CEN/TR 15124:2005

SLOVENSKI STANDARD
01-september-2005
1DþUWRYDQMHSULSUDYDLQXSRUDEDQRWUDQMLKPDYþQLKRPHWRY
Design, preparation and application of internal gypsum plastering systems
Planung, Zubereitung und Ausführung von Gips-Innenputzsystemen
Ta slovenski standard je istoveten z: CEN/TR 15124:2005
ICS:
91.100.10 Cement. Mavec. Apno. Malta Cement. Gypsum. Lime.
Mortar
91.180 1RWUDQMD]DNOMXþQDGHOD Interior finishing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15124
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
June 2005
ICS 91.100.10; 91.180
English version
Design, preparation and application of internal gypsum
plastering systems
Planung, Zubereitung und Ausführung von
Gipsinnenputzsystemen
This Technical Report was approved by CEN on 13 May 2005. It has been drawn up by the Technical Committee CEN/TC 125.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15124:2005: E
worldwide for CEN national Members.

Contents
Page
Foreword. 3
1 Scope. 4
2 Terms and definitions . 4
3 Materials and accessories . 5
4 Design - factors influencing the selection of gypsum plastering systems. 6
5 Characteristics of gypsum plastering systems.8
6 Types and standards of plaster finish . 13
7 Application. 14
Annex A (informative) Fixing applied backgrounds . 16
Bibliography . 19

Foreword
This document (CEN/TR 15124:2005) has been prepared by Technical Committee CEN/TC 125
"Masonry", the secretariat of which is held by BSI.
The initial draft of this document was prepared by the European section of International Union of
Contractors of Plastering, Dry Lining, Stucco and Related Activities (UIEP) at the request of the
CEN Technical Sector Board (Resolution No.BTS1/56/1991). It has been revised by
CEN/TC125/JWG5 in conjunction with CEN/TC241 using a document prepared by Eurogypsum. The
CEN technical report gives in different sections guidance for building details, design and materials
considerations, the selection of mixes and the application of gypsum plasters. Relevant data are
summarized in a series of tables. This document applies to gypsum plasters conforming to prEN
13279-1, applied as an internal plaster The recommendations are framed in logical sequence, namely
materials and accessories; properties of backgrounds that influence the choice of suitable gypsum
plastering systems; guidance on preparation of surfaces to be plastered; choice of suitable gypsum
plastering systems; methods of application. It is essential that the design clauses are read in
conjunction with the clauses on background and preparation.
It is not the function of this document to assign responsibility for the design and application of any
work or actions mentioned within to any specific party. Such responsibility is a matter for other
documentation associated with the work, e.g. the contract.
It has been assumed in the drafting of this document that the application of its provisions is entrusted
to appropriately qualified and experienced people, for whose guidance it has been prepared.
This TR should be read in conjunction with EN 13914-2.
The following similar Technical Reports are also available:-
CEN/TR 15123:2005 Design, preparation and application of internal polymer plastering systems
CEN/TR 15125:2005 Design, preparation and application of internal cement and/or lime
plastering systems.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Report: Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

1 Scope
This document concerns the design, preparation and application of plaster based on gypsum, for
internal plastering on all types of background used under normal conditions. It includes plastering
onto both new and old backgrounds and the maintenance and repair of existing work. It concerns
materials, backgrounds, preparation of the surface to be plastered, choice of suitable gypsum
plastering system, methods of application and inspection and testing of plastering.
Gypsum plastering mixes with special properties intended to enhance thermal insulation, fire
resistance, acoustic insulation and to increase radiation absorption are also covered.
Because of the many and varied materials and practices in Europe it is not possible for certain
aspects of the standard to enter into sufficient detail to be fully usable to practitioners in each country.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
gypsum building plaster
plaster consisting of at least 50 % gypsum binder as the principle active binding component. Additives
and aggregates may be added by the manufacturer
2.2
gypsum plaster coat
obtained by application of one or more layers with one or more mixes of the same product
2.3
gypsum plaster layers
gypsum plaster applied wet on wet to obtain the final thickness with one or more mixes of the same
product, when all operations are completed before the gypsum plaster has set
2.4
gypsum plaster multi-coat
plaster system using a sequence of plaster coats to achieve the required thickness when all
operations are completed after the gypsum plaster has set but not dry. A mechanical key is required
between each coat
2.5
gypsum plastering system
gypsum plaster coat or sequence of gypsum plaster coats to be applied to a background, including
the possible use of a support and/or reinforcement and/or pre-treatment
2.6
one coat gypsum plaster
gypsum plaster applied in one coat which fulfils all the functions of an undercoat and a final coat
2.7
gypsum multi-coat plastering system
gypsum plaster coat or sequences of gypsum plaster coats (see 2.8 and 2.9)
2.8
gypsum undercoat
lower plaster coat(s) of a plastering system which needs a final coat

