b'- - - - - - - - - - - - - -~l of resis and the reciprocal of "k" or "C," the greater tance its value the more is the resistance indicated.con ,KOPPERS Intothe "U" value of a orderdetermineceiling, floorroof or wall assembly, one must know the thermaldu ("k") or conductance ("C") of all the elements ctivity or materials making up the complete assembly. These values may be determined in the laboratory byI N D U S T R I E Smeans of aplate test apparatus. Alltbooks on insuhottexlation list the condu ity or conductance for the most ctivcommonly used building materials. Conductivity or conductance of individualare materialsCOMMERCIAL ROOFING not directlyleheat loss calculations. Insapplicab totead they must beconvertedinto a resistance"R"=DEPARTMENT or t .the resistance of all theup the Aftermaterials making assembly(includingresistanceforsurfaceandairBUILT-UP ROOFING:Coal TarBitumen spaces) are known,"U" value may be calculated byTar GlasFelt theTM the formula:Tarred Felt Polyester Reinforced Flashings "U"=______ 1 R R to Applied) RRtal(Cold or Hot 123 F the "U" value of acommercial roof or example,typical assembly featuring built-up roofing, 1 -inch thick fiber/2board roof insulation, aretarder, steel deck, deadMODIFIEDKoppers System 2000 vapor air5/8-inch m fiber suspendedBITUMEN MEMBRANES:ModifiedBitumen space andineralceiling would be:APP Smooth &Mineral Surface MaterialResistance (R)SBS Smooth & Mineral Surface Outside air . 0.17SBSMineralFire Rated Surface Built-up roofing (0.375 inch) 0.33 1/2-inch fiberboard insulation KOP-R-lsocyanurate 1.39INSULATION: Vapor retarder nilKOP-R-Composite nilKOP-R-Woodfiber Steel deck Air(heat flow up) space0.93 5/8-inch mineral suspended ceiling tile 1.56 Inside surface MAINTENANCEEmulsion Coatings 0.61 Rtal . .4.99PRODUCTS:Cutback Coatings to1 Aluminum Roof Coatings U=- - =0.20Resaturants totalCements R4.99 PolyesterMats Being ageneration member of the Midwest third Roofing Contractors Association, Isay my opinionGlass Fabric mustREINFORCING FABRICS: of the organization is somewhat biased.is noCotton Fabric But there thatFume Recovery FRS-6000 doubtMRCA has been an invaluable asset to our business company. The technical information provided, management skills gained, legal advice received and long-term personal relationships formed, have allowedKOPPERSKOPPERS INDUSTRIES, INC.160 I our company to grow and prosper for 50 years.KOPPERS BUILDING, ROOM Fred Naucke,INDUSTRIES436SEVENTH AVENUE Crampton Company15219-1800 DalePITTSBURGH, PA Fort Smith, A 1-800-558-2706 rk. FAX:(412) 227-2262 iii!III'