1、BS 8481:2006Design, preparation and application of internal gypsum, cement, cement and lime plastering systems SpecificationICS 91.180NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPublishing and copyright informationThe BSI copyright notice displayed in this d
2、ocument indicates when the document was last issued. BSI 2006ISBN 0 580 49184 6The following BSI references relate to the work on this standard:Committee reference B/544Draft for comment 06/30140171 DCPublication historyFirst published, September 2006Amendments issued since publicationAmd. no. Date
3、Text affectedBS 8481:2006 BSI 2006 iBS 8481:2006ContentsForeword iii1 Scope 12 Normative references 13 Terms and definitions 24 Materials and accessories 45 Design factors influencing the selection of gypsum plastering systems 76 Characteristics of gypsum plastering systems 87 Design factors influen
4、cing the selection of cement, cement and lime plastering systems 138 Characteristics of cement, cement and lime plastering systems 139 Backgrounds, including preparation for cement, cement and lime plastering systems 1710 Preparation and application of cement, cement and lime plasters 2111 Maintenan
5、ce and repair (other than restoration of old and historic buildings) 23AnnexesAnnex A (normative) Fixing applied backgrounds 25Annex B (informative) Restoration of plasters on old and historic buildings 28Bibliography 31List of figuresFigure A.1 Typical applications of metal beads and temporary form
6、work around openings 27List of tablesTable 1 Thermal conductivity values of gypsum plaster according to density 10Table 2 Nominal and minimum thickness of undercoat(s) of a multi-coat system or one-coat system 11Table 3 Recommended thicknesses for various types of one-coat cement, cement and lime pl
7、asters to solid backgrounds 16Table 4 Recommended total thicknesses for multi-coat systems consisting of cement, and cement and lime plasters onto solid walls and soffits (the underside of floor slabs) 16Table 5 Recommended pre-treatments for various cement, cement and lime plastering systems and fo
8、r various backgrounds 19Table 6 Mixes suitable for plastering 21Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 31 and a back cover.BS 8481:2006ii BSI 2006 This page deliberately left blank BSI 2006 iiiBS 8481:2006ForewordPublishing information
9、This British Standard was published by BSI and came into effect on 29 September 2006. It was prepared by Technical Committee B/544, Plastering, rendering, dry lining. A list of organizations represented on this committee can be obtained on request to its secretary.SupersessionThis British Standard t
10、ogether with BS EN 13914-2 and PD CEN/TR 15123 supersedes BS 5492:1990, which is withdrawn.Relationship with other publicationsBS 8481 is largely based on an amalgamation of two CEN Technical Reports: CEN/TR 15124:2005, Design, preparation and application of internal gypsum plastering systems. CEN/T
11、R 15125:2005, Design, preparation and application of internal cement and/or lime plastering systems.However certain additions and deletions have been made to these texts to make them appropriate to working conditions found in the UK.Information about this documentWhere the guidance for the use of gy
12、psum plastering systems differ from that for plastering systems based on cement, cement and lime, the guidance for the former precedes that for the latter. 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 st
13、andard 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.A CEN Technical Report is also available which gives the equivalent inform
14、ation for internal polymer plastering systems:CEN/TR 15123:2005, Design, preparation and application of internal polymer plastering systems.It has been assumed in the preparation of this British Standard that the execution of its provisions will be entrusted to appropriately qualified and experience
15、d people, for whose use it has been produced.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Its requirements are expressed in sentences in which the principal auxiliary verb is “shall”.Commentary, explanation and general informative material is
16、presented in smaller italic type, and does not constitute a normative element.BS 8481:2006iv BSI 2006Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a Britis
17、h Standard cannot confer immunity from legal obligations. BSI 2006 1BS 8481:20061 ScopeThis British Standard specifies the design, preparation and application of plaster based on gypsum, cement, cement and lime, for internal plastering on all types of background used under normal conditions. It incl
18、udes 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, cement, cement and lime plastering systems, methods of application and inspection and testing
