SFS - A designer’s guide to specifying warranted austenitic ......A designer’s guide to...

A designer’s guide to specifying warranted austenitic stainless steel fasteners and sealants

CI/SfB Reference by RIBA SfB Agency

Xt6January 2008

email: [email protected]: 0113 2085 578TechnicalFax: 0113 2085 539 1

Contents

Introduction to the SFS Group of companies

Section 1 Introduction 1.1 Performancecriteriaoffastenersandsealants 1.2 Industryassociationsandpartnershipswithleadingsystemsuppliers 1.3 Examplesofrecentinnovations

Section 2 Durability (Corrosion resistance) 2.1 Theproblem 2.2 Fastenermaterials 2.3 Limitationsofcoatedcarbonsteel 2.4 Typesofstainlesssteel 2.5 Carbonorstainless?Specificationselectionconsiderations 2.5aSystemmaterials 2.5bDesignliferequirements 2.5cExternalenvironment 2.5dInternalenvironment/buildinguse 2.5eProject-basedlongtermwarrantyrequirements 2.6 Fastenermaterialselectortable 2.7 SFSintecausteniticstainlesssteelfastenerrange

Section 3 Weathersealing 3.1 Theproblem 3.2 Washerdesign 3.3 Specialistfastenerdesignforweathersealing 3.4 Specialistwarrantedsealants&clampingfastenersforweathersealing

Section 4 The “Part L” issue - Airsealing and thermal bridging 4.1 OverviewofBuildingRegulations-2002&2006-Theproblem 4.2 Eliminationofthermalbridgingbythermallybrokenfasteners 4.3 Achievingairtightnesswithwarrantedsealants&clampingfasteners

Section 5 Aesthetics by design 5.1 Theproblem 5.2 Factory-colouredsolutions 5.2a Mouldedheadsolution 5.2b Unobtrusiveheadsolution 5.2c Obtrusiveheadsolution 5.2d Singlepointglassfixings

Section 6 Technical performance 6.1-6.15 Technicalperformancecriteria

Section 7 Specification design support 7.1 Modelspecifications 7.2 Innovationandquality 7.3 Technicaladvisoryservice 7.4 Training-CPDSeminarsandon-siteSection 8 Case studies

A designer’s guide to the specification of warranted fasteners and sealants

Co

ntents


Introduction to the SFS Group of companies

TheSFSGroupofcompanies,whichhasitsheadquartersinHeerbrugg,Switzerland,isoneoftheworldsleadingdevelopers,manufacturersandsuppliersofhighprecisioncomponentsforavarietyoftechnicalindustries.

TheSFSGroupdirectlyemploysover3900personnelandin2006turnedover£530million.

Global manufacturingTheGrouphasglobalmanufacturingthroughcentresinSwitzerland,France,USA,Italy,SwedenandUK.

Global sales and marketingProductsaresuppliedintotheglobalmarketthroughSFSsalesandmarketingorganizationsstrategicallylocatedinmanycountries.

UK HeadquartersTheUKheadquarters,whichincludesmanufacture,logistics,andsalesandmarketing,isbasedinLeeds.FastenershavebeenmanufacturedonthisKirkstallRoadsiteforover100yearsandin1997theplantwasredevelopedresultinginafacilityunrivalledintheUKfastenerindustry.FromthissiteSFSintecLtdcanofferarchitects,designers,consultingengineersandcladdingenvelopecontractorsaprovencommitmenttoproductquality,soundtechnicalsolutionsandefficientservice.

Commitment to investment and innovationTheSFSGrouphasaphilosophyofgrowingitsbusinessbyitscommitmenttoreinvestingtoensurestate-of-the-artfacilitiesand,throughitsextensiveresearchanddevelopmentdepartment,tocontinualinnovationofnewproductsandservices.

Industry associations SFSintecisactivelyrepresentedonthetechnicalcommitteesoftheleadingroofingandcladdingassociationswhoseektoencouragebestpracticeandconformancetoallrelevantregulations.


Globalsalesandmarketing

Globalmanufacturing

Section 1 IntroductionThespecificationofthefastener,despitebeingsuchasmallcomponent,iscriticaltotheperformanceoftheroofingandcladdingsystem.Thefastenerworksinclosecombinationwithsealingproducts,thereforethespecificationofthefastenerandsealingproductsneedtobeaddressedattheearlystagesofdetaildesignoftheprojecttoenablethecompletedenvelopetoperformitsrequiredfunctionthroughoutthefulltermofthesystem’sserviceanddesignlife.

1.1 Performance criteriaThisguideaddressestheprincipleperformancecriteriaoffastenersandsealants,namely;

Durability (corrosion resistance)WeathersealingThe “Part L” issues of airsealing and thermal bridgingAestheticsTechnical performance

Eachparticularapplicationwillneedthevariousproductstocomplywithatleastthreeofthesecriteriaandoften,aswithexternallyexposedfasteners,willrequireallfive.Failureoftheproductstosatisfythesecriteriamayleadtotheinevitable,andsometimescatastrophic,failureofthesystemor,attheveryleast,costlyremedialworks,sometimesevenbeforetheprojectcanbehandedovertotheClient.

Thisguidewillgiveyouthekeyinformationneededforyoutospecifyfastenersandassociatedsealstominimizetheriskofsystemfailure.

1.2a Industry associations Theguidancegiveninthisdocumentisgenerallyconsistentwithpublicationslistedbelowfromtheseassociations,aswellasthatgivenwithinBS5427:Part1:1996-thecodeofpracticefortheuseofprofiledsheetforroofandwallcladdingonbuildings.

NFRC -TheNationalFederationofRoofingContractorsAguidetogoodpractice,ThirdEdition1999andsubsequentTechnicalBulletinsMCRMA -TheMetalCladdingandRoofingManufacturersAssociationDesignGuides&TechnicalPapersEPIC-EngineeredPanelsInConstruction

SPRA-TheSinglePlyRoofingAssociationSingleply-CodeofPractice

MMC Alliance-Modernmethodsofconstruction

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Sectio

n 1Intro

ductio

n


1.2b Partnerships with leading system suppliersSFSintecalsoworkscloselywithmanyoftheUK’sleadingmanufacturersofroofandcladdingmaterialstokeepuptodatewiththeirowndevelopmentsaswellasseekingtodevelopmoreefficientfasteningandsealingsolutionsfortheirsystems.

1.3 Examples of recent innovations

1.3a Development with Corus Building Systems (KalZip)DevelopmentofSDKselfdrillingfastenersforsecuringaluminiumhalterstoreduceinstallationtimeoftheKalZipsystemandensurehalterfastenerscannotbeoverdriveninsiteconditions.

1.3b Development with SarnafilDevelopmentofathermallybrokenfasteningsystemtoeliminatetheeffectofcoldbridgingwithinsulationandmembranefasteners.

1.3c Development with Ward Insulated PanelsDevelopmentofaself-coringfastenertoeliminatetimeconsumingprecoringandbackfillingontheirTopdekpreengineeredinsulatedroofmembranesystem.


Section 2 Durability ( Corrosion resistance )Definition-“likelytolast”,“remainingusefulforlongperiods”,

“resistingwearanddecay”Ref;Oxford Dictionary

2.1 The problemIfthecontractorisallowedtousecarbonsteelfastenersfortheroofingandcladding,corrosionwillresultinanumberofproblems,andifallowedtoprogress,ultimatefailureofthesystemmayoccur.

2.1a Problems due to corrosion of the head and washerStainingofthecladding

Reductioninpulloverperformance

Potentialleakageinto/throughthesystem

Increasedmaintenance&remedialwork

2.1b Problems due to corrosion of the shankReductionintensileperformance

Reductioninshearperformance

Reductioninpulloutvalues

Stainingtointeriorsurfaces

2.1c Problems due to hidden corrosionWhilstcorrosionofexposedheadsontheexternalfaceofthebuildingandcorrosionofthevisibleshankinsidethebuildingarebotheasilyidentified,whatisconsideredamuchgreaterstructuralandsecurityriskisthatofcorrosionwithintheroofingorcladdingsystem.Thiswouldnotbevisibleandwouldonlymanifestitselfuponultimatefailureofthefastener,whichwouldresultinpartial,andpotentiallytotal,detachmentofthesystem.

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Sectio

n 2D

urability


2.2 Fastener materialsThreadedfastenersforroofingandcladdingsystemsareavailableinthemarketplacemostcommonlyintwomaterials,coatedcarbonsteelandstainlesssteel.

Aluminiumthreadedfastenersarealsoavailable,howevertheirrangeofapplicationisgenerallyrestrictedtosecuringaluminiumprofilestotimbersupportsandlimitedapplicationsofaluminiumtoaluminium.

2.2a Coated carbon steelCarbonsteelrapidlycorrodesonexposuretohumidity.Fastenersinthismaterialaresuppliedwithsomeformofprotectivecoating,typicallymetallicororganic,oracombinationofthetwo.Cadmiumhasinthepastalsobeenusedasaprotectivecoatingbysomefastenermanufacturers.However,thisisacontrolledsubstancethatishazardoustohealthandthereforereputablemanufacturerswhooperaterecognisedQualityandEnvironmentalManagementSystems,aswellasenforcingHealthandSafetyProcedures,nolongerusecadmiumasaprotectivecoatingonthreadedfasteners.

2.2b Stainless steelForincreaseddurability(corrosionresistance),fastenersarealsomanufacturedinvariousgradesofstainlesssteel.

TherelativemeritsofthesegradesarediscussedingreaterdetailinSection2.4

OverthefollowingparagraphsinSection2.3ofthisguidewillbeexplainedthelimitationsofcoatedcarbonsteelandthetypesof“stainless”steelsappropriatetoroofingandcladdingfasteners,andthedifferentaspectsthatshouldbeconsideredinorderthatthechoice,appropriatetotheproject,canbemadebetweencoatedcarbonor“stainless”steel.


2.3 Limitations of coated carbon steel

2.3aUncoatedcarbon steel rapidly corrodesuponexposuretohumidityandpollutedenvironments

Surfacecoatingswithexcellentcorrosionresistancecanbeappliedtoprolongafastener’slifebuttheywillonly slow down the corrosionprocess

Theeffectivenessofthesecoatingscanonlybegaugedafterconsideringtheconditionof the coating once the fastener has been appliedwithintheconstruction

Thesecorrosionresistantsurfacecoatingstendtohavepoor abrasion resistance

2.3b Pitched roofing and cladding systems;Coatingsonfastenerswithinmosttypesofmetalpitchedroofingandcladdingsystemswillinevitablysufferdamage during installationasthemajorportionoftheshankpenetratesthemetalweathersheetandpurlin.

