b'FIRE RATINGSROOF FIRE RATINGS AND ROOF FIRE CLASSIFICATIONBY NICOLAS DEMERS AND HAROLD LOUWERSE, RRO, P.L.ENG., OF STANTEC CONSULTING LTD.A sdesigners(architectsandon external fires on top of roofs, not firesbuilding, and to provide responding fire-engineers), as well as contrac- inside buildings. fighters with time to arrive and attempt to tors and suppliers, we all playDisclaimer: Theauthorsarenotcodesave the building. In Canada, testing ofaroleinconstructingsome- analysisprofessionals.ThisarticleshouldnotmaterialstoCAN/ULC-S101,Standard thing that lasts. We all have an importantreplace advice from a code professional. We haveMethods ofFire Endurance Tests ofBuilding role in ensuring our homes, our placesput together this article attempting to clear upConstructionMaterials,isveryimportant of work or our places of play are safe,industry myths and misconceptions with respectin determining the fire-resistance rating. both now and for generations to come.to fire-resistance ratings and roofclassifications,However,itisimportanttonotethat Meetingminimumcoderequirementsand to educate a broader audience ofarchitects,the fire-resistance rating is not the only and ultimately ensuring that human lifeengineers, contractors, suppliers and other industryfire-relatedratingorclassificationthat is protected are of the utmost impor- professionalswithintheroofingindustry.Weneeds to be considered. tance.Manyofourminimumstan- recommend that you seek independent consulta-dards in the building code are a directtion with respect to your situation and/or projectMATERIAL RATINGSresult of previous failures and lessonsand not rely on this article for advice. BoththeASTM(AmericanSocietyfor learned,andthatwillcontinueasweTestingandMaterials)andtheCSA move forward. As we see regular wildfireFIRE-RESISTANCE RATING (CanadianStandardsAssociation)both activity in British Columbia, the need for understanding the implications of thoseThe NBC (National Building Code) andoffer fire testing standards for construc-minimum standards and what they meantheBCBC(BritishColumbiaBuildingtion materials, but the terminology, test is important to ensure we, as a designCode)bothspecifyrequirementsformethodologyandfinalclassification communityandbuilderindustry,arefire-resistanceratingswithinbuildings,differslightly,whichshouldbeconsid-designingandconstructingroofsthatwhich can vary depending on the build- eredtolimittheriskofconfusion. help protect our families, our neighbours,ings size and occupancy. Fire-resistanceFirst,theASTM,asitsnamesuggests, our businesses and our communities. Weratings express the time that an elementisanAmericanclassification.Whileit hope that, through this article, greatercan resist fire while maintaining its func- is very similar in scope to the Canadian awarenessaboutfire-resistanceratingstion or containing the spread of fire. Theclassificationsystem,itshouldnotbe and roof fire classification may help dopurpose of a fire-resistance rating is totaken as a proof of meeting the require-just thatand who knows, maybe saveprovidetheoccupantsofthebuildingments.ASTMstandardsthatrelatetoa building or a life. This article focuseswithenoughtimetosafelyescapethefire-resistance include:18 lROOFINGBClSUMMER 2025'