b'MIDWESTRoofingControdors Association,Inc.Mo,lAddress: 1000Power&LqhlBldq. KnnsosCt11,Miuo11Pi G.W.POWERSDALECRAMPTONJOHN C.SHEAROBERTD.MARQUISRobe!D. Lions PresidentSecretoryVice PresidentVice PresidentE~eculiveSecrelor11 1020 N. 22nd St.710 Division Street3919 N. 16th Street1724 CompbeU Lincoln,NebroskoFort Smith, ArkansasOmaha,NebraskaKansas City, MissouriGRand1-0848 VolumeVII Issue1BULLETINJune1963 EXPANSION ,CONTRACTIONANDPROPERDESIGNBy RobertD.Marquis KansasCity,Mo. Presentedatthe13thAnnualMRCAConvention Nooneinthebuildingindustrywilldenythatbuildings move- somewithtemperature ,somewithmoisture,somewithload stress.Weareheretoacknowledgethismovementandtostudyhow itaffectsthebuilt-uproofingsystem. Afewbuildingshavehadroofslastforyearsandyears withvirtuallynoproblems .Agreatmanyotherbuildingshave ._ hadroofsthathavehadcontinualfailures.The"GutsofaGood Roof"programinstigatedbyMRCAatthe1960ConventioninOmaha, Nebraska,provedbeyondashadowofadoubtthatbuilt-uproofs couldlast20 ,~0 ,40 ,oreven50years.ManyMRCAmembersturned insamplesoftheseroofsthatdidnotfail.Theseroofsamples w turnedovertoaverycompetentlaboraroryforfullanalysis. ere Illustration#1showsthetensilestrengthperinc_ ofwidthof h theseoldroofsthatdidnotfail: - ell:U,M~ STM:Nt.Tli OF (IITftACTtO "1.T - TCNS1u:STACHC.THo, au111: !000j28\'" 90N ~~~U~.~.""\':~- ~t.AC.L\'-""" ~ ,,C:QMPARA.TIV ~TR(NC,THor .,DU\'{\\.,_U \\\'A,111:YING,INAGCr"o~lOTQMY[Al\'t5 ,-.,., .M IDWTIIOOPINO CONTflACTOfl8 A880CIATION'