19、of plastering.Recommendations on gypsum, cement, cement and lime plastering mixes with special properties intended to enhance thermal insulation, fire resistance, acoustic insulation and to increase radiation absorption maintenance and repair are also covered. NOTE Relevant data are summarized in a
20、series of tables.This standard should be read in conjunction with BS EN 13914-2 especially regarding surface, requirements, flatness, verticality, angularity, types of finish and smoothness which are not dealt with in this standard. 2 Normative referencesThe following referenced documents are indisp
21、ensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.BS 4027, Specification for sulfate-resisting Portland cementBS EN 197-1, Cement Part 1: Composi
22、tion, specifications and conformity criteria for common cementsBS EN 413-1, Masonry cement Part 1: Composition, specifications and conformity criteriaBS EN 459-1, Building lime Part 1: Definitions, specifications and conformity criteriaBS EN 934-3, Admixtures for concrete, mortar and grout Part 3: A
23、dmixtures for masonry mortar Definitions, requirements, conformity, marking and labellingBS EN 998-1:2003, Specification for mortar for masonry Part 1: Rendering and plastering mortarBS EN 10223-3, Steel wire and wire products for fences Part 3: Hexagonal steel wire netting for engineering purposesB
24、S EN 10230-1, Steel wire nails Part 1: Loose nails for general applicationsBS EN 10244-1, Steel wire and wire products Non-ferrous metallic coatings on steel wire Part 1: General principlesBS EN 10244-2, Steel wire and wire products Non-ferrous metallic coatings on steel wire Part 2: Zinc or zinc al
25、loy coatingsBS EN 12878, Pigments for the colouring of building materials based on cement and/or lime Specifications and methods of testBS 8481:20062 BSI 2006BS EN 13055-1, Lightweight aggregates Part 1: Lightweight aggregates for concrete, mortar and groutBS EN 13139, Aggregates for mortarBS EN 132
26、79-1:2005, Gypsum binders and gypsum plasters Part 1: Definitions and requirementsBS EN 13496, Thermal insulation products for building applications Determination of the mechanical properties of glass fibre meshesBS EN 13658-1, Metal lath and beads Definitions, requirements and test methods Part 1:
27、Internal plasteringBS EN 13658-2, Metal lath and beads Definitions, requirements and test methods Part 2: External renderingBS EN 13914-2:2005, Design, preparation and application of external rendering and internal plastering Part 2: Design considerations and essential principles for internal plaste
28、ring3 Terms and definitionsFor the purposes of this British Standard, the terms and definitions given in BS EN 13914-2 and the following apply.3.1 Plaster definitions3.1.1 plastermixture based on one or more binders, applied while plastic and hardens after application, used to obtain an internal sur
29、face finishNOTE Plaster does not acquire its final characteristics until it has set on the building component.3.1.2 gypsum plasterplaster consisting of at least 50% gypsum binder as the principle active binding component NOTE Additives and aggregates might be added by the manufacturer.3.1.3 designed
30、 mixesplaster designed and manufactured to fulfil stated properties and subjected test requirements (performance concept)3.1.4 prescribed mixesplaster made in predetermined proportions the properties of which are assumed from the stated proportions of the constituents (recipe concept)3.2 Application
31、 definitions3.2.1 plasteringapplication of plaster3.2.2 plaster coatobtained by application of one or more layers with one or more mixes of the same product BSI 2006 3BS 8481:20063.2.3 plastering systemplaster coat or sequence of plaster coats applied to a background, including the possible use of a
32、 support and/or reinforcement and/orpre-treatment3.2.4 one-coat plasterplaster applied in one-coat which fulfils all the functions of a plastering system3.2.5 multi-coat plasterplaster system using a sequence of plaster coats to achieve the required thickness when all operations are completed after
33、the plaster has set but not dry3.2.6 undercoatlower plaster coat or plaster coats of a plastering system3.2.7 final coatlast plaster coat of a multi-coat plastering system3.2.8 dubbing outprocess of filling large localized irregularities in the background, such as hollows, prior to the application o
34、f an undercoat3.3 Background definitions3.3.1 backgroundsurface of a construction element to which a plastering system is to be applied3.3.2 keyroughness of a surface which enables plaster to make a bond 3.3.3 supportproduct attached to the background to which a plaster is applied so that the plaste
35、ring system is largely independent of the background (e.g. lathing)3.3.4 reinforcementmaterial incorporated within a plaster coat to improve resistance to cracking (e.g. mesh)3.3.5 bonding agentproprietary material used to provide adhesion of the plastering system to the background where necessary3.
