The different parts of the EN 13914 series of standards specify requirements and recommendations for detailing, design and material considerations, the selection of mixes and the applica
Trang 1Design, preparation and application of external rendering and internal plastering
Part 2: Internal plastering
BSI Standards Publication
Trang 2This British Standard is the UK implementation of EN 13914-2:2016 It supersedes BS EN 13914-2:2005 which is withdrawn.
The UK participation in its preparation was entrusted to Technical Committee B/519, Masonry and associated testing.
A list of organizations represented on this committee can be obtained
on request to its secretary.
National Annex NA provides additional information and guidance from the UK committee.
This publication does not purport to include all the necessary provisions
of a contract Users are responsible for its correct application.
© The British Standards Institution 2017
Published by BSI Standards Limited 2017 ISBN 978 0 580 98043 5
Amendments/corrigenda issued since publication
31 March 2017 National Annex NA added
Trang 3NORME EUROPÉENNE
English Version
Design, preparation and application of external rendering
and internal plastering - Part 2: Internal plastering
Conception, préparation et mise en oeuvre des enduits
extérieurs et intérieurs - Partie 2: Enduits intérieurs Planung, Zubereitung und Ausführung von Außen- und Innenputzen - Teil 2: Innenputze
This European Standard was approved by CEN on 2 January 2016
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member
This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom
EUROPEAN COMMITTEE FOR STANDARDIZATION
C OMITÉ E URO PÉEN DE N ORMA LI SA TIO N EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved
worldwide for CEN national Members Ref No EN 13914-2:2016 E
Trang 4Contents
PageEuropean foreword 3
1 Scope 4
2 Normative references 4
3 Terms and definitions 5
4 Materials and accessories 9
4.1 General 9
4.2 Factory-made and semi-finished factory-made plasters — properties 9
4.3 Materials for site-made plasters 10
4.4 Water 10
4.5 Reinforcement, carriers and beads 11
4.6 Fixings 12
4.7 Substructures 12
5 Essential principles and building programme 12
5.1 Essential principles 12
5.2 Building programme 13
6 Design 13
6.1 General 13
6.2 Factors influencing the plastering system 13
6.3 Durability 17
6.4 Thermal insulation 18
6.5 Acoustic properties 19
6.6 Plasters with enhanced resistance to soluble salts 19
6.7 Plasters with enhanced protection from x-ray radiation 19
6.8 Plastering system for decorative finish 19
6.9 Thickness of plaster coats on walls and ceilings 19
6.10 Types and standards of plaster finish 21
6.11 Air tightness 23
7 Preparation and application of plasters 24
7.1 Storage 24
7.2 Cleanliness and protection of the works 24
7.3 Considerations by the designer for application matters 24
7.4 Considerations by the applicator 25
8 Maintenance and repair (other than restoration) 27
8.1 General 27
8.2 Inspection 27
8.3 Efflorescence 27
8.4 Repairs to cracks 27
Annex A (normative) Design considerations for work and acceptance of smooth plaster finishes under aspects of lighting 29
Annex B (informative) Methods of minimizing the occurrence of cracks 31
Annex C (informative) Fixing applied backgrounds 32
Annex D (informative) Restoration of plasters 35
Bibliography 37
European foreword
This document (EN 13914-2:2016) has been prepared by Technical Committee CEN/TC 125 “Masonry”, the secretariat of which is held by BSI This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights This document supersedes EN 13914-2:2005 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/TC 125/WG 5 in conjunction with experts of CEN/TC 241 Relevant data are summarized in a series of tables This part of EN 13914 applies to the design of plaster made of mortars containing inorganic and organic binders and mineral aggregate1 ) which is applied to internal vertical and soffit surfaces of structures As this standard is a code-like document as opposed to the more conventional European product standard, it is appropriate to mention that, as with product standards, the use of the verbal form 'shall' denotes a requirement for which verification of compliance has to be able to be demonstrated Recommendations are denoted by the verbal form 'should' and should be followed unless there is a justifiable reason for not doing so It is not the function of this standard to assign responsibility for the design and application of any work or actions mentioned herein 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 persons, for whose guidance it has been prepared The content of CEN Technical Reports containing guidance relating to the design, preparation and application of plaster and plastering systems for gypsum (CEN/TR 15124), cement and/or lime (CEN/TR 15125) and polymer plasters (CEN/TR 15123) has been included According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom 1) The aggregate can be omitted from mortars made from gypsum plaster or anhydrite binders. Trang 5Contents
PageEuropean foreword 3
1 Scope 4
2 Normative references 4
3 Terms and definitions 5
4 Materials and accessories 9
4.1 General 9
4.2 Factory-made and semi-finished factory-made plasters — properties 9
4.3 Materials for site-made plasters 10
4.4 Water 10
4.5 Reinforcement, carriers and beads 11
4.6 Fixings 12
4.7 Substructures 12
5 Essential principles and building programme 12
5.1 Essential principles 12
5.2 Building programme 13
6 Design 13
6.1 General 13
6.2 Factors influencing the plastering system 13
6.3 Durability 17
6.4 Thermal insulation 18
6.5 Acoustic properties 19
6.6 Plasters with enhanced resistance to soluble salts 19
6.7 Plasters with enhanced protection from x-ray radiation 19
6.8 Plastering system for decorative finish 19
6.9 Thickness of plaster coats on walls and ceilings 19
6.10 Types and standards of plaster finish 21
6.11 Air tightness 23
7 Preparation and application of plasters 24
7.1 Storage 24
7.2 Cleanliness and protection of the works 24
7.3 Considerations by the designer for application matters 24
7.4 Considerations by the applicator 25
8 Maintenance and repair (other than restoration) 27
8.1 General 27
8.2 Inspection 27
8.3 Efflorescence 27
8.4 Repairs to cracks 27
Annex A (normative) Design considerations for work and acceptance of smooth plaster finishes under aspects of lighting 29
Annex B (informative) Methods of minimizing the occurrence of cracks 31
Annex C (informative) Fixing applied backgrounds 32
Annex D (informative) Restoration of plasters 35
Bibliography 37
European foreword
This document (EN 13914-2:2016) has been prepared by Technical Committee CEN/TC 125 “Masonry”, the secretariat of which is held by BSI
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights
This document supersedes EN 13914-2:2005
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/TC 125/WG 5 in conjunction with experts of CEN/TC 241 Relevant data are summarized in a series of tables This part
of EN 13914 applies to the design of plaster made of mortars containing inorganic and organic binders and mineral aggregate1 ) which is applied to internal vertical and soffit surfaces of structures
As this standard is a code-like document as opposed to the more conventional European product standard, it is appropriate to mention that, as with product standards, the use of the verbal form 'shall' denotes a requirement for which verification of compliance has to be able to be demonstrated Recommendations are denoted by the verbal form 'should' and should be followed unless there is a justifiable reason for not doing so
It is not the function of this standard to assign responsibility for the design and application of any work
or actions mentioned herein 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 persons, for whose guidance it has been prepared
The content of CEN Technical Reports containing guidance relating to the design, preparation and application of plaster and plastering systems for gypsum (CEN/TR 15124), cement and/or lime (CEN/TR 15125) and polymer plasters (CEN/TR 15123) has been included
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom
1) The aggregate can be omitted from mortars made from gypsum plaster or anhydrite binders.