2.3c New flat roof constructionsThereislessriskofcoatingdamagewithinnew“flat”roofingconstructionsasthefastenerisusuallyappliedthroughlessabrasivematerialssuchastheinsulationboardsandweatherproofinglayer(s)-thereforethecoatingsaremoreeffective,however;

2.3d Refurbishment over flat roofsThereisanincreasedriskofcorrosionofcarbonsteelasthecoatingmaybeabradedasitpassesthroughmaterials(chippings)withintheexistingbuild-up.Additionallythereistheprobabilityofincreasedmoisturecontentwithintheexistingbuildupwhichwouldacceleratethecorrosionrate.

2.3 Keynote summaryWill coated carbon steel satisfy all your requirements?

Coating damage reduces fastener life

Corrosion leads to reduced technical performance

Corrosion leads to potential water ingress

Corrosion reduces aesthetic value

Coated carbon steel may be adequate for some less onerous applications - however consider possible change in use during building lifespan

Corrosion of carbon steel fasteners may lead to high consequential damage costs, disruption costs and expensive remedial costs

Fasteners must have at least an equal life to the proposed roof system

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2.4 Other types of “stainless” fasteners.Becauseofthehightechnologicalinvestmentrequiredforthemanufactureofbi-metallicausteniticstainlessselfdrillingfasteners,alternativematerialsandmethodsofhardeninghavebeenintroducedbysomedistributorsclaimingaperformancecomparabletobi-metalausteniticgrades.Independenttestshavehighlightedfundamentalweaknesseswiththesealternativestainlessproducts.

2.4a Nitrided stainless fastenersThereisaprocessavailablewhichhardensstainlesssteelthreadedwire,includingausteniticgrades,sufficientlytoenablethemtoself-drillmildsteelwithouttheneedtoincorporatethehardenedcarbonsteeldrillpoint(bi-metallic)element.

However,theprocessusedresultsinchromiumbeingwithdrawnfromthesurfaceofthestainlesswirewhichreducesitscorrosionresistance.Thismethodisreferredtoasnitriding.

Toreinstatecorrosionprotection,thefastenersmaythenbecoatedwith,typically,azinc/organiccoating….similartothecoatingappliedtocarbonsteelfasteners.

Itisthiscoatingthatprovidesthecorrosionprotectionand,asdescribedinSection2.1&2.3,thecoatingwillbeinevitablydamagedduringinstallation,whichwouldacceleratethecorrosionrateandthusprovideonlytemporarycorrosionprotection.

2.4b Modified martensitic stainless fastenersWhilstmartensiticgradesofstainlesssteelfastenerswithonly11%chromiumareknowntohavepoorcorrosionresistance,someaspectsoftheircorrosionperformancemaybeimprovedbymodificationofthematerialinvolvingchangingtheelementmixoftheirformulationandapplyingcertainmanufacturingtechniques.

Onesuchmanufacturingtechniqueinvolvesutilizingawirewithanextremelyhardsurface(>550HV)whichenablesthemtoselfdrillmildsteelwithouttheneedtoincorporatethehardenedcarbonsteeldrillpoint(bi-metallic)element.SuppliersclaimthismaterialoffershigherresistancetocorrosionwhensubjectedtoacceleratedKesternichandSaltspraytests-thisissubjecttothethreadformingqualityachievedwhichhasbeenshowntobevariable.

Hydrogen and stress corrosion brittleness

However,real-lifeexposuretestsinanumberofenvironmentalconditionshaveshownthistypeoffastenermaterialtobesubjecttohydrogenandchlorideinducedstresscorrosionandbrittleness-thiswouldn’thavebeenevidentunderKesternichandSaltspraytesting.Thistypeofbrittlecorrosionisinherentinthehardmaterialandisnotnecessarilyvisibletothenakedeye.

AsaresultofextensiveresearchworkcarriedoutbycorrosionexpertsinGermany,SwedenandtheUKonthistypeofmaterial,SFSintechavebeenadvisedthattherisksassociatedwithmodifiedmartensiticfastenersforroofingandcladdingaresignificantandthereforewecontinuetocomplywithindustryguidelinesandStandardsbymanufacturingstainlesssteelselfdrillersfromausteniticgradeswithabi-metallichardeneddrillpoint.

2.4 Keynote summaryAustenitic stainless steel fasteners, such as grades 304 and 316, have been proven over a period exceeding 40years in environmental conditions worldwide. Austenitic grades are the only type recommended within BS5427:Part :1996.

To enable selfdrilling through mild steel (of up to 14mm thickness), fasteners in these grades are manufactured with a bi-metallic hardened carbon steel drillpoint.


Corrosionofnitridedstainless

Non-chromesurfacelayeronnitridedstainless

Brittlefailureofmodifedmartensiticstainless

Stesscracksinmodifedmartensiticstainless

2.4 Types of stainless steel“Rusting”isregardedbymanyasaprocesswhichisnotapplicabletostainlesssteel-thisishoweverincorrect.“Stainless”steelisagenerictermcoveringover200differenttypesofalloywhichall,tovaryingdegrees,stain-lessthancarbonsteel.Stainlesssteelscanbeclassifiedintothreemaingroups;

Austenitic, Ferritic and Martensitic.

2.4a Austenitic stainless steelOnlygradesconformingtoBS5427:1996(seenote1)Containsatleast17%chromiumContainsatleast8%nickelMolybdenummaybeaddedforenhancedcorrosionresistanceNon-hardenable(seenote2)Non-magnetic(seenote3)Lowthermalconductivity;25%ofcarbonandmartensiticstainlesssteelBestknowngradesare304and316

Excellentcorrosionresistance(seenote4)

These characteristics make austenitic stainless steels the only suitable type for selfdrilling/threadforming fasteners for roofing and cladding.

2.4b FerriticContainsatleast12%chromiumLowerductilitythanmartensiticsandausteniticsCannotbehardenedSusceptibletobrittleness

These characteristics make ferritic stainless steels unsuitable for the manufacture of selfdrilling/threadforming fasteners for roofing and cladding.

2.4c MartensiticContainstheminimumchromiumcontentof11%PoorcorrosionresistanceSusceptibletostresscorrosionCanbehardened(attheexpenseoffurtherstresscorrosionrisk)Highthermalconductivity(similartocarbonsteel)MagneticModifiedformsavailablebutstresscorrosionconsideredtoogreatarisk

(see2.4bonpage11)

These characteristics make martensitic stainless steels unsuitable for self drilling/threadforming fasteners for roofing and cladding.

Note 1-Clause2.8.3fromBS5427:Part1:1996-Codeofpracticefor:Theuseofprofiledsheetforroofandwallcladdingonbuildings.Part1:Design.Note 2-Thethreadrollingprocesshardensthethreadssufficientlytothreadformbutnotenoughforselfdrillingintomildsteelsupportsegpurlinsandrails.Therearespecialtechniqueswhichincorporateaheattreated(hardened)carbondrillpointtobejoinedtoanausteniticstainlessfastenertoallowselfdrilling.Thesemaybereferredtoasbi-metalfasteners.Itisvitalthat,onceinstalled,allthreadswithinandabovethesupportareausteniticstainless.Note 3-Extremecoldformingofausteniticstainlesssteelwirecanimpartasmalldegreeofresidualmagnetismwithoutadverselyaffectingthematerialsproperties.Note 4-Itisacknowledgedwithinindustrydocumentationthatcertaingradesofstainlesssteel,includingsomeausteniticgrades,maybeatriskofchlorine-inducedstresscorrosioninconditionswhichmayoccurforexample,inswimmingpoolhalls.Poolhalldesign,plannedoperatingandmaintenanceconditionsmustbecarefullyconsideredbywatertreatmentexperts,aswellasarchitectsanddesigners,tominimiseanyrisk.Gradesofstainlesssteelwhichmaybesusceptibletochlorine-inducedstresscorrosionshouldbelimitedtothosecomponentsusedin“nonsafety-critical”applications,i.e.inthoseconditionswhichwouldnotresultinpersonalrisk/injuryintheeventoffailure.Thereisnohistoryoffailureofthreadformingroofingandcladdingfastenersoverswimmingpoolsandwewouldnotconsidersuchfastenersforsecuringoverpurlin/railmetalcladdingsystemsas“safety-critical”.Austeniticstainlessfasteners,typically304,offerthedesignerappropriateandreadilyavailablesolutionswithproveninsignificantrisk.

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2.5 Coated carbon or austenitic stainless steel? Selection considerations:Inorderthatadesignerorspecifiercanmaketheappropriateselectionbetweencoatedcarbonsteelorausteniticstainlesssteel,thefollowingconsiderationsshouldbeaddressed;

2.5a System materials2.5b Design life requirements2.5c External environment2.5d Internal environment / building use2.5e Project-based long term warranty requirements

All these should be considered in the overall risk assessment.

TheseconsiderationshavebeentabulatedunderSection2.6toassistinfastenermaterialselection.


2.5a System materials

2.5a i) Pitched roofing and cladding systemsCompatibilitywiththesheet/systemmaterialaswellasthepurlin/railwillinfluencethechoicebetweencoatedcarbonsteelorausteniticstainlesssteelfasteners.

Typicalmaterialsforthesystemandsupportmayinclude;

StainlesssteelCoatedmildsteelAluminiumFibrecementCementitiousboardsHighpressurelaminates“Plastics”-GRP,polycarbonatesandPVCTimber

2.5a ii) Flat roofing systemsItisgenerallythecompatibilityofthedeckthathasadirectinfluenceonthechoicebetweencoatedcarbonsteelorausteniticstainlesssteelfasteners.

Decktypesinclude;Coated(galvanized)steelAluminiumTimber“Concrete”

2.5a iii) Cautionary notes;Refurbishment over existing roof coverings -generallyflatroofing.Theinsulationtypewithinflatroofingdoesn’tgenerallyinfluencethefastenermaterial,however,onrefurbishment,wheretheexistinginsulationandweatherproofingistoremain,itistheconditionratherthantypeoftheexistingbuildupwhichwillinfluencethefastenermaterialchoice.Ifthereisdampnesswithintheexistingbuildupitwouldbeprudenttouseausteniticstainlessfasteners.

Timber preservatives;Timbercomponentsusedwithinconstructionareoftentreatedwithpreservatives.GuidanceontimberpreservationisincludedwithinBS4072:Part2:1987andBS5268:Part5:1989.GenerallytreatmentsfallintoeithertheOSorCCAtype(organicsolventsorcopper/chromium/arsenic).OStypetreatmentsarenotconsideredtohaveanycorrosiveeffectoncoatedcarbonsteelfasteners,however,ifthetimberislikelytobecomewet,corrosionwouldbeexpected.ThepresenceofCCApreservativesintheseconditionswillincreasetheriskofcorrosion.“Ifthetimberislikelytobecomewetandalongservicelifeisrequired,usefittingsofausteniticstainlesssteel…inpreferencetoothertypese.g.carbonsteel”.

2.5a Keynote summaryIt is industry practice to use austenitic stainless steel fasteners in combination with aluminium and stainless sheet/system materials. Coated carbon steel fasteners could be considered with all other system materials depending on their suitability relative to the following Selection considerations under 2.5 b) - e).

