a designer’s guide to specifying warranted 316 austenitic ... · 1.1 performance criteria of...
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CI/SfB Reference by RIBA SfB Agency
Xt6October 2015
A designer’s guide to specifying warranted 316 austenitic stainless steel fasteners and sealants
WelcometothelatesteditionoftheSFS“Adesigner’sguidetospecifyingwarranted316austeniticstainlesssteelfastenersandsealants”.
WehaverevisedandupdatedthepublicationtoreflectchangesinourproductsandservicestomeetchangesinUKconstructionlaw.InparticularthemandatoryuseofCEmarkingforconstructionmaterialsfrom2013togetherwiththeintroductionofnewENandrevisedBSstandardswhicharereplacingtheoldBSversionsacrossalldisciplines.Forexample,fordurabilitystandards,wenowworktoEN12944andthe2015revisededitionofBS7543andforwindloads,EN1991ratherthanBS6399.
ThesenewENstandardsareinsomecasesmoreonerousthantheoutgoingBSbuthaveadistinctadvantageinthattheyarerecognisedEurope-wide,simplifyingregulationandcross-bordertradingatatimewhenUKconstructorsareincreasinglylookingtoEuropeforbusinessopportunities.
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Contents
Introduction to the SFS Group of companies
Section 1 Introduction 3 1.1 Performancecriteriaoffastenersandsealants 3 1.2 Industryassociationsandpartnershipswithleadingsystemsuppliers 3 1.3 Examplesofrecentinnovations 4
Section 2 Durability (corrosion resistance) 5 2.1 Theproblem 2.2 Fastenermaterials 6 2.3 Limitationsofcoatedcarbonsteel 7 2.4 Typesofstainlesssteel 8-9 2.5 Carbonorstainless?Specificationselectionconsiderations 10 2.5aSystemmaterials 11 2.5bDesignliferequirements 12-13 2.5cExternalenvironment 14 2.5dInternalenvironment/buildinguse 15 2.5eProject-basedlongtermwarrantyrequirements 16 2.6 Fastenermaterialselectortable 17 2.7 SFSintecausteniticstainlesssteelfastenerrange 18-19
Section 3 Weathersealing 20 3.1 Theproblem 20 3.2 Washerdesign 21 3.3 Specialistfastenerdesignforweathersealing 22
Section 4 The “Part L” issue - Airsealing and thermal bridging 23 4.1 OverviewofBuildingRegulations-2002,2006,2010&2013-Theproblem 23 4.2 Eliminationofthermalbridgingbythermallybrokenfasteners 24 4.3 Achievingairtightnesswithwarrantedsealants&clampingfasteners 24
Section 5 Aesthetics by design 25 5.1 Theproblem 25 5.2 Factory-colouredsolutions 26 5.2a Paintedheadsolution 26 5.2b Unobtrusiveheadsolution 26
Section 6 Technical performance 27 6.1-6.15 Technicalperformancecriteria 27-31
Section 7 Specification design support 32 7.1 Modelspecifications 32-33 7.2 Innovationandquality 34 7.3 Technicaladvisoryservice 35 7.4 Training-CPDSeminarsandon-site 35
Section 8 Case studies 36
Co
ntentsContents
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Introduction to the SFS Group of companies
TheSFSGroupofcompanies,whichhasitsheadquartersinHeerbrugg,Switzerland,isoneoftheworldsleadingdevelopers,manufacturersandsuppliersofhighprecisioncomponentsforavarietyoftechnicalindustries.
TheSFSGroupdirectlyemploysover7000personnelandin2014turnedover£880million.
Global manufacturingThegroupmanufacturesglobally,withplantsacrossEurope,NorthAmerica,ScandinaviaandAsia.
Global sales and marketingProductsaresuppliedintotheglobalmarketthrough70SFSsalesandmarketingorganisationsstrategicallylocatedin25countries.
UK headquartersTheUKheadquarters,whichincludesmanufacture,logistics,andsalesandmarketing,isbasedinLeeds.FastenershavebeenmanufacturedonthisKirkstallRoadsiteforover100years.FromthissiteSFSintecLtdcanofferarchitects,designers,consultingengineersandcladdingenvelopecontractorsaprovencommitmenttoproductquality,soundtechnicalsolutionsandefficientservice.
Commitment to investment and innovationTheSFSGrouphasaphilosophyofgrowingitsbusinessbyitscommitmenttoreinvesting,toensurestate-of-the-artfacilitiesand,throughitsextensiveresearchanddevelopmentdepartment,tocontinualinnovationofnewproductsandservices.
Industry associations SFSintecisactivelyrepresentedonthetechnicalcommitteesoftheleadingroofingandcladdingassociationswhoseektoencouragebestpracticeandconformancetoallrelevantregulations.
Globalmanufacturing
Globalsales&marketing
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Sectio
n 1Intro
ductio
nIntroduction
Section 1 IntroductionThespecificationofthefastener,despitebeingsuchasmallcomponent,iscriticaltotheperformanceoftheroofingandcladdingsystem.Thefastenerworksinclosecombinationwithsealingproducts,thereforethespecificationofthefastenerandsealingproductsneedtobeaddressedattheearlystagesofdetaildesignoftheprojecttoenablethecompletedenvelopetoperformitsrequiredfunctionthroughoutthefulltermofthesystem’sserviceanddesignlife.
1.1 Performance criteriaThisguideaddressestheprincipleperformancecriteriaoffastenersandsealants,namely;• Durability (corrosion resistance)• Weathersealing• The “Part L” issues of airsealing and thermal bridging• Aesthetics• Technical performance
Eachparticularapplicationwillneedthevariousproductstocomplywithatleastthreeofthesecriteriaandoften,aswithexternallyexposedfasteners,willrequireallfive.Failureoftheproductstosatisfythesecriteriamayleadtotheinevitable,andsometimescatastrophic,failureofthesystemor,attheveryleast,costlyremedialworks,sometimesevenbeforetheprojectcanbehandedovertotheClient.
Thisguidewillgiveyouthekeyinformationneededforyoutospecifyfastenersandassociatedsealstominimizetheriskofsystemfailure.
1.2a Industry associations Theguidancegiveninthisdocumentisgenerallyconsistentwithpublicationslistedbelowfromtheseassociations,aswellasthatgivenwithinBS5427:Part1:1996-thecodeofpracticefortheuseofprofiledsheetforroofandwallcladdingonbuildings.
NFRC -TheNationalFederationofRoofingContractorsAguidetogoodpractice,ThirdEdition1999andsubsequentTechnicalBulletins
• The Rainscreen Association
MCRMA -TheMetalCladdingandRoofingManufacturersAssociationDesignGuides&TechnicalPapers
EPIC-EngineeredPanelsInConstruction
SPRA-TheSinglePlyRoofingAssociationSingleply-CodeofPractice
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1.2b Partnerships with leading system suppliersSFSintecalsoworkcloselywithmanyoftheUK’sleadingmanufacturersofroofandcladdingmaterialskeepinguptodatewiththeirdevelopmentsand,inpartnershipwiththem,seekingwaystoproducemoreefficientfasteningandsealingsolutionsfortheirsystems.
1.3 Examples of recent innovations
1.3a Development with Kalzip Ltd DevelopmentofSL3“thicktothin”selfdrillingfastenersforsafeandsecurefixingoftophatsectionstothinmetaldecks.
1.3b Development with single ply manufacturers including the Sika GroupDevelopmentofisoweld®-arevolutionaryheat-inductionweldingsystemforthesecurementofsingleplymembranesinafieldpatternratherthanin-seam.
1.3c Development with Kingspan Insulated PanelsDevelopmentofaself-coringfastenertoeliminatetimeconsumingprecoringandbackfillingontheirTopdekpre-engineeredinsulatedroofmembranesystem.
Introduction
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Section 2 Durability (corrosion resistance)• Definition-“likelytolast”,“remainingusefulforlongperiods”,“resistingwearanddecay”Ref;Oxford Dictionary
2.1 The problemIftheinstallerisallowedtousecarbonsteelfastenersfortheexternalenvelope,theinevitablecorrosionbroughtaboutbyexposuretotheelementswillresultinanumberofproblems;iftheseareleftunattendedthenultimatefailureofthesystemisaveryrealpossibility.