Trang 61 Scope
This European Standard deals with the design considerations and essential principles for internal
plastering systems and application of plastering systems
The different parts of the EN 13914 series of standards specify requirements and recommendations for
detailing, design and material considerations, the selection of mixes and the application of gypsum
plasters, gypsum/lime plasters, lightweight plasters, lime/gypsum-, cement- and cement/lime-based
plasters, lime-based plasters, clay plasters, silicate plasters, organic plasters, polymer-modified plasters,
— structural repair of concrete;
— prefabricated fibre-reinforced plaster elements
Owing to the many and varied materials and practices and different climatic conditions 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 Such guidance to complement, but not alter, any basic European
recommendations is given in documentation prepared by each country Aspects of this European
Standard, the basic recommendations of which may need to be complemented, are indicated where they
occur by a footnote referencing this clause
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
EN 197-1, Cement — Part 1: Composition, specifications and conformity criteria for common cements
EN 413-1, Masonry cement — Part 1: Composition, specifications and conformity criteria
EN 459-1, Building lime — Part 1: Definitions, specifications and conformity criteria
EN 998-1:2010, Specification for mortar for masonry — Part 1: Rendering and plastering mortar
EN 1008, Mixing water for concrete — Specification for sampling, testing and assessing the suitability of
water, including water recovered from processes in the concrete industry, as mixing water for concrete
EN 10088-1, Stainless steels — Part 1: List of stainless steels
EN 10244-1, Steel wire and wire products — Non-ferrous metallic coatings on steel wire — Part 1:
General principles
EN 10244-2, Steel wire and wire products — Non-ferrous metallic coatings on steel wire — Part 2: Zinc or
zinc alloy coatings
EN 10346, Continuously hot-dip coated steel flat products for cold forming — Technical delivery conditions
EN 12878, Pigments for the colouring of building materials based on cement and/or lime — Specifications and methods of test
EN 13055-1, Lightweight aggregates — Part 1: Lightweight aggregates for concrete, mortar and grout
EN 13139, Aggregates for mortar
EN 13279-1, Gypsum binders and gypsum plasters — Part 1: Definitions and requirements
EN 13658-1, Metal lath and beads — Definitions, requirements and test methods — Part 1: Internal plastering
EN 13914-1:2016, Design, preparation and application of external rendering and internal plastering — Part 1: External rendering
EN 15824, Specifications for external renders and internal plasters based on organic binders
EN ISO 16120-2, Non-alloy steel wire rod for conversion to wire — Part 2: Specific requirements for general-purpose wire rod (ISO 16120-2)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 998-1, EN 13279-1,
EN 13914-1, EN 13658-1, EN 15824 and the following apply
3.1 plaster (noun)
mixture of different materials (binders, additives, admixtures, water, aggregates) to obtain a surface finish which is applied internally to walls and ceilings
3.2 plastering (verb)
application of plaster
3.3 gypsum plaster
all kinds of gypsum building plaster, gypsum based building plaster and gypsum-lime building plaster used in buildings
[SOURCE: EN 13279-1:2008, 3.2]
3.4 mineral based plaster
plaster with one or more inorganic binders
3.5 organic plaster
factory made plaster with one or more organic binders in paste or powder form
Trang 71 Scope
This European Standard deals with the design considerations and essential principles for internal
plastering systems and application of plastering systems
The different parts of the EN 13914 series of standards specify requirements and recommendations for
detailing, design and material considerations, the selection of mixes and the application of gypsum
plasters, gypsum/lime plasters, lightweight plasters, lime/gypsum-, cement- and cement/lime-based
plasters, lime-based plasters, clay plasters, silicate plasters, organic plasters, polymer-modified plasters,
— structural repair of concrete;
— prefabricated fibre-reinforced plaster elements
Owing to the many and varied materials and practices and different climatic conditions 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 Such guidance to complement, but not alter, any basic European
recommendations is given in documentation prepared by each country Aspects of this European
Standard, the basic recommendations of which may need to be complemented, are indicated where they
occur by a footnote referencing this clause
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
EN 197-1, Cement — Part 1: Composition, specifications and conformity criteria for common cements
EN 413-1, Masonry cement — Part 1: Composition, specifications and conformity criteria
EN 459-1, Building lime — Part 1: Definitions, specifications and conformity criteria
EN 998-1:2010, Specification for mortar for masonry — Part 1: Rendering and plastering mortar
EN 1008, Mixing water for concrete — Specification for sampling, testing and assessing the suitability of
water, including water recovered from processes in the concrete industry, as mixing water for concrete
EN 10088-1, Stainless steels — Part 1: List of stainless steels
EN 10244-1, Steel wire and wire products — Non-ferrous metallic coatings on steel wire — Part 1:
General principles
EN 10244-2, Steel wire and wire products — Non-ferrous metallic coatings on steel wire — Part 2: Zinc or
zinc alloy coatings
EN 10346, Continuously hot-dip coated steel flat products for cold forming — Technical delivery conditions
EN 12878, Pigments for the colouring of building materials based on cement and/or lime — Specifications and methods of test
EN 13055-1, Lightweight aggregates — Part 1: Lightweight aggregates for concrete, mortar and grout
EN 13139, Aggregates for mortar
EN 13279-1, Gypsum binders and gypsum plasters — Part 1: Definitions and requirements
EN 13658-1, Metal lath and beads — Definitions, requirements and test methods — Part 1: Internal plastering
EN 13914-1:2016, Design, preparation and application of external rendering and internal plastering — Part 1: External rendering
EN 15824, Specifications for external renders and internal plasters based on organic binders
EN ISO 16120-2, Non-alloy steel wire rod for conversion to wire — Part 2: Specific requirements for general-purpose wire rod (ISO 16120-2)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 998-1, EN 13279-1,
EN 13914-1, EN 13658-1, EN 15824 and the following apply
3.1 plaster (noun)
mixture of different materials (binders, additives, admixtures, water, aggregates) to obtain a surface finish which is applied internally to walls and ceilings
3.2 plastering (verb)
application of plaster
3.3 gypsum plaster
all kinds of gypsum building plaster, gypsum based building plaster and gypsum-lime building plaster used in buildings
[SOURCE: EN 13279-1:2008, 3.2]
3.4 mineral based plaster
plaster with one or more inorganic binders
3.5 organic plaster
factory made plaster with one or more organic binders in paste or powder form
Trang 83.6
designed plaster
plaster whose composition and manufacturing method is chosen by the producer in order to achieve
specified properties (performance concept)
[SOURCE: EN 998-1:2010, 3.3.1, modified]
3.7
prescribed plaster
plaster made in pre-determined proportions, the properties of which are assumed from the stated
proportion of the constituents (recipe concept)
plaster coat or sequence of plaster coats to be applied to a background, including the possible use of a
support and/or reinforcement and/or pre-treatment
3.11
site made plaster
plaster batched and mixed on site
3.12
one coat plaster
plaster applied in one coat which fulfils all the functions of a plastering system
material incorporated within a plaster coat to improve resistance to cracking (e.g welded wire mesh,
glass fibre mesh, fibres)
[SOURCE: EN 13914-1:2016, 3.17, modified]
3.16
reinforcing coat
polymer modified, mineral or organic plaster layer with a mesh embedded into it and applied over an
undercoat or defective background which contributes to the minimising of cracks
[SOURCE: EN 13914-1:2016, 3.18, modified]
3.17 final coat
last coat, decorative or not, of a plaster system [SOURCE: EN 13914-1:2016, 3.19, modified]
3.18 background
surface of a construction element to which a plaster or a plaster system is to be applied [SOURCE: EN 13914-1:2016, 3.22, modified]
3.19 preparatory treatment
actions to be taken on backgrounds with devices, machines and/or tools, to remove dust and unstable
or deleterious material e.g efflorescence [SOURCE: EN 13914-1:2016, 3.23]
3.20 key
property of a background or plaster coat which allows the bonding of a plaster without the need for a pre-treatment or carrier
[SOURCE: EN 13914-1:2016, 3.24, modified]
3.21 pre-treatment