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2.5b Design life requirementsTheclient,orhisagent,shouldspecifytheintendeddesignlifeoftheproposedbuildingandindividualproducts,componentsorassemblies.

BS7543:1992 Guide to: Durability of buildings and building elements, products and components

GuidanceisgiveninTables1and2belowandourinterpretationwithregardsfastenermaterialselectionisreproducedopposite.

Table 1 - Categories for design life for buildings

Note 1:Specificperiodsmaybedeterminedforparticularbuildingsinanyofcategories2to5providedtheydonotexceedtheperiodsuggestedforthenextcategorybelowonthetable;forexamplemanyretailandwarehousebuildingsaredesignedtohaveaservicelifeof20years.Note 2:Buldingsmayincludereplaceableandmaintainablecomponents-seeTable2below

It is clearly evident that many of the buildings where fasteners and cladding envelope sealants are used within the roofing and cladding construction are going to be, at the least, in Category 3, Medium Life, 30 years minimum.

Table 2 - Categories of design life for components or assemblies

DependinguponthedesignlifeforthecompletebuildingasselectedfromTable1,thecomponentsandsystems,forexampletheroofingandcladdingenvelope,arethenselectedbutalsohavetobecategorizedfromTable2aseitherreplaceable,maintainableorlifelong.

ExtractsfromBS7543:1992arereproducedwiththepermissionoftheBSI.CompleteeditionsofthestandardscanbeobtainedfromBSICustomerServices,389ChiswickHighRoad,LondonW44AL


Category Description Building life

of Category

Examples

1. Temporary Agreedperiod

upto10years

NonPermanentsitehutsandtemporaryexhibitionbuildings

2. ShortLife Minimumperiod

10years

Temporaryclassrooms;buildingsforshortlifeindustrialprocesses,office

internalrefurbishment;retailandwarehousebuildings

3. Mediumlife Minimumperiod

30years

Mostindustrialbuildings;housingrefurbishment

4. NormalLife Minimumperiod

60years

Newhealthandeducationalbuildings;newhousingandhighquality

refurbishmentofpublicbuildings

5. LongLife Minimumperiod

120years

Civicandotherhighqualitybuildings

Category Description Life Typical examples

1. Replaceable Shorterlifethanthebuildinglifeand

repacementcanbeenvisagedatdesignstage

Mostfloorfinishingsandserviceinstallation

components

2. Maintainable Willlast,withperiodictreatment,forthelifeof

thebuilding

Mostexternalcladdings,doorsandwindows

3. Lifelong Willlastforthelifeofthebuilding Foundationsandmainstructuralelements

2.5b Design life requirementsAshasbeennotedfromtheTable1onthepreviouspage,thedesignlifeforthemajorityofindustrial,commercialandpublicsectorbuildings,aswellasotherspecialistusebuildings,willfallwithintheMediumLifecategoryofaminimum30years.Table2thengivesthedesignlifeforthecomponentsorassembliesusedwithintheconstruction.

Fasteners and sealant design life relative to Table 2:

2.5b i) Question: Can fasteners and cladding envelope sealants be classed as “Replaceable” ?Non-exposedfastenersandsealingproducts,bothweatherandairseals,canoftenonlybeaccessedbyremovaloftheexternalweatheringsheet.Insomecasesremovaloftheweatheringsheetinordertoaccessconcealedfasteners,withinitsrequireddesignlife,maynecessitatethatitbetotallyrenewed.Iffastenersandsealsweretodegradewithinthedesignlifeofthesystem,theninstallingnewfasteners,bothexposedandnon-exposed,intotheirexistinglocationwouldoftenresultingreatlyreducedpulloutvaluesandthereforepresentastructuralrisk(unlessapurpose-designed“repair”fastenerwereused).Asafurtherexample,insulatedpanelfastenershaveenlargedthreadsundertheheadto“support”theouterskinandmaintainaweatherseal(section3.3a).Ifthefastenerprematurelycorrodes,thentheresultingleakagemaydamagethesheetaroundtheholesuchthatsimplyinstallinganewfastenermaynotprovidetherequiredlevelsofsheetsupport.

Answer-FastenersandsealingproductsarenotclassedasReplaceable

2.5b ii) Question: Can fasteners and cladding envelope sealants be classed as “Maintainable” ?Asnotedabove,non-exposedfastenersandsealscanonlybeaccessedbyremovaloftheexternalweatheringsheet.Exposedfastenersmay,intheory,havetheirvisibleparts“recoated”butthisshouldnotberegardedasacceptableatthedesignstageofaproject.Furthermore,applyinganewcorrosionprotectivecoatingtothevisiblehead,providinganappropriatepretreatmentcanbecarriedout,aswellasbeing,inmostcases,aestheticallyunacceptable,wouldnotreinstatecorrosionprotectiontotheconcealedshankwhichmayalsobesufferingfromcorrosion.

Answer-FastenersandsealingproductsarenotclassedasMaintainable

2.5b Keynote summaryFasteners and cladding envelope sealants are not Replaceable or Maintainable. They therefore have to be designed and selected to be Lifelong. ie they must have a design life at least equal to that of the roofing and cladding system within which they are used.

Coated carbon steel fastenerscouldbeconsideredforonlyTemporaryandShortLifebuildingsandlimitedbuildingtypesintheMediumLifecategory.Austenitic stainless steel fastenersshouldbeconsideredasthepreferredchoiceforMediumLifecategoriesandtheonlyappropriatechoiceforNormalandLongLifecategories

Weather and air sealing product specificationsshouldalsobecompatiblewiththedesignlifeofthesystemanditsfasteners.



2.5d Internal environment / building useSomebuildinguses,andtheprocessestheyhouse,canpresentveryonerousinternalenvironmentalconditionsuponthefastenersandseals.Insuchcases,coatedcarbonsteelwouldnotbeconsideredanappropriatefastenermaterialchoice.

2.5d i) Building use - “At risk” categories;Duetotheirgeneralfunctionandinternalconditions,austeniticstainlesssteelfastenersshouldbeconsideredonthefollowingbuildingcategories

Leisureindustry…Swimmingpools,sportscentres,stadia.

Schools

Hospitals

Transportindustry…Airportterminalsandbuildings,ferryanddocklandfacilities,railwaybuildings

Waterindustry…sewageandwatertreatmentworks,pumpingstations

Powerstations

Manufacturing…Paper,pharmaceuticals,chemicals,brick&masonryproducts,breweries,textiles,food&drink

2.5d ii) Building use - further “At risk” categories;Additionally,therearesomeotherbuildingcategorieswhich,eventhoughtheirinternalenvironmentmaybenon-aggressive,demandthatausteniticstainlessfastenersbeconsidered.Thepotentialforleakageresultingfromcorrosionofcoatedcarbonsteelmayresultindamagetoexpensive/sensitiveequipmentandcouldalsobeextremelydisruptivetotherunningofthebusiness.

Hygiene,Foodprocessing

Electronics,computerequipment

Highvaluegoods

2.5d iii) Building use - lower risk categoriesTypicalbuildinguseswherecoatedcarbonsteelfastenershavebeenshowntoperformadequatelyforperiodsoffunctionallifeexpectancyupto25yearsandthereforewherecoatedcarbonsteelcouldbeconsideredinclude;

Retail

Distribution

Manufacturingof“dry”goodssuchasassemblylines,windowsanddoors,automotiveproducts,whitegoodsetc.

2.5d Keynote summaryFrom the above it can be seen that the internal environment / building use has a major influence on the choice of fastener material and that austenitic stainless steel should, in most instances, be specified. Specifying austenitic stainless would also eliminate any future risk if the building use changes.

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2.5c External environmentTheUKsclimateisclassedaswarmtemperatewithraininallfourseasons.BuildingsintheUKarethereforesubjectedtoawiderangeofexternalenvironmentalconditionswhich,initself,presentsonerousconditionsforroofingandcladdingsystemsintermsofresistancetowind,wateringress,UVandcorrosion.

Inadditiontotheclimaticconditionspresentduringeachseason,thelocalatmosphericconditionsintheimmediatevicinityofthebuildingarecriticalintheselectionofcoatedcarbonorausteniticstainlesssteelfasteners.

Typical atmospheres may be divided as in the following table;

Marine Upto2kmfromthesea.Highlevelsofchlorides

Coastal Between2kmand10kmfromthesea

Industrial Atmosphereheavilypollutedbysulphurdioxideandother pollutants,typicallynitricoxides,chlorine,hydrogenchloride, formicacid,aceticacid,allinthevicinityofcorresponding industrialplants.

Urban Denselypopulatedandpollutedbysulphurdioxide

Rural Smallertownsandvillagesgenerallyfreefromatmospheric pollutionconducivetocorrosion.

Note;Veryoftenthesedifferenttypesofatmosphereoverlap,thuspresentinganevenmoreaggressiveexternalenvironmentforboththecladdingsystemanditsfasteners.Forexample,therearemanymarineandcoastalareaswhichareheavilyindustrialised.

2.5c Keynote summaryThe corrosion rate of coated carbon steel fasteners is difficult to predict, however it can be stated with a degree of certainty that;

Coated carbon steel fastenerswouldcorrodewhenexposedtoanyoftheseexternalenvironmentsandthecorrosionratewillincreaseasyoumoveupthetable.

Austenitic stainless steel fastenersaredurableinalltheseexternalenvironmentsandshouldbespecifiedinmarineandcoastalenvironmentsand,inmanycases,wouldberecommendedinindustrialatmospheres.

Cladding envelope sealing productsspecificationsshouldalsobecompatiblewiththedesignlifeofthesystemanditsfasteners.

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Marine

Rural


2.5e Project-based long term warranty requirementsThereisanincreasingdemandbyclientsandbuildingownersfortheperformanceofproductswithinthebuildingconstructionandenvelopetobewarranted.Theroofingandcladdingindustryhasrespondedtothesedemandsandvariouswarrantyschemesarenowavailable.

2.5e i) Industry Association system based;Warrantiesareavailablethroughanumberofindustryassociations-somewarrantworkmanshipaswellasmaterials.Usuallyaninsurancepremiumisrequiredtobepaidwhichisapercentageoftheenvelopecontractvalue.

2.5e ii) System suppliers warranty schemes;Theprinciplesystemsuppliermayoperatewarrantyschemesforthecompletesystem.Sotheycaneliminatetheriskofsystemfailureduetoancillaryproducts,theprinciplesystemsupplierwillspecifycomponentstobeusedinconjunctionwiththeirproductstomakeupatotalsystem.Warrantiesarethenobtainedfromtheirpartnersuppliersandinstallersandasingletotalsystemproject-specificwarrantyisthenpassedtotheclient.

Systemsupplierwarrantyschemesdonotnecessarilyrequireapolicypremiumtobepaidbytheclient.

SFSintecworkscloselywiththeleadingsystemsupplierswhospecifyfastenersandancillaryproductssuchassealantsappropriatetothewarrantyperiodrequired.

