b'_e_c_h_n_i_ a_n_d_ R U t _e___ _ _ _ _ ________~ c_a_l_ _e_s_e _a_r_c_h_ _p_d_a_ _ Bits and Pieces About~ Built-up Roofing Reprintedwithperm1ss10nsion and contraction, tend toperfunctorymanner.One fromAugust1997issueofseparateintocracksandmethodminates all which eliContractors Guide - For sub o chances of error is to mark ther felt ruptures. scription information call 847/@Roof surfaced with slate, tilewith aof chalk all worn piece 588-3333.and, to adegree, slagspots,felts, lesserbrokenblisters, orl (aggregate) protectflashingsthat havepulled graveInstead of following a ques the felt andbitumenfromaway from the walls, flashing tion-and-answerformat,I willdisintegration. Smooth sur ruptures and other locations outline areas where there are con facedroofsareentirelyrequiring repairs. When all stant discussions and questionsunprotected and shouldsuchlocationshavebeen be on built-up roofing membranesresurfaced with roof emul markedwithchalk,ii is a as to application, repairings or a coatingatleastgood plan, in the case of a andion common problems encounteredevery three years d ingvery badly worn roof, to epend ask in roofThellowingupon the conditions of thetheproperty owner or his assemblies.fofive areas are topics of frequentroofandtheareaoftheagentinspect theA toroof. discussion.country. Where good qualitynumber of areas marked with oIna built-uproof(BUR),materialsa used,thesechalkgivesaneloquent re roofing felts do not wear out.surface coatings willkeepargument, even to a layman, They dry out. BURinintact the original saturants!n favorarooflb, roofsofnewcover shelteredlocationsorininthefelt and result inamg. moistclimateshaveantrouble-free roof for as longoRoof coatings will infuse felt indefiniteleaseoflifeasasthelife of thebu Id ngwith new life but they cannot ii compared with roof cover with repairs b beexpectedtosealholes eing required ings in locations where theyonlytheareas.and breaks in the membrane. atflashing attractIilast rays@)The first step inaWhencracksare encountherst andrepairing tored they of the sun. The process ofbuilt-up roof isclear thete ,should be cleaned distilla on which results ins u r- outwith plastic ti and covered manufacturedasphaltorcement into which is imbedcoal tar pitch doesded roughly a 4-inch strip of notendatthemembrane.Onold, manufacturer\'sneglected roofs, patches will still. The distil befoundhereandthere lationpro where the felt hasentirely ceedsonthedisintegrated. At these locaroofmoreortions the felt surrounding the lessrapidlypatches should be cut to a according to how much sun widthof a minimum of4 light is absorbed by the roof.face of aldebris. In theinches. Theinsideofthe Icase The waterproofing qualitiesof anaggregateroofthispatch is then covered with of alt-up roof depend oninvolves the scrapingandplastic cement into which is buithe saturant employed in theremovalofthesurfacingimbeddeda pieceoffelt prepar d. felt. Under attack by the sunfrom the area to bee whichbutts,butdoesnot the bitumen is transformedAlso, ainspectionlap, the su felt. The thoroughrrounding into vapor,leaving aof the roof surface and flash surfacereceivesanother hard, dr b le felt whose fibers,ingsisnecessary.Thistrowel coat of cement".L y,ritt and through alternating expan- should not be performed in aC on page 13 ontinued'