Designation:D4897/D4897M−16StandardSpecificationforAsphalt-CoatedGlass-FiberVentingBaseSheetUsedinRoofing1ThisstandardisissuedunderthefixeddesignationD4897/D4897M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thisspecificationcoversasphalt-impregnatedandcoatedglass-fiberbasesheetwithmineralsurfacingonthetopsideandcoarsemineralgranulesonthebottomsideforuseasthefirstplyofaroofingmembrane.Thesebasesheetsprovideforthelateralreleaseofpressureinroofingsystemsbecausetheyarenotsolidlyattachedandthecoarsegranularsurfaceprovidesanopen,porouschannelinthehorizontalplanebeneaththemembrane.Thebasesheetsshallbepermittedtobewithorwithoutperforationsorembossings.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D146/D146MTestMethodsforSamplingandTestingBitumen-SaturatedFeltsandWovenFabricsforRoofingandWaterproofingD228/D228MTestMethodsforSampling,Testing,andAnalysisofAsphaltRollRoofing,CapSheets,andShinglesUsedinRoofingandWaterproofingD1079TerminologyRelatingtoRoofingandWaterproofing3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthisspecification,refertoTerminologyD1079.4.Classification4.1TypeII—Heavy-dutyasphalt-coatedglass-fiberventingbasesheet.5.MaterialsandManufacture5.1Thematshallbeathinp...