2.5e iii) Component suppliers warranties;Asanalternativetothewarrantyschemesabove,theclient(throughhisarchitect/designer)maywishtospecifyandobtainseparateindividualproductwarrantiesfromallthevarioussupplierswhosecomponentsareusedorspecifiedwithinthesystem,andalsotheinstallerifworkmanshipistobewarranted.

2.5e Keynote summaryProject-specific warranty;Clientsshouldbeencouragedtoobtainwarrantieswhichareproject-specific,andoftenupto30years-andtheseshouldincludeallcomponentscriticaltothebuildingenvelope.Onlyausteniticstainlessfastenerswouldbedeemedtoprovidetherequiredlevelofperformance.

Beware,warrantiesshouldnotbelimitedtosimplysupplyingmoreproducts-theclientshouldseekthere-assurancethatthewarrantycovers“making good the roof”.Theclientshouldensurethesuppliertakesfullresponsibilitywithinthewarrantyoffered.

Products Liability Insurance;ThechoiceofsuppliershouldalsobelimitedbywhethertheirproductionplantsoperateQualityandEnvironmentalManagementSystemsandhavecertificationshowingconformanceto,forexample,ISO9001:2000andISO14001:1996.


2.6 Fastener material selector table Thesections2.1to2.5ofthisguidehavedrawntotheattentionofthedesignerandspecifiertheproblemsrelatingtofastenerDURABILITYandexplainedthedetailedconsiderationsthatmustbemadeinorderthatthecorrectfastenermaterialcanbespecified.Thetablebelowhasbeendesignedtoassistthespecifierintheselectionofthemostappropriatefastenermaterialforeachindividualproject.

Table showing guide to selection of exposed fastener material

Note 1 -Sheet/deckmaterial

Thistablegivesguidanceonthefunctional life expectancyoftheexposedfastenerinvarioussheetmaterials.Consultwiththesheetmanufacturerregardingthemostappropriatesheetmaterialandcoatingsystemanditsfunctionallifeintheparticularenvironment.

Note 2-Non-exposedfasteners

Forcarbonsteelfastenerswhicharenon-exposedtotheexternalenvironmentthefunctionallifewouldbesimilartothosetabledaboveforcarbonsteelwithintegralcolourhead.

Note 3-Warranty

TheperiodsshownintheTableareforfunctional life expectancy.Asitisdifficulttopredictapreciselifeexpectancyofcarbonsteel,itwouldbeprudenttousetheminimumperiodsfordesignpurposes.

Whereafastenerwarrantyisrequired,SFSinteccanwarrantcarbonsteelupto10yearsandausteniticstainlesssteelupto30years.PleaserefertoSection2.5eonpage18forwarrantyoptionsandconsultSFSintecforyourProject-SpecificWarranty.


Fastener material

Environment Functional life expectancy of fastener

Max Sheet/deck material ( see note 1 )warrantyof fastener

Internal External Aluminium Coated steel Stainlesssteel

GRP/PVC fibrecement

Coated carbon steel & push-on cap

Dry/LowHumidity

Urban/rural 10/20 10 0 ✔ 0 ✔

Industrial 10/15 10 0 c 0 c

Coastal/Marine - - 0 ✘ 0 ✘

HighHumidity

Urban/rural 10/15 10 0 c 0 c

Industrial 10 10 0 c 0 c


Coated carbon steel with integral colour head

Dry/LowHumidity

Urban/rural 15/25 10 0 ✔ 0 ✔

Industrial 15/20 10 0 c 0 c


HighHumidity

Urban/rural 10/15 10 0 c 0 c

Industrial 10 10 0 c 0 c


Austentitic stainless steel

AllConditions

Urban/rural 30+ 30 ✔ ✔ ✔ ✔

Industrial 30+ 30 ✔ ✔ ✔ ✔

Coastal/Marine 30+ 30 ✔ ✔ ✔ ✔

Key Recommended✔ NotRecommended✘ Unsuitable0 Checkwithmanufacturerregardingsuitabilityc

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APPLICATION DESCRIPTION CODE FASTENER

APPLICATION DESCRIPTION CODE FASTENER

SX3/10-L12-S16*-5.5 x 28S19 washer to roof

S19 washer to roof

SX14/12-L12-S16*-5.5 x 40

SXL2-L12-A14-5.5 x 22

SXCP5-S19*-5.5 x Length

SXCP14-S19*-5.5 x Length

SLP2-S-A14-4.8 x 20

SDK2-S-377-6.0 x 35/45

SDK3-S-377-6.0 x 35/45

SX2/18-A166.3 x 35/45

TDC-S-S16-6.3 x Length

TDB-S-S16-6.3 x Length

SX3/10-D12-5.5 x 28

SX3/10-S16*-5.5 x 28

SX14/12-S16*-5.5 x 40

SL2-S-S14-4.8 x 22

TI-S-6.3 x Length

Telescope TH-75 x Length Fastener IT2-S-C-4,8xLengthTelescope TH-42 x Length Fastener IT2-S-C-4,8xLength

GA-AS-S16-6.5 x45 C

GAZ-811-Ø 22 x 32mm

41AL-PUNKT-30-8Metric Screw M8x45Wood Screw 8x60

41AL-SENK-30-6CountersunkBolt M6x40Wood screw 6x60

SFS

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21

20

A designer’s guide to the specification of warranted fasteners and sealants A designer’s guide to the specification of warranted fasteners and sealants

Drillerforcoldrolledsteelwithirius®head,colouredwherevisible.

Drillerforhotrolledsteelwithirius®head.

Drillerforclamping/stitchingwithirius®head,colouredwherevisible.

DrillerforinsulatedpanelstocoldrolledsteelwithcolouredSelamouldedhead.

DrillerforinsulatedpanelstohotrolledsteelwithcolouredSelamouldedhead.

Drillerforclamping/stitchingwithcolouredSelamouldedhead.

Drillerforsecuringstandingseamsystemhalterstodeckswithspecialdrivesystemtoeliminateovertorque.

Drillerforsecuringstandingseamsystemhalterstocoldrolledpurlins/tophatswithspecialdrivesystemtoeliminateovertorque.

Drillerforsecuringstandingseamsystemhalterstocoldrolledpurlins/tophatswithhexagonalhead.

Tapperforcoldrolledsteelwithhexagonalhead.

Tapperforhotrolledsteelwithhexagonalhead.

Drillerforsecuringstandingseamsystemclipstocoldrolledpurlins/spacerswithlowprofilehead.

Drillerforsecuringmetaldeckingtocoldrolledpurlinswithhexagonalhead.

Drillerforsecuringmetaldeckingtohotrolledpurlinswithhexagonalhead.

Drillerforclamping/stitchingdecksidelapswithhexagonalhead.

Thermallybrokenfasteningsystemforinsulationtometaldeck,comprisingofafastenerinstalledthroughapolyamide“telescopetube”

Thermallybrokenfasteningsystemforinseamfasteningofsingleplymembranesthroughinsulationtometaldeck,comprisingofafastenerinstalledthroughapolyamide“telescopetube”

Tapperforattachmentofbracketsandsupportstoconcrete.

TapperforsecuringHPLpanelstosteel,aluminiumandtimbersubstrateswithmalethreadonheadtotaketheGAZDesignerRangebelow.

Powdercoatedaluminiumormillfinish304gradeausteniticstainlessDesignerHeads.

304gradestainlesssteeloraluminiumsinglepointraisedheadglassfixings.

304gradestainlesssteeloraluminiumsinglepointflushheadglassfixings.12

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Single ply membrane over insulationon metal deck.

Rainscreen systems.

Single point glass fixings - raised head.

Single point glass fixings - flush head.

Site assembled liner panel systems.

Insulated panel systems.

Aluminium standing seam systems.

Clip fix systems.

2.7 SFS intec austenitic stainless steel fastener range Having explained in Section 2 the durability benefits associated with austenitic stainless fasteners, designers can be reassured that austenitic stainless fasteners for virtually all roofing and cladding applications are available in the marketplace.

Thetablesinthissectiongivesexamplesoffastenersavailablerelativetothevarietyofroofingandcladdingsystems.Unlessnotedotherwise,allfastenersshownaremanufacturedfrom300seriesausteniticstainlesssteel.TherearemanyothertypesavailableandSFSintecwillbepleasedtogiveadviceonspecificapplicationsonthecontactdetailsbelowore-mailingdetails/[email protected]

SFSintechas,inconsultationwithaleadingsealantmanufacturer,developedarangeofweatherandairsealantsdesignedexclusivelytoaspecificationwhichenablesthemtobewarrantedforperiodsupto30yearsandthuscompatiblewiththeSFSintecausteniticstainlesssteelfastenersshownabove.ThesizesofthestripsealantsareasrecommendedbyleadingsystemsuppliersandeitherSFSintecortheappropriatesystemmanufacturercouldbeconsultedforthepositioningandsizeofthestripsealantsspecifictothechosensystem.TherangeissupportedbytestdataconductedinaccordancewiththeNFRCTechnicalBulletin36andisclassedasacross-linkedbutylTypeA+andiscolouredpinkforeaseofidentification.FurtherinformationwithregardsweatherandairsealingisgiveninSections3.4&4.3ofthisguide.

6mmx5mmSFSsealTypeA+pinkstrip

4mmbeadSFSsealTypeA+pinkstrip

6mmbeadSFSsealTypeA+pinkstrip8mmbeadSFSsealTypeA+pinkstrip

18mmx4mmUSFSsealTypeA+pinkstrip

22mmx5mmUSFSsealTypeA+pinkstrip

50mmx1mmSFSPolybandTypeA+pinkstripType A+ sealants for metal roofing

and cladding


Section 3 Weathersealing

3.1a Poor washer designExposedfastenersi.e.thosewhichpenetratetheexternalweatheringsheet,havetosealthepenetrationinthesheetforthedesignlifeoftheroofingandcladdingsystem.Exposedfastenersarethereforesuppliedwithasealingwasher.Thedesignofthewasher,andinsomeapplicationsthedesignofthefasteneritselfatthesheetinterface,isthereforecriticaltoensurelongtermperformancecompatiblewiththerestofthesystem.

The total sealing washer design must therefore be resistant to the following;

Environmental conditions;General weathering

Water ingress

Acid rain

Ultra-violet rays

Ageing

Mechanical loadings;Pullover (wind suction)

Abrasion

Splitting

Vibration

Movement (wind/thermal) of sheet

Site applications;Overdriving

Oblique/Non-perpendicular driving

3.1b Poor sealant designEndlapsandsidelapsonprofiledexternalroofsheets,aswellastheexternalflashingsatalljunctions,needtobeeffectivelysealedtoprovidecontinuityoftheweathertightenvelope

Thesesealantshavetowithstandmanyoftheenvironmentalconditionsandmechanicalloadingsasnotedaboveforthefasteners.Manyofthesealantsuppliersarenotpreparedtogivemeaningfulwarrantiesontheirstandardsealantranges,suchthattheycouldbecompatiblewithafastenerorsystemwarrantyof30yearsasreferredtounderSection2.5ofthisguide.

