1、BS 8747:2007Reinforced bitumen membranes (RBMs) for roofing Guide to selection and specificationICS 91.060.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when th
2、e document was last issued. BSI 2007ISBN 978 0 580 50900 1The following BSI references relate to the work on this standard:Committee reference B/546/1Draft for comment 06/30058801 DCPublication historyFirst published June 2007Amendments issued since publicationAmd. no. Date Text affectedBS 8747:2007
3、 BSI 2007 iBS 8747:2007ContentsForeword iiIntroduction CEN test methods referenced in this standard 11 Scope 12 Normative references 23 Terms and definitions 24 Membrane selection guidelines 55 System selection 166 Bonding and installation of an RBM 18AnnexesAnnex A (informative) CE marking informat
4、ion for an RBM product 20Annex B (informative) Guide to specifying RBM equivalent to Type 1F or Type 5U reinforced bitumen roofing underlay 21Annex C (informative) Guide to specifying RBM equivalent to Type 3G glass-fibre reinforced bitumen perforated venting layer 23Annex D (informative) Worked exa
5、mples 24Bibliography 32List of tablesTable 1 Tensile strength of membrane classes 12Table 2 Resistance to impact 12Table 3 Resistance to static loading 12Table 4 Combinations of D subclass and L subclass to give P class 12Table 5 Membrane classification by performance requirement 14Table 6 Compariso
6、n between BS 747 membranes and the SNPN system 15Table 7 Flow chart for system selection Warm deck roofs 16Table 8 Flow chart for system selection Inverted warm roofs 18Table B.1 Mass per units area for constituents of Type 1F and Type 5U RBMs 22Table C.1 Mass per units area for constituents of Type
7、 3G RBMs 24Summary of pagesThis document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 32, an inside back cover and a back cover.BS 8747:2007ii BSI 2007ForewordPublishing informationThis British Standard is published by BSI and came into effect on 29 June 2007. It was pr
8、epared by Subcommittee B/546/1, Reinforced bitumen membranes. A list of organizations represented on this committee can be obtained on request to its secretary.Relationship with other publicationsSome products included within this Standard used to be commonly referred to as roofing “felts”, and were
9、 covered by BS 747:2000. The new European product standard BS EN 13707, which will replace BS 747, refers to these as “flexible bitumen sheets for roof waterproofing”. This could be confusing to the UK construction industry. Therefore, the title of this guide reflects the current terminology used in
10、 the UK and in the Code of Practice, BS 8217. These products are now referred to as “Reinforced Bitumen Membranes (RBMs) for Roofing”.In flat roofing applications, these materials are almost always used with a fully supporting substrate. The exception is on a profiled metal deck, where the top flats
11、 (crowns) of the profile are used for support. General flat roofing design is covered in BS 6229. Specific roof design and installation of these membranes is covered in BS 8217. BS 8747 gives guidance on the selection and use of RBMs, including those specified in BS EN 13707. Guidance in specifying
12、RBMs equivalent to those specified in BS 747:2000 (but not covered by BS EN 13707) is included in Annexes B and C.Publications are also available that give useful advice on construction safety (see Bibliography).Information about this documentThis guide provides “primary advice” to the specifier wit
13、h respect to the production of an effective roof, and is intended as a link document between the material product standard and the final contract specification. This British Standard takes the form of guidance and recommendations. It cannot be quoted as a specification, and claims of compliance to i
14、t cannot be made. NOTE It has been assumed in the drafting of this guide that the design and construction of flat roofs is entrusted to appropriately qualified and competent people. It has also been assumed that the building owner will adopt the recommendations in respect of planned inspection and m
15、aintenance of a roof during service.Contractual 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 British Standard cannot confer immunity from legal obligations. BSI 200
16、7 1BS 8747:2007Introduction CEN test methods referenced in this standardThe overall aim of the Construction Products Directive (CPD) 1 is to reduce barriers to trade throughout the European Economic Area. The CPD has, as an ideal, the concept of performance related test methods. The relationship bet
17、ween the results of test methods and the performance on a roof for reinforced bitumen membranes (RBMs) has not been proven, thus it should not be assumed that the results of such tests indicate accurately the in-service performance of the membrane(s) tested. The test methods in BS EN 13707 have been