2.1a Problems due to corrosion of the head and washer• Stainingofthecladding
• Reductioninpulloverperformance
• Potentialleakageinto/throughthesystem
• Increasedmaintenanceandremedialwork
2.1b Problems due to corrosion of the shank• Reductionintensileperformance
• Reductioninshearperformance
• Reductioninpulloutvalues
• Stainingtointeriorsurfaces
2.1c Problems due to hidden corrosionWhilstcorrosionofexposedheadsontheexternalfaceofthebuildingandcorrosionofthevisibleshankinsidethebuildingarebotheasilyidentified,whatisconsideredamuchgreaterstructuralandsecurityriskisthatofcorrosionwithintheroofingorcladdingsystem.Thiswouldnotbevisibleandwouldonlymanifestitselfuponultimatefailureofthefastener,whichwouldresultinpartial,andpotentiallytotal,detachmentofthesystem.
Totalerosionofacarbonsteelfastenershank.Notethatthisproductwasoriginallymanufacturedwithastainlesssteelcapformedoverthehead,whichhasnotcorrodedtothesameextent.Thecorrodedportionwasbehindtheweathersheetandnotexposedtotheelements.
Sectio
n 2D
urability
Durability (corrosion resistance)
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2.2 Fastener materialsThreadedfastenersforroofingandcladdingsystemsareavailableinthemarketplacemostcommonlyintwomaterials,coatedcarbonsteelandstainlesssteel.
Aluminiumthreadedfastenersarealsoavailable,howevertheirrangeofapplicationisgenerallyrestrictedtosecuringaluminiumprofilestotimbersupportsandlimitedapplicationsofaluminiumtoaluminium.
2.2a Coated carbon steelCarbonsteelrapidlycorrodesonexposuretohumidity.Fastenersinthismaterialaresuppliedwithsomeformofprotectivecoating,typicallymetallicororganic,oracombinationofthetwo.Cadmiumhasinthepastalsobeenusedasaprotectivecoatingbysomefastenermanufacturers.However,thisisacontrolledsubstancethatishazardoustohealthandthereforereputablemanufacturerswhooperaterecognisedQualityandEnvironmentalManagementSystems,aswellasenforcingHealthandSafetyProcedures,nolongerusecadmiumasaprotectivecoatingonthreadedfasteners.
CR6andCR3coatings
Hexavalentchromate[CR6]finishesonzincplateditemsarealsohazardousandarenowbannedinsomeareasofindustryacrosstheEU.Trivalentchromatefinishes[CR3]arestillusedinthefastenerindustrybutSFShavenotusedthemforsometime.
2.2b Stainless steelForincreaseddurability(corrosionresistance),fastenersarealsomanufacturedinvariousgradesofstainlesssteel.
TherelativemeritsofthesegradesarediscussedingreaterdetailinSection2.4
OverthefollowingparagraphsinSection2.3thisguidewillexplainthelimitationsofcoatedcarbonsteelandthetypesof“stainless”steelsappropriatetoroofingandcladdingfasteners.Wewillalsoexaminethedifferentaspectsthatshouldbeconsideredinorderthatthechoice,appropriatetotheproject,canbemadebetweencoatedcarbonor“stainless”steel.
AsfortheUKconstructionindustryhasnowmovedtomandatoryCEmarkingofbuildingmaterialsfrom2013,SFSnowusesthemethodologyfoundinEN12944forassessingbuildingdurability.EN12944istheEuropeanstandardandhasadetailedtableofexposurecategories.BS7543:2015canalsobeusedforassessingthedurabilityofthebuildinganditscomponents.
Durability (corrosion resistance)
CorrosionofcoatedcarbonsteelunderKesternichtesting
Austeniticstainlesssteelfasteners
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2.3 Limitations of coated carbon steel
2.3a• Uncoatedcarbon steel rapidly corrodesuponexposuretohumidity
andpollutedenvironments
• Surfacecoatingswithexcellentcorrosionresistancecanbeappliedtoprolongafastener’slifebuttheywillonly slow down the corrosionprocess
• Theeffectivenessofthesecoatingscanonlybegaugedafterconsideringtheconditionof the coating once the fastener has been appliedwithintheconstruction
• Thesecorrosionresistantsurfacecoatingstendtohavepoor abrasion resistance
2.3b Pitched roofing and cladding systemsCoatingsonfastenerswithinmosttypesofmetalpitchedroofingandcladdingsystemswillinevitablysufferdamage 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 summary Will 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
Durability (corrosion resistance)
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2.4 Types of stainless steel“Rusting”isregardedbymanyasaprocesswhichisnotapplicabletostainlesssteel-thisishoweverincorrect.“Stainless”steelisagenerictermcoveringover200differenttypesofalloywhichall,tovaryingdegrees,stain-lessthancarbonsteel.Stainlesssteelscanbeclassifiedintothreemaingroups;
Austenitic, Ferritic and Martensitic.
2.4a Austenitic stainless steel• OnlygradesconformingtoBS5427:1996(seenote1)• Containsatleast17%chromium• Containsatleast8%nickel• Molybdenummaybeaddedforenhancedcorrosionresistance• Non-hardenable(seenote2)• Non-magnetic(seenote3)• Lowthermalconductivity;25%ofcarbonandmartensiticstainlesssteel• Bestknowngradesare304and316• Excellentcorrosionresistance(seenote4)
These characteristics make austenitic stainless steels the only suitable type for selfdrilling/threadforming fasteners for roofing and cladding.NoteBSEN10088-2hasintroducedarevisedsteelcodingsystem;theoldgradeAustenitic304isnow1.4301andAusteniticgrade316isnow1.4401.Specialhighperformancegrade1.4547hashighMolybdenumcontentforextraresistancetoChlorideattack.[seenote4]
2.4b Ferritic• Containsatleast12%chromium• Lowerductilitythanmartensiticsandaustenitics• Cannotbehardened• Susceptibletobrittleness
These characteristics make ferritic stainless steels unsuitable for the manufacture of selfdrilling/threadforming fasteners for roofing and cladding.
2.4c Martensitic• Containstheminimumchromiumcontentof11%• Poorcorrosionresistance• Susceptibletostresscorrosion• Canbehardened(attheexpenseoffurtherstresscorrosionrisk)• Highthermalconductivity(similartocarbonsteel)• Magnetic• Modifiedformsavailablebutstresscorrosionconsideredtoogreatarisk
(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.Wherefastenersareusedforstructuralorsafetycriticalapplications,measuresshouldbetakentoensurethatasoundandreliablevapourbarrierisinplacetopreventChlorinerichcondensationfromreachingthefastenersinquestion.Wherethisisnotpractical,thenalternativefastenermaterialssuchasaluminiumorAusteniticstainlesssteelgrade1.4547shouldbeconsidered.
Durability (corrosion resistance)
SFS316austeniticstainlessselfdriller
HarryBrearley(1871-1948)-creditedwiththeinventionof“rustlesssteel”in1913atSheffield
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2.4 Other types of “stainless” fastenersBecauseofthehightechnologicalinvestmentrequiredforthemanufactureofbi-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 brittlenessHowever,real-lifeexposuretestsinanumberofenvironmentalconditionshaveshownthistypeoffastenermaterialtobesubjecttostresscorrosionandbrittleness-thiswouldn’thavebeenevidentunderKesternichandSaltspraytesting.Thistypeofbrittlecorrosionisinherentinthehardmaterialandisnotnecessarilyvisibletothenakedeye.
AsaresultofextensiveresearchworkcarriedoutbycorrosionexpertsinGermany,SwedenandtheUKonthistypeofmaterial,SFSintechavebeenadvisedthattherisksassociatedwithmodifiedmartensiticfastenersforroofingandcladdingaresignificantandthereforewecontinuetocomplywithindustryguidelinesandStandardsbymanufacturingstainlesssteelselfdrillersfromausteniticgradesusingthetriedandtested‘bi-metal’format.
2.4 Keynote summaryAustenitic stainless steel fasteners, such as grade 316, have been proven over a period exceeding 40 years 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
Brittlefailureofmodifiedmartensiticstainless
Stresscracksinmodifiedmartensiticstainless
Durability (corrosion resistance)
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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.
Durability (corrosion resistance)
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2.5a System materials2.5a i) Envelope systemsCompatibilitywiththesheet/systemmaterialaswellasthepurlin/railwillinfluencethechoicebetweencoatedcarbonsteelorausteniticstainlesssteelfasteners.Typicalmaterialsforthesystemandsupportmayinclude;• Stainlesssteel• Coatedmildsteel• Aluminium• Fibrecement• Cementitiousboards• Highpressurelaminates• “Plastics”-GRP,polycarbonatesandPVC• Timber
2.5a ii) Flat roofing systemsItisgenerallythecompatibilityofthedeckthathasadirectinfluenceonthechoicebetweencoatedcarbonsteelorausteniticstainlesssteelfasteners.Decktypesinclude;• Coated(galvanized)steel• Aluminium• Timber• “Concrete”
2.5a iii) Cautionary notesRefurbishment over existing roof coverings -generallyflatroofing.Theinsulationtypewithinflatroofingdoesn’tgenerallyinfluencethefastenermaterial,however,onrefurbishment,wheretheexistinginsulationandweatherproofingistoremain,itistheconditionratherthantypeoftheexistingbuildupwhichwillinfluencethefastenermaterialchoice.Ifthereisdampnesswithintheexistingbuildupitwouldbeprudenttouseausteniticstainlessfasteners.Phenolicfoaminsulationwasusedonaverysmallnumberofflatroofprojectssomeyearsago.Ifitispresentbeneathaleakingroof,corrosionofgalvanisedmetalcomponentswithinthebuildupmayoccurasaggressivechemicalscanleachoutofthefoamboard.Contact SFS technical department for further information.