application of a material on the background to improve the application properties of the plaster (e.g spatterdash, primer, bonding agent)
[SOURCE: EN 13914-1:2016, 3.25, modified]
3.22 bond
mechanical and/or chemical adhesion between the plaster and the background [SOURCE: EN 13914-1:2016, 3.26, modified]
3.23 bonding agent
proprietary material used to provide or improve adhesion of the plaster or plaster system to the background where necessary
[SOURCE: EN 13914-1:2016, 3.27, modified]
3.24 primer
material for pre-treatment of the background Note 1 to entry: For example primers can be used to reduce suction or to stabilize the surface of the background
Trang 93.6
designed plaster
plaster whose composition and manufacturing method is chosen by the producer in order to achieve
specified properties (performance concept)
[SOURCE: EN 998-1:2010, 3.3.1, modified]
3.7
prescribed plaster
plaster made in pre-determined proportions, the properties of which are assumed from the stated
proportion of the constituents (recipe concept)
plaster coat or sequence of plaster coats to be applied to a background, including the possible use of a
support and/or reinforcement and/or pre-treatment
3.11
site made plaster
plaster batched and mixed on site
3.12
one coat plaster
plaster applied in one coat which fulfils all the functions of a plastering system
material incorporated within a plaster coat to improve resistance to cracking (e.g welded wire mesh,
glass fibre mesh, fibres)
[SOURCE: EN 13914-1:2016, 3.17, modified]
3.16
reinforcing coat
polymer modified, mineral or organic plaster layer with a mesh embedded into it and applied over an
undercoat or defective background which contributes to the minimising of cracks
[SOURCE: EN 13914-1:2016, 3.18, modified]
3.17 final coat
last coat, decorative or not, of a plaster system [SOURCE: EN 13914-1:2016, 3.19, modified]
3.18 background
surface of a construction element to which a plaster or a plaster system is to be applied [SOURCE: EN 13914-1:2016, 3.22, modified]
3.19 preparatory treatment
actions to be taken on backgrounds with devices, machines and/or tools, to remove dust and unstable
or deleterious material e.g efflorescence [SOURCE: EN 13914-1:2016, 3.23]
3.20 key
property of a background or plaster coat which allows the bonding of a plaster without the need for a pre-treatment or carrier
[SOURCE: EN 13914-1:2016, 3.24, modified]
3.21 pre-treatment
application of a material on the background to improve the application properties of the plaster (e.g spatterdash, primer, bonding agent)
[SOURCE: EN 13914-1:2016, 3.25, modified]
3.22 bond
mechanical and/or chemical adhesion between the plaster and the background [SOURCE: EN 13914-1:2016, 3.26, modified]
3.23 bonding agent
proprietary material used to provide or improve adhesion of the plaster or plaster system to the background where necessary
[SOURCE: EN 13914-1:2016, 3.27, modified]
3.24 primer
material for pre-treatment of the background Note 1 to entry: For example primers can be used to reduce suction or to stabilize the surface of the background
Trang 10[SOURCE: EN 13914-1:2016, 3.28]
3.25
spatterdash
technique for pre-treatment characterized by brushing, throwing or spraying of site or factory made
mortar onto a background to improve its bonding properties and/or to regulate the suction of the
background
[SOURCE: EN 13914-1:2016, 3.29]
3.26
dubbing out
process of filling large localized irregularities in the background, such as hollows, prior to the
application of a plaster coat
[SOURCE: EN 13914-1:2016, 3.30, modified]
3.27
carrier
product attached to the background to which a plaster is applied so that the plaster system is largely
independent of the background (e.g lathing)
[SOURCE: EN 13914-1:2016, 3.31, modified]
3.28
crazing
network of short, irregular and very fine cracks up to approximately 0,2 mm in width
Note 1 to entry: Hairline cracks do not impair the function of the plaster and are therefore acceptable to a limited
Plasters can be produced entirely in the factory, partly in the factory (semi-finished) or on site
4.2 Factory-made and semi-finished factory-made plasters — properties
4.2.1 General
Factory-made and semi-finished factory-made plasters shall comply with the requirements of EN 998-1,
EN 13279-1 or EN 15824 for those parts of the process either wholly or partly carried out in the factory, unless otherwise specified by the manufacturer For those parts of the process for semi-finished factory-made plasters completed on site, only materials permitted by the manufacturer shall be used
No addition of any material is permitted for wet ready-to-use plasters Unless otherwise specified by the manufacturer, no addition, other than water in the recommended proportions, shall be added to dry factory-made plasters Only materials conforming to the requirements of 4.3 should be used
4.2.3 Lime, cement and lime/cement plasters
For mixtures based on cement and/or lime, factory-made and semi-finished factory-made plasters shall conform to EN 998-1 for those parts of the process either wholly or partly carried out in the factory For those parts of the process for semi-finished factory-made plasters completed on site, the materials should conform to the recommendations of 4.3
Depending on the materials of the plaster mix shrinkage may take place during the drying out process Cement and/or lime undercoats should be sufficiently roughened to provide a key for subsequent coats Each undercoat should be allowed to harden before applying the subsequent coat
These plasters can also be polymer-modified
4.2.4 Plasters based on organic binders
These plasters harden essentially by physical drying; they shall comply with EN 15824
The adhesion to different dry backgrounds including paints is usually sufficient
Trang 11[SOURCE: EN 13914-1:2016, 3.28]
3.25
spatterdash
technique for pre-treatment characterized by brushing, throwing or spraying of site or factory made
mortar onto a background to improve its bonding properties and/or to regulate the suction of the
background
[SOURCE: EN 13914-1:2016, 3.29]
3.26
dubbing out
process of filling large localized irregularities in the background, such as hollows, prior to the
application of a plaster coat
[SOURCE: EN 13914-1:2016, 3.30, modified]
3.27
carrier
product attached to the background to which a plaster is applied so that the plaster system is largely
independent of the background (e.g lathing)
[SOURCE: EN 13914-1:2016, 3.31, modified]
3.28
crazing
network of short, irregular and very fine cracks up to approximately 0,2 mm in width
Note 1 to entry: Hairline cracks do not impair the function of the plaster and are therefore acceptable to a limited
Plasters can be produced entirely in the factory, partly in the factory (semi-finished) or on site
4.2 Factory-made and semi-finished factory-made plasters — properties
4.2.1 General
Factory-made and semi-finished factory-made plasters shall comply with the requirements of EN 998-1,
EN 13279-1 or EN 15824 for those parts of the process either wholly or partly carried out in the factory, unless otherwise specified by the manufacturer For those parts of the process for semi-finished factory-made plasters completed on site, only materials permitted by the manufacturer shall be used
No addition of any material is permitted for wet ready-to-use plasters Unless otherwise specified by the manufacturer, no addition, other than water in the recommended proportions, shall be added to dry factory-made plasters Only materials conforming to the requirements of 4.3 should be used
4.2.3 Lime, cement and lime/cement plasters
For mixtures based on cement and/or lime, factory-made and semi-finished factory-made plasters shall conform to EN 998-1 for those parts of the process either wholly or partly carried out in the factory For those parts of the process for semi-finished factory-made plasters completed on site, the materials should conform to the recommendations of 4.3
Depending on the materials of the plaster mix shrinkage may take place during the drying out process Cement and/or lime undercoats should be sufficiently roughened to provide a key for subsequent coats Each undercoat should be allowed to harden before applying the subsequent coat
These plasters can also be polymer-modified
4.2.4 Plasters based on organic binders
These plasters harden essentially by physical drying; they shall comply with EN 15824
The adhesion to different dry backgrounds including paints is usually sufficient
Trang 12They need to be used in accordance with the manufacturer's recommendation or with any relevant
national regulations
4.3 Materials for site-made plasters
4.3.1 General
Constituent materials with established suitability shall be used, as detailed in 4.3.2 to 4.3.5 Mix
proportions, if applicable, are given in national standards
4.3.2 Mineral binders
Mineral binders with established suitability shall be used Binders shall conform to the relevant
standards listed in Table 1
Table 1 — Mineral binders
suitable for each and every application a
Masonry cements EN 413-1 Building lime EN 459-1 Gypsum binder EN 13279-1
a Refer to final paragraph of Clause 1 for further information
