1、BSI Standards PublicationBS 85500:2015Flood resistant and resilientconstruction Guide toimproving the floodperformance of buildingsPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standards Institution 201
2、5Published by BSI Standards Limited 2015ISBN 978 0 580 86313 4ICS 91.120.30; 91.120.99The following BSI references relate to the work on this document:Committee reference CB/501Draft for comment 15/30299685 DCPublication historyFirst published November 2015Amendments issued since publicationDate Tex
3、t affectedBS 85500:2015 BRITISH STANDARDContentsForeword iiIntroduction 11 Scope 12 Normative references 13 Terms and definitions 24 Context 35 Response of buildings 46 Design strategies 127 New buildings 158 Retrofit 279 Doors, windows and air vents 2810 Fixtures, fittings and services 3011 Other i
4、ssues 31Bibliography 32List of figuresFigure1Typical flood durations 4Figure 2 Potential routes for entry of flood water into a dwelling 7Figure3Water ingress into properties through the ground: Ground bearingfloor 8Figure4Water ingress into properties through the ground: Suspendedfloor 8Figure 5 Gr
5、ound-supported floor Preferred option 18Figure 6 Suspended floor Restricted option 19Figure 7 Solid external walls 24Figure 8 Cavity external walls Clear cavity 24Figure 9 Cavity external walls Part-filled cavity: Option A 25Figure 9 Cavity external walls Part-filled cavity: Option B 25List of table
6、sTable 1 Possible flood damage for a typical residential property 5Table 2 Floors: Potential flood impacts 9Table3Walls: Potential flood impacts 11Table 4 Selection of strategy 15Summary of pagesThis document comprises a front cover, an inside front cover, pages i to ii,pages 1 to 32, an inside back
7、 cover and a back cover.BRITISH STANDARD BS 85500:2015 The British Standards Institution 2015 iForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 30 November 2015. Itwas prepared by T
8、echnical Committee CB/501, Flood risk and watercourses. A listof organizations represented on this committee can be obtained on request toits secretary.Relationship with other documentsThis British Standard is based upon the guide Improving the flood performanceof new buildings - flood resilient con
9、struction published by the Department forCommunities and Local Government in May 2007. It takes account of additionalresearch into the reaction of modern materials and construction methods toflooding and has been extended to apply to retrofitting of floodresistance/resilience to existing buildings,
10、as well as to new buildings. It providesgreater detail than the core document of the same title that can be freelydownloaded from http:/ about this documentCopyright is claimed on Figure 2. Copyright holders are CIRIA, Griffin Court,15 Long Lane, London EC1A 9PN and the Environment Agency, Rio House
11、,Waterside Drive, 710715 Aztec West, Almondsbury, Bristol BS32 4UD.Use of this documentAs a guide, this British Standard takes the form of guidance andrecommendations. It should not be quoted as if it were a specification or a codeof practice and claims of compliance cannot be made to it.Presentatio
12、nal conventionsThe guidance in this standard is presented in roman (i.e. upright) type. Anyrecommendations are expressed in sentences in which the principal auxiliaryverb is “should”.Commentary, explanation and general informative material is presented insmaller italic type, and does not constitute
13、a normative element.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDARDBS 85500:2
14、015ii The British Standards Institution 2015IntroductionThis British Standard is intended to help identify when flood resilient andresistant construction is appropriate and to give guidance on achieving these.This standard is applicable to new buildings, extensions and the retrofitting ofexisting pr
15、operties.National and local planning policies discourage inappropriate development inareas at risk of flooding. This standard does not promote development in floodrisk areas, but provides guidance on reducing the potential consequences wherebuildings are located in an area at risk of flooding.This s
16、tandard is intended to help manage residual risk after other measures orapproaches, such as avoiding risk, locating development in an area of low risk orraising floor levels (see 6.2), have been implemented.1 ScopeThis British Standard gives recommendations and guidance on how to improvethe resistan
17、ce and resilience of buildings to reduce the impacts of flooding fromall sources, by the use of suitable materials and construction details. Specifically,it provides:a) recommendations for the adoption of flood resistant and resilientconstruction measures, including when to apply resistance and when