Only grade 1.4401 [316 Grade] stainless steel fasteners should be used to fix through Phenolic foam insulation boards.
2.5a Keynote summaryIthasalwaysbeengoodindustrypracticetouseausteniticstainlesssteelfastenersincombinationwithaluminiumandstainlesssteelmaterialstoavoidbi-metallicreactions.However,therearemanyfactorsthatinformtheselectionofthefastenermaterialinotherapplications.UsingtheexposureguidancegiveninBSEN12944[seesection2.6],higherperforminggradessuchas1.4401[316grade]and1.4547[A5grade]shouldbeactivelyencouragedwheretheservicelifeoftheenvelope/waterproofingmaterialisexpectedtoexceed20years.
Durability (corrosion resistance)
“Old”rooftobeoverlaid
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2.5b Design life requirementsTheclientordesignershouldspecifytheintendeddesignlifeoftheproposedbuildinganditsindividualbuildingelements,productsandcomponents.Referencemaybemadetothe2015revisededitionofBS7543.Asaguide,wegivebelowourinterpretationofextractsofBS7543:2015relativetofastenersaspartoftheroofingandcladdingenvelope.
Theclientshoulddefinethedesignlifeofthebuildingintheinitialbrief,whichshouldreflecttheoverallrequirements.DesignlifecategoriesforpartsaregiveninTable1andcategoriesforeffectsoffailurearegiveninTable2.Inadditiontheclientmightwishtospecifythedesignlifeforspecificassets,forexample,thefasteners.AnexampleofreferenceservicelivesforspecificcomponentsisgiveninAnnexDofthestandard.
Table 1 - Categories of design life
Category
Description
Life
Short-term Shorterlifethanthebuildingandreadilyreplaceable
Replaceable Shorterlifethanthebuildingandreplacementcanbeenvisagedatdesignstage
Maintainable Lasts,withperiodictreatment,forthelifeofthebuilding
Lifelong Lastsforthelifeofthebuilding
OtherthanShort-termbuildings,typically10yeardesignlife,carbonsteelfastenersarenotconsideredsuitable.
Thisflowchartbelow,Figure3fromBS7543:2015,asksthequestionsaboutaccessibilityofcomponentsandalsowhethertheycanbemaintainedorreplaced.Ifnot,thenthedesignhastobebasedonlastingthelifeofthebuilding,or,asinthecaseoffasteners,thelifeofthematerialtheyarefastening.Figure 3 - Decision process in support of categorization of design life (offasteners)
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
BSIStandardsPublicationBS7543:2015
Durability (corrosion resistance)
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2.5b ii) Question: Can fasteners and cladding envelopesealants be classed as “maintainable” ?Asnotedabove,non-exposedfastenersandsealscanonlybeaccessedbyremovaloftheexternalweatheringsheet.Exposedfastenersmay,intheory,havetheirvisibleparts“recoated”butthisshouldnotberegardedasacceptableatthedesignstageofaproject.Furthermore,applyinganewcorrosionprotectivecoatingtothevisiblehead,providinganappropriatepretreatmentcanbecarriedout,aswellasbeing,inmostcases,aestheticallyunacceptable,wouldnotreinstatecorrosionprotectiontotheconcealedshankwhichmayalsobesufferingfromcorrosion.Answer-Fastenersandsealingproductsarenotclassedasmaintainable
Table 2 - Categories of effects of failure
Category Effect Life
A Dangertolife(orinjury) Suddencollapseofstructure
B Riskofinjury Loosestairnosing
C Dangertohealth Seriousdamppenetration
D Costlyrepair Extensivescaffoldrequired.Durabilitycriticalcomponentfailure(seenotebelow)
E Costlybecauserepeated Windowfasteningreplacement
F Interruptiontobuildinguse Heatingfailure
G Securitycompromised Brokendoorlatch
H Noexceptionproblems Replacementoflightfittings
Note - Individual failures can be in two or more categories.
Manyofthebuildingswherefastenersareusedtosecuretheroofingandcladdingenvelopehavedesignserviceliferequirementsintherangeof25to60yearsand,asthefastenersarepotentiallyofrelativelyhighrisk,typicallycategoryA,B,CorDasdefinedintable2above,andtheyarenotconsideredreplaceableormaintainable,theywouldneedtobedesignedtobelifelongastable1(totheservicelifeoftheroofing/claddingsystem)
2.5b Keynote summaryCoated carbon steel fastenersshouldbeconsideredonlyforshortlife,temporarybuildingsandthoseincategoryC1intheEN12944tableshownin2.6,page17ofthisGuide.
Forallotherapplications,Austenitic stainless steel fasteners in Grade A2 or A4isthepreferredchoiceforallotherbuildings-specifiersshouldselecttheappropriategradetosuittheexpectedexposureandservicelifeusingthetableabove
Weatherandairsealingproductsshouldmatchthedesignlifeoftheroofingorcladdingsystemandtheappropriatefastenermaterial.
Durability (corrosion resistance)
Fastenerscanbeclassedas”highrisk”-CategoriesA-D
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2.5c External environmentTypicalUKatmospheresmaybedividedasinthefollowingtablewhichshouldbeconsideredtogetherwiththeBSEN12944tableinsection2.5b:
Inadditiontotheclimaticconditionspresentduringeachseason,thelocalatmosphericconditionsintheimmediatevicinityofthebuildingarecriticalintheselectionofcoatedcarbonorausteniticstainlesssteelfasteners.
Typical atmospheres may be divided as in the following table;
Marine C5-M Upto2kmfromthesea.Highlevelsofchlorides
CoastalC4 Between2kmand10kmfromthesea BS7543:2015ClauseA.1.3Coastalregions; Seafogsormistsmightalsolingerwithinseveralmiles ofcoasts.Particularconsiderationshouldbegivento wind-blownsaltatmosphereandhowfarinlandthiswill impactthedesignspecification.
Industrial C5-I Atmosphereheavilypollutedbysulphurdioxideandother pollutants,typicallynitricoxides,chlorine,hydrogenchloride, formicacid,aceticacid,allinthevicinityofcorresponding industrialplants.
Urban C3 Denselypopulatedandpollutedbysulphurdioxide,also propertiesadjoiningbusymotorwayjunctionsorelevated sectionswhichcanbeexposedtoroadsaltsprayinwinter.
Rural C2 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 fastenerswouldcorrodewhenexposedtoany
oftheseexternalenvironmentsandthecorrosionratewillincreaseasyoumoveupthetable.
• Austenitic stainless steel fastenersaredurableinalltheseexternalenvironmentsandshouldbespecifiedinmarineandcoastalenvironmentsand,inmanycases,wouldberecommendedinindustrialatmospheres.A4(316)gradeisparticularlyrecommendedforindustrialandcoastalregionswheredesignliferequirementexceed15-20years.
• Cladding envelope sealing productsspecificationsshouldalsobe
compatiblewiththedesignlifeofthesystemanditsfasteners.
Marine
Rural
Durability (corrosion resistance)
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2.5d Internal environment / building useSomebuildinguses,andtheprocessestheyhouse,canpresentveryonerousinternalenvironmentalconditionsuponthefastenersandseals.Insuchcases,coatedcarbonsteelwouldnotbeconsideredanappropriatefastenermaterialchoice.
2.5d i) Building use - “at risk” categoriesDuetotheirgeneralfunctionandinternalconditions,austeniticstainlesssteelfastenersshouldbeconsideredonthefollowingbuildingcategories
• Leisureindustry…swimmingpools,sportscentres,stadia.
