives;
— admixtures;
— water;
— movement joints:
— sealants;
— primers;
— back-up material;
— special components (profile, etc.).
Additional intermediate layers can be the following:
— primers;
— separating layer;
— filling out layer;
— levelling layer;
— anti-fracture/de-coupling membranes;
— waterproofing membrane;
— insulating layers (sound, thermal);
— reinforced screed, etc.
5.3 Basic information
For each material, the following basic information should be provided.
a) Classification
With reference to ISO 13006, ISO 13007-1, ISO 13007-3, ISO 13007-5.
b) Safety requirements
The specification should define the safety requirements.
NOTE Safety requirements can be defined in national regulations.
c) Materials transport, storage use
d) Technical information
The technical information for a given material is usually in the form of a document, supplied by the
manufacturer, containing a list of the technical characteristics as specified in the standards (where
available, see Section 2 and Bibliography) and the results of the respective measurements, carried
out according to the standardized test methods.
The information document is a basic requirement for the correct and knowledgeable selection,
application, and use of materials for thin tiling.
6 © ISO 2015 – All rights reserved

— All materials
— The delivery of materials should be so arranged as to minimize handling.
— Adequate precautions should be taken to prevent damage. Products should be stored in
clean, dry, frost free (if necessary) secure storage to avoid theft and damage.
— The materials should be transported, stored, prepared, and used strictly in accordance
with the manufacturer’s instructions (when applicable).
— Thin ceramic panels can require specially designed equipment and more than one person
for handling them during and after removal from the manufacturer’s original packaging,
as well as for the actual installation of the panels (see Figure 1). This is because very large
thin ceramic panels can deform and fracture if lifted or moved incorrectly.
— Cement and cement-based materials
— Cement should be stored under dry conditions, and used in order of delivery.
— Cement that contains air set lumps should not be used.
— Grout
— In order to avoid colour differences, the same batches of sand and cement should be used
for mixing the grout.
— Sand and aggregates
— Sand and aggregates should be protected from contamination.
— Any contaminated sand or aggregates should not be used.
— Water
— Water should be clean. Seawater is not suitable.
— All containers used for storing or carrying water should be clean.
Vacuum
Pads
Figure 1 — Light alloy frame with vacuum pads
6 Specification
6.1 General
The specification of tiling using thin ceramic tiles or thin ceramic panels aims to identify and define,
in any specific situation, one or more correct fixing method, suitable to achieve an acceptable finish
complying with the general requirements of regularity, durability and safety (see Clause 8).
Specification is considered to be a duty of the designer or specifier in consultation with the project
owner and with the specification approved by the project owner.
6.2 The project data
The project information constitutes the basis of the thin tiling specification.
6.2.1 Installation location and working conditions
The following criteria should be considered at the design stage as a basis for the specification of the
materials and the thin tiling system.
Information on the location of the installation:
— the position of the thin tiling: horizontal (floors), vertical (walls), other (for example, inclined, vault,
ceiling, etc.);
— the location of the thin tiling: outdoor/external or indoor/internal;
— the nature of the location: private/residential or public;
— the destined use of the location: domestic or commercial, private or public, etc.;
8 © ISO 2015 – All rights reserved

— the specific activities which will be carried out in the thin tiled area.
Information on working conditions:
— climate (for external thin tiling);
— location (for example, urban, industrial, etc.) for external thin tiling;
— expected traffic type (for example, pedestrian, wheels, etc.) and intensity (for floors);
— expected static and dynamic loads on thin floor tiling;
— presence of water or other fluids on the thin tiled surface;
— presence of chemicals on the thin tiled surface.
The information above should be used to anticipate:
— the expected level of mechanical, abrasive, chemical wetting, and thermal loads acting on the thin
tiling and the suitability for purpose of the thin tile or panel selected, and
— general (not individual) requirements regarding safety (for example, slip resistance, hygiene, etc.)
or other additional requirements.