18、 toapply resilience; andb) guidance on the design and specification of flood resistance and resiliencefor new buildings, extensions and retrofits.The guidance covers masonry, light-weight steel-frame and timber-framebuildings.It is not applicable to:1) the structural design or layout of buildings;2)
19、 the selection, fixing and deployment of flood protection products which arecovered by other standards, such as PAS 1188 and Delivering benefitsthrough evidence: Temporary and Demountable Flood Protection Guide 1;3) the design of watertight concrete, which is specified in BS EN 1992-3;4) the constru
20、ction of amphibious or floating properties;5) the construction of properties on stilts; or6) detailed avoidance measures outside the perimeter (footprint) of thebuilding, such as local land raising above the predicted flood level.2 Normative referencesThe following documents, in whole or in part, ar
21、e normatively referenced in thisdocument and are indispensable for its application. For dated references, onlythe edition cited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.BS 8102, Code of practice for protection of below ground st
22、ructures againstwater from the groundBS 8533, Assessing and managing flood risk in development Code of practiceBRITISH STANDARD BS 85500:2015 The British Standards Institution 2015 1BS EN 13914-1, Design, preparation and application of external rendering andinternal plastering Part 1: External rende
23、ringPAS 1188-1, Flood protection products Specification Part 1: Building apertureproducts3 Terms and definitionsFor the purposes of this British Standard, the following terms and definitionsapply.3.1 flood avoidanceconstruction of a building and its surrounds in such a way as to avoid (at sitelevel)
24、 it being floodedEXAMPLESRaising ground or floor level above the predicted flood level, re-siting outsideflood risk area, landscaping to direct/divert flood water away from building, theuse of bunds.3.2 flood resistanceconstruction of a building in such a way as to prevent or minimize flood waterent
25、ering the building and damaging its fabricNOTE Also known as “dry-proofing”.EXAMPLEUse of low-permeability materials.3.3 flood resiliencemeasures that can be incorporated into the building fabric and/or fixtures andfittings that can be installed to reduce the consequences of flood water enteringthe
26、propertyNOTE 1 This allows easier drying and cleaning following a flood and reduces theamount of time until the building can be reoccupied.NOTE 2 Also known as “wet-proofing”.EXAMPLESUse of sacrificial materials for internal or external finishes, e.g. gypsumplasterboard placed so that it can easily
27、be removed below the flooded leveland replaced, or materials that can resist the effects of flooding, e.g. tiledfinishes.3.4 water entry strategydesign strategy based on allowing water to enter a property rather thanpreventing its ingress3.5 water exclusion strategydesign strategy based on the use o
28、f impermeable materials to minimize theingress of water into a propertyBRITISH STANDARDBS 85500:20152 The British Standards Institution 20154 Context4.1 Resistance and resilience informed by flood risk assessmentNational and local planning policies discourage inappropriate development inareas at ris
29、k of flooding. This British Standard does not promote development inflood risk areas, but provides guidance on reducing the potential consequencesfor buildings located in an area at risk of flooding.The resistance and resilience measures recommended in this standard are basedon a design strategy cho
30、sen in accordance with 6.1, which in turn should beinformed by a site-specific flood risk assessment for the building or developmentsite. These measures should only be applied after other measures, such asavoiding risk by locating development in an area of low risk or raising floorlevels, have been
31、implemented (see 6.2).The flood risk assessment should be carried out in accordance with BS 8533. Keyparameters of this assessment are the expected flood depth, duration andfrequency, since these determine the likelihood of being able to keep water outof the building (resistance), and whether it is
32、more cost-effective to plan forwater ingress (resilience). In general terms, flooding associated with greaterdepths and longer durations requires the adoption of the water entry strategy,while shallow and short-duration flood water requires a water exclusion strategyand measures that do not need to
33、be deployed by the householder. While theinitial design strategy is based on the flooding characteristics, this might bechanged subsequently to reflect the building construction type and performancerequirements, the sensitivity of contents, the capability and circumstances of thehouseholder, and the
34、 budget.4.2 Types of flood and their characteristicsFigure 1 shows typical durations for different types of flooding.Overland flow or exceedance of the sewerage infrastructure typically affects aproperty for up to a few days. However, in some areas the duration of floodingcould be limited to only a
