Designation:D1970/D1970M−21StandardSpecificationforSelf-AdheringPolymerModifiedBituminousSheetMaterialsUsedasSteepRoofingUnderlaymentforIceDamProtection1ThisstandardisissuedunderthefixeddesignationD1970/D1970M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoverspolymermodifiedbituminoussheetmaterialsintendedforuseasunderlaymentonroofeaves,orvalleys,orboth,topreventleakageofshingle,tile,ormetalroofsfromwaterback-upduetoicedams.1.2Theseunderlaymentsheetshaveastickyadhesivelayerwhichisexposedbyremovalofaprotectivesheet.Thetopsurfaceissuitabletoworkonduringtheapplicationoftheexposedroofing.1.3TableofContents:SectionScope1ReferencedDocuments2Terminology3Workmanship,Finish,andAppearance4PhysicalRequirements5Sampling6TestMethods7Conditioning7.1Thickness7.2MaximumLoadandElongationatBreak7.3AdhesiontoPlywood7.4ThermalStability7.5Flexibilityat–29°C[–20°F]7.6TearResistance7.7MoistureVaporPermeability7.8CapabilitytoSealAroundNail(HeadofWaterTest)7.9WaterproofIntegrityofSideLapSeam(HeadofWaterTest)7.10Inspection8RejectionandRehearing9PackagingandPackageMarking10Keywords111.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnonconformancewiththestandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.6Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDeve...