6.2.2 Backgrounds
The nature of the background is a prime consideration in deciding the fixing method (specification of
materials — in particular, adhesives — and of the thin tiling system, as well as of any intermediate
substrate or other preparatory treatment that may be necessary before tiling). The characteristics of
the background that influence the choice of fixing method are summarized in Table 1.
The characteristics listed in Table 1 can be used as a framework in order to evaluate backgrounds
at the thin tiling design stage, as well as providing indications for the specification of the thin tiling
system (see 6.4).
The mechanical properties of the background are very important factors to be considered when
specifying thin ceramic tiling.
The following general rules should be adopted.
— Backgrounds for thin tiling should be dry, dimensionally stable, rigid, sound, and free from
contamination.
— Cementitious-based backgrounds are subject to long-term drying shrinkage. The associated risks
can be reduced by selecting a suitable time schedule and procedures to allow the background
materials to cure sufficiently where the majority of the shrinkage will have occurred prior to the
installation of thin ceramic tiles or panels, while recognizing that some shrinkage will also occur
afterwards. The size of thin ceramic tile or panel specified is also an important factor in this respect,
e.g. the effect of long-term background shrinkage on thin ceramic panels can be more severe than
for smaller thin ceramic tiles.
— Levelling and/or filling out layers, e.g. suitable levelling compounds, etc., should be used when
desired by project owner to improve the background flatness/finish, or to compensate for floors
out of level and walls out of plumb.
NOTE The flatness of backgrounds intended to receive thin ceramic tiles should be appropriate when there
is no gap wider than 3 mm between the background and a 2 m straightedge. Better surface regularity of the
background can be required for large format thin ceramic tiles or panels.
— Special intermediate substrates can be used for waterproofing, or for sound /thermal insulation if
approved by the manufacturer of the thin ceramic tile or thin ceramic panel.
— In the case of deformable backgrounds, the application of a suitable strengthening layer (e.g.
dimensionally stable backer board or a reinforced screed) should be considered.
— Existing mature floor and wall coverings with the above recommended mechanical, integrity,
regularity and surface characteristics can be suitable backgrounds for thin ceramic tiling.
Table 1 — Background characteristics
Characteristics Description
Mechanical Mechanical strength — Compressive strength — Resistance to rupture or dam-
age under working loads
— Bending strength
— Ability to support the per-
— Pull off strength
manent load of the tiling (tiles,
mortar bed, etc.)
Deformation under load — Compression — Tendency of the support to
deform under static and dynamic
— Deflection
load
— Creep
Deformation without load — Shrinkage — Movements due to non-load
factors
— Plastic deformation
— Chemical shrinkage
— Thermal and Damp
Conditions
Surface soundness — Ability to support the weight
(walls) of the tiling system
Regularity Flatness — Departure from planarity
(depressions, protuberances,
bumps)
Surface finish — Texture of surface
Chemical/Physical Water absorption — The amount and rate at which
the background absorbs water
from the tile bedding
Water resistance — The behaviour of the back-
ground exposed to contact with
water (both during tile installa-
tion and in use
Chemical — Compatibility between the
background surface and the
material or layers laid on it
6.3 Selection and specification of the materials
The selection of the materials (thin ceramic tiles, thin ceramic panels, adhesives or grouts) is a basic
step in the specification of “thin” ceramic tiling, since it can significantly influence the achievement
of satisfactory compliance with the general requirements of regularity, durability, and safety, which
define the quality of thin ceramic tiling (see Clause 8).
A very wide range of products are available on the market: products with different appearance (for
example, tiles having different thickness, format, colours, surface texture, decorations, etc.), different
technical characteristics, and associated different expected performance levels (for example, in terms
of resistance to mechanical loads, or to frost and other extreme conditions of temperature or humidity).
The technical characteristics of thin ceramic tiles and panels, adhesives and grouts will be documented
in the manufacturer’s technical specifications, which therefore, represent basic documents for the
selection of materials. Three general criteria for the selection of the materials should be adopted, see
6.3.1 to 6.3.3.
