b'APPROXIMATELY$2 billion worth of 1\\wereinstalledonbuildings roofs throughouttheUnitedStateslastyear, ranging from small tract homes to multimillion-dollar commercialinstallations. The $2 billion figure represented some threemillion square feetof roofing, and withthegrowingpopulationandcontinuing prosperity, these figuresundoubtedly will increase steadily during coming years. Notonlyare ourgrowingpopulation andeconomicprosperityexpectedcoaid the growththe roofing industry, another of contributing factor has emerged in recent years. This is the trend away from multistoriedcommercialbuildingstowardthe one-story shopping center or service center. Thefar-reachingeffectofthistrendis shown by the fact chat the roof area of a multi-storybuildingaveragesapproximately five per cent of the wall area, bur the roof area of a one-story acre-size commercial or industrialstructure may be asBurns cleaner, testified Wayne Vose, vice president of RiggRoofing&Supply Co., Tucson, much as 200 times the wall area!Ariz.TheRiggCompanyhasconverteditsentire"fleet"of14 kettlestoLP-gasfuel. Despite the fact that roofing has grown intoatwo-billion-dollarindustry,it re CutRoofingCostsWith mainsessentiallyasmall-companyindustry, for 80 per cent of all jobs are handled hy outfits with less than 30 employees.op LP-Gas Asinanysmallorganization,roofing companies must conduct an economic eration to compete in the mass production trend of the construction industry.is theBurners One money-saving device being adopted by an increasing number of roofers use of liquefied petroleum gasburners to heat asphalt and tar. This is the same LPgl\\S used on farms and in areas beyond citytrolspreventoverheatingthatcanharm gasmainsasfuelforkitchen ranges androofing materials.Second,automatic conother household appliances, aswell as in trolsrequirelessattention,thuscutting dustrial fuel fortrucks, tractors and otherdown labor cost. Third, the sealed LP-gas commercial applications.system eliminates fire hazard when refilling The use of LP-gas to heat roofers\' ket fuel tanks. tleshasgrownduring the past10yearsNumerous other reasons for converting from zero to an estimated one-third of allto LP-gas are available from roofing conkettles in the industry, although such esti tractors in all parts of the nation. mates range all the way from 15 to 50 perForexample,DemingRoofingand cent of thetotal. Alarge portion of theSheetMetalCompany,Inc.,ofSeattle, remainder is heated by kerosene, and alsoWashington, converted its burner systems some fuel oil.because kerosene carboned up the burners. ThreemainadvantagesarecitedforAlso, water often wasfoundin the keroliquefied petroleum gas. First, burner con- sene. AfterchangingtoLP-gas,thecarbon problem waseliminated aswell aswater in the fuel. In addition, it wasfound that LP-gasheatedthetarkettlesfaster,and that refueling time was cut down sizcably. Above:DemingRiggRoofing&SupplyCompany,at jobinprogressTucson, Arizona, made its first conversion fueledbyLP.toLP-gasin1959andsincethenhas Left:EskoCo., Chicago usesbeenconvertingitsentire"fleet"of14 LPtoheataroofing kettles. 1,600gallon"We decidedtoswitchtoLP-gasbetanktrailer.causeit\'scheaperandit burnscleaner," WayneVose,vicepresident,said."Formerlywecleanedtheburnersoncea month; now we clean them between three and six months." (Continued on page 27) 26OCTOBER,1963'