4.3.3 Aggregates
Aggregates shall conform to EN 13139 for dense aggregates or EN 13055-1 for light aggregates, as
appropriate
4.3.4 Admixtures for cement- and/or lime-based plasters
The admixtures used should conform to EN 934-3 However, admixtures falling outside the scope of
EN 934-3 can be used in accordance with the manufacturer's instructions
4.3.5 Colouring agents
Colouring agents (e.g inorganic and organic pigments or pigment preparations, dyes, natural minerals)
should not have any influence on the behaviour of the fresh or hardened render They shall be stable,
unaffected by alkalinity or exposure to light and shall not easily be leached out by water
The use of colouring agents on the construction site shall always be subject to prior tests
Pigments shall conform to EN 12878
A uniform shade of the finishing coat is not generally ensured
4.3.6 Fibres
Natural and synthetic fibres, that do not affect the chemical or physical stability of the plaster, may be
used either added on site or in premixed or factory made plasters
Fibres shall be dry, clean and free from oil or grease
4.4 Water
Water used for plasters shall fulfil the requirements of EN 1008 Drinking or potable water is suitable
4.5 Reinforcement, carriers and beads
Reinforcement, carriers and beads should conform to the recommendations given in Table 2
Plastic beads may be used if they comply with the manufacturer's recommendation
Table 2 — Materials for reinforcement, carriers and beads
Reinforcement Glass fibre mesh EN 13496 Alkali-resistant glass fibre mesh can be used
for all types of plaster The use of resistant glass fibre mesh is not suitable for products containing cement and/or lime
non-alkali-The minimum mesh size to be used should correspond to the type of plaster used (e.g
4 mm x 4 mm)
For plasters with a grain size of less than
1 mm the mesh size should be not less than 2,5 mm x 2,5 mm
Expanded metal (stainless steel or zinc- coated steel)
plain or profiled welded wire mesh (stainless steel or zinc coated)
EN 13658-1 Stainless steel in accordance to EN 10088-1
(austenitic steel) Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 The square mesh should be not less than
12 mm and not more than 50 mm with wires not less than 0,9 mm
Where the aggregate grain size exceeds 3 mm the use of a mesh larger than 15 mm should
be considered
(stainless steel or coated steel)
zinc-EN 13658-1 Profiled wire lath - in longitudinal direction
or evenly distributed indentations to provide rigidity and easy fixing to the background
Expanded metal (stainless steel or zinc- coated steel)
Stainless steel in accordance with
EN 10088-1 (austenitic steel) Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 Profiled welded wire
mesh (stainless steel or zinc- coated)
Beads (e.g corner beads)
Stainless steel and zinc coated steel EN 13658-1 Stainless steel in accordance with EN 10088-1 (austenitic steel)
Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 Plastic and plastic
Other products and/or techniques may be used and defined at national level a
a Refer to final paragraph of Clause 1 for further information
Trang 13They need to be used in accordance with the manufacturer's recommendation or with any relevant
national regulations
4.3 Materials for site-made plasters
4.3.1 General
Constituent materials with established suitability shall be used, as detailed in 4.3.2 to 4.3.5 Mix
proportions, if applicable, are given in national standards
4.3.2 Mineral binders
Mineral binders with established suitability shall be used Binders shall conform to the relevant
standards listed in Table 1
Table 1 — Mineral binders
suitable for each and every application a
Masonry cements EN 413-1 Building lime EN 459-1
4.3.4 Admixtures for cement- and/or lime-based plasters
The admixtures used should conform to EN 934-3 However, admixtures falling outside the scope of
EN 934-3 can be used in accordance with the manufacturer's instructions
4.3.5 Colouring agents
Colouring agents (e.g inorganic and organic pigments or pigment preparations, dyes, natural minerals)
should not have any influence on the behaviour of the fresh or hardened render They shall be stable,
unaffected by alkalinity or exposure to light and shall not easily be leached out by water
The use of colouring agents on the construction site shall always be subject to prior tests
Pigments shall conform to EN 12878
A uniform shade of the finishing coat is not generally ensured
4.3.6 Fibres
Natural and synthetic fibres, that do not affect the chemical or physical stability of the plaster, may be
used either added on site or in premixed or factory made plasters
Fibres shall be dry, clean and free from oil or grease
4.4 Water
Water used for plasters shall fulfil the requirements of EN 1008 Drinking or potable water is suitable
4.5 Reinforcement, carriers and beads
Reinforcement, carriers and beads should conform to the recommendations given in Table 2
Plastic beads may be used if they comply with the manufacturer's recommendation
Table 2 — Materials for reinforcement, carriers and beads
Reinforcement Glass fibre mesh EN 13496 Alkali-resistant glass fibre mesh can be used
for all types of plaster The use of resistant glass fibre mesh is not suitable for products containing cement and/or lime
non-alkali-The minimum mesh size to be used should correspond to the type of plaster used (e.g
4 mm x 4 mm)
For plasters with a grain size of less than
1 mm the mesh size should be not less than 2,5 mm x 2,5 mm
Expanded metal (stainless steel or zinc- coated steel)
plain or profiled welded wire mesh (stainless steel or zinc coated)
EN 13658-1 Stainless steel in accordance to EN 10088-1
(austenitic steel) Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 The square mesh should be not less than
12 mm and not more than 50 mm with wires not less than 0,9 mm
Where the aggregate grain size exceeds 3 mm the use of a mesh larger than 15 mm should
be considered
(stainless steel or coated steel)
zinc-EN 13658-1 Profiled wire lath - in longitudinal direction
or evenly distributed indentations to provide rigidity and easy fixing to the background
Expanded metal (stainless steel or zinc- coated steel)
Stainless steel in accordance with
EN 10088-1 (austenitic steel) Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 Profiled welded wire
mesh (stainless steel or zinc- coated)
Beads (e.g corner beads)
Stainless steel and zinc coated steel EN 13658-1 Stainless steel in accordance with EN 10088-1 (austenitic steel)
Zinc-coated steel in accordance with
EN ISO 16120-2 and EN 10346 Plastic and plastic
Other products and/or techniques may be used and defined at national level a
a Refer to final paragraph of Clause 1 for further information
Trang 14Metal lathing, reinforcement and beads of whatever type shall be suitable for internal use Careful
consideration should be given to the choice of the material for its use in typical applications in wet
areas, e.g commercial kitchens
Products made of special alloys such as coated zinc alloy shall be in accordance with EN 10346
4.6 Fixings
Consideration should be given to the corrosion resistance of beads fixed with mortar
It is recommended that mortar systems be used with the same binder system and not to mix e.g
gypsum with cement
If the beads, lathing or reinforcement are mechanically fixed with nails, screws or staples, attention
shall be given to the compatibility of the fixing with the bead, lathing or reinforcement
The fixings shall be in accordance with EN 10088-1 (austenitic steel) if stainless steel is used and with
EN ISO 16120-2, EN 10346, EN 10244-1 and EN 10244-2 if zinc-coated steel is used
4.7 Substructures
Substructures may consist of galvanized steel, stainless steel or timber The carrier is fixed to the
substructure in order to receive the plaster Substructures shall be of sufficient strength so that the
carrier and the plaster applied to the carrier are both held rigidly
5 Essential principles and building programme
5.1 Essential principles
The design shall include drawings and specifications, e.g quantities, prepared in detail to afford proper
guidance in the preparation of estimates and the execution of the work
Prior to the commencement of the contract there should be an exchange of information between all
parties concerned
When preparing plastering details the designer shall take into account the following points:
a) nature and condition of the background, including any necessary preparatory treatment or
pre-treatment;
b) functional requirements;
c) type of plaster and other materials to be used in the plastering system It is recommended that
these materials should conform to the appropriate documents where available and where not
available should conform to standards accepted in the place of use;
d) type of finish/appearance;
e) thickness required including:
1) the finished sizes and heights of rooms or other spaces;
2) details of the nature of the junctions with door frames, ceilings, linings etc.;
3) the positioning of installations and fittings;
4) any other situations which may affect the plaster thicknesses;