10 © ISO 2015 – All rights reserved

6.3.1 Criterion of performance
This criterion is based on the comparison of
— the expected loads and needs associated with the intended end-use and expected working conditions
of the thin tiling (see 6.2.1), as well as to the characteristics of the background (see 6.2.2), with
— the technical characteristics and performance level of the thin tiles or panels, adhesive etc., as
documented in their respective technical specification (see Clause 5).
The criterion of performance is the following:
“The performance level of the material selected should not be lower than the expected demands of the
end-use environment as communicated by the project owner.”
6.3.2 Criterion of compatibility
The criterion of compatibility is the following: “the materials selected should be reciprocally compatible.”
The information on compatibility or possible incompatibilities is usually found in the technical
specification or informative documentation supplied by the manufacturer. (For example, some thin
tiles and panels are only suitable for walls and some adhesives are designed for particular types of
background materials.)
6.3.3 Criterion of safety
The criterion of safety is the following:
“The materials selected should be selected considering their safe use and meet local building
code regulations for safety, understanding that individual use and owner maintenance also affect
individual safety.”
EXAMPLE In external walls, the use of thin tiles of a suitable type and size can be specified taking into
account the fixing system, which for large format thin tiles and panels might need to be mechanical.
6.3.4 Adhesives
The specification of the adhesives should be considered according to the above criteria, taking into
account the relevant project data (see 6.2): installation location and working conditions, backgrounds
and, finally, the specified thin tile or panels.
The following indications are reported as an example of guidelines for the specification of the adhesives
for thin tiles and panels installation. Always seek the advice of the tile and adhesive manufacturers
before selecting a suitable tile adhesive.
Typically, for cementitious backgrounds, e.g. mature cement:sand render or cement:sand screed and
existing stable backgrounds, i.e. natural stone, agglomerated stone, ceramics, etc., C2S1 adhesive
(see ISO 13007-1) is suitable for the installation of thin ceramic tiles, or, for walls, C2ES2 and C2FES2
adhesives are suitable for large format thin ceramic tiles or thin ceramic panels.
These adhesives may also be suitable for installing thin ceramic tiles and panels onto dry and stable
gypsum based backgrounds, i.e. gypsum plaster or calcium sulfate screeds subject to appropriate
preparation of the backgrounds and the application of a suitable primer.
R2 adhesive (see ISO 13007-1) may also be appropriate for use on these and other suitable backgrounds.
The choice of a notched trowel which is suitable for the application of adhesive beds depends on the
type of installation, the tolerance in the background, the size of the tile, and the type of adhesive. The
objective being to achieve solid bedding.
For all internal wall tiling with large format thin ceramic tiles and thin ceramic panels and for thin
ceramic tiles which are expected to be exposed to thermal or damp conditions, the adoption of the
floating and buttering method is advisable. For external wall tiling with large format thin tiles and thin
panels, mechanical fixing should be considered.
Where large format thin porcelain tiles or panels are installed onto impervious backgrounds, e.g.
existing porcelain or glazed tiling or plastic decoupling systems, etc., some cement based adhesive
bedding materials may remain wet, underneath the thin porcelain tiles or panels for a considerable
period of time, possibly weeks because any “free water” in the adhesive is not able to be absorbed into
either the impervious background or through the impervious porcelain large format tiles or panels.
Usually, this should not significantly affect the adhesion or the hardening characteristics of most
proprietary manufactured rapid drying cementitious adhesive bedding systems, but some slow drying
cement based adhesives which cannot dry out properly may also remain “soft”, which will adversely
affect the adhesion properties of the adhesive and the stability/durability of the tiling.
6.4 Specification of the thin tiling
6.4.1 Thin tiling system
Thin tiling systems can be classified essentially according to:
— the type of thin ceramic tile or thin ceramic panel,
— the type of adhesive,
— the need of specified layer(s) under the thin tile bed,
— the mechanical fixing,
examples of additional layers: screed, reinforced screed; levelling out layer; levelling layer;
separating layer; etc.( see 3.2),
— the method of application of the bedding (see 3.3):
— floating method;
— buttering method;
— floating and buttering method;
— unbonded method – floors (de-coupling systems).
