Designation:D6777−16AnAmericanNationalStandardStandardTestMethodforRelativeRigidityofPoly(VinylChloride)(PVC)Siding1ThisstandardisissuedunderthefixeddesignationD6777;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thisproceduredescribesamethodtodetermineanumericalvalueindicatingtherelativerigidityorstiffnessofvinylsidingpanels.Thisprocedureisnotintendedforroutinequalitycontrolinspectionduringthemanufactureofvinylsiding.Therigidityofvinylsidingisbelievedtobecontrolledprimarilybyitsconfigurationandisnotbelievedtobesignificantlyinfluencedbymanufacturingvariables.1.2Vinylsidingwithhigherrigidityisofteneasiertohandleandinstallthansidingoflowerrigidity.Itisexpectedtoprovideastraighterappearancewheninstalledonwallshavinganunevensurface.1.3AllothervinylsidingrequirementsandtestmethodscanbeidentifiedthroughSpecificationD3679.1.4ThereisnoknownISOequivalenttothisstandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D618PracticeforConditioningPlasticsforTestingD883TerminologyRelatingtoPlasticsD1600TerminologyforAbbreviatedTermsRelatingtoPlas-ticsD3679SpecificationforRigidPoly(VinylChloride)(PVC)SidingD5947TestMethodsforPhysicalDimensionsofSolidPlasticsSpecimens3.Terminology3.1Definitions—DefinitionsareinaccordancewithTermi-nologyD883andD1600unlessotherwiseindicated.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1relativerigidity(ofPVCsiding)—stiffnessofapieceofvinylsiding.3.2.2rigidityindex(ofPVCsiding)—amountofsamplesagordeflectionrelativetosamplelength.The“rigidityindex”isdefinedas100minusthedeflectionvalue,dividedbyth...
