Designation:C840−17StandardSpecificationforApplicationandFinishingofGypsumBoard1ThisstandardisissuedunderthefixeddesignationC840;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thisspecificationcoverstheminimumrequirementsforthemethodsofapplicationandfinishingofgypsumboard,includingrelateditemsandaccessories.1.2Detailsofconstructionforaspecificassemblytoachievetherequiredfireresistanceshallbeobtainedfromreportsoffire-resistancetests,engineeringevaluations,orlistingsfromrecognizedfiretestinglaboratories.1.2.1Wherethisspecificationismorestringent(sizeorthicknessofframing:sizeandspacingoffasteners)thanthefire-ratedconstruction,thisspecificationshallgovern.1.3Wheresoundcontrolisrequiredforagypsumboardassembly,detailsofconstructionshallbeinaccordancewithreportsofacousticaltestsofassembliesthathavemettherequiredacousticalvalues.1.4Unheatedspacesabovegypsumboardceilingsshallbeproperlyventilated(seeAppendixX2).1.5Thevariousapplicationsystemsarelocatedinthefollowingsections:IApplicationofSingle-plyGypsumBoardtoWoodFramingMembers8IIApplicationofTwo-plyGypsumBoardtoWoodFramingMembers9IIIApplicationofGypsumBoardbyAdhesiveNail-ontoWoodFramingMembers10IVSemi-solidGypsumBoardPartitions11VSolidGypsumBoardPartitions12VIApplicationofGypsumBoardwithAdhesivestoInteriorMasonryorConcreteWalls13VIIApplicationofGypsumBoardtoRigidFoamInsulation14VIIIApplicationofGypsumBoardtoSteelFramingandFurring15IXArchesandBendingRadii16XApplicationofGypsumBoardtoReceiveTilebyAdhesiveApplication17XIExteriorApplicationofGypsumWallboardandExteriorGypsumSoffitBoard18XIIFloatingInteriorAngles19XIIIControl(Expansion)Joints20XIVFoil-backedGypsumBoard21XVApplicationofVinylFacedGypsumBoard221.6Thevaluesstatedininch-poundu...