The choice of the thin tiling system should take into consideration the performance characteristics of
the thin ceramic tiles or thin ceramic panels, the characteristics of the background, and the expected
end-use environment as communicated by the project owner.
6.4.2 Thin tile joints
Thin tiles and panels should be positioned with regular straight joints, the width of which should be
specified taking into account the thickness, size, and dimensional tolerances of the thin tiles or panels,
the characteristics of the background, the installation method and the expected end-use of the thin
tiling, and anticipated loads likely to be imposed. There should be sufficient joint space between the
thin ceramic tiles or panels for grout to penetrate to the full depth of the joint. Thin ceramic tiles and
panels should not be butt jointed. Joints between thin ceramic panels should increase in width pro-
rata to panel size so that for, e.g. 3-m-long thin ceramic panels, the recommended minimum joint width
between 3 m panels should be 5 mm.
Inevitably, when solidly bedding thin tiles and panels into the adhesive bedding, much of the shallow
joint between the thin tiles/panels will become partially filled with residual adhesive which should, as
12 © ISO 2015 – All rights reserved

far as is practicable, be removed from the joints in order to provide adequate joint depth and volume to
receive the specified tile grout. Failure to do this can result in unsightly grout and reduced performance.
The joints between thin ceramic tiles and panels are usually the most vulnerable points of a thin tiling
installation — thin tile edges may be less resistant to static, dynamic and impact loads, than the edges
of thicker tiles. Therefore, the grout can be specified taking into account both the need of protecting
thin tile edges and the destination environment as communicated by the project owner. Grout should be
well compacted into the tile/panel joints and finished as flush as is practicable with the surface of the
thin tiles/panels.
NOTE In the specification of the grouts, the relevant information/instruction of the manufacturer can be
considered. Grouts classified as CG2 (see ISO 13007-3) or reaction resin based may be considered.
6.4.3 Movement joints
NOTE Thin ceramic tiles and thin ceramic panels (porcelain) have similar coefficient of thermal expansion
characteristics to porcelain as defined in ISO 13006.
The effect of thermal expansion/contraction on smaller format thin tiles, e.g. 200 mm × 200 mm is
relatively insignificant across a temperature range which could be reasonably anticipated (depending
upon area of usage, see 6.2.1). This is because the minimal expansion/contraction of the thin tile is, to
some degree “cushioned” by the grout joints between each tile, because the compressive strength of a
proprietary cement-based tile grout, e.g. CG2 (see ISO 13007-3) is lower than the compressive strength
of porcelain.
For larger format thin tiles and panels, any thermal expansion/contraction is cumulative across the
area of the thin tile or panel so that, for a ceramic panel, e.g. 3 m long, the expansion of the panel across
a temperature range of 30 °C equates to approximately 0,65 mm which, as a percentage of a 5-mm-wide
joint between adjacent panels, equates to an approximately 12,5 % compaction/expansion requirement
of the joint grouting mortar, as well as a significant lateral deformation capacity of the panel bedding
adhesive; depending upon any corresponding temperature change within the background structure
onto which the panels are installed.
Usually in normal environments, the temperature of the tiling layer and its background (internal tiling)
may not vary from each other to such extremes, but where thin tiles and panels, particularly dark coloured
ones are installed externally or in areas subject to intense direct sunlight, e.g. sun rooms, conservatories,
atria, etc., the thin tiling layer can heat up and cool very quickly while the background may not.
Conversely, any significant drying shrinkage of the background which continues after thin tiles or
panels have been installed directly onto it may result in the build-up of lateral stresses within the tiling
system. The larger the size of thin tile or panels, the greater is the degree of “stress” that will develop.
Failure in the form of fracturing of the thin tiles/panels, or debonding of the tiles/panels from the
background can result.
Consideration should be given at the design stage to the provision of movement joints (structural
joints, perimeter joints, intermediate joints). The specification for the movement joint should include
information on type, materials, construction, dimensions (width and depth), and position.
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