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Sectio

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eathersealing

3.2 The sealing washer solution.Long-term securitySFSintechasconsideredallthevariousperformancerequirementsofthesealingwasher,inconjunctionwiththefastenerdesignrelativetotheparticulartypeofroofingsystem,andhasengineeredweathersealingdesignstoprovidelong-termsecuritycompatiblewiththefastenerandthematerial/systembeingfastened.

3.2a EPDM sealing elementSealingwashersshouldbespecifiedwithanEPDMelastomer(EthylenePropyleneDieneMonomer)asthesealingelement.Anelastomerisamaterialwhichcanberepeatedlystretched(andcompressed)toatleasttwiceitsoriginallengthandwillthenreturntoitsoriginallengthimmediatelytheloadisreleased.Duetoitsoverallperformance,EPDMisanestablishedmaterialwithinthefastenerandbuildingindustriesand,inmostinstances,hasreplacedneoprenewhoselimitationsincludereducedresistancetogeneralweathering,ultra-violetradiation,waterandtemperature,aswellasageing.

ThethicknessandhardnessoftheEPDMshouldbedesignedrelativetothefastenertypeandwasherdiameter,forexamplewherasthenormalhardnessis70/80shore,onclampingandinsulatedpanelfastenersamuchsofterEPDMof40shoreisused,referto3.3a&b.

3.2b Metal backingToensuretheEPDMcompressesevenlyandformsasealagainstboththesheetandthefastenershank,theEPDMshouldbevulcanizedtoametalbackingwasher.Merelyglueing,asisthepracticeofsomemanufacturers,wouldpresentariskoftheEPDMdelaminating.Theproblemwithloosesealingelementsisclearlyillustratedonthepreviouspagewhere,foranumberofreasonsassociatedwithpoorfastenerdesign,thesealingelementhas“extruded”beyondtheheadofthefastenerandhasbeendestroyedwiththeresultthatthesealwillnolongerbeeffective.

3.2c DiametersSealingwashersareavailableinawiderangeofdiametersfrom,typically,12mmto32mm.

Forprimaryvalleyfixingofthrough-fixedmetalroofweathersheetsandinsulatedroofpanels,19mmisusuallythepreferreddiameter.

For“plastics”rooflightprofiles-typicallyGRPandpolycarbonate,largerdiameterwashers,typically32mm,orinsomeinstancescrownsaddlewashers,arerecommended.

Forwallingsystemsandsecondary(clamping)fasteners,smallerdiameters,typically12mm-16mm,areused.


19mm&32mm

12mm&16mm


3.3 Specialist fastener designs to ensure weathersealing3.3a Insulated panel fastenersThe problemFactoryformedinsulatedpanels,andalsosite-assembled,bytheirverynature,havea“non-rigid”section(theinsulationcore)betweentheexternalskinandthesupportingpurlin.Notallinsulatedpanelfastenersareadequatelydesignedfortheapplicationandthereforefailtoprovidethelong-termcompressionandsealingofthewasherleadingtowateringress.

Purpose-designed insulated panel fastenersThesearedesignedwith“dualthreads”.Theloweronesthreadformintothepurlinandaretypically5,5mmdiameter.Attheheadandwasherendofthefastenerthereisatopthreadsectionofanincreaseddiameterdesignedtosupporttheouterskinofthepanelandthusimpartpermanentcompressionofthewasher.

Top thread performanceThishastobedesignedtoaccommodateallpositiveloadingconditionsincludingconcentratedfootloads.Thetopthreadshouldbedesignedtosupportaloadof1.26kNconcentratedonthepanelaroundthefastener.AtestthatcouldbeadoptedisdefinedinBS5427:Part1:1996,AnnexA,ClausesA.4.3&A.5.c.Insulatedpanelfastenersshouldbedesignedwithaminimumtopthreaddiameterof7mmwiththisperformancerequirementinmind.Manyalternativesuppliershavetopthreadssignificantlylessthan7mm,typically6.1-6.4mmmaximum,andthereforethesupportgivenwillinevitablybereducedthusleadingtoaweathersealrisk.

Thread-free sectionForoptimumperformance,designsmayalsoincorporateathread-freefeatureimmediatelybehindandbelowthewasheroninsulatedpanelfasteners.ThisenablestheweatherskintobepermanentlysupportedthuscompressingtheEPDMwasher.Thiscompressionandsealwillbemaintainedeveninconditionswherethefastenerisusedtodrawthepanelbacktothesupportorwherefastenersareoverdriven.Alternativedesignswithtopthreadsextendingrightuptotheheadpresentamajorriskinboththeseconditions.

3.3b Clamping fasteners to ensure weathersealingClampingfastenersarepurpose-designedtoclampthinmaterialstogether(e.g.sidelapsofprofiledmetalsheets)andforfixingflashingsandclosurestoprofiledmetalsheetsandtothemselves.Useofinnappropriatefastenersmayleadtoovertorqueinwhichcase,notonlyisweatherandairtightnesscompromised,butalsothestructuralperformanceofthefastenerislostandcomponentsmaybecomedetached.Clampingfastenersshouldincorporatefeaturestoensurestructuralperformanceandweathertightness.

Reduced diameter drillpoint-highpulloutandclampingforcesWRS washer-thickerandsofter(40shore)thanonprimaryfastenerstoensureasealoverarangeofapplicationthinnesses.Thread free (free spin) zone-todrawandclampthematerialstogetherandtoeliminateanyweatherandairtightnessriskassociatedwithover-driving.

3.4 Specialist warranted sealants to ensure weathersealing Refertosection4.3.

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Insulatedpanelfasteners

Clampingfastener

Section 4 The “Part L” issue - Airsealing & Thermal Bridging

4.1a Overview of April 2002 Part AD-L2A ThechangesintheBuildingRegulations,whichbecameeffectiveinApril2002,soughttoaddresstheproblemsresultinginheatlossthroughthecladdingenvelope.Thosemostrelevanttofastenersandsealantsresultedininsulationthicknessesinthecladdingenvelopevirtuallydoubling(U-valuereductions)andareductionintheproblemofair-leakagethroughthesystemprincipallybyinstallingadditionalairseals.Anothercontributortoheatlossisthermalbridgingthroughthesystem.Thiscouldbethroughpoordesignatjunctionsandalsoviametalfastenerswhichpassthroughthewholesystem,particularlyonmechanicallyfastenedflatroofingsystemswherethereistypicallyahigherdensityoffasteners.

4.1b April 2006 Part AD-L2A England & Wales Part F2:2006 N. Ireland and Section 6:2007 Scotland (in preparation)

AfurtherenhancementoftheRegulationsrequiresthedesignerstousetheNationalCalculationMethodology(NCM)todeterminetheenergyuseofthewholebuilding,includingthefabric,lighting,heating,ventilationandcoolingsystems.Thenewsoftwarecalculationtool-theinterfaceforSimplifiedBuildingEnergyModel(iSBEMv1.2.a)isusedwithintheNCMforbuildingsotherthandwellings.ThetargetistofurtherreducetheTER(TargetEmissionRate)fromthe2002notionalbuildinglevelbyaround24%.

What impact will these changes make on the external cladding envelope?- U-values -Itisgenerallyfeltthat,withthenewcalculationmethodologyforthebuildingsCO2emissions,afurtherreductioninU-values(ie.increasinginsulationthicknesses)ofthecladdingenvelopewillonlyhaveminimaladditionalpracticalimpactonthebuildingsenergyefficiencyoverthechangesalreadyimplementedin2002.

- Natural lighting -Oncertaintypesofbuilding,theprovisionofnaturalrooflightingmayallowareductionintheuseageofelectriclightingthusmakingsignificantcontributionstothebuildingsenergyefficiency.ThiswillusuallymorethancompensateforthehigherU-valuesnormallyassociatedwiththerooflightelementoftheroof.

- Cold Bridging-Elimination/reductioninthermalbridgeswillremainanimportantdesignconsiderationatjunctions,interfacesandfasteners.

- Air-tightness-Increasingair-tightnessfromthe2002levelsof10m3/sqm/hrwillgenerallyshowagreaterbenefitandafurtherincreaseinair-tightnessmaybechosenbythedesignerasasignificantcontributoryfactortocompliancetotheBuildingRegulations.


Sectio

n 4T

he “Part L” issue


4.2 Elimination of cold bridges by using thermally broken fastenersOnmechanicallyfastenedinsulationboardsandroofingmembranes,“thermallybroken”fasteners(Telescope)presentapracticalandeconomicsolution.Itshouldalsobenotedthatthethermalconductivityofausteniticstainlesssteelfastenersisonly25%ofcarbonsteelfasteners(referto2.4c)andthisgivesafurtheroptiononthrough-fixedflatandpitchedcladdingsystems.

4.3 Achieving airtightness with warranted sealants Generally,toachievetheserequiredlevelsofairtightness,additionalsealingmaterialshavetobeincludedwithinthesystem.Thesesealsareusuallyinstalledattheinnerliningpositioniebelowtheinsulation…thefollowingsection4.3givesfurtherinformationonthespecificationoftheseals.

CorusColorshavepublishedaTechnicalPaperentitled“Creatinganair-tightbuildingenvelope-April2006”whichgivesfurtherusefulguidanceonachievingair-tightnessonbuilt-upandinsulatedpanelsystems.

Warranted sealantsThereareanumberofmechanicalandacceleratedtestsdevelopedbysealantmanufacturersforroofingandcladding.ThebasictestsdeemwhetherthesealsareclassedasTypeAorTypeB.TheNFRCpublishedTechnicalBulletin36whichgivesasummary.However,thereisaneedforthesealstobewarrantedforupto30yearsthusbeingcompatiblewiththeausteniticstainlessfastenersandsheetsystemasreferredtoinsection2.5.SFSintecworkedcloselywithaleadingsealantmanufactureranddevelopedahighperformancebutylstripsealantrangeforprofiledroofingandwallingsystems.TheirperformanceunderallthemechanicalandacceleratedtestsexceededthebasicrequirementofaTypeAsealantsuchthatSFSintecareabletoissueawarrantyforupto30years.ThiswarrantedSFSintecsealantisreferredtoasTypeA+andiscolouredpinkforeaseofidentification.

Clamping fasteners (referto3.3b)

Toensurethatthewarrantedsealantsperformeffectivelywithintheapplication,theyhavetoworkincombinationwiththepurposedesignedclampingfastenersdiscussedwithinsection3.3b.


ThreadfreezoneforweathertightclampingonSFSstitchingfasteners

Coldbridgingviaall-carbonsteelfasteners

Section 5 Aesthetics by designHistorical backgroundDuringthe1970s,themarketshareforcolour-coatedcladdingmaterialsdramaticallyincreasedprincipallywithintheindustrialandretailbuildingsectors,andtodaycolour-coatedcladdingrepresentsover90%oftheirtotalmarket.