f) information about the different building surfaces to receive the various types of cornices, arises, corner treatments, metal accessories (such as angles and beads), expansion joints, etc.;
g) work of other trades, particularly in connection with service pipes, conduits, wiring etc that are to
be covered by or buried in the plaster;
h) compatibility of the plaster with adjacent materials
5.2 Building programme
In preparing a time schedule for the work involved in a building, each operation should be considered
in relation to the others
Agreement shall be reached between all parties on the programme times for all necessary operations and the correct sequence for carrying out these operations The programme should be kept up-to-date
as the project proceeds and damage by subsequent trades should be avoided
The following items shall be considered by those involved in planning the programme:
a) plastering should only commence in those parts of the building which are weather-tight;
b) time for the background to be completed and for all the preceding trades to be complete;
c) time for the background to be examined and to dry out;
d) background and air temperatures shall not fall below 5 °C, except for silicate plasters, which shall not be used below 8 °C (alternatively heating may be provided to maintain these temperatures); e) time for preparation of the background, application and drying out of each coat of plaster;
f) time for inspection and repair, if necessary;
g) time for the plaster to dry out prior to painting or other decoration;
h) avoidance of late changes/alterations
6 Design
6.1 General
This section gives general advice Where there are more detailed national regulations regarding design they shall take precedence
6.2 Factors influencing the plastering system
6.2.1 Design functions and properties of a plastering system
A plastering system should fulfil some of the following general functions or properties:
— to even out any small unevenness in the background and provide a smooth and flat surface (see Tables 5 and 6);
— to provide a decorative finish or a background for such a finish;
— to have sufficient strength;
— to provide an appropriate vapour permeability;
Trang 15Metal lathing, reinforcement and beads of whatever type shall be suitable for internal use Careful
consideration should be given to the choice of the material for its use in typical applications in wet
areas, e.g commercial kitchens
Products made of special alloys such as coated zinc alloy shall be in accordance with EN 10346
4.6 Fixings
Consideration should be given to the corrosion resistance of beads fixed with mortar
It is recommended that mortar systems be used with the same binder system and not to mix e.g
gypsum with cement
If the beads, lathing or reinforcement are mechanically fixed with nails, screws or staples, attention
shall be given to the compatibility of the fixing with the bead, lathing or reinforcement
The fixings shall be in accordance with EN 10088-1 (austenitic steel) if stainless steel is used and with
EN ISO 16120-2, EN 10346, EN 10244-1 and EN 10244-2 if zinc-coated steel is used
4.7 Substructures
Substructures may consist of galvanized steel, stainless steel or timber The carrier is fixed to the
substructure in order to receive the plaster Substructures shall be of sufficient strength so that the
carrier and the plaster applied to the carrier are both held rigidly
5 Essential principles and building programme
5.1 Essential principles
The design shall include drawings and specifications, e.g quantities, prepared in detail to afford proper
guidance in the preparation of estimates and the execution of the work
Prior to the commencement of the contract there should be an exchange of information between all
parties concerned
When preparing plastering details the designer shall take into account the following points:
a) nature and condition of the background, including any necessary preparatory treatment or
pre-treatment;
b) functional requirements;
c) type of plaster and other materials to be used in the plastering system It is recommended that
these materials should conform to the appropriate documents where available and where not
available should conform to standards accepted in the place of use;
d) type of finish/appearance;
e) thickness required including:
1) the finished sizes and heights of rooms or other spaces;
2) details of the nature of the junctions with door frames, ceilings, linings etc.;
3) the positioning of installations and fittings;
4) any other situations which may affect the plaster thicknesses;
f) information about the different building surfaces to receive the various types of cornices, arises, corner treatments, metal accessories (such as angles and beads), expansion joints, etc.;
g) work of other trades, particularly in connection with service pipes, conduits, wiring etc that are to
be covered by or buried in the plaster;
h) compatibility of the plaster with adjacent materials
5.2 Building programme
In preparing a time schedule for the work involved in a building, each operation should be considered
in relation to the others
Agreement shall be reached between all parties on the programme times for all necessary operations and the correct sequence for carrying out these operations The programme should be kept up-to-date
as the project proceeds and damage by subsequent trades should be avoided
The following items shall be considered by those involved in planning the programme:
a) plastering should only commence in those parts of the building which are weather-tight;
b) time for the background to be completed and for all the preceding trades to be complete;
c) time for the background to be examined and to dry out;
d) background and air temperatures shall not fall below 5 °C, except for silicate plasters, which shall not be used below 8 °C (alternatively heating may be provided to maintain these temperatures); e) time for preparation of the background, application and drying out of each coat of plaster;
f) time for inspection and repair, if necessary;
g) time for the plaster to dry out prior to painting or other decoration;
h) avoidance of late changes/alterations
6 Design
6.1 General
This section gives general advice Where there are more detailed national regulations regarding design they shall take precedence
6.2 Factors influencing the plastering system
6.2.1 Design functions and properties of a plastering system
A plastering system should fulfil some of the following general functions or properties:
— to even out any small unevenness in the background and provide a smooth and flat surface (see Tables 5 and 6);
— to provide a decorative finish or a background for such a finish;
— to have sufficient strength;
— to provide an appropriate vapour permeability;
Trang 16— to achieve adequate air tightness;
— to conform with local fire regulations
Special plasters can provide enhanced properties for the following aspects:
— to improve the thermal properties of a building element (see 6.4);
— to improve the acoustic properties of a building element (see 6.5);
— to improve the fire resistance of a building element;
— to enhance the protection against soluble salts and moisture (renovation plaster);
— to enhance the protection against high humidity;
— to improve protection against radiation (see 6.7);
— to improve the strength for coatings with high tensile stresses, heavy coverings (tiles), etc
6.2.2 Background characteristics as part of a plastering system
In deciding the system to be chosen consideration shall be given to whether the background provides
adequate support, strength, rigidity and adhesion
Other means of providing support and/or additional adhesion/pre-treatment shall be used if the
characteristics of the background mentioned above are inadequate
Difficulty in application can sometimes be experienced when plastering on high-suction backgrounds
due to rapid moisture loss from the plaster Special measures are required to remedy this problem (e.g
primer to reduce suction, spatterdash, additive, bonding agent)
The potential pre-treatment of the background is dependent on the suction behaviour of the surface, the
strength of the background and the plastering material specified Polymer-modified lime cement,
cement plasters and organic plasters usually have sufficient adhesion to most backgrounds to avoid the
need for any pre-treatment
In the case where heavy coverings, such as ceramic tiles, are to be used or thicker plasters are needed,
consideration should be given by the designer as to whether the bond strength and tensile strength of
the plaster in relation to the background is sufficient
General advice on whether the various types of background are likely to require the use of special
plasters, pre-treatments or additional support is given in Table 3
Table 3 — Summary of the measures to be taken prior to plastering on to various types of
backgrounds
1 Clay masonry A special pre-treatment of the background is normally not necessary
when the background demonstrates uniform normal suction.
