b'Air Supported Structure Speeds AIDED BY IMAGINATIVE USE ofthe sides, to formatriangle covering Roofing ofan air-supported structure to stabilize13,000 square feet.Two fansinflated sprayingenvironmentsonbigroofs,the structure to a pressure of one-half WesternWaterproofingCo.hasfin pound per square inch and changed the Mammothished the 465,000-square foot urethaneairinsideeveryfour-and-a-halfminfoam roof of the Louisians Superdomeutes. Superdomeinjust 162calendar days.WesternWaterproofingworkedin "Ifhadn\'t controlled the roofingthree-daycycles.Onthefirstday, we environment and worked out astrictthreemenundertheair-supported schedule, we could never have coveredstructure appliedaone-inchlayerof the Superdome in so short a time. Theurethane foamat adensityofthree dome is 27 stories high, and the strongpoundspercubicfoot.Acoatof windsatthatheightwouldhaveHypalon was sprayed over the foam on knockedoutmanydaysofurethanethe secondday.Onthe sameday,a spraying. The air-supported structurepriming coat of urethane was sprayed also let us keep spraying on rainy daysover the adjacent 13,000-foot segment - something you can\'t usually do withbeforethetentwasmovedoverit. urethane," Ben Bishop, Vice PresidentTwentymenspentthethirdday of the St. Louis company says.movingthetenttotheadjacent Completion of the roof was crucial - segment.Aftertheair-supported inside work can now proceed in a drystructurewasmoved,twomore atmosphere.Hypaloncoatsweresprayedonthe TheSuperdomeis680feetinfoam to a thickness of 25 mils.Workdiameter, rises 27 stories and enclosesmen unfastened the structure, at the 125millioncubicfeetofspace.Thebottom,topandononeside,then HoustonAstrodomewouldfitcom flipped it over and refastened it on the fortablyinside.Roofingthe465,000- other side. square foot dome required more thanThe dome roof deck was fluted steel. 300,000 pounds of Isonate System CPRU-Thane200urethaneslabstock, 385-3urethanesprayfoamandoneespecially shaped to fit the flutes, was million linear feet of U-Thane 200 ure installed to fillthe flutes prior to the thaneslabs- suppliedbyCPRone-inchlayerofsprayedurethane. DivisionofTheUpjohnCompany,Thismethodofapplicationwasthe Torrance,Calif.exclusive choice of the contractor and CPRurethaneroofingmaterialsowner. werespecifiedbytheLouisianaWestern Waterproofing facedprobStadium &Exposition District.Theylems in hoisting more than 150 tons of passed the test requirements for resis urethane and coating chemicals to the tance to windup-liftin200mile-per topof themammothbuilding - 273 hour winds, as well as fire tests at Ohiofeet off the ground. A tractor hitched State University.to a wagon was used to haul drums up Facedwitha162-daydeadlinetothe ramps inside the Superdome to the prime,foamandcoatthedome,so-called500-level.NewOrleans Western Waterproofing Vice Presidentordinancesprohibitingstorageof Ben Bishopbrought an air-supportedchemicals at the 500-level meant that structure up to cover segments of theWestern Waterproofing could bring up dome with a stable environment, freeonly a one-day\'s supply (seven drums of ofwindandrainduringthecriticalisocyanate component, seven drums of steps of applying urethane and the firstpolyol and four drums of Hypalon) at a of three coats of elastomer.time - at a speed of two to three miles The tent-like structure arrived fromper hour. Birdair Structures, Inc., Buffalo, N.Y.,A compressor at the 500-level drove in three sections totaling 6,000 pounds.threepumps,whichmovedisocyaWestern Waterproofing used an 32-tonnates, polyol and coating up to the base crane to haul it up to the dome.Theofthedomeitself.Atthebase, tent was bound to the base and peak ofWestern Waterproofing stationedthe thedome,andlasheddownatcontrol consoles and smaller pumps for seven-and-a-halffootintervalsalongthe spray guns. 6American Roofer&Building Improvement ContractorNov. - Dec. 1974'