Colour-coatedmaterialsarealsonowwidelyusedaspartofthecladdingenvelopeonmanyotherbuildingtypessuchaseducational,healthcare,residential,leisureandtransport-relatedbuildings.

Freedom of designTherangeofshapesandprofilestowhichthesecolouredmaterialscanbeformedhasgiventhearchitectmuchfreedomofdesignandgreatattentionisnowpaidtotheaestheticsofconstructiondetailsandinterfacesratherthanmerelytheirfunctionalperformance.Designersareabletousecolourandshapetocreateaestheticappealandimpacttoattractinvestorsandtosupporttheirclientscorporateimage.

Colouring of fastenersWherevisiblefastenersareusedtosecurethesecolouredmaterials,itis,virtuallywithoutexception,desirablethatthefastenerheadispermanentlycoloured.

5.1 The problemSomecontractorsmaychoosetofixthecolouredcladdingmaterialswithplainhexagonalheadedfastenersandthensite-applyapush-fitcolourcap.

There are many potential problems with this option;

i)Capsmaybemissedoff

ii)Capsmaybecomedislodgedafterinstallation

iii)Capsareexpensivetoreplace

iv)The“plastic”maysufferUVdegradation

v)Thecapmaysufferfromcolourinstability

vi)Capsmayentrapmoisture-leadingtocorrosionstaining

vii) Capsdonotofferlifespansmatchingthecladding

viii) Capsareslowtoinstall

Theseareproblemsforboththecontractor,whomayhavetomakereturnvisitstoreplacecaps(snagging),andtothebuildingownerwhosuffersalossofaestheticappealandimageandtheexpenseassociatedwithrestoringtheoriginalintendedfinish.


Sectio

n 5A

esthetics


5.2 Factory-coloured solutionsToaddressthemanyproblemsassociatedwithpush-fitcaps,SFSintechasdevelopedrangesofcolouredandaestheticallyshapedfasteningsystemswhichhaveevolvedwiththeintroductionofnewcladdingmaterialsandprofiles.Thesehavebeendesignedwiththedesiresofthespecifiers,contractorsandbuildingownerstakenintoconsideration.

5.2a The moulded head solutionTheoriginalSelacolouredheadwasdevelopedbackinthe1980sandisproducedbyinjectionmouldingthethrough-coloureddryvirginnylonaroundthemetalheadformofthefastenertoformanintegralbi-hexagonalcolouredhead.Thistraditionalmouldeddesignensuresapermanentcolour-matchedheadfromthemomentofinstallation,thusprovidingthecontractorandbuildingownerwithasimplesolutiontoalltheproblemsassociatedwithpush-fitcaps.

5.2b The “unobtrusive” solutionWherethedesignerselectsawallcladdingmaterialorprofileforitshighaestheticappeal,itmaybemoredesirablethatthefasteningsystemisunobtrusiveandblendsinwiththecladding.Somewallingsystemsaredesignedsuchthatthefastenersaretotallyconcealed,forexample,flatormicro-ribbedinsulatedwallpanelsareoftenfixedthroughtheir“tongue&groove”joint.

However,therearemanywallingsystemswhicharevisiblyfixedandtheraisedheadsoftraditionalmouldedheadedfasteners,eventhoughtheymayofferlongtermcolourmatching,maynotmeettheaestheticrequirements.

Lowprofilecolouredheadformshavebeendevelopedspecificallyforapplicationswherethefastenerhastofulfillallitsnormalstructuralrequirementswhilst,atthesametime,blendinunobtrusivelywiththecladding.

Theirius®headformmaybepowdercoatedforcolourmatchingpurposesandtheinnovativeunderheaddrivesystemenableseaseofinstallationwhilstalsoofferingahighleveloftamper-resistance-aestheticswithsecurity.


Selaheadform

Irius®headform

UnobtrusiveIrius®atWalesMillenniumCentre

ColouredIrius®headform

5.2c The “obtrusive” solutionAsacompleteoppositetothe“unobtrusive”headstyleoftheirius®range,thedesignermaywishthatthefastenersaredeliberately“obtrusive”andcreatesurfacefeatureson,forexample,flatcladdingpanels.

SFSintecthereforedevelopedthedesignerrangeoffastenerswheretheboldoutstandingheadformishighlyvisible.

Thereisarangeofprofileheadsineitherausteniticstainlessoraluminium,whichmaybepowdercoatedforcolourmatchingorcontrastingpurposes.

Thefeatureheadsaremanuallyscrewedontothemalethreadontheheadoftheprimaryfastenerwhichsecuresthepanelstothestructure.

Topreventtheheadsfrombeingremoved,forexampleoninstanceswherethefastenersmaybewithinreach,theyarefactory-coatedwithathreadlockingcompoundwhichisactivatedduringapplication.

5.2d Glass attachment with style and eleganceGlasshasneverbeeninsomuchusearchitecturally.Therearestructurallystrongandaestheticallypleasingfixingsystemsavailableforavarietyofglassapplications;

Single-point fixings-Single-pointglassfixingsystemsaredesignedtomeetthestringentrequirementsintermsofboththeirvisualappearanceandtheirstructuralsafety.Thecombinationofchromiumandglassoffersanappealingeffectpopularwithbothclientsandarchitectsalike.Combiningthepracticalwiththeaestheticallypleasingoftencreatesrealarchitecturalworksofart.

Canopy attachment systems-Canopysystemsarenowavailableasaninnovativetotalpackagewhichenablesglasscanopiestobeattachedwithsingle-pointglassretainers.Theindividualcomponentsofthesystemcanbecombinedtosuitthetypeofcanopyandsubstructure.Theentiresystemremainsbiaxiallyflexiblethroughtheuseofforksandrings.Theadvantageofthisisthatthecanopystructureisresistanttopressureandsuctionloading.

Balustrades and Staircases-Glassfixingsalsoenablebanistersandbalustradestobecreatedsimplyandeconomically.Theholdersaredesignedassleeves.Noweldingonsiteisnecessaryastheretainersarefastenedwithpress-fitnutsandcorrespondingbolts.Highqualitymaterialsandfinishesprovideapermanentandsecureretentionoftheglasspanels.

SFSinteccanworkwiththearchitectandglasssystemsuppliertoprovidefixingsolutions.



Sectio

n 6Technical

Section 6 Technical performance criteriaApartfromdurability,weathersealing,airsealing,andaesthetics,fastenershavetobecapableofwithstandingawiderangeofloadingsandotherperformancecriteria.Thesetechnicalperformancecriteriatendtobespecifictotheparticulartypeofcladdingsystemandthereforefastenersaredesignedsuchastogiveoptimumperformancecompatiblewiththerequirementsoftheparticularsystem.

Typicaltechnicalperformancecriteriawhichinfluencefastenerdesigninclude;

6.1 Pullout and tensile forces 6.9 Clamping & sealing6.2 Pullover resistance 6.10 Shear performance6.3 Concentrated foot loadings 6.11 Non-fragility6.4 Dynamic bend resistance 6.12 Material compatibility6.5 Unwinding 6.13 Windloadings 6.6 Clamping of membrane 6.14 Fastener frequencies 6.7 Thermal/cold bridging 6.15 Tooling6.8 Overdriving resistance

6.1 Pullout and tensile resistanceThisistheabilityofthefastenersthreadedconnectionbetweenthetwocomponentstoremainintactandresistallaxialandtensileloadings.

Selfdrilling fastenersItisnowawidelyacceptedindustrypracticethatselfdrillingfasteners,whichareinstalledinasingleoperation,arepreferredtotappers,whichrequiretheadditionalpredrillingoperation.

Selfdrillersarenowavailableforthemajorityofcladdingsystemsformetalsupportthicknessesupto14mm.

Thebenefitofselfdrillersisnotlimitedtotheobviousoneoftimesaving.Selfdrillersalsoprovidemoreconsistentandoptimumpulloutresistancefromthesupportingmaterial.Tappersrequiretheinstallertouseanon-worndrillofthecorrectdiameterspecifictothemetalthickness,andtopredrillwithoutwobble,otherwisethepulloutvaluesachievedwillbevaried(ahighstandarddeviation)andsignificantlylowerthanpublisheddatafromlaboratorytesting.

Selfdrillersaremanufacturedwiththeirownintegraldrillpointswhichareengineeredtoefficientlydrillandthreadformintoapredeterminedmetalthickness,resultinginmuchmoreconsistentperformancethusreflectingpublishedtestvalues.

Thedrillpointdiameterandlengthispurpose-designedforaspecificrangeofmetalthicknesses.

Toassisttheengineerandspecifier,SFSintecpublishesresultsoflaboratorytestingonallfasteners.Thisincludesfastenerpullout,showingthemeanultimatefailureloadandalsothestandarddeviation.Thisenablesthecalculationofthecharacteristicvalueforeachfastenertowhichanappropriatesafetyfactorcanthenbeapplied.BS5427:Part1:1996AnnexBmaybeusedforreference.


Pullouttesting

Purpose-designeddrillpoints

Section 6 Technical performance criteria continued

6.2 Pullover resistanceThisistheabilityofthefastenertopreventthesheetmaterialfailingbypullingovertheheadofthefastener.

AsreferredtoinSection3onWeathersealing,resistancetopulloverfailureofthesheetisinfluencedbythesheetmaterialthicknessandtensilestrengthincombinationwiththestrengthanddiameterofthewasher.

Thefastenersupplierspecifiedshouldbeabletoprovidetheengineerwithpublishedtestresultsofvariouswasherdiametersinvarioussheetmaterialsandthicknesses.

6.3 Concentrated foot loadingsThetwoprincipleapplicationswherefootloadingshavetobeconsideredinfastenerdesignaremetalfacedinsulatedroofpanelsandsingleplyroofmembranesoverinsulationboards

Insulated roof panels

AsdescribedinSection3.3a,thetopthreadofinsulatedpanelfastenershastobedesignedsothatitwillcontinuetosupporttheexternalskinofthepanelagainsttheconcentrateddynamicloadsimpartedbyfoot-traffic.Withtheappropriatesafetyfactor,thetopthreadshouldbedesignedtosupportaloadof1.26kNconcentratedonthepanelaroundthefastener.AtestthatcouldbeadoptedisdefinedinBS5427:Part1:1996,Codeofpracticefor:Theuseofprofiledsheetforroofandwallcladdingonbuildings,AnnexA,ClausesA.4.3&A.5.c.

SFSintecsinsulatedpanelfastenersaredesignedwithaminimumtopthreaddiameterof7mmwiththisperformancerequirementinmind.

Manyalternativesuppliershavetopthreadssignificantlylessthan7mm,typically6.0-6.4mm,andthereforethesupportgivenwillinevitablybereducedthusleadingtoaweathersealrisk.

Thisenlargedthreadalsoworksincombinationwiththethread-freezone,whosefunctionisalsodescribedinSection3.3a,toensurebothawalkableandweathertightconnection.