• Transportindustry…airportterminalsandbuildings,ferryanddocklandfacilities,railwaybuildings
• Waterindustry…sewageandwatertreatmentworks,pumpingstations
• Powerstations,wastetoenergyplants
• Manufacturing…paper,pharmaceuticals,chemicals,brick&masonryproducts,breweries,textiles,food&drink
2.5d ii) Building use - further “at risk” categoriesAdditionally,therearesomeotherbuildingcategorieswhich,eventhoughtheirinternalenvironmentmaybenon-aggressive,demandthatausteniticstainlessfastenersbeconsidered.Thepotentialforleakageresultingfromcorrosionofcoatedcarbonsteelmayresultindamagetoexpensive/sensitiveequipmentandcouldalsobeextremelydisruptivetotherunningofthebusiness.
• Hygiene,Foodprocessing
• Electronics,computerequipment
• Highvaluegoods
• Schools
• Hospitals
2.5d iii) Building use - lower risk categoriesTypicalbuildinguseswherecoatedcarbonsteelfastenershavebeenshowntoperformadequatelyforperiodsoffunctionallifeexpectancyupto25yearsandthereforewherecoatedcarbonsteelcouldbeconsideredinclude;
• Retail
• Distribution
• Manufacturingof“dry”goodssuchasassemblylines,windowsanddoors,automotiveproducts,whitegoodsetc.
2.5d Keynote summaryFromtheaboveitcanbeseenthattheinternalenvironment/buildingusehasamajorinfluenceonthechoiceoffastenermaterialandthatausteniticstainlesssteelshould,inmostinstances,bespecified.Specifyingausteniticstainlesswouldalsoeliminateanyfutureriskifthebuildingusechanges.
Durability (corrosion resistance)
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2.5e Project-based long term warranty requirementsThereisanincreasingdemandbyclientsandbuildingownersfortheperformanceofproductswithinthebuildingconstructionandenvelopetobewarranted.Theroofingandcladdingindustryhasrespondedtothesedemandsandvariouswarrantyschemesarenowavailable.
2.5e i) Industry association system basedWarrantiesareavailablethroughanumberofindustryassociations-somewarrantworkmanshipaswellasmaterials.Usuallyaninsurancepremiumisrequiredtobepaidwhichisapercentageoftheenvelopecontractvalue.
2.5e ii) System suppliers warranty schemesTheprinciplesystemsuppliermayoperatewarrantyschemesforthecompletesystem.Sotheycaneliminatetheriskofsystemfailureduetoancillaryproducts,theprinciplesystemsupplierwillspecifycomponentstobeusedinconjunctionwiththeirproductstomakeupatotalsystem.Warrantiesarethenobtainedfromtheirpartnersuppliersandinstallersandasingletotalsystemproject-specificwarrantyisthenpassedtotheclient.
Systemsupplierwarrantyschemesdonotnecessarilyrequireapolicypremiumtobepaidbytheclient.
SFSintecworkcloselywiththeleadingsystemsupplierswhospecifyfastenersandancillaryproductssuchassealantsappropriatetothewarrantyperiodrequired.
2.5e iii) Component suppliers warrantiesAsanalternativetothewarrantyschemesabove,theclient(throughthearchitect/designer)maywishtospecifyandobtainseparateindividualproductwarrantiesfromallthevarioussupplierswhosecomponentsareusedorspecifiedwithinthesystem,andalsotheinstallerifworkmanshipistobewarranted.
2.5e Keynote summaryProject-specific warrantyClientsshouldbeencouragedtoobtainwarrantieswhichareproject-specific,andoftenupto30years-andtheseshouldincludeallcomponentscriticaltothebuildingenvelope.Onlyausteniticstainlessfastenerswouldbedeemedtoprovidetherequiredlevelofperformance.
Beware,warrantiesshouldnotbelimitedtosimplysupplyingmoreproducts-theclientshouldseekthere-assurancethatthewarrantycovers“making good the roof”.Theclientshouldensurethesuppliertakesfullresponsibilitywithinthewarrantyoffered.
Products liability InsuranceThechoiceofsuppliershouldalsobelimitedbywhethertheirproductionplantsoperateQualityandEnvironmentalManagementSystemsandhavecertificationshowingconformanceto,forexample,ISO9001:2000andISO14001:1996.X
LInsurancecertificate
SFS
intecprojectwarranty
TataSteelPanelsandProfiles
Durability (corrosion resistance)
email: [email protected] Helpline: 0113 2085 578
17
2.6 Exposure and corrosion - selecting the correct productBSEN12944givesguidanceonvariousenvironmentalexposuresandassociatedcorrosionrisks.Theremaybetimesandlocationswheretheexposurecategoryishigherthanexpected.ForexamplealightingcolumnlocatedbyanelevatedmotorwaymightbeconsideredtobecategoryC3,butwhensubjectedtolocalconditionssuchaswintersaltspray,mightinfactbeexposedtocategoryC5-M.
Recommended fastener material to suit EN 12944 exposure categories
Thisrevisedandupdatedapplicationtablesimplifiestheselectionoftheappropriatefastenermaterial.
Warranted performanceStainlesssteeltype304austeniticfastenersarewarrantedforcategoryC1,C2,C3and,withpriorapproval,categoryC4.Stainlesssteeltype316iswarrantedforallapplicationsuptoandincludingC5-I,andwithpriorapproval,categoryC5-M.Stainlesssteeltype1.4547iswarrantedforanyswimmingpoolhallsandcertainchemicalprocessingplants.*priorapprovalisrequiredasapplicationsvaryfromprojecttoproject.Itisnotpossibletocoverallpossibilitiesindatasheetsandsoconsultationisrequired.Therefore,giventhecomplexchemistryinvolved,usersarestronglyadvisedtocontactSFStechnicaldepartmenttodiscussindividualprojectsintheC5-IandC5-Mcategories.Wewouldbepleasedtoadviseanddevelopspecificationstosuit.
Service lifeTherearemanyfactorsthataffecttheservicelifeofmetalproductsinconstructionprojects.Theservicelife,unlikethewarrantyperiod,isforguidanceonlyandisgenerallytakentobetheuseful,practicalworkinglifeofaproductasinstalled.Forfasteners,becausethereisnomaintenanceinterval[fastenersbeingconsideredtobeinaccessibleandnotserviceableoncefixed]theusefulservicelifewouldcometoanendwhen,forexample,
• thebuildingisdismantledoralterationsarecarriedoutwhichrequireremovaloftheweatherproofinglayer andassociatedfasteners
• thefixinghasfailedorissoheavilycorrodedthatmechanicalfailureisimminent
• deteriorationoftheweatherproofinglayerbecomestooextensivetoremainwindandweathertight
• weatherpenetrationoffastenersealingwashershasoccurredorairleakageissignificant.
Forcarbonsteelfasteners,servicelifeinaC1categorymaybeacceptable,perhaps15-20years,butthesameproductusedinsaycategoryC3mightstarttosuffercorrosionwithin12monthsofinstallationandbeattheendoflifeandreadyforreplacementinlessthan7years.InC4conditions,corrosionmightberapid,withfailurewithin5years.
Poorworkmanship,incorrectproductselection,adverseweatherconditions,exposuretoindustrialoratmosphericpollutants,distancefromthesea,winterroad-saltsprayfromadjoiningbusyroads,accidentaldamage,alterationstothebuilding,highinternaltemperaturesorhumiditylevels,interstitialcondensation,highradiationlevelsandincompatiblemetalcomponentswillallaffecttheservicelifeofthecomponent.
Constructionprofessionalsmustselectanappropriatefastenermaterialthatwillmatchtherequiredservicelife,warrantyperiodandbuildingfabriclifegiventheexposurecategorythatisanticipated.SpeculativebuildingprojectsshouldbeconsideredtobecategoryC3asaminimumsinceoccupiersofrentedbuildingsmaybefromanyindustryandtheimpactoftheirproductionprocessesonthefabricwillbeentirelyunpredictable.