18、 developed in response to product characteristics identified from the Building Regulations 2 or their counterparts in the various Member States. Some of these are required only for installation of the product. The CEN test methods and product standards have been developed by a committee of experts f
19、rom Member States. These test methods were based on current standards such as ISOs where possible but in most cases the scope of existing standards did not coincide entirely with the scope of the CEN standards. Roof waterproofing is an example of this. Most of the test methods are therefore new and
20、there is no history of past values to rely upon for a given product. CEN product standards also stipulate whether the manufacturer declares a value for a given test method, together with a declared tolerance, or states a manufacturers limiting value. BS 747:2000 was a recipe standard. As such it was
21、 known in the roofing industry that rag-based bitumen felts did not perform as well as polyester-based products. Because of this, it was easy for a specifier to use a BS 747:2000 Type 3 for say garages or sheds, and BS 747:2000 Type 5 for roofs over offices and computer installations.This will not b
22、e possible with BS EN 13707, because it gives no indication as to what values, as a result of carrying out tests, are required or appropriate for given end uses.This committee has selected, through expert knowledge and a limited amount of testing, those test methods which it is believed are most sui
23、table and relevant to performance on a roof, and has assigned threshold values which can be used to conveniently group the products into bands of performance. The worked examples are also based upon industry knowledge and experience. Table 5 correlates end use and substrate with membrane type and ch
24、oice. 1 ScopeThis British Standard gives guidance to assist the selection and specification of a system of appropriate layer(s) of reinforced bitumen membrane (RBM) for each flat and/or sloping roofing project, tailored to the particular requirements of that project.It provides a grouping system to
25、assist the specifier, utilizing material properties as tested according to BS EN 13707.BS 8747:20072 BSI 20072 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references,
26、the latest edition of the referenced document (including any amendments) applies.BS 476-3:2004, Fire tests on building materials and structures Part 3: Classification and method of test for external fire exposure to roofsBS 6100-1.3.2:1989, Glossary of building and civil engineering terms Part 1: Ge
27、neral and miscellaneous Section 1.3: Parts of construction works Subsection 1.3.2: Roofs and roofingBS 6229:2003, Flat roofs with continuously supported coverings Code of practiceBS 8217:2005, Reinforced bitumen membranes for roofing Code of practiceBS EN 12311-1:2000, Flexible sheets for waterproof
28、ing Determination of tensile properties Part 1: Bitumen sheets for roof waterproofingBS EN 12691: 2006, Flexible sheets for waterproofing Bitumen, plastic and rubber sheets for roof waterproofing Determination of resistance to impactBS EN 12730:2001, Flexible sheets for waterproofing Bitumen, plasti
29、c and rubber sheets for roof waterproofing Determination of resistance to static loadingBS EN 13707:2005, Flexible sheets for waterproofing Reinforced bitumen sheets for roof waterproofing Definitions and characteristics3 Terms and definitionsFor the purposes of this British Standard, the definition
30、s given in BS 6100-1.3.2:1989 and those following shall apply. These definitions align with those used in other pertinent UK standards; they might differ slightly from those included within European Standards.This standard introduces and confirms a new primary abbreviation/acronym as mentioned in th
31、e foreword: RBMs will henceforth be defined as “reinforced bitumen membranes”.3.1 built-up reinforced bitumen membranebuilt-up RBMgenerally, two or more layers of reinforced bitumen membrane, fastened to the substrate, bonded together with sealed joints to form a continuous waterproof covering 3.2 s
32、ingle-layer reinforced bitumen membrane single-layer RBMspecifically designed bituminous single-layer systems with sealed joints, forming a continuous waterproof covering, and installed according to the manufacturers specific instructions BSI 2007 3BS 8747:20073.3 access roofroof used to provide acc
33、ess to plant or equipment3.4 base layerpreparatory layerlayer of reinforced bitumen membrane which is laid first3.5 bonding bitumenoxidized bitumen, or other suitable bitumen compound melted and used hot as a bonding agent3.6 capsheetuppermost layer of reinforced bitumen membrane which is self-finis
34、hed, i.e. incorporates a protective finish (e.g. mineral or foil-faced)3.7 carriermaterial incorporated into or onto the factory-made bitumen membrane to ensure its stability and/or mechanical resistance3.8 cold deck roof cold roofroof where the principal thermal insulation is placed at or immediate