Single ply membranes over insulation boards

Themembranemustbeprotectedagainsttheriskoftheinsulationandmembranefastenerpuncturingthemembraneasaresultoffoottrafficcausinglocalcompressionoftheinsulationboard.

TelescopesystemssuchastheSFSintecIsotakrangeareautomatically“treadfast”asthefastenerheadissetdowntowardsthebottomofthetelescope.

Onallmetalfastener/washercombinations,thefastenershouldhaveanenlargedthreadontowhichtheinsulationandseamwasherissupported.


Pullovertesting

SheetsupportandthreadfreesectiononSFSinsulatedpanelfasteners

“Treadfast”telescope


6.4 Dynamic bend resistanceWhereinsulatedpanelsarethrough-fixed,thefastenersarealsosubjecttorepetitivebendingforces.Theseforcesaretypicallygeneratedbypaneldeflectionsfrom(wind)loadingsandthermalmovement.Thisbendingtendstobegreaterinhot-rolledsteelpurlinswhichtendtobelessflexiblethanthinnercold-rolledpurlins.

TheEuropeanConventionforConstructionalSteelwork(ECCS)Document66,PreliminaryRecommendationsforSandwichPanelsdefinesatestmethodtowhichfastenermanufacturershavetobeabletodemonstratecomplianceandadvisethemaximumallowabledeflectionrelativetosteelsupportandpanelthickness.

6.5 UnwindingPitched roofing systemsHistorically,thisphenomenomhasnotbeenwidespreadwithinpitchedroofingsystems.However,whereconditionsofpotentiallyhighdifferentialmovementbetweenthesheetand“lightweight”framingpresentthemselves,cautionintheselectionofthemostappropriatefastenertypeshouldbeexercised,andSFSintecwouldwelcomebeingconsulted.

Flexible membrane systems to “thin” metal decksAsthewindpassesovertheflexiblemembraneaneccentricforcepassesthroughthefastener.TheSFSisofastsystemisabletoaccommodatethesedynamicwindloadsbynatureofits“reduced”diameterdrillpoint,thetaperedlead-inthreadsectionanditsshallowthreadpitchangle.Thesefeaturescombinetogivetotalthreadengagementwithinthedeckandtoalsoprovidetheoptimumpulloutfrom“thin”,0.63mmminimum,steeldecks.

6.6 Clamping of membraneOnin-seamfastenedsingleplymembranes,thewasherorstressplateisdesignedtoresistanysidewardsmovementofthemembranewhichcouldultimatelyleadtotearing,slippageandfailureofthemembrane.SFSinteccanofferavarietyofstressplatedesignswhich,duetotheirhighclampingqualitiesmayallowa25%increaseinthefastenersafeworkingload.

Unlessthemembranesuppliertakesfullresponsibilityforthefastenerfrequencycalculations,confirmationshouldbesoughtfromtheparticularmembranesupplierthattheproposedfasteningsystemanditspermissibleloadingsareappropriatetotheirmembrane.

6.7 Thermal/cold bridgingApprovedDocumentAD-L2:2006requiresthedesignertocalculatethermalbridgesandconsidertheireffectonbothcondensationandalsoheatlossthroughthebuildingenvelope.

Incertaintypesofroofingandcladdingsystems,fastenersmayaddtoheatlossdependingontheirspecification.

Thethermalconductivityofcarbonsteelasafastenermaterialis60W/mKwhereasausteniticstainlessisonly17W/mK.ThereforespecifyingausteniticmayallowthinnerinsulationtobeusedandstillachievecompliancewiththeBuildingRegulations.

Asanexample,inatypicalflatroofapplicationwith4fastenerspersqm,theadditionalheatlossthrough100mminsulationwithcarbonfastenersexceeds1.5%comparedtoonly0.25%withausteniticstainlessfasteners.Wherecoatedcarbonsteelofferssufficientdurability,thenusingathermallybrokentelescopicsystem(seesection4.2)wouldalsoallowthinnerinsulationtobeused.


SFSisofastdrillpointandthreadform

Coldbridgingviaall-carbonsteelfasteners

ECCSBendtest

Section 6 Technical performance criteria continued

6.8 Overdriving resistanceOverdrivingoffastenersmayleadtothreadstrippingwithinthesupportingstructure,particularlyin“thin”coldrolledsections.“Traditional”designsofselfdrillingthreadedfastenersrelyupontheinstallertotakethenecessarycarenottooverdrive,eitherbyuseofdepthlocatorsonscrewgunsorexperience.Fortwoparticularapplicationswherethefastenerperformanceiscriticialfortheintegrityofthesystem,SFSintechasdevelopedinnovativesolutionswhich,bydesign,cannotbeoverdriven.

SDK fasteners for aluminium haltersDuetothehighexpansionrateofaluminiumsheets,fastenerssecuringhaltersforaluminiumstandingseamsystems,suchasKalZip,EuroseamandKeyBemo,oftenhavetowithstandveryhighandrepetitiveshear/tensileforces.Toeliminatetheriskofsystemfailureduetooverdrivenfasteners,theSDKdesignoffastenerisdrivenviathesquarepegontheheadwhichisdesignedtobreakoffwhenthefasteneristightenedtothecorrectlevel.

“Thick to thin” applicationsOnsomebuilt-upmetalsystems,particularlywherethereisanacousticand/orhighinsulationrequirement,a“thick”tophatmaybeinstalledontothe“thin”liner/deck.Traditionallyarivetwouldhavebeenusedastheriskofoverdrivingwith“standarddesign”drillersisconsideredtoogreat.Howeverarivetisextremelyslowtoinstall.

SFSintecdevelopedtheselfdrillingfastenershownoppositewhichcombinesspeedwithsecurity-thefastenercannotbeoverdrivenasthespeciallydesignedwasherflattenswithinthefree-spinzonetoaccommodatethecombinedthicknessesofthetophatandliner/deck.

6.9 Clamping & sealingInSections3and4theimportanceoffastenerswithregardsweatherandairsealingwasdiscussed.SFSintecsstitchingandclampingfastenersarepurpose-designed.BehindthesoftEPDMwasherisanunthreaded(free-spin)zonewhichenablesthetwothinsheetstobedrawnandclampedtogetherthuscompressingtheweatherorairsealant.

6.10 Shear performanceInsomeapplicationsfastenersaresubjectedtoadirectshearloading.SFSintecpublishesdocumentationwhichgivestheengineertheshearvalueofthefastenerandalsoofthefastenerinarangeofapplications.

6.11 Non-fragilityTheAdvisoryCommitteeforRoofwork(ACR)publishanumberofguidancedocumentswhichallcontributetotheaimofenablingroofworktobedesignedandcarriedoutwithminimalrisktoanypersonnelwhoeitherconstructtherooforwhosubsequentlyneedtotrafficacompletedroof.

Fastenertypesandfrequenciesplayamajorroleinachievinganon-fragilestatusformetalroofsystemsandtheRedBook-ACR[M]001:2005detailsthetestingmethodologyfornon-fragility.

Important note:itisnowacceptedpracticetouse5.5mmdiameterwasheredfastenersforroofliningpanelsratherthan4.8mmnon-washeredfasteners.Forlongtermnon-fragilitybeyondtheconstructionphase,austenitic stainlesssteel fastenerswouldbetherecommendedchoiceduetotheirprovendurability.


SFSintecclampingfastener


6.12 Material compatibilityTheriskofcorrosionofthesheetmaterialduetothefastenerandalsothefastenerduetothematerialitisfasteninginto/throughhastobeconsideredbythedesigner.

Bi-metallic corrosionPD6484:1979-“Commentaryoncorrosionatbimetalliccontactsanditsalleviation”maybereferredtoinorderthatanyriskcouldbeassessed.Considerationmustalsobemadetotherelativesurfaceareasofthemetalsincontactandthemoisturecontentaroundtheconnection.Generally,thefastenermustbemorecorrosion-resistantthanthematerialitisfasteninginto/through.Therefore,itisconsideredappropriateforausteniticstainlessfastenerstobeusedincombinationwithaluminiumorgalvanizedsteelsheets/supports.Zinccoatedcarbonsteelfastenersshouldonlybeconsideredforgalvanizedsheets-refertotableinsection2.6.

Corrosion within timberTimbermaybeincorporatedintotheroofingandcladdingsystemasabeam,purlin,spacer,counterbattenand/ortilingbatten.Timberisamoistureabsorbentmaterialandsotoprolongthelifeoftimberitmaybetreatedwithapreservative.Thesetreatmentsaretypicallydividedintotwotypes-OrganicSolvents(OS)andCopperChromeArsenic(CCA)andarecoveredinBS4072:Part2:1987andBS5268:Part5:1989.

TheCCAtreatments,inparticular,canbeverycorrosivetozinccoatedcarbonsteelfastenersanditisthereforerecommendedthatwithCCAtreatments,andalsowithOStreatmentsifthemoisturecontentislikelytobeat>15%forprolongedperiods,austeniticstainlessfastenersbespecified.

6.13 WindloadingsBS6399:Pt2:1997isthecodeofpracticeforwindloadsandisreferencedintheBuildingRegulationsforEngland,ScotlandandWales.InIreland,CP3:ChapterV:1972isreferenced.

WindloaddataisoftenprovidedbytheEngineer,andusedbytheContractorand/orthesystemsupplierinthedetaileddesignandspecificationoftheroofingandcladdingsystem.

Wherethisinformationisnotavailable,fastenersuppliersmaybeconsultedtoassist,uponrequest,andsubmitwindloadcalculationsrelevantforthefasteningproposalsoftheroofingandcladdingsystem.Suchcalculationsshouldbeverifiedbytheprojectengineer.6.14 Fastener frequenciesSFSintecpublishesawiderangeoftechnicalperformancedataonitsfasteners.Generallythepublishedvaluesaretheultimatemeanandthestandarddeviationvalues.Safetyfactorshavetobeappliedtothesefigurestoestablishthesafeworkingloadofthefastener.BS5427:Pt1:1996AnnexBgivesguidanceonthiscalculation.SFSinteccanhelpinterprettheseloadsrelativetotheproposedroofingandcladdingsystem.

Theremayalsobetestdatacompiledbythesystemmanufacturerfromwhichthemaximumallowablefastenerloadshavebeendetermined.

Onceallrelevantloadings,structuralframedetailsandtheproposedroofingandcladdingsystemspecificationhavebeenestablished,thefastenersuppliermaybecalledupontoworkincloseco-operationwiththerelevantparty,eg.designer,systemsupplier,contractor,todeterminethefastenerfrequenciesspecifictotheproject.

6.15 ToolingSections6.1to6.14showsthewiderangeofperformancecriteriafastenershavetobecapableofwithstanding.Thesecriteriatendtobespecifictotheparticulartypeofroofingandcladdingsystemandthereforefastenersaredesignedsuchastogiveoptimumperformancecompatiblewiththerequirementsoftheparticularsystem.Whilstsomefastenershavebeendesignedsuchthattheycannotbemis-installed(referto6.8&6.9),toolingsystemsforotherfastenertypesareavailablewhichassisttheContractorintermsofbothspeedandconsistency,aswellasprovidingsecuritytotheClient.