Corrosivity Category C1-verylow C2-Low C3-Medium C4-High C5-I-Veryhigh
(industrial)C5-M-Veryhigh(Marine)
Swimming Pools& Chemical Plants
Examplesoftypical
environmentsina
temperateclimate
(informativeonly)
Interior-Heatedbuildingswith
cleanatmosphere
Ruralareas-lowlevelsofpollution
-Unheatedbuildingswhere
condensationmayoccur
Urbanandindustrialareas
moderatepollutionCoastalarea
withlowsalinity-Productionroomswithhighhumidity
andsomeairpollution
Industrialandcoastalareaswithmoderatesalinity
Industrialareaswithhighhumidityandaggressiveatmosphere.Permanent
condensationandhighpollution
Coastalandoffshoreareaswithhighsalinity
Permanentcondensationandhighpollution
Withinpoolhallsand
certainchemicalprocessing
plants-fastenersthatpenetrateorarebelowvclandexposedtochlorinevapour
A5 1.4547Max Warranty
✔40+
✔40+
✔40+
✔35
✔25
✔25
✔20
A4 - 316 1.4401Max Warranty
✔40+
✔40+
✔40
✔30
✔20
✘✔15
✘-
A2 - 304 1.4301Max Warranty
✔30
✔25
✔20
✘✔15
✘✔10
✘-
✘-
KEY✔ ✔ ✘✔ ✘
Suitable but not economic Recommended Requires approval Not suitable
Popular Name
EN Name
Durability (corrosion resistance)
www.sfsintec.biz/uk18
APPLICATION DESCRIPTION CODE FASTENER
APPLICATION DESCRIPTION CODE FASTENER
SX3/9-L12-S19-6.0 x 29 x A4 (x colour if applicable)
(x colour if applicable)
SX14/12-L12-S19-5.5 x 40 x A4
SL2-S-L12-S14-6.3 x 28 x A4 x colour
SXC5-S19-5.5 x Length x A4 x colour
SXC14-S19-5.5 x Length x A4 x colour
SL2-S-S16-6.3 x 28 x A4 x colour
SDK2-S-377-6.0 x 35/45
SDK3-S-377-6.0 x 35/45
SL3/2-5-S-SV16-6 x 27 x A4
SX2/18-A16 5.8 x 38SX2/28-A16-5.8 x 48
SX3/9-S16-6.0 x 29 x A4
SX14/12-S16-5.5 x 40 x A4
SL2-S-S14-5.5 x 27 x A4
Telescope tube R75 x length fastener BS-S-4,8 x length Telescope tube R45 x length fastener BS-S-4,8 x length
m1tr- M8, M10 or M12 x Length
MBRK-S4-H18-10 x Length
SX-S16 x Length x A4
SX3/15-D12-5,5 x 30 x colour
SLA5/4-6-S4-6.0 x 19
SFS
TSFS
T
20
1617
SFS
TSFS
T
20
18
Drillerforcoldrolledsteelwithirius®powdercoatedcolouredheadwherevisible.
Drillerforhotrolledsteelwithirius®head.
Drillerforclamping/stitchingwithirius®powdercoatedcolouredheadwherevisible.
Drillerforinsulatedpanelstocoldrolledsteelwithpowdercoatedcolouredhead.
Drillerforinsulatedpanelstohotrolledsteelwithpowdercoatedcolouredhead.
Drillerforclamping/stitchingwithpowdercoatedcolouredhead.
Drillerforsecuringstandingseamsystemhalterstodeckswithspecialdrivesystemtoeliminateovertorque.
Drillerforsecuringstandingseamsystemhalterstocoldrolledpurlins/tophatswithspecialdrivesystemtoeliminateovertorque.
Drillerforsecuringstandingseamsystemhalterstocoldrolledpurlins/tophatswithhexagonalhead.
Drillerforsecuringtophatspacertosteellinerdeck.
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2
3
4
5
6
7
8
9
10
10
Site assembled liner panel systems.
Insulated panel systems.
Aluminium standing seam 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*,allfastenersshownaremanufacturedfrom316seriesausteniticstainlesssteel.TherearemanyothertypesavailableandSFSintecwillbepleasedtogiveadviceonspecificapplicationsonthecontactdetailsbelowore-mailingdetails/[email protected]
Durability (corrosion resistance)
email: [email protected] Helpline: 0113 2085 578
19
APPLICATION DESCRIPTION CODE FASTENER
APPLICATION DESCRIPTION CODE FASTENER
SX3/9-L12-S19-6.0 x 29 x A4 (x colour if applicable)
(x colour if applicable)
SX14/12-L12-S19-5.5 x 40 x A4
SL2-S-L12-S14-6.3 x 28 x A4 x colour
SXC5-S19-5.5 x Length x A4 x colour
SXC14-S19-5.5 x Length x A4 x colour
SL2-S-S16-6.3 x 28 x A4 x colour
SDK2-S-377-6.0 x 35/45
SDK3-S-377-6.0 x 35/45
SL3/2-5-S-SV16-6 x 27 x A4
SX2/18-A16 5.8 x 38SX2/28-A16-5.8 x 48
SX3/9-S16-6.0 x 29 x A4
SX14/12-S16-5.5 x 40 x A4
SL2-S-S14-5.5 x 27 x A4
Telescope tube R75 x length fastener BS-S-4,8 x length Telescope tube R45 x length fastener BS-S-4,8 x length
m1tr- M8, M10 or M12 x Length
MBRK-S4-H18-10 x Length
SX-S16 x Length x A4
SX3/15-D12-5,5 x 30 x colour
SLA5/4-6-S4-6.0 x 19
SFS
TSFS
T
20
1617
SFS
TSFS
T
20
18
Drillerforsecuringmetaldeckingtocoldrolledpurlinswithhexagonalhead.
Drillerforsecuringmetaldeckingtohotrolledpurlinswithhexagonalhead.
Drillerforclamping/stitchingdecksidelapswithhexagonalhead.
Thermallybrokenfasteningsystemforinsulationtometaldeck,comprisingofafastenerinstalledthroughapolyamide“telescopetube”.
Thermallybrokenfasteningsystemforinseamfasteningofsingleplymembranesthroughinsulationtometaldeck,comprisingofafastenerinstalledthroughapolyamide“telescopetube”.
316austeniticsteelthroughboltforsecuringrainscreenbracketrytoconcretesubstrate.
Selfdrillerforsecuringverticalaluminiumrailstoaluminiumbrackets.
Selfdrillerforsecuringaluminiumrainscreenpanelstoaluminiumrailsandframeworkover2.5mmthicknesswithpowdercoatedlowprofilecolouredhead.
Nylonplugand316austeniticscrewforthroughfixingbracketrytoconcrete/masonrysubstrates.
Drillerforbracket,thermalpad,boardlinerintosteelframingsystem.
11
12
13
14
15
18
17
19
20
1514
13
12
11
Single ply membrane over insulationon metal deck.
Rainscreens - Bracket to steel framing
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+ Pink Strip sealants for metal
roofing and cladding
Rainscreens - Rail to bracket
Rainscreens - Panel to rail
16
19
20
Durability (corrosion resistance)
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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.
Loosesealingelementnotretainedunderhead
PoorqualityEPDMshowingUVdegradation
Weathersealing
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21
Sectio
n 3W
eathersealing
3.2 The sealing washer solutionLong-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,forexamplewhereasthenormalhardnessis70/80shore,onclampingandinsulatedpanelfastenersamuchsofterEPDMwithahighrecoveryfromcompressionvalue(70%)isused,referto3.3a&b.
3.2b Metal backingToensuretheEPDMcompressesevenlyandformsasealagainstboththesheetandthefastenershank,theEPDMshouldbevulcanizedtoametalbackingwasher.Merelyglueing,asisthepracticeofsomemanufacturers,wouldpresentariskoftheEPDMdelaminating.Theproblemwithloosesealingelementsisclearlyillustratedonthepreviouspagewhere,foranumberofreasonsassociatedwithpoorfastenerdesign,thesealingelementhas“extruded”beyondtheheadofthefastenerandhasbeendestroyedwiththeresultthatthesealwillnolongerbeeffective.
3.2c DiametersSealingwashersareavailableinawiderangeofdiametersfrom,typically,12mmto29mm.
Forprimaryvalleyfixingofthrough-fixedmetalroofweathersheetsandinsulatedroofpanels,19mmisusuallythepreferreddiameter.
For“plastics”rooflightprofiles-typicallyGRPandpolycarbonate,largerdiameterwashers,typically29mm,orinsomeinstancescrownsaddlewashers,arerecommended.
Forwallingsystemsandsecondary(clamping)fasteners,smallerdiameters,typically12mm-16mm,areused.
19mm&29mm
12mm&16mm
Weathersealing
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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”.Theloweronesthreadformintothepurlinandaretypically5.5mmminimumdiameter.Attheheadandwasherendofthefastenerthereisatopthreadsectionofanincreaseddiameterdesignedtosupporttheouterskinofthepanelandthusimpartpermanentcompressionofthewasher.
Top thread performanceThishastobedesignedtoaccommodateallpositiveloadingconditions,includingconcentratedfootloads,whilstmaintainingoptimumpulloverperformanceofthewashers.Insulatedpanelfastenersshouldbedesignedwithatopthreadwiththisoverallperformancerequirementinmind.Thismaybebyhavingatopthreadofc7mmdiameteror,ifless,thenthethreadformdesignsshouldprovidetherequiredsupport.Manyalternativesuppliershavetopthreadsofpoordesignwhichareunabletoaccommodatealltheseloadingsandthereforethesupportgivenwillinevitablybereducedthusleadingtoaweathersealrisk.