36、3.6 spatterdash and stipplepre-treatments to prepare a background for plasteringNOTE Stipple is only used in the form of site plaster.3.4 Other definitions3.4.1 efflorescenceformation of crystals on a surface during drying caused by the presence of soluble saltsBS 8481:20064 BSI 20063.4.2 crazingnet
37、work of short, irregular and very fine surface cracks up to approximately 0.2 mm in width NOTE Hairline cracks do not impair the function of the plaster and are therefore acceptable to a limited extent.4 Materials and accessories4.1 Materials for site-made plasters4.1.1 Binders4.1.1.1 Gypsum binders
38、 and gypsum plastersIf specified, only gypsum binders and gypsum plaster conforming to BS EN 13279-1 shall be used.4.1.1.2 Common cements including coloured cementWhere used, common cements, including coloured and pigmented cements, shall conform to the requirements of BS EN 197-1. NOTE Not all type
39、s and classes of cement are suitable for each and every application.4.1.1.3 Masonry cementWhere used, masonry cement shall conform to the requirements of BS EN 413-1.4.1.1.4 Sulfate resistant cementsIf specified, sulfate resistant cements conforming to BS 4027 shall be used. 4.1.1.5 Building limeWhe
40、re used, building lime shall conform to the requirements of BS EN 459-1.4.1.2 AggregatesWhere used, aggregates with established suitability for use plasters shall be used. Aggregates shall conform to BS EN 13139 for dense aggregates or BS EN 13055-1 for light aggregates as appropriate. 4.1.3 Admixtu
41、res for cement and/or lime based plastersWhere appropriate, admixtures with established suitability for plasters shall be used.Admixtures conforming to the requirements of BS EN 934-3 shall be used; however, admixtures falling outside the scope of BS EN 934-3 can be used given established usage and
42、shall be applied in accordance with manufacturers instructions. BSI 2006 5BS 8481:20064.1.4 Additions4.1.4.1 Bonding agentsBonding agents suitable for the individual application shall be used. The manufacturers instructions shall be followed.4.1.4.2 PigmentsPigments conforming to BS EN 12878 shall b
43、e used however; pigments falling outside the scope of BS EN 12878 can be used given established usage and shall be applied in accordance with manufacturers instructions.For both the manufacturers instructions shall be followed.4.1.4.3 FibresCOMMENTARY ON 4.1.4.3 Fibres can be used in specialized app
44、lications such as restoration work, sprayed plasterings and plasterings on lathing or insulation board.Only fibres which do not affect the chemical or physical stability of the plaster shall be used.NOTE Fibres should be compatible with the binder.4.2 WaterThe water shall be of a quality such that i
45、t does not adversely affect the plaster.NOTE 1 Water fit for drinking is suitable for mixes for plastering. NOTE 2 Attention is drawn to the requirements of BS EN 1008 in cases where water supplies are of doubtful quality.4.3 Types of cement, cement and lime plasters based on BS EN 998-14.3.1 Genera
46、lCOMMENTARY ON 4.3.1Ready mixed cement, cement and lime plasters can be mixed entirely in the factory or partly in the factory and then completed on site. Alternatively plaster can be mixed entirely on site.4.3.2 Factory made and semi-finished factory made cement, cement and lime plastersWhen using
47、mixes based on cement, cement and lime, factory made and semi-finished factory made plasters conforming to BS EN 998-1 shall be used for those parts of the process either wholly or partly carried out in the factory. NOTE For those parts of the process for semi-finished factory made plasters complete
48、d on site see 4.1 and 4.2.BS 8481:20066 BSI 20064.3.3 Site-made cement, cement and lime plasters4.3.3.1 GeneralSite-made plasters shall be made from constituents given in 4.1 and 4.2 and mixed in accordance with 10.2 with the correct proportions (see 10.1).4.3.3.2 Site-made, designed mixesCOMMENTARY
49、 ON 4.3.3.2 Site-made, designed mixes should not be made on site unless the contractor has taken special measures to exercise the necessary degree of control (see Clause 11).4.3.3.3 Site-made, prescribed mixesNOTE 1 Other than ensuring and checking that these mixes are correctly batched, prescribed mixes are not required to meet any test criteria.NOTE 2 It should be made clear whether mix proportions are by weight or by volume and whether they are based on