2 Concrete and calcium silicate brick- or blockwork Depending on suction and bond; may require use of a spatterdash pre-treatment or bond with polymer-modified cement mortar or metal
lathing.
3 Lightweight clay blockwork The suction should be checked to ensure that it is similar to that of normal
clay bricks If not, special precautions may be necessary.
4 Lightweight blockwork:
lightweight aggregate concrete
Ordinary suction: no pre-treatment necessary High-suction: use a spatterdash treatment or metal lathing
5 Large lightweight concrete elements Special precautions in accordance with the recommendations of the manufacturer of the element or plaster
Gypsum plasters are not recommended.
6 Lightweight blockwork:
autoclaved aerated concrete Depending on the absorption characteristics, may require use of a suction-reducing treatment.
7 Lightweight concrete blockwork A polymer-modified spatterdash or a bonding agent is recommended, depending on the plaster and the smoothness and suction of the
blockwork.
8 Normal weight and dense aggregate concrete blockwork
Depending on suction and bond; may require use of a spatterdash treatment or bond with polymer-modified cement plaster or carrier
Bonding agent recommended for gypsum plaster.
9 Sandstone blockwork Use a spatterdash or a dubbing-out coat if necessary
10 Dense or poured concrete with a smooth surface Use a pre-treatment Bonding agent recommended for gypsum plaster Certain polymer-modified lime cement, cement and organic plasters may
be applied without pre-treatment.
11 Formwork blocks — cement/aggregate based Use a special pre-treatment as recommended by the block manufacturer
12 Cement/wood based blockwork a) lime/cement plaster: none, but use glass fibre mesh b) lime/cement lightweight plaster: none, but use glass fibre mesh
c) lime/cement thermal insulating plaster: none, but use glass fibre mesh A metal carrier is recommended depending on the thickness of the coat
d) gypsum plaster: none, but use glass fibre mesh Spatterdash can be used.
13 Wood wool boards (with or without thermal
insulation) b c
a) lime/cement plaster: none, but use glass fibre mesh b) lime/cement lightweight plaster: no pre-treatment necessary The undercoat is unreinforced: apply a reinforcing coat after sufficient drying time
c) lime/cement thermal insulating plaster: none, but use glass fibre mesh or metal carrier
d) gypsum plaster: none, but use glass fibre mesh Spatterdash can be used.
Trang 17— to achieve adequate air tightness;
— to conform with local fire regulations
Special plasters can provide enhanced properties for the following aspects:
— to improve the thermal properties of a building element (see 6.4);
— to improve the acoustic properties of a building element (see 6.5);
— to improve the fire resistance of a building element;
— to enhance the protection against soluble salts and moisture (renovation plaster);
— to enhance the protection against high humidity;
— to improve protection against radiation (see 6.7);
— to improve the strength for coatings with high tensile stresses, heavy coverings (tiles), etc
6.2.2 Background characteristics as part of a plastering system
In deciding the system to be chosen consideration shall be given to whether the background provides
adequate support, strength, rigidity and adhesion
Other means of providing support and/or additional adhesion/pre-treatment shall be used if the
characteristics of the background mentioned above are inadequate
Difficulty in application can sometimes be experienced when plastering on high-suction backgrounds
due to rapid moisture loss from the plaster Special measures are required to remedy this problem (e.g
primer to reduce suction, spatterdash, additive, bonding agent)
The potential pre-treatment of the background is dependent on the suction behaviour of the surface, the
strength of the background and the plastering material specified Polymer-modified lime cement,
cement plasters and organic plasters usually have sufficient adhesion to most backgrounds to avoid the
need for any pre-treatment
In the case where heavy coverings, such as ceramic tiles, are to be used or thicker plasters are needed,
consideration should be given by the designer as to whether the bond strength and tensile strength of
the plaster in relation to the background is sufficient
General advice on whether the various types of background are likely to require the use of special
plasters, pre-treatments or additional support is given in Table 3
Table 3 — Summary of the measures to be taken prior to plastering on to various types of
backgrounds
1 Clay masonry A special pre-treatment of the background is normally not necessary
when the background demonstrates uniform normal suction.
2 Concrete and calcium silicate brick- or blockwork Depending on suction and bond; may require use of a spatterdash pre-treatment or bond with polymer-modified cement mortar or metal
lathing.
3 Lightweight clay blockwork The suction should be checked to ensure that it is similar to that of normal
clay bricks If not, special precautions may be necessary.
4 Lightweight blockwork:
lightweight aggregate concrete
Ordinary suction: no pre-treatment necessary High-suction: use a spatterdash treatment or metal lathing
5 Large lightweight concrete elements Special precautions in accordance with the recommendations of the manufacturer of the element or plaster
Gypsum plasters are not recommended.
6 Lightweight blockwork:
autoclaved aerated concrete Depending on the absorption characteristics, may require use of a suction-reducing treatment.
7 Lightweight concrete blockwork A polymer-modified spatterdash or a bonding agent is recommended, depending on the plaster and the smoothness and suction of the
blockwork.
8 Normal weight and dense aggregate concrete blockwork
Depending on suction and bond; may require use of a spatterdash treatment or bond with polymer-modified cement plaster or carrier
Bonding agent recommended for gypsum plaster.
9 Sandstone blockwork Use a spatterdash or a dubbing-out coat if necessary
10 Dense or poured concrete with a smooth surface Use a pre-treatment Bonding agent recommended for gypsum plaster Certain polymer-modified lime cement, cement and organic plasters may
be applied without pre-treatment.
11 Formwork blocks — cement/aggregate based Use a special pre-treatment as recommended by the block manufacturer
12 Cement/wood based blockwork a) lime/cement plaster: none, but use glass fibre mesh b) lime/cement lightweight plaster: none, but use glass fibre mesh
c) lime/cement thermal insulating plaster: none, but use glass fibre mesh A metal carrier is recommended depending on the thickness of the coat
d) gypsum plaster: none, but use glass fibre mesh Spatterdash can be used.
13 Wood wool boards (with or without thermal
insulation) b c
a) lime/cement plaster: none, but use glass fibre mesh b) lime/cement lightweight plaster: no pre-treatment necessary The undercoat is unreinforced: apply a reinforcing coat after sufficient drying time
c) lime/cement thermal insulating plaster: none, but use glass fibre mesh or metal carrier
d) gypsum plaster: none, but use glass fibre mesh Spatterdash can be used.
Trang 18Background Pre-treatment a
14 Old plaster surfaces Old plaster surfaces can be reworked using bonding and renovation
mortar suitable for this purpose It is recommended that any cracks present in the old plaster be repaired Alternatively, a special plastering mortar with a reinforcement mesh can be applied over the whole surface
Gypsum plaster is not recommended on organic based plaster
A bonding agent or polymer-modified cement or cement lime plaster is necessary on cement-based plaster.
15 Multi-coat plaster — plaster
surfaces A primer may be necessary prior to application of the final coat.
16 Extruded and expanded
polystyrene boards c a) on small XPS-areas (up to 60 cm width) for lightweight lime/cement
plasters: pre-treatment with bonding agent (premixed modified plaster) necessary, but use glass fibre mesh in the undercoat
polymer-b) on large XPS-areas: lightweight lime/cement plasters: pre-treatment with bonding agent (premixed polymer-modified plaster) necessary
The undercoat is unreinforced Apply a reinforcing coat after sufficient drying time
c) Gypsum plasters: smooth XPS-boards should be roughened and plastered with plaster containing glass fibre or wire mesh
d) lime or lime/cement plasters do not provide enough adhesion on smooth XPS-boards so that special precautions need to be taken
e) EPS-boards can be plastered directly with a reinforcing coat Special pre-treatment required.
17 Mineral wool Depending on the type of mineral wool and the thickness of the plaster, an
additional carrier may be required, e.g metal or fibre mesh.