Thread-free sectionForoptimumperformance,designsshouldalsoincorporateathread-freefeatureimmediatelybehindandbelowthewasheroninsulatedpanelfasteners.ThisenablestheweatherskintobepermanentlysupportedthuscompressingtheEPDMwasher.Thiscompressionandsealwillbemaintainedeveninconditionswherethefastenerisusedtodrawthepanelbacktothesupportorwherefastenersareoverdriven.Alternativedesignswithtopthreadsextendingrightuptotheheadpresentamajorriskinboththeseconditions.
3.3b Clamping fasteners to ensure weathersealingClampingfastenersarepurpose-designedtoclampthinmaterialstogether(e.g.sidelapsofprofiledmetalsheets)andforfixingflashingsandclosurestoprofiledmetalsheetsandtothemselves.Useofinappropriatefastenersmayleadtoovertorqueinwhichcase,notonlyisweatherandairtightnesscompromised,butalsothestructuralperformanceofthefastenerislostandcomponentsmaybecomedetached.Clampingfastenersshouldincorporatefeaturestoensurestructuralperformanceandweathertightness.
• Reduced diameter drillpoint-highpulloutandclampingforces• WRS washer-thickerandsofterwithahighrecoveryfromcompressionvalue(70%)toensure
asealoverarangeofapplicationthinnesses.• Thread free (free spin) zone-todrawandclampthematerialstogetherandtoeliminateany
weatherandairtightnessriskassociatedwithover-driving.
3.3c Specialist fasteners designed to prevent overdrivingOverdrivingfastenersintothin[<1mm]steelsheetisanincreasingproblemasbuildingdesignersselecteverthinnersheetmaterialforstructuralapplications.Typicalsitelabour’spracticeistoremovedepthcontroldevicesfrompoweredscrewdrivers.Thisleavestheinstallerwithlittlecontroloverthesettingofthefastener,whichhappensveryrapidlywhenitisbeingdriveninatmorethan1000rpm.Overdrivingcrushesthesealingwashersoreducingthewatertightsealandwilleasilystripthethreadforminsteeluptoabout2mmthick,leadingtoimmediatefixingfailure.Inthickersteels,thegripofthethreadisnotdamaged,butthehightorqueimpartedtothefastenerwillresultinveryhighresidualtensilestresses.Overdrivingisthemostcommoninstallationfaultobservedintheworkplaceandiscausedbylackoftrainingandabeliefin“thetighterthebetter”.Totrytoovercomethisfixingissue,SFShaveengineeredarangeofproductsspecificallydesignedtopreventoverdriving.Thethreadfreezonementionedaboveisonesuchmeasure;othersinclude:
• SDKandSOLfasteners,whichfeatureadrivepinthatbreaksoffatapresenttorque
• SL3“thicktothin”fastenersdesignedtoclampthicktophatsectionstothinmetaldecksusingacombinationofaspecialsprungwasher,deepthreadsandafreespinzone
• Irius®underheaddrivesystem
• TUSsystemforrainscreenpanels
Insulatedpanelfasteners
Clampingfastener
Weathersealing
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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%.
4.1c October 2010 Part AD-L2 England and Wales Technical Standard J [Scotland] - Overview The2010ApprovedDocumentsandRegulationsaresimilartothe2006version,howevertherearemanychangestotheiSBEMsoftwarewhichmodelstheCO2outputofthebuilding.Mostnotableare:*Usingarangeofnotionalbuildingstomodelvarioustypesofusage[previously‘onesizefitsall’]andvaryingtheCO2reductionlevelstosuitthenotionalbuildingtypesratherthanablanketreduction*Ashiftto3differentlightinglayoutsfornaturallightsituations-sidelit,overheadlitandnolightapplications*Retainingthe2006Uvaluelevelsas‘back-stop’levels*Focusonreducingcoldbridgingbyaddingpenaltiesforpoordesignofdetails*Overallacombinedreductionofabout27%intheallowableCO2leveloverthe2006level
TheiSBEMcalculationnowhasbesubmittedattheplanningstageandconfirmedwith
an‘asbuilt’calculationattheendoftheproject.
What impact will these changes make on the external cladding envelope?- U-values -Itisgenerallyfeltthat,withthenewcalculationmethodologyforthebuildingsCO2emissions,afurtherreductioninU-values(ie.increasinginsulationthicknesses)ofthecladdingenvelopewillonlyhaveminimaladditionalpracticalimpactonthebuildingsenergyefficiencyoverthechangesalreadyimplementedin2002.
- Natural lighting -Oncertaintypesofbuilding,theprovisionofnaturalrooflightingmayallowareductionintheusageofelectriclightingthusmakingsignificantcontributionstothebuildingsenergyefficiency.ThiswillusuallymorethancompensateforthehigherU-valuesnormallyassociatedwiththerooflightelementoftheroof.
- Cold bridging-Elimination/reductioninthermalbridgeswillremainanimportantdesignconsiderationatjunctions,interfacesandfasteners.
- Air-tightness-Increasingair-tightnessfromthe2002levelsof10m3/sqm/hrwillgenerallyshowagreaterbenefitandafurtherincreaseinair-tightnessmaybechosenbythedesignerasasignificantcontributoryfactortocompliancetotheBuildingRegulations.
The2010revisiontoPartL2Arequiresallowableairleakageratestohalveto5m3/m2/hour.ThischangewillbringsignificantCO2reductionstotypicalindustrialtypebuilding-industrystudieshaveshownreductionsintheregionof3to4kGsofCO2/m2whenmeasuredagainstthebenchmark2002specificationusingasimpleindustrialunitlayout.
Sectio
n 4T
he “Part L” issue
The “Part L” issue - Airsealing and thermal bridging
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4.2 Elimination of cold bridges by using thermally broken fastenersForsingleplymembraneroofingsystems,boththeinsulationandthemembranemaybemechanicallyfixed.PartL2A,withits’increasingfocusonreducingcoldbridging,hasledSFSintectointroducearangeofthermallyisolatedfastenersforthesepopularroofingsystems.Becausethemetallicfastenerelementislocateddeepwithintheinsulationlayer,heatflowsaresignificantlyreducedovertheoldstylemetalplateandscrewapproach.
Asthemarketleader,SFSintec’sISOTAKsystemoffersawideselectionoftelescopictubesandhighperformancefastenerstosuitanyapplicationincludingtimber,steelandconcretedecks.WorkinginpartnershipwithboththeinsulationandmembranemanufacturershasenabledSFSintectodevelopproductsthatofferveryhighlevelsofclampupforcetoresistwindloads,whilstreducingheatlossbysome10%ontypicalapplications.
4.3 Achieving airtightness with warranted sealants Generally,toachievetheserequiredlevelsofairtightness,additionalsealingmaterialshavetobeincludedwithinthesystem.Thesesealsareusuallyinstalledattheinnerliningpositioniebelowtheinsulation…thefollowingsection4.3givesfurtherinformationonthespecificationoftheseals.
TataSteelhavepublishedaTechnicalPaperentitled“Creatinganair-tightbuildingenvelopeColorcoat®TechnicalPaper-whichgivesfurtherusefulguidanceonachievingair-tightnessonbuilt-upandinsulatedpanelsystems.
Warranted sealantsThereareanumberofmechanicalandacceleratedtestsdevelopedbysealantmanufacturersforroofingandcladding.ThebasictestsdeemwhetherthesealsareclassedasTypeAorTypeB.TheNFRCpublishedTechnicalBulletin36whichgivesasummary.However,thereisaneedforthesealstobewarrantedforupto30yearsthusbeingcompatiblewiththeausteniticstainlessfastenersandsheetsystemasreferredtoinsection2.5.
SFSintecworkedcloselywithaleadingsealantmanufactureranddevelopedahighperformancebutylstripsealantrangeforprofiledroofingandwallingsystems.TheirperformanceunderallthemechanicalandacceleratedtestsexceededthebasicrequirementofaTypeAsealantsuchthatSFSintecareabletoissueawarrantyforupto30years.ThiswarrantedSFSintecsealantisreferredtoasTypeA+andiscolouredpinkforeaseofidentification.
Clamping fasteners (referto3.3b)Toensurethatthewarrantedsealantsperformeffectivelywithintheapplication,theyhavetoworkincombinationwiththepurposedesignedclampingfastenersdiscussedwithinsection3.3b.
ThreadfreezoneforweathertightclampingonSFSstitchingfasteners
Coldbridgingviaall-carbonsteelfasteners
The “Part L” issue - Airsealing and thermal bridging
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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.
