b'J WEATHERINGOFINSULATION(Continued from page 19 TOBECONTINUEDNEXTMONTHtures attained by an insulated built-up roof membrane as a result of solar heating.In 1957, Ballantyne and Spencer[7]reported \'Figures in brackets refer to list of references at the end of this paper.theresultsof astudyof temperaturesattainedinbituminous roofs with black, white, or aluminum painted surfaces. TABLE1.SOLARREFLECTIVITYOFTheir resultsindicatedthatreductionsof15 Formore in maximumtemperatureswhenexposedtosolarheatingwere VARIOUSSURFACESobtained by treating ablack, bituminous surface with a suitable white coating, andtoalesser extent with an aluminumpaint. *Coefficient ofStephenson(8)reportedthatthemaximumroofingsurface MATERIALSolar Reflectivitytemperature and the rates of change of temperature were higher when the insulation was placedbetweentheroof deck andthe Asphalt and Bituminous Compounds0.07waterproof layerthanwhentheinsulation wasplacedbeneath Bituminous Roofing Felt0.10the deck. Asbestos Cement, old and dirty0.17Martin [9]recognized the degrading effectsof thehigh temAsbestos Cement, new0.39peraturesbuilt up inroofing placedover insulation andstated Galvanized Iron, old and dirty0.10that it was essential to provide a reflective surface in such cases. Galvanized Iron, new0.35He further reported the coefficients of solar reflectivity of various Slate, blue-grey0.15surfaces and the approximate values are listed in Table 1. Marble, white0.56In a paper on the thermal movements and stresses in concrete Sand, fine and white0.59slabsin relation cotropical conditions,HendryandPage[101 Paint,light grey0.25enumerated and discussed a number of factors on which the rate Paint,red0.26of temperature rise will depend. Paint, aluminum0.46For exam pie, the auoindicatedthatheating due to solar th rs Paint, light green0.50radiation wasinfluenced bythethermal properties of theroof Paint, light cream0.65system, the surface absorptivity and emissivity for short and long Paint, white0.75wave radiation, and the weather conditionsco which the surface White wash0.80was exposed. In discussing roof insulation, they further state that insulation *Coefficientofrefledivityisdefinedasthenumericalratioofradianton the top of a concrete deck decreasesthetemperature of the energy reflected to the radiant energy impinging on a surface.concrete, but raisesthe temperatureof thebuilt-up membrane, Soure; Martin,K.G., BuildingMaterialsMagazine,Vol.2, No. 5,MayJune 1961.which may lead to the accelerated deterioration of the latter. CONVENTIONCALENDAR March3-6,1963.CanadianRoofingCon N.R.C.A. tractorsAss\'n,QueenElizabethHotel.CONVENTION Montreal,Que.,Canada.J.Chevalier, Sec\'y,405CoteDesNeiges,Montreal,(Continued lrom page14) Canada. Mar.5-7,1963.NewEnglandApprovedThe consensus of opinion of the experts RoofersAssociation,HotelBeacon,1200pertswasthat,aswith conventionalmaBeaconSt.,Brookline, Mass. JonCazeault, Secretary,36LeslieAve.,Weymouth88,terials, asatisfactoryjobrequiredcareful Mass.preparation of the roof surface and of the Mar.14,15,16,1963,H.I.P.,HomeIm application. provement Products Association, New YorkAt thebuilt-up roofing forum in addiColiseum, New York City, Henry Kirschner,tiontoWilliamCullen,AlfMyhreof 2217 Tribune Tower, Chicago, Illinois.DuPontandProfessorDonBrotherson March14-16.SoutheastTradeExposition,oftheUniversityofIllinoispresented sponsoredbySheetMetal,Roofing,Healing,AirConditioningContractorsAss\'n.conflictingviewsontheneedforvapor B.L.Noblitt,Sec\'y,208R RockBldg., edbarriers over roof decks. Atlanta 3,Ga.ModeratorJohnHartmanassistedby April18-20,1963.Roofing&SheetMetalJ.Roy Martin, Jr., Milton Olson and John Contractors Ass\'n of Florida, Jack Tar Har Reuter, forded a variety of questions from risonHotel,Clearwater,Fla.,JohnStarr, Sec\'y, 806 Pierce St., Clearwater, Fla.the audience, who kept three microphones May20-23.InternationalSymposiumonbusy on the floor. Humidity and Moisture,Sheraton-ParkHo The Steep Roofing forum conducted by tel, Washington,D.C.CheckwithArnoldJohn Probst and paneled by Ed. Daly, Lyle Wexler,NationalBureauofStandards,ThomasandGunnarMorteson,sufferedAbove:BillRosenow,Chicago,demonstrates Washington25,D.C.theremarkable"nailpicker-upper"just June,1963. RoofingContractors\' Ass\'n. offromalack of audience appeal as it wasintroducedbyJulienBenjaminCampany. California,SanDiego,Calif.Exactdatesheld at the same time as the popular builtand meeting place will be announced later.uproofingforum. HowardE.Becker,Sec\'y,P.O.Box759,Despitethe slim attendance theforumTheConventionclosedwiththecusStockton. Calif.demonstrated an interesting trend- a trendtomarybanquetandthepresentationto July,1964.InternationalFederationofawayfromchoosingcheaper, light-weightthe assembly of thenew president of the RoofingContractors,Vienna,Austria. American secretary, J. C. Gudas, Room 508,shinglestoheavyweightunitsrecom National Roofing Contractors\' Association, Great Lakes Building, Chicago 6,Ill.mendedbyunderwritersandinsuranceMileOlson,OlsonRoofingCompany, firms.Omaha, Nebraska for the term 1963-64. 22MARCH,1963'