18 Timber framework Use of a carrier system is required.
19 Areas containing more than
one type of background, e.g
mixed masonry, timber
framework with infill
(masonry, loam, etc.)
Depending on the type of plaster being applied, either a carrier system or reinforced undercoat will be required.
20 Gypsum plaster boards A bonding agent/primer may be required depending on the type of
plasterboard and the thickness and type of plaster.
a The manufacturer of the background material/product may recommend special pre-treatments
b Wood wool should be dry and should not be exposed to wet conditions
c Board joints should be tight Methods of preparing board surfaces are:
— overlaying with reinforcement;
— for boards made of polystyrene and polyurethane that have rough surfaces, proprietary pre-treatment systems
are available using thin layers of polymer-modified cement-based plasters Such products should be left for at least
one day before application of the plastering system
6.2.3 Service conduits
Service conduits and similar items that are to be built into a wall should be positioned within the
thickness of the background wherever possible Generally speaking, lathing or reinforcement may be
required where service conduits are plastered over If it is necessary to plaster behind service conduits
additional work will be required
6.2.4 Compatibility of backgrounds and plaster coats
Consideration shall be given to the compatibility between plastering systems and the background and, where appropriate, between successive plaster coats
To achieve compatibility, consideration shall be given to:
a) movement of the background caused by load-dependent and load-independent deformations, e.g structural movement, moisture and thermal movements;
b) efflorescence, salt formation at the interface;
c) defects or irregularities in the background, e.g lack of adequate bond, weakness, contamination; d) inadequate suction control;
e) films of unset plaster produced by premature drying;
f) selection of suitable plasters with the appropriate binder in multi-coat systems from the background to the finish layer of the plastering system;
g) any combination of these causes
NOTE Such compatibility is necessary to avoid bond failure either between successive coats or between the plaster and the background
6.2.5 Drying and hardening times
Sufficient time shall be allowed for drying and hardening before the ultimate finish, e.g decoration, and consideration shall be given to the length of time available for these processes and to the likely ambient conditions
It is essential that both the background and plaster have dried sufficiently before permanent decorative coats, e.g wall papering or painting, are applied
Some plasters do not chemically set but harden by means of physical drying It shall be ensured that these plasters can dry quickly enough If drying is too slow, supplementary use of machine-drying can
be necessary Where appropriate, the drying conditions shall be monitored to ensure they are adequate and these shall be documented
Coordination with following trades, e.g floor screeding, should take place to avoid the plaster being exposed to additional moisture, preventing the plaster from drying out
6.3 Durability
6.3.1 General
The plastering system should perform satisfactorily if the background is erected and the plastering prepared and applied in accordance with the relevant standards
The durability of plaster can be affected by the following:
— incompatible background (see 6.2.4);
— contamination from the background other than from salts, e.g oil, dust;
— incorrect usage e.g in wet areas, on weak backgrounds or the use of an unsuitable water/binder ratio;
Trang 19Background Pre-treatment a
14 Old plaster surfaces Old plaster surfaces can be reworked using bonding and renovation
mortar suitable for this purpose It is recommended that any cracks present in the old plaster be repaired Alternatively, a special plastering
mortar with a reinforcement mesh can be applied over the whole surface.
Gypsum plaster is not recommended on organic based plaster.
A bonding agent or polymer-modified cement or cement lime plaster is necessary on cement-based plaster.
15 Multi-coat plaster — plaster
surfaces A primer may be necessary prior to application of the final coat.
16 Extruded and expanded
polystyrene boards c a) on small XPS-areas (up to 60 cm width) for lightweight lime/cement
plasters: pre-treatment with bonding agent (premixed modified plaster) necessary, but use glass fibre mesh in the
17 Mineral wool Depending on the type of mineral wool and the thickness of the plaster, an
additional carrier may be required, e.g metal or fibre mesh.
18 Timber framework Use of a carrier system is required.
19 Areas containing more than
one type of background, e.g.
mixed masonry, timber
framework with infill
(masonry, loam, etc.)
Depending on the type of plaster being applied, either a carrier system or reinforced undercoat will be required.
20 Gypsum plaster boards A bonding agent/primer may be required depending on the type of
plasterboard and the thickness and type of plaster.
a The manufacturer of the background material/product may recommend special pre-treatments.
b Wood wool should be dry and should not be exposed to wet conditions.
c Board joints should be tight Methods of preparing board surfaces are:
—overlaying with reinforcement;
—for boards made of polystyrene and polyurethane that have rough surfaces, proprietary pre-treatment systems
are available using thin layers of polymer-modified cement-based plasters Such products should be left for at least
one day before application of the plastering system.
6.2.3 Service conduits
Service conduits and similar items that are to be built into a wall should be positioned within the
thickness of the background wherever possible Generally speaking, lathing or reinforcement may be
required where service conduits are plastered over If it is necessary to plaster behind service conduits
additional work will be required
6.2.4 Compatibility of backgrounds and plaster coats
Consideration shall be given to the compatibility between plastering systems and the background and, where appropriate, between successive plaster coats
To achieve compatibility, consideration shall be given to:
a) movement of the background caused by load-dependent and load-independent deformations, e.g.structural movement, moisture and thermal movements;
b) efflorescence, salt formation at the interface;
c) defects or irregularities in the background, e.g lack of adequate bond, weakness, contamination;d) inadequate suction control;
e) films of unset plaster produced by premature drying;
f) selection of suitable plasters with the appropriate binder in multi-coat systems from thebackground to the finish layer of the plastering system;
g) any combination of these causes
NOTE Such compatibility is necessary to avoid bond failure either between successive coats or between the plaster and the background
6.2.5 Drying and hardening times
Sufficient time shall be allowed for drying and hardening before the ultimate finish, e.g decoration, and consideration shall be given to the length of time available for these processes and to the likely ambient conditions
It is essential that both the background and plaster have dried sufficiently before permanent decorative coats, e.g wall papering or painting, are applied
Some plasters do not chemically set but harden by means of physical drying It shall be ensured that these plasters can dry quickly enough If drying is too slow, supplementary use of machine-drying can
be necessary Where appropriate, the drying conditions shall be monitored to ensure they are adequate and these shall be documented
Coordination with following trades, e.g floor screeding, should take place to avoid the plaster being exposed to additional moisture, preventing the plaster from drying out
6.3 Durability
6.3.1 General
The plastering system should perform satisfactorily if the background is erected and the plastering prepared and applied in accordance with the relevant standards
The durability of plaster can be affected by the following:
— incompatible background (see 6.2.4);
— contamination from the background other than from salts, e.g oil, dust;
— incorrect usage e.g in wet areas, on weak backgrounds or the use of an unsuitable water/binder ratio;
Trang 20— incorrect application conditions, e.g humidity and temperature (see 5.2 d));
— drying time (see 6.2.5) and drying conditions;
— persistent high humidity and dampness after drying and setting (see 6.3.2)
6.3.2 Effects of moisture
Walls, ceilings and other backgrounds to be plastered should be sufficiently dry2 ) for plastering to be
applied without adverse effects, be contained within a weather-resistant shell and, where appropriate,
be designed and built to contain a damp-proof course or other means of preventing damp rising from
Condensation in a building can be of a temporary or permanent nature If adequate ventilation is not
provided during the drying or hardening phase, the strength and the surface finish (e.g accumulation of
binder on the surface) of the plaster may be impaired and the time at which decoration may start may
be delayed The responsibility for providing ventilation should be clarified
6.3.4 Corrosive effect on metals in contact with plasters
Any embedded metal, e.g service pipes or profiles, shall be compatible with the plaster system chosen
Matured plasterwork may be regarded as dry and therefore non-corrosive
Corrosion-resistant materials shall be used under persistently wet conditions
6.3.5 Resistance to cracking
The design of the structure shall have taken into account the need for preventive measures to avoid
possible movements of the background, e.g in mortar joints
NOTE 1 Cracking may occur at positions of higher stresses, e.g at corners of openings The use of
reinforcement in the plaster will not prevent cracking caused by structural factors
NOTE 2 A limited number of hairline cracks including crazing up to approximately 0,2 mm in width are not
significant as they do not impair the durability of the plastering
6.3.6 Impact and abrasion resistance
All plastering systems are susceptible to damage by impact or abrasion In areas exposed to higher
levels of impact and abrasion, additional measures for the protection of the plaster surface shall be
considered These include the selection of a suitable plastering system and/or the provision of
protective rails/profiles fixed to the surface (e.g corners) of the plaster
6.4 Thermal insulation
Special plasters with improved thermal insulating properties shall be used (e.g EN 998-1:2010, 3.5.6) if
enhanced thermal-insulating properties are required
2) Refer to final paragraph of Clause 1 for further information.