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UVfadingofmouldedheads
Pushfitcapacceleratingcorrosion
Aesthetics by design
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5.2 Factory-coloured solutionsToaddressthemanyproblemsassociatedwithpush-fitcaps,SFSintechasdevelopedrangesofcolouredandaestheticallyshapedfasteningsystemswhichhaveevolvedwiththeintroductionofnewcladdingmaterialsandprofiles.Thesehavebeendesignedwiththedesiresofthespecifiers,contractorsandbuildingownerstakenintoconsideration.
5.2a The powder coated head solutionPowdercoatingoffersanumberofbenefits.Itistough,durableandaccuratelymatchesthecolourofthesurroundingweathersheet.ItisonlyveryslightlyaffectedbyUVlight,andsofadingorweatheringisuncommon.Thefastenerheadremainssmallandcompactandthereisnobulkyplastictocausevisualintrusion.
5.2b The “unobtrusive” solutionWherethedesignerselectsawallcladdingmaterialorprofileforitshighaestheticappeal,itmaybemoredesirablethatthefasteningsystemisunobtrusiveandblendsinwiththecladding.Somewallingsystemsaredesignedsuchthatthefastenersaretotallyconcealed,forexample,flatormicro-ribbedinsulatedwallpanelsareoftenfixedthroughtheir“tongue&groove”joint.
However,therearemanywallingsystemswhicharevisiblyfixedandtheraisedheadsoftraditionalmouldedheadedfasteners,eventhoughtheymayofferlongtermcolourmatching,maynotmeettheaestheticrequirements.
Lowprofilecolouredheadformshavebeendevelopedspecificallyforapplicationswherethefastenerhastofulfilallitsnormalstructuralrequirementswhilst,atthesametime,blendinunobtrusivelywiththecladding.
Theirius®headformmaybepowdercoatedforcolourmatchingpurposesandtheinnovativeunderheaddrivesystemenableseaseofinstallationwhilstalsoofferingahighleveloftamper-resistance-aestheticswithsecurity.
Irius®headform
UnobtrusiveIrius®atWalesMillenniumCentre
ColouredIrius®headform
Paintedheadform
Aesthetics by design
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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 Safety & 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.ThisenablesthecalculationofthestandarddeviationandthecharacteristicvalueasassessedusingthemethodlaiddowninBSEN10204:2004.
6.1aTheSFSintecTechnicalValuedocumentspresenttestvaluesfordifferentfasteners.Whenpossible,theresultshavebeenevaluatedaccordingtotheEuropeanstandardsandrequirementsfortheCEmark.Fortheevaluation,theEuropeanOrganisationforTechnicalApprovals(EOTA)haspublishedaguideline1)“FasteningScrewsforMetalMembersandSheeting”.Hereisashortsummaryoftheguidelineregardingtheevaluationofcharacteristicvaluesandonecalculationexample.
Characteristic Value Rk of a Fastening Capacity
AcharacteristicvalueRkfortensionandshearresistanceofthefasteningiscalculatedaccordingtotheequation1. Rk =(Favg-k*s)*a (1) ,where Rkisthecharacteristicfasteningcapacity Favgistheaveragevalueoftheultimatefailureloads kisthestatisticalcoefficientaccordingtoasamplesizen sisthestandarddeviation aistheadjustmentcoefficientforthetestresults
Pullouttesting
Purpose-designeddrillpoints
Technical performanceS
ection 6
Technical
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6.1a ContinuedTheadjustmentcoefficientcomesfromtheequation2.Thepurposeoftheadjustmentistoreduceeffectsofmaterialpropertydeviation.
a =(Rm,min/Rm,obs)*(tmin/tobs)≤1 (2) ,where Rm,ministheminimumtensilestrengthofarelevantproductstandard Rm,obsistheactualtensilestrengthofthetestspecimen tministheminimumthicknessaccordingtoarelevantproductstandard tobsistheactualthicknessofthetestspecimen
Statistical evaluation and k value
Thetestresultsareevaluatedaccordingtostatisticalmethods.Theresultsareassumedtofollowalog-normaldistribution.Fortheevaluationofa5%fractilevalueandaconfidencelevelof75%ischosenaccordingtotheEOTAguidelineandISO12491:19972).Table1showsthestatisticalfactorkaccordingtoasamplesizenormallyneededforthetests.
Table1.k-valuesforthesamplesizen.
n=samplesize n=6 n=10 n=12 n=20
kvalue 2,34 2,10 2,05 1,93
Note!Allcalculations,measurements,fastenersanddesignmethodshavetobeverifiedbyaresponsibledesigneroranengineer,regardingthecorrespondingstructureandload.Pleaseconsultyournationalnormsandapprovals.
6.2 Pullover resistanceThisistheabilityofthefastenertopreventthesheetmaterialfailingbypullingovertheheadofthefastener.
AsreferredtoinSection3onweathersealing,resistancetopulloverfailureofthesheetisinfluencedbythesheetmaterialthicknessandtensilestrengthincombinationwiththestrengthanddiameterofthewasher.
Thefastenersupplierspecifiedshouldbeabletoprovidetheengineerwithpublishedtestresultsofvariouswasherdiametersinvarioussheetmaterialsandthicknesses.
6.3 Concentrated foot loadingsThetwoprincipleapplicationswherefootloadingshavetobeconsideredinfastenerdesignaremetalfacedinsulatedroofpanelsandsingleplyroofmembranesoverinsulationboards.
Insulated roof panelsAsdescribedinSection3.3a,thetopthreadofinsulatedpanelfastenershastobedesignedsothatitwillcontinuetosupporttheexternalskinofthepanelagainsttheconcentrateddynamicloadsimpartedbyfoot-traffic.
Thismaybebyhavingatopthreadofc7mmdiameteror,ifless,thenthethreadformdesignsshouldprovidetherequiredsupport.Manyalternativesuppliershavetopthreadsofpoordesignwhichareunabletoaccommodatealltheseloadingsandthereforethesupportgivenwillinevitablybereducedthusleadingtoaweathersealrisk.
Thisenlargedthreadalsoworksincombinationwiththethread-freezone,whosefunctionisalsodescribedinSection3.3a,toensurebothawalkableandweathertightconnection.
Single ply membranes over insulation boardsThemembranemustbeprotectedagainsttheriskoftheinsulationandmembranefastenerpuncturingthemembraneasaresultoffoottrafficcausinglocalcompressionoftheinsulationboard.TelescopesystemssuchastheSFSintecIsotakrangeareautomatically“treadfast”asthefastenerheadissetdowntowardsthebottomofthetelescope.Whereoldstylemetalplateandscrewsystemsareused,thescrewshouldhaveanenlargedthreadundertheheadtoengagewiththeplatewashersoastoresistfoottrafficloads.
Pullovertesting
SheetsupportandthreadfreesectiononSFSinsulatedpanelfasteners
“Treadfast”telescopeIsotak
Technical performance
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6.4 Dynamic bend resistanceWhereinsulatedpanelsarethrough-fixed,thefastenersarealsosubjecttorepetitivebendingforces.Theseforcesaretypicallygeneratedbypaneldeflectionsfrom(wind)loadingsandthermalmovement.Thisbendingtendstobegreaterinhot-rolledsteelpurlinswhichtendtobelessflexiblethanthinnercold-rolledpurlins.
TheEuropeanConventionforConstructionalSteelwork(ECCS)Document66,PreliminaryRecommendationsforSandwichPanelsdefinesatestmethodtowhichfastenermanufacturershavetobeabletodemonstratecomplianceandadvisethemaximumallowabledeflectionrelativetosteelsupportandpanelthickness.
By2013,manyfastenersforroofingandcladdingwillfeatureCEmarkinginaccordancewiththeEuropeanConstructionProductsDirective.AssessmentforCEmarkingwillincludeaseriesoftestswhichwillincludeabendtestsimilartotheECCStestoutlinedabove.ItisexpectedthattheCEtestprogramwillreplacetheECCSmethodinduecourse.
6.5 UnwindingPitched roofing systemsHistorically,thisphenomenonhasnotbeenwidespreadwithinpitchedroofingsystems.However,whereconditionsofpotentiallyhighdifferentialmovementbetweenthesheetand“lightweight”framingpresentthemselves,cautionintheselectionofthemostappropriatefastenertypeshouldbeexercised,andSFSintecwouldwelcomebeingconsulted.
Flexible membrane systems to “thin” metal decksAsthewindpassesovertheflexiblemembraneaneccentricforcepassesthroughthefastener.TheSFSISOTAKsystemisabletoaccommodatethesedynamicwindloadsbynatureofits“reduced”diameterdrillpoint,thetaperedlead-inthreadsectionanditsshallowthreadpitchangle.Thesefeaturescombinetogivetotalthreadengagementwithinthedeckandtoalsoprovidetheoptimumpulloutfrom“thin”,0.63mmminimum,steeldecks.