35、few hours because the source of the flooding is anintense rainfall event. Such flooding would be expected to have a shallowdepth. In contrast, groundwater is associated with extensive rainfall over a longperiod that has filled the available below-ground storage. Once established, thisflooding can co
36、ntinue for many weeks or months. Although groundwaterflooding affects fewer properties than other sources of flooding it often causesmore damage. Failure of flood defences can result in significant flood depthsand velocities in the zone immediately behind them, with impacts such asbuilding damage or
37、 fatalities.All of these flood characteristics (depth, duration and frequency of occurrence)are important in the choice of design strategy and the measures employed todeal with the flooding. However, although flooding can result from a singleevent or source, it more commonly occurs through a combina
38、tion of events.Intense rainfall can lead to overland flow, but also cause watercourses to fill andovertop their banks. The flooding characteristics are determined as part of thesite flood risk assessment (see 6.1).If the likely flood depths (generally of existing properties) are determined to behigh
39、 (600 mm), a structural engineer should be consulted to assess thestructural integrity of the building and potential strengthening measures.BRITISH STANDARD BS 85500:2015 The British Standards Institution 2015 3Figure 1 Typical flood durations4.3 Construction opportunitiesNew buildings should be loc
40、ated, designed and constructed such as to preventthem from being flooded, taking account of the type, depth, duration andfrequency of flooding.When any work is being undertaken on an existing building (including floodreinstatement), the opportunity should be taken to improve the flood resistanceand
41、resilience characteristics of the building, even if it has not been flooded buthas been identified as at risk in the flood risk assessment.An extension should provide at least the same level of flood resistance andresilience as the rest of the building, taking account of the flood risk assessment.Ho
42、wever, where the existing building does not have the necessary level of floodresistance, as established from the flood risk assessment, the extension should beappropriately flood resilient. Ideally, flood resistance and resilience should beprovided as part of the construction work, to allow for the
43、resilience of thewhole building to be improved over time as opportunities arise.4.4 Other considerationsThe design of flood resistance and resilience of a building needs to take accountof the requirements of local planning (including listed building status,conservation areas and other designations),
44、 Building Regulations 2, 3 and 4and health and safety. Existing construction and occupation types need to beconsidered.5 Response of buildings5.1 GeneralThe impact of flood water on a building depends on the nature of the floodingand the design and construction of the property. In order to be able t
45、o improvethe flood performance of the building it is first necessary to understand theimpact of flooding on the materials, components and elements of the building.A risk-based approach can then be adopted.BRITISH STANDARDBS 85500:20154 The British Standards Institution 2015Resistance and resilience
46、measures are aimed at minimizing water entry andavoiding excessive damage to the building, respectively, and both can reducedisruption to the occupiers.The impacts of flooding on buildings include the following:a) direct deterioration of materials, components and elements resulting inimmediate chang
47、e of their form and properties without returning to theirprevious condition after drying;b) direct structural damage caused by the depth, duration and velocity of floodwaters on the building structure, including debris impact;c) inundation or saturation of materials that cannot be dried or recovered
48、economically on site;d) temporary contamination of the internal and external surfaces, as well ascavities in walls and floors; andNOTE 1 Temporary contamination by flood water does not normally representa health hazard once dry and thoroughly cleaned as necessary.e) indirect secondary damage, such a
49、s mould growth and other problemsarising from high atmospheric moisture.NOTE 2 Secondary damage can be minimized by prompt action after anincident, especially drying measures.Table 1 summarizes the potential flood impact on property, based upon depthand velocity, while Figure 2 demonstrates potential routes for entry of floodwater into a dwelling.Table 1 Possible flood damage for a typical residential propertyFloodwater levelDamage to the building Damage to services andfittingsBelow