35、ly above the ceiling, resulting in the roof covering and structural deck being substantially colder in winter than the interior of the buildingNOTE Generally, the cold deck flat roof is no longer recommended, due to the difficulty in providing an effective vapour control layer at ceiling level, the
36、limitations of providing adequate ventilation above the insulation to prevent condensation, and the associated thermal losses. 3.9 detailing capsheetcapsheet used on detail works and upstands, offering more flexibility for forming these3.10 full bondinguse of a continuous coat of bonding bitumen (or
37、 other approved adhesive), or torch application, to fully adhere a layer of reinforced bitumen membrane 3.11 gritting solutionbitumen compound, formulated to bond a layer of site-applied chippings to the surface of the top layer 3.12 intermediate layerany layer of reinforced bitumen membrane which i
38、s applied between the base layer, and the top layer (or capsheet) 3.13 inverted roofupside-down roofprotected membrane roofroof where the principal thermal insulation is placed above the roof covering, resulting in the roof covering, structural deck and ceiling being at a temperature close to that o
39、f the interior of the buildingNOTE Generally the principal insulation is secured by ballast, however proprietary lightweight systems are available which do not rely on separate ballast.BS 8747:20074 BSI 20073.14 manufacturers declared valueMDVvalue declared by the manufacturer accompanied by a decla
40、red tolerance3.15 manufacturers limiting value MLVvalue stated by the manufacturer to be met during testing, which can be a minimum or a maximum value according to statements made under product characteristics within a standard3.16 partial bondinguse of a controlled and regular quantity of bonding b
41、itumen (or other approved adhesive) or torch application, so as to provide adhesion over a proportion of the total area of the substrate3.17 roof deckpart of the roof construction, which supports the waterproofing system, including as appropriate the vapour control layer and insulation board(s)3.18
42、substratesurface upon which a built-up reinforced bitumen membrane (RBM) is laid3.19 tapered insulationthermal insulation boards of varying thickness, designed and pre-cut or pre-formed to create or augment drainage falls when laid in a prescribed pattern3.20 terrace roofflat roof for use as an amen
43、ity area, usually having a specialist, separate, protective surface finish3.21 top layeruppermost layer of reinforced bitumen membrane, which will require the application of separate surface protection3.22 vapour control layer VCLconstruction material (usually a reinforced bitumen membrane) that sub
44、stantially reduces the transfer of water vapour through the roof build-upNOTE The performance of a vapour control layer is dependent upon the material, workmanship and buildability. The material chosen for a specific building should be suitable for its internal conditions. 3.23 warm deck roofwarm ro
45、ofroof where the principal thermal insulation is placed above the deck and a vapour control layer and immediately below the roof covering, resulting in the structural deck and ceiling being at a temperature close to that of the interior of the building BSI 2007 5BS 8747:20074 Membrane selection guid
46、elines4.1 GeneralThe primary reference for flat roof design is BS 6229, and the code of practice for RBM roofing is BS 8217, which should be consulted in conjunction with this Guide, for the selection of RBMs as the waterproofing system. This guide assumes that the roof deck/substrate has already be
47、en selected and thermal requirements considered. The choice of suitable membrane(s) will be dependent upon a number of factors, including: roof deck/substrate; slope/pitch; building and roof use; location and exposure; intended access to the building and/or roof areas (by following trades, or for ma
48、intenance, etc.); possible unauthorized access to the building and/or roof areas (by vandals, etc.); insulation type under consideration; the extent and complexity of detailing; fire performance requirements; surface finish; and durability/service-life requirements.Any specification for overlaying o
49、f existing materials should be based upon a close condition survey, and if necessary, core sampling and non-destructive testing, to establish the exact makeup and condition of the lower layers and substrate. In refurbishment projects, consideration should be given to correcting any inadequacy of falls, by the use of tapered insulation boards or re-decking with improved falls. It is more than likely that such projects will need to comply with regulatory requirements for
