b'The root structure consistedof 32 pie flashing job in the history of building conshaped wedges formed by cable supportedstruction. girdersradiatingoutwardfromthecen aPlastic flashing waseven considered asSILK-HATIED ter of the elliptical roof.possible roofing material for the job, but Tomake the flashing installation evenbecause of limited field experience in this moreofaproblemthepie-shapedsec area, it was decided to use a conventionalR GREET tionswere furtherbroken up bypurlinsasphalt built-up roof.OOFERS runningcircumferentiallyandbuttingIn his presentation to the Building Reinro the web section of the main girders.searchInstitute,JoeClarkreported, The roof structure, supported from the"There is no question but the choice of a bottomflangeof the steelmembers,leftflexible plastic flashing enabled us to save literally miles of exposed steel which hadmanyvaluablehoursonthejobcomtObe flashed inco the built-up roofing ap pared towhat wouldhavebeenpossible pliedbetweenthespider\'swebof steel.with conventionalflashingsystems." Over 40,000linealfeetof flashingwereThe plastic flashing was supplied to the used-almost 8 miles.jobin36inchwiderollscontaininga Tomake theapplication of theflash squareofmaterialI/ 16thofaninch ingmorelaborious,thepurlinshadthick.Theflashinghadcobecutinro scuppers cut into them to permit the flowsmallerwidthstosuittheflashingreof watertothe low sectionsof theroof.quirements. Since thisjob was completed, "Scuppers"areidentifiedmorewithsea themanufacturersoftheflashingpackgoingships,literallyrectangularholesage it in 12, 18 and 24 in. widths in adcut into steel plates at deck level for sur dition to the 3foot wide rolls. face drainage.Regardingthe application of the flashOtherflashing areas included cable an ing, adhesive was used where the flashing chors,stairandwalkwaysupportswhichwasbonded cothesteelandhot asphalt protrudedthroughtheroof,ventstackwhereitwasmoppedtothebuilt-up flashing,publicaddressspeakerenclos roofing. ures and a concrete edge beam which com Solvent welding with methylethylkepletely surrounded the four-acreroof.tonewasadopted at alljointsandsheet overlaps.Wheretheflashinghadtobe turned sharplyaround inside and outside cornersheatfromatorch or hot air gun enabledtherooferstohandmoldthe sheetstosecureaperfectseal.InsideHave you everseearooferwearing a corners were made with dog-ear folds.highsilkhat?Youhaven\'t!Well,you The main run of steel web was flashedwill, if youattend the1962INTERNAbyapplying adhesivetothe steelandtoTIONALROOFINGCONVENTION. theplasticflashingandthenmacingthe"Toppers"arewornbyGermanrooftwosurfaces,beingcarefultoavoidairingmechanicsonlyonceremoaialocentrapment.casions, but it once was part of a uniform The adhesive used was a nitrile rubber worn byjourneymen roofers. based adhesive in a solvent carrier- a con The uniform consists of a black velvet, tact type. Because of this it was necessarydouble-breastedvestcutlowenoughto to positionthe flashing carefully in placeshowconsiderableexpanseofshirtand Thisroofwassubiecttomorethantheusua Iasinsecondstheinitialtackbecame so movement whichmade flashingquitedifficult.strong thatdifficultywasencounteredintie,andblackvelvet,bell-bottomed freeing it from the grip of the adhesive.trousers. Thenecktie, alsoblackis usuallydecCopperflashing,originallyconsideredAt particularly difficut areas where con oratedwith agoldpin fashionedin the forthejobwasrejectedwhentheNewsiderablemovementwasexpected,suchshape of a roofer\'s slating hammer. YorkRoofingCompanypointedout theas at the rearof the cable anchors, a beadAcrossthevestisagoldchainwith manycomplications,theneedforweld ofpolysulfidecaulkingcompoundwashanging from it medallions or craft syming or clamping of the top of the copperadded at the top edge of the flashing. Thisbols.Thecostumeisalsowornbycaredgetomiles of steel.was also done at all 90inside corners.pentersandmasons,thelatterwearing Also pointed out was the fact, based onPlasticflashingsdo exhibitsome tend white trousers. experiencewithdissimilar materials,thatencetowardsshrinkageanditwasfeltRoofers, carpenters and masons, although eachof theconcretedecksections,sur thatthecaulkingattheinsidecornerstheyhave their separate tradeunions are roundedbywebsof purlins and girders,where ic would be most likely co pull awayall membersof the fivehundred year old would expand and contract independentlywas added insurance.SchwarzeEhrbarkeit( the BlackHonor), witheach other. The maingirdersthem When the job was completed, Joe Clarka medieval guild of workmen whose craft selvesweredesignedforflexingandmight have been excused forkeeping hiswas building, long before the separation of would continually be in movement.fingerscrossedintheexpectationthatthe craft intovariousspecializations. Itwasimperativethattheflashinghere and there among the miles of flash GuildsmenoftheBlackHonorwere chosenbeflexibleandelasticenoughtoing, a leak or two would develop.proud of theirskills.Asdelegates tothe allow forthe planned seasonalandstruc Ifhedid, he can uncrossthose fingers1960InternationalRoofingConvention turalmovement of thedeck.for chislargestflashingjob in the worldnoted,pride incraftsmanshipisstill apThe success of plastic flashing materialshas stood up to all the rigors of cwo com parent in Europe. on otherjobs convinced the architectsofplete seasonal changes with piled up snowTheword"journeyman"wasevolved the suitability of the flexible flashing ma and freeze- that cycles on the roof duringbythe guilds.Whenan apprentice"finterialonwhatdefinitelywasthelargestthe past two winters.ished histime,"he wasinitiatedimo the 34JANUARY,1962'