b'PageNo.4 "GutsofaGoodRoof 11programof1960,showthatthermalshock isnot ,tearingupourbuilt-uproofs. Anotherlaboratorytestofinteresttothebuilt-up roofingcontractortestedboththeloadandtheelongationcapabilitiesofbuilt-uproofs.Illustration#4showsthecomposite resultofmanytests: l.OAD-llONGAflON, IUIUeU, 1001S soT;MPERATURE:21)0,:: SlRAIH RATE:.009 1 1 ,1 . ,,. UNWEATHEREO DEAD LEVEL A.SP HALT IAT 25-.30 ll,/1,Vply 0!i\' c ./V1- -Ij,,\'-1~- _____!TARRED FELT, PITCH ,,_. / __?2PLYPERI.IA PLY HO. 11, -m- PLYINS. COYIER, TAPED JT. ,z,;:;;;1ROOF PLYPAPUFELT,ASPHALT-,!T, rA Pl Y ASBUTOS FflASPH.-01,J FELTScRossw,se f PU CENT L0NCATIOH Thesetestswererunonfourdifferentspecification roofs.No.1wasa4-plytarredfeltroof.No.2wasapermaglas typeroof.No.3wasanasphaltfeltroof.No.4wasanasbestos andasphaltroof.Inorderthatthesetestscouldberunwithas perfectlycontrolledsamplesaspossible,aroofduplicatingmachine wasdesignedandbuilt.Withthismachineitispossibletobuild upinthelaboratorymanysamplesofroofs,leavingoutasmuch humanerroraspossible.Thefirstlineonthegraphistheresult ofthetarredfeltroof .Ithadaloadcapacityperinchofwidth ofapproximately225lbs .,andwhilethisroofwasbeingloadedwith 225lbs.itdidstretchalmost1%.At250lbs .andthe1%stretch, -theroofingsampledidfail.LineNumber2isaperma-plyorfiberglasroofthathadapproximatestrengthof160lbs.andcouldbe stretchedabout1-1/2%.Number3isthe4-plyasphaltfeltroof thathadastrengthofapproyimately150lbs.perinchandaload elongationof3%.Number4wasanasbestosfeltroofthathada teststrengthofabout100lbs.andaloadelongationofalittle over1-1/2%.Eventhestrongestofthesebuilt-uproofsisweal comparedtothesurfacesto which itmaybeattached. Illustration#5isacartoonexampleofelongation: 100 ROOFMEMBRANE lffl-~ .W) ,,. .JCOUAP LO:XG1"0N- .lQlDN:LEASCD ELASTICITY- ~ - -'