2.9
gypsum final coat
last gypsum plaster coat of a multi-coat plastering system
2.10
key
roughness of a surface which enables plaster to make a bond with it
2.11
background
surface of a construction element to which a plastering system is to be applied
2.12
reinforcement
material incorporated within a plaster coat to improve resistance to cracking (e.g. mesh)
2.13
support
product attached to the background to which a plaster is applied so that the plastering system is
largely independent of the background (e.g. lathing)
2.14
efflorescence
formation of crystals on a surface during drying caused by the presence of soluble salts
3 Materials and accessories
3.1 Gypsum binders and Gypsum plasters
Gypsum binders and gypsum plasters should conform to prEN 13279-1.
NOTE Building lime should conform to the requirements of EN 459-1.
3.2 Aggregates
Aggregates should conform to the requirements of EN 13139 or EN 13055-1 as appropriate. Other
aggregates may be used which do not exert a harmful influence on the gypsum plaster.
3.3 Bonding agents
Only bonding agents with a proven performance should be used. With all bonding agents it is
essential that the manufacturer’s instructions should be precisely followed.
3.4 Pigments
Pigments should conform to the requirements of EN 12878. Other pigments should be used only if
they are known to be satisfactory. For both, the manufacturer’s instructions should be strictly followed.
3.5 Fibres
Fibres may be used in specialized applications such as restoration work, sprayed gypsum plasterings
and gypsum plasterings on lathing or insulation board.
The fibres should not adversely affect the chemical or physical stability of the plaster and they should
be compatible with the gypsum plaster.
3.6 Water
The water should be of a quality such that it does not adversely affect the plaster.
Water fit for drinking is suitable for mixes for plastering
NOTE Attention is drawn to the requirements of EN 1008 in cases where water supplies may be of doubtful
quality.
3.7 Reinforcement, lathing and beads
Metal lathing, reinforcement and beads of whatever type, should conform to EN 13658-1 Metal lath
and beads – Definitions requirements and test methods – Part 1: internal plastering.
3.8 Fixings
Fixings for lathing and beads such as nails, screws, staples and steel wire should be made of
compatible material and should conform to EN 10223-3, EN 10230-1, EN 10244-1 or EN 10244-2.
3.9 Firrings
Firrings should consist of protected or stainless steel channels, rods, steel wire or timber.
Firrings should be of sufficient size so that the lathing and the gypsum plaster applied to the lathing is
held rigidly.
Firrings made of timber should have been given a preservative treatment.
4 Design - factors influencing the selection of gypsum plastering systems
4.1 Functions and properties that may be required
The function and properties achievable are determined by the choice of gypsum binder and gypsum
plaster type.
A gypsum plastering system will need to fulfil some of the following functions or properties:
 to even out any small unevenness in the background and provide a flat surface (see Table 2);
 to provide a decorative finish or a background for such a finish;
 to be vapour permeable;
 to have a fire reaction conforming with a local requirement;
 to have enhanced strength;
 to have enhanced resistance to abrasion.
Special plasters can provide enhanced properties for the following aspects:
 to improve the fire resistance of a building element (see 5.2);
 to improve the thermal properties of a building element (see 5.3);
 to improve the acoustic properties of a building element (see 5.4);
 to enhance the protection against radiation .
4.2 Factors influencing the choice of gypsum plaster type or systems
The designer should consider all functional and aesthetic aspects of the building.
The choice of gypsum plaster(s) or gypsum plaster system is determined principally by:
a) type of building (private houses, buildings); purpose of building (flat, school, hospital, office); uses
(for example: wet room);
b) the characteristics of the background;
c) the ambient and operating conditions;
d) the traditional usage in any particular area;
e) the type of finish required.
4.3 Background
Consideration should be given to the compatibility between the gypsum plastering system and the
background. To achieve this compatibility, the following items should be considered:
a) The background should provide adequate support: strength, rigidity and adequate key and
suction for the adhesion of the gypsum plaster.
b) Masonry should conform to the requirements of ENV 1996-2.
c) Boards, slabs and polystyrene should be fixed securely and should only be plastered when they
are dry and dimensionally stable.
d) It is important to avoid:
1) movement of the background, including structural, moisture and thermal movements;
2) defects in the background, e.g. lack of adequate key, weakness, contamination.
3) inadequate suction control;
4) efflorescence
Such compatibility is necessary to avoid bond failure between successive coats or between the first
gypsum plaster coat and the background.
If any of these inadequate characteristics of the background exist, then other means of providing
support and/or additional adhesion should be used.
If it is necessary to plaster over an existing substrate, ensure that it will have sufficient bond strength
to support and provide adhesion for the new plaster. For most plaster types adhesion is provided by
key and suction from the background.
Care should be taken in the following circumstances:
 high and/or variable suction: when the suction is high a pre-treatment incorporating a primer
agent should be used;
 low key and suction: when the key and suction of a background is insufficient, then a pre-
treatment incorporating a bonding agent should be used.
Where a gypsum plaster coat is applied to cement or cement lime background, it is important that the
entire substrate is mature, clean and dry and a proper key provided, otherwise difficulty with
decoration due to the migration of alkalis may be experience
...