Windcreates+veand-ve(suction)loadsonroofingandcladding

Sectio

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Section 7 Specification design support

7.1 Fastener and sealant specifications for roofing and cladding

Specification advisory service for architects and designersAttheearlydetaildesignstageofaprojectcomplexandsometimesconflictingrequirementscanplacediversedemandsonthefastenerandsealants.Consultationwithanexperiencedtechnicalteamfromthefastenersuppliercanhelpyoutoresolvefastenerandsealingissuesduringtheplanningstages,workingsidebysidewitharchitectsanddesignerstoensurethatperformancerequirementsofthebuildingenvolopearemet,andthecontractspecificationproceedswithoutahitch.

Assessing and specifying the right productsEverycontractisdifferent,andwiththeincreasingnumberofproductsonthemarket,andevermorepressureonyourtime,justhowdoyousiftthroughthemassofinformationavailabletospecifythecorrectfastenersandsealants.

The answer is to let SFS intec help.

TheSFSintecspecificationteamisgeareduptoworkingwitharchitects,designers,contractorsandstructuralengineerstoprovideinformed,detailedandreliablespecificationguidance.

SFSinteccanprepareproject-specificfastenerandsealantspecificationsforinclusionwithintenderdocumentation.Thesespecificationsmaybeineitherprescriptiveorperformanceformatasadoptedbytheparticularpractice.

NBS Plus ForthosethatprescribetoNBS,SFSintecausteniticstainlessfastenersandwarrantedsealantsarenowlistedwithinNBSPlus,partoftheNBSindustrystandardspecificationsoftwareusedbyarchitects,engineers,buildingsurveyorsandotherconstructionindustryprofessionals.ThismeansthatthetechnicalinformationandguidanceforourproductsispresentedtoNBSsubscribers,inNBSformat,atthepointinthespecificationappropriatetoourproducts.Furthermoreyouwillbeabletoaccessourwebsitewww.sfsintec.biz/ukthroughthedirectlinkfromNBSPlustoobtainfurtherinformation.WecanalsoprovideguidanceforthecompletionofNBSclausesuponrequest.AllinformationfoundwithinNBSPlusisupdatedthreetimesayearensuringthatspecifiershaveaccesstoourmostrecentproductinformation.

CPD seminars SFSintecalsooffertheirRIBA-accreditedCPDtechnicalseminarwhich,inconjunctionwiththisguide,helpsyoutobecomefamiliarwithissuesconcerningfastenersandsealants,aswellasenablingyoutoacquireyourRIBACPDpoints!Contactusonthedetailsbelow.




Examplespecificationforprimarylinerpanelfasteners.

Examplespecificationforinsulatedpanelfasteners.

Examplespecificationforsealants. ExamplespecificationforinsulatedpanelfastenersandsealantpreparedinNBSformat.

7.1a Project-based specification sheets

Examplesofthetypesofproject-basedspecificationsforfastenersandsealantsareshownbelow.ByusingthecodesanddescriptionspreparedbySFSintec,thespecifierhasthechoiceofissuingspecificationsineitherperformance,prescriptiveorNBSformats.

7.2 Innovative solutions to benefit everyone – from architect through to client Asbuildingdesignmovesforward,architects,designers,andcontractorsfacenewchallengesandnewproblems–whichmustbemetwithinnovativeproductsolutions.AtSFSintecweaimtomeet–andexceed–yourexpectationsofproductperformancethroughconstantresearchanddevelopmentintopractical,effectivefastenersandairsealingsolutions.Throughourcloserelationshipwithtesthouses,researchlaboratoriesandmanufacturersofroofingandcladdingsystems,plusourownin-houseresearchintometallurgy,drilltechnologyandcorrosiontesting,weareabletobringyouthemosttechnologicallyadvancedsolutionstotoday’smarketneeds.

Long-term partnerships with roofing system suppliersRoofingandcladdingsystemmanufacturersareconstantlyimprovinganddevelopingtheirproducts,andSFSintecismatchingthesedevelopmentswithnewfastenertechnologies.IntheUKandworldwide,SFSintectechnicalspecialistsareworkinginpartnershipwiththemarketleadingsystemmanufacturersinexternalcladding,insulationsystemsandroofingsystemstobringcompetitive,high-performancefastenersolutionstothemarket.SFSintecproductsareendorsed–sometimesexclusively–bymanyoftheUKindustry’smajorsystemssupplierssuchasCorusPanelsandProfilesandtheirPlatinumWarrantySystem–testimonytoourcommitmenttoapartnershipapproachtoprovidingpractical,customisedsolutionsfortoday’scompetitivemarket.

Adding value to the project: the SFS intec quality guaranteeInthiscompetitivemarket,clientsarealwayslookingforaddedvalue–whetheritmeansahigherlevelofspecification,greaterlongevityofthebuilding,lowmaintenanceorimprovedperformance.Creatingthataddedvaluemeansbeingabletorelyoneventhesmallestcomponentinthebuildingtosupportthedemandforoverallquality.

Recognisedworldwideforitscommitmenttothehigheststandardsofproductperformanceandcustomerservice,SFSintecfastenerproductsandairsealingsolutionscanplayanimportantpartinhelpingyoutodelivercustomersatisfaction.ThroughouttheSFSintecorganisation,specialised,on-goingtrainingensuresthatyoubenefitfromaninformed,technicallyawareandexperiencedteam–atalllevels.Intermsofproduction,theSFSintecexactingqualityassurancesystemstandsuptoanyinternationalrequirement,soyoucanhavecompleteconfidenceinthetechnicalvaluesandperformancespecificationsoftheproductsyouspecifyanduse.

Quality and environmentSFSintecproductsandinstallationsystemsaremanufacturedtothehighestqualitystandards,soyoucanspecifywithconfidence.Since1987,SFSintechasbeencertifiedtoISO9001.Earlyin1996,ourmainmanufacturingplantgainedtheISO14001environmentalstandardalongwithVDANo6.Fromproductionthroughtopackaging,wedon’tjustaimtomeetquality,environmentalandsafetyrequirements–weworktoexceedthem.


CorusPanelsandProfilesLtdPlatinumWarranty


7.3 Achieving results through technical advisory service

Helping you choose the right fastening systemChoosingtherightfasteningsystemcanbedecisiveintermsofthelongevityandsafetyoftheroof.AswellasoutliningSFSintec’spolicyoncustomerservice,fastenerproductdevelopmentandcost-effectivesystemstechnology,thisproductselectorgivesyouaclearguidetothemostsuitablefastenersfordifferentapplicationswithinthefieldofpitchedroofingandcladding,makingspecificationquickerandsimpler.Butifyoudoneedpersonaladvice,pleasedon’thesitatetogetintouchwithourtechnicalteamwhocanadviseyoufurther.

Total technical support from specification to site testsIncorrectcalculations,specificationdetailsorinstallationcanleadtocostlydelaysonsite.Butasthedemandsonbuildingstructuresincrease,andthevarietyofoptionswidens,choosingthecorrectfastenerandairsealingsolutionforthejobisbecomingmoreofatestingtask.Tohelpyoutogetthingsrightfromstarttofinish,theSFSintectechnicalteamiscommittedtoprovidingyouwiththesupportyouneed,including:

• Expert product specification and air sealing solution advice.• Guidance on choosing a system to meet the specific warranty requirements of your contract.• Training your team in the best use of your chosen system.• Help with calculating fastener quantities and costs.• Informed, reliable technical help whenever you need it throughout the contract.

7.4 TrainingCPD seminars SFSintecalsooffertheirRIBA-accreditedCPDtechnicalseminarwhich,inconjunctionwiththisguide,helpsyoutobecomefamiliarwithissuesconcerningfastenersandsealants,aswellasenablingyoutoacquireyourRIBACPDpoints!Contactusonthedetailsbelow.

On-site trainingPrecisionduringinstallationcanbethedifferencebetweenasecurerooforperformanceproblems.Tohelpyoueliminateanyrisk,SFSintecoffersfreetrainingintheuseofSFSinteconsitefastenerinstallationtools,whicharepurpose-designedensuringthatconsistencyoffixingisachieved.Whetheryourequireoneofourtechnicaltrainingteamtocarryouttrainingon-site,oryouprefertovisitthetechnicaltrainingcentreatourLeedsoffices,ourexpertiseisonlyaphone-callaway.


Section 8 Case studies

8.1 Heathrow Airport, Terminal 5

Specialist contractor; HathawayRoofingLtd Project requirements; Durability Section 2.5b & d Componentsupplierwarranty Section 2.5e Aesthetics Section 5 Technicalperformance Section 6 Designsupport Section 7

SFS intec products; Austeniticstainlesssteel Section 2.7 SFSproject-specificwarranty Section 2.5e iii) irius®colourheads Section 5.2b SDKhalterfixings Section 1.3a & 6.8 Clampingfasteners Section 3.3, 4.3, 6.9 Technical&designsupport Section 6 & 7


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8.2 British Car Auctions, Bedford

Specialist contractor; CommercialCladdingServicesLtd Project requirements; Durability Section 2.5b Systemsupplierswarranty Section 2.5e Aesthetics Section 5 Weather&airsealing Section 3 & 4 Technicalperformance Section 6

SFS intec products; Austeniticstainlesssteel Section 2.7 Project-warrantytosystemsupplier Section 2.5e ii) irius®colourheads Section 5.2b Clampingfasteners Section 3.3, 4.3, 6.9 Weather&airsealantsTypeA+ Section 3.4 & 4.3



8.3 Wales Millennium Centre, Cardiff

Specialist contractor; KelseyRoofingIndustriesLtd Project requirements; Durability Section 2.5b & c Componentsupplierwarranty Section 2.5e Aesthetics Section 5 Technicalperformance Section 6 Designsupport Section 7

SFS intec products; Austeniticstainlesssteel Section 2.7 SFSproject-specificwarranty Section 2.5e iii) irius®colourheads Section 5.2b SDKhalterfixings Section 1.3a & 6.8 Clampingfasteners Section 3.3, 4.3, 6.9 Technical&designsupport Section 6 & 7


NOTES

To make you more competitive.

SFS intec Ltd.Fastening Systems153 Kirkstall RoadLeeds LS4 2AT

Tel: 0113 2085 500Fax: 0113 2085 539Email: [email protected]: www.sfsintec.biz/uk

For further information please contact:

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intecreservestherighttochangetechnicalspecifications

CPD seminars SFSintecofferstheirRIBA-accreditedCPDtechnicalseminarwhich,inconjunctionwiththisguide,helpsyoutobecomefamiliarwithissuesconcerningfastenersandsealants,aswellasenablingyoutoacquireyourRIBACPDpoints!Contactusonthedetailsbelow.

SFS - A designer’s guide to specifying warranted austenitic ......A designer’s guide to...

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