6.5 Acoustic properties
Special plasters with specific proven sound absorption properties, such as acoustic plasters, can be used
if enhanced sound absorption properties are required
NOTE Acoustic plasters are factory-made plasters to improve acoustic properties which can be applied to different backgrounds and in one or more layers
6.6 Plasters with enhanced resistance to soluble salts
Renovation plasters are pore-rich special plasters with very high water vapour permeability and reduced capillary conductivity They are used for plastering moist and/or salt encrusted masonry In accordance with the basic principle, the dissolved salts are transported by capillary action into the porous space and crystallize there without the salts becoming visible on the plaster surface or the structure of the plaster being destroyed by damaging salts
6.7 Plasters with enhanced protection from x-ray radiation
Special plasters with specific, proven X-ray absorption characteristics, such as barite plasters, should be used if enhanced protection against X-ray radiation is required
6.8 Plastering system for decorative finish
The final surface of a plastering system should be specified to be compatible with the decoration to be applied Thinner types of decoration will require the use of smoother plastered surfaces (see 6.10.2) Whatever the plastering system and finish and however skilled and conscientious the operative, plastering is a craft and it should be appreciated that it is not possible to achieve a completely smooth and true surface finish Painting will tend to reveal any inherent surface irregularities These minor imperfections will be highlighted when gloss or semi-gloss paints are used, particularly where the plasterwork is subjected to intense or shallow-angle lighting Therefore these types of finishes and lighting require special additional measures to be taken Otherwise, the consequential minor irregularities will have to be accepted See also Annex A
NOTE The absorbency of plaster surfaces can vary Special precautions may need to be taken to achieve uniform absorption such as application of a primer to avoid any unsatisfactory appearance of the applied finish, e.g paint
6.9 Thickness of plaster coats on walls and ceilings
6.9.1 General purpose
In designing the plastering system, consideration shall be given to what may be required to overcome variations in the background, for fire protection, acoustic absorption, sound insulation, thermal insulation or protection against radiation
If the background to be plastered contains indentations, their dimensions, depth and spacing shall be specified so that allowance can be made for the additional material required
NOTE The thinner the plaster coat specified, the more important it is that the background to which it is applied is true and flat (see 6.10.3)
6.9.2 Solid backgrounds
For solid backgrounds (e.g concrete, masonry works) the thicknesses should be in accordance with Table 4
Trang 21— incorrect application conditions, e.g humidity and temperature (see 5.2 d));
— drying time (see 6.2.5) and drying conditions;
— persistent high humidity and dampness after drying and setting (see 6.3.2)
6.3.2 Effects of moisture
Walls, ceilings and other backgrounds to be plastered should be sufficiently dry2 ) for plastering to be
applied without adverse effects, be contained within a weather-resistant shell and, where appropriate,
be designed and built to contain a damp-proof course or other means of preventing damp rising from
Condensation in a building can be of a temporary or permanent nature If adequate ventilation is not
provided during the drying or hardening phase, the strength and the surface finish (e.g accumulation of
binder on the surface) of the plaster may be impaired and the time at which decoration may start may
be delayed The responsibility for providing ventilation should be clarified
6.3.4 Corrosive effect on metals in contact with plasters
Any embedded metal, e.g service pipes or profiles, shall be compatible with the plaster system chosen
Matured plasterwork may be regarded as dry and therefore non-corrosive
Corrosion-resistant materials shall be used under persistently wet conditions
6.3.5 Resistance to cracking
The design of the structure shall have taken into account the need for preventive measures to avoid
possible movements of the background, e.g in mortar joints
NOTE 1 Cracking may occur at positions of higher stresses, e.g at corners of openings The use of
reinforcement in the plaster will not prevent cracking caused by structural factors
NOTE 2 A limited number of hairline cracks including crazing up to approximately 0,2 mm in width are not
significant as they do not impair the durability of the plastering
6.3.6 Impact and abrasion resistance
All plastering systems are susceptible to damage by impact or abrasion In areas exposed to higher
levels of impact and abrasion, additional measures for the protection of the plaster surface shall be
considered These include the selection of a suitable plastering system and/or the provision of
protective rails/profiles fixed to the surface (e.g corners) of the plaster
6.4 Thermal insulation
Special plasters with improved thermal insulating properties shall be used (e.g EN 998-1:2010, 3.5.6) if
enhanced thermal-insulating properties are required
2) Refer to final paragraph of Clause 1 for further information.
6.5 Acoustic properties
Special plasters with specific proven sound absorption properties, such as acoustic plasters, can be used
if enhanced sound absorption properties are required
NOTE Acoustic plasters are factory-made plasters to improve acoustic properties which can be applied to different backgrounds and in one or more layers
6.6 Plasters with enhanced resistance to soluble salts
Renovation plasters are pore-rich special plasters with very high water vapour permeability and reduced capillary conductivity They are used for plastering moist and/or salt encrusted masonry In accordance with the basic principle, the dissolved salts are transported by capillary action into the porous space and crystallize there without the salts becoming visible on the plaster surface or the structure of the plaster being destroyed by damaging salts
6.7 Plasters with enhanced protection from x-ray radiation
Special plasters with specific, proven X-ray absorption characteristics, such as barite plasters, should be used if enhanced protection against X-ray radiation is required
6.8 Plastering system for decorative finish
The final surface of a plastering system should be specified to be compatible with the decoration to be applied Thinner types of decoration will require the use of smoother plastered surfaces (see 6.10.2) Whatever the plastering system and finish and however skilled and conscientious the operative, plastering is a craft and it should be appreciated that it is not possible to achieve a completely smooth and true surface finish Painting will tend to reveal any inherent surface irregularities These minor imperfections will be highlighted when gloss or semi-gloss paints are used, particularly where the plasterwork is subjected to intense or shallow-angle lighting Therefore these types of finishes and lighting require special additional measures to be taken Otherwise, the consequential minor irregularities will have to be accepted See also Annex A
NOTE The absorbency of plaster surfaces can vary Special precautions may need to be taken to achieve uniform absorption such as application of a primer to avoid any unsatisfactory appearance of the applied finish, e.g paint
6.9 Thickness of plaster coats on walls and ceilings
6.9.1 General purpose
In designing the plastering system, consideration shall be given to what may be required to overcome variations in the background, for fire protection, acoustic absorption, sound insulation, thermal insulation or protection against radiation
If the background to be plastered contains indentations, their dimensions, depth and spacing shall be specified so that allowance can be made for the additional material required
NOTE The thinner the plaster coat specified, the more important it is that the background to which it is applied is true and flat (see 6.10.3)
6.9.2 Solid backgrounds
For solid backgrounds (e.g concrete, masonry works) the thicknesses should be in accordance with Table 4