Ice Dams

OK lets talk about Ice Dams. They are caused from attics being to warm. You attic should be only a few degrees warmer than the exterior temperature. You want a minimal of R-30 of insulation, plus it needs to be well ventilated, with a inlet and outlet, to circulate the air out (See tables on the Internet for roof ventilation calculations). When attics are too warm, it melts the snow unnaturally from underneath. As this water flows to the edge of the roof, cold air passes above and below this water, creating ice build- up otherwise known as a ice dam. When the snow starts to melt naturally it flows down the roof but cant get over the dam and starts to pool, working its way under shingles or any other opening. The size of the water pool and whether it will reach the inside of your home is determined by the size of your overhang and pitch of your roof. A small or no overhang and low pitch roof makes you more vulnerable to water infiltration. A membrane called Ice and water shield helps to prevent this. But is best applied behind the gutters. This usually means replacing gutters or removing and reinstalling them. I hope this is useful for next year! Mike Gosser