b'" ~~ ~ ~~~ resist such efforts on the roof.roofcoveringsareimpervious Also,buildingownersoftenandshouldnotbea problem install electric cables along theunless someobstructioninteredges of the roof and in valleys.rupts the gravity flow down the Unfortunately, the melting effec surface of asteep roof. sloping or tiveness of such heat cables is limited to only ainches fromSolutions few the cable. With the electric cablesAccordingtoa numberof limited at the lower edge of thesources, based upon many years roof, secondary ice dams developof experience and research, there higher on the roof similar to par are three approaches to solve the tial raking or shoveling the roof atice dam problem as follows: the lower edge of the roof.oAttic insulation @Attic ventilation Definitions~shingle Waterproofing In simple terms, an ice dam isunderlayment ice that has formed at the eaves, in gutters and above the gutters toSummaryFABRICATEDMETA~DECK various lengths on the roof shin In summary, the causes of ice gles of a pitched roof.It formsdams on aroof are many,FURNISHED ANDINSTALCED/ pitched because of melted snow runningand,insomecases,complex. to the eave\'s edge and freezingT likelihood is unpredictableSTOCK DECK SALES heir because theroof is coldattheandweatherrelated.Insome eave compared to the warmer roofcases they can be prevented, andServing Chicago/and For OverYears surface of escaping attic heat. Forin most casesit is possible to25 leakage to occur, there must bestop them from causing damage. water at the roof surface, open toWinter is now upon us. Onefllt ings to permit water entry, andshould consider doing something forces acting to move it inward. Iftheir roof ifhave had ice they anyoneof these conditionsisdams inwinters to pasteliminate eliminated, water damage will notthe damage they can cause. It is occur. When there is snow on theimportanttohaveyourroofArea ConstructionTrodes,Inc. roof of abuilding, th inspectedwinter hits to be heatederebefore1723 Ii.WHson Street, Bo.to.vio.,IL60510 wi 11be water at the roof surface,surethatitcansurvivethe(630)879-7757Fox(630) 879~813l sheathing or decking, either fromupcoming effects of snow and ice. melting snow by heat loss fromThis article originally appeared ApprovedMember the building or by heat from thein the December 1994 issue of- - -eakage - lNfl sun. L will not occur if theContractors Guide.~~ Iii!1'