Designation:C578−17StandardSpecificationforRigid,CellularPolystyreneThermalInsulation1ThisstandardisissuedunderthefixeddesignationC578;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thisspecification2coversthetypes,physicalproperties,anddimensionsofcellularpolystyreneboardswithorwithoutfacingsorcoatingsmadebymolding(EPS)orextrusion(XPS)ofexpandablepolystyrene.Productsmanufacturedtothisspecificationareintendedforuseasthermalinsulationfortemperaturesfrom-65to+165°F(-53.9to+73.9°C).Thisspecificationdoesnotapplytolaminatedproductsmanufac-turedwithanytypeofrigidboardfacerincludingfiberboard,perliteboard,gypsumboard,ororientedstrandboard.1.1.1ForTypeXIIIonly,thisspecificationcoversthephysicalproperties,anddimensionsofcellularpolystyreneintendedforuseasthermalinsulationfortemperaturesfrom−297to+165°F(−183to+73.9°C).1.2Consultthemanufacturerforspecificrecommendationsandpropertiesincryogenicconditions.1.2.1Thisspecificationdoesnotcovercryogenicpropertiesexceptforthek-factorsforTypeXIIIinAppendixX1.ForTypeXIIIinspecificcryogenicapplications,themanufacturerandpurchasershallagreeupontheactualtemperaturelimitsandphysicalpropertyrequirementsinadditiontothek-factorsinAppendixX1.1.3Theuseofthermalinsulationmaterialscoveredbythisspecificationmayberegulatedbybuildingcodesthataddressfireperformance.Forsomeenduses,specifiersshouldalsoaddresstheeffectofmoistureandwindpressureresistance.GuidelinesregardingtheseenduseconsiderationsareincludedinAppendixX1.1.4Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcer...