6.6 Clamping of membraneForin-seamfasteningofsingleplymembranes,telescopicfastenersaredesignedtoresistanysidewardsmovementofthemembranewhichcouldultimatelyleadtotearing,slippageandfailureofthemembrane.SFSinteccanofferavarietyoffastenerandtubedesignswhich,duetotheirhighclampingqualitiesmayallowa25%increaseinthefastenersafeworkingload.
Unlessthemembranesuppliertakesfullresponsibilityforthefastenerfrequencycalculations,confirmationshouldbesoughtfromtheparticularmembranesupplierthattheproposedfasteningsystemanditspermissibleloadingsareappropriatetotheirmembrane.
6.7 Thermal/cold bridgingApprovedDocumentAD-L2requiresthedesignertocalculatethermalbridgesandconsidertheireffectonbothcondensationandalsoheatlossthroughthebuildingenvelope.
Incertaintypesofroofingandcladdingsystems,fastenersmayaddtoheatlossdependingontheirspecification.
Thethermalconductivityofcarbonsteelasafastenermaterialis60W/mKwhereasausteniticstainlessisonly17W/mK.ThereforespecifyingausteniticmayallowthinnerinsulationtobeusedandstillachievecompliancewiththeBuildingRegulations.
Asanexample,inatypicalflatroofapplicationwith4fastenerspersqm,theadditionalheatlossthrough100mminsulationwithcarbonfastenersexceeds1.5%comparedtoonly0.25%withausteniticstainlessfasteners.Wherecoatedcarbonsteelofferssufficientdurability,thenusingathermallybrokentelescopicsystem(seesection4.2)wouldalsoallowthinnerinsulationtobeused.
highperformancedrilltip
Coldbridgingviaall-carbonsteelfasteners
laboratorytesting
Technical performance
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6.8 Overdriving resistanceOverdrivingoffastenersmayleadtothreadstrippingwithinthesupportingstructure,particularlyin“thin”coldrolledsections.“Traditional”designsofselfdrillingthreadedfastenersrelyupontheinstallertotakethenecessarycarenottooverdrive,eitherbyuseofdepthlocatorsonscrewgunsorexperience.Fortwoparticularapplicationswherethefastenerperformanceiscriticialfortheintegrityofthesystem,SFSintechasdevelopedinnovativesolutionswhich,bydesign,cannotbeoverdriven.
SDK fasteners for standing seam 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.SFSintec’sstitchingandclampingfastenersarepurpose-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
Technical performance
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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 WindloadingsThenewBSEN1991methodusesanationalannexetoprovidewindvaluesfortheUnitedKingdomandthishascomeintoforcefromJanuary2011,replacingBS6399(andinIrelandCP3).However,EN1991producesdifferentvaluesforagivenlocationwhencomparedwiththeearlierBS6399methodandsosomeworkhasbeencarriedoutusingahybrid,takingvaluesfromboththeBSandENdataandthisseemstobethewayforward(atspring2011).
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 ToolingSections6.1to6.14showthewiderangeofperformancecriteriafastenershavetobecapableofwithstanding.Thesecriteriatendtobespecifictotheparticulartypeofroofingandcladdingsystemandthereforefastenersaredesignedsuchastogiveoptimumperformancecompatiblewiththerequirementsoftheparticularsystem.Whilstsomefastenershavebeendesignedsuchthattheycannotbemis-installed(referto6.8&6.9),toolingsystemsforotherfastenertypesareavailablewhichassisttheContractorintermsofbothspeedandconsistency,aswellasprovidingsecuritytotheClient.
Windcreates+veand-ve(suction)loadsonroofingandcladding
Technical performance
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Section 7 Specification design support
7.1 Fastener and sealant specifications for roofing and cladding
Specification advisory service for architects, designers and consultantsAttheearlydetaildesignstageofaproject,complexandsometimesconflictingrequirementscanplacediversedemandsonthefastenerandsealants.Consultationwithanexperiencedtechnicalteamfromthefastenersuppliercanhelpyoutoresolvefastenerandsealingissuesduringtheplanningstages,workingsidebysidewitharchitectsanddesignerstoensurethatperformancerequirementsofthebuildingenvelopearemet,andthecontractspecificationproceedswithoutahitch.
7.1aDilapidation and remedial worksConsultantsthatspecialiseinsurveyingpropertiesthatarechanginghandsoraresubjecttowarrantydisputeswillfindtheSFSintectechnicalservicetobeaninvaluablesourceofadvice,builtonyearsofexperience.
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.
Specification design support
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Sectio
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7.1a Project-based specification sheets
Examplesofthetypesofproject-basedspecificationsforfastenersandsealantsareshownbelow.ByusingthecodesanddescriptionspreparedbySFSintec,thespecifierhasthechoiceofissuingspecificationsineitherperformance,prescriptiveorNBSformats.
Specification design support
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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’smajorsystemssupplierssuchasTataSteelPanelsandProfilesandtheirPlatinumWarrantySystem–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.
TataSteelandProfilesPlatinumWarranty
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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,ourexpertiseisonlyaphonecallaway.
Mobile training unitFeatures:• Allweathercapability-comfortableheatedoutdooraccommodationfor upto9people;upto30peopleindoorsatyourpremises• Handondemonstrationsandvideos• Onboardpowersupply• FullrangeofSFStoolingsystemsandproducts• Programmesincludepitchroofing,flatroofing,cladding,rainscreenand facades,logisticsande-business• CPDCertificatesforattendees
Brings SFS intec to your doorstep...
Specification design support
www.sfsintec.biz/uk36
Section 8 Case studies
8.1 First Direct Arena, Leeds
Specialist contractor; Lakesmere
Designer; Populous Project requirements; Durability Section 2.5b Aesthetics Section 5 Weather&airsealing Section 3 & 4 Technicalperformance Section 6
SFS intec products; Austeniticstainlesssteel Section 2.7 irius®colourheads Section 5.2b Clampingfasteners Section 3.3, 4.3, 6.9 Weather&airsealantsTypeA+ Section 3.4 & 4.3
Case studies
email: [email protected] Helpline: 0113 2085 578
37
Sectio
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ase studies
Section 8 Case studies
8.2 WJEC Building, Cardiff
Specialist contractor; SevernInsulation
Designer; CapitaArchitecture 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
Section 8 Case studies
8.1 First Direct Arena, Leeds
Specialist contractor; Lakesmere
Designer; Populous Project requirements; Durability Section 2.5b Aesthetics Section 5 Weather&airsealing Section 3 & 4 Technicalperformance Section 6
SFS intec products; Austeniticstainlesssteel Section 2.7 irius®colourheads Section 5.2b Clampingfasteners Section 3.3, 4.3, 6.9 Weather&airsealantsTypeA+ Section 3.4 & 4.3
Case studies
www.sfsintec.biz/uk38
Section 8 Case studies
8.3 Cairngorm Funicular Railway
Specialist contractor; AbbeyRoofingSpecialists 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
Case studies
email: [email protected] Helpline: 0113 2085 578
39
Section 8 Case studies
8.4 ExCel London Phase 2
Specialist contractor; HathawayRoofing 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
Section 8 Case studies
8.3 Cairngorm Funicular Railway
Specialist contractor; AbbeyRoofingSpecialists 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
Case studies
www.sfsintec.biz/uk40
Case studies
Section 8 Case studies
8.5 Matalan, Kirkby
Specialist contractor; Longworth
Designer; Fletcher-Rae 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 irius®colourheads Section 5.2b Clampingfasteners Section 3.3, 4.3, 6.9 Weather&airsealantsTypeA+ Section 3.4 & 4.3
email: [email protected] Helpline: 0113 2085 578
41
Section 8 Case studies
8.5 Matalan, Kirkby
Specialist contractor; Longworth
Designer; Fletcher-Rae 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 irius®colourheads Section 5.2b Clampingfasteners Section 3.3, 4.3, 6.9 Weather&airsealantsTypeA+ Section 3.4 & 4.3
SFS intec Ltd.Fastening Systems153 Kirkstall RoadLeeds LS4 2AT
Tel: 0113 2085 500Email: [email protected]: www.sfsintec.biz/uk
For further information please contact:
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CPD seminars SFSintecofferstheirRIBA-accreditedCPDtechnicalseminarwhich,inconjunctionwiththisguide,helpsyoutobecomefamiliarwithissuesconcerningfastenersandsealants,aswellasenablingyoutoacquireyourRIBACPDpoints!Contactusonthedetailsbelow.