Ice dams (and icicles) form when the snow melts, runs down your roof and refreezes near the edge. This only occurs when part of your roof warms to above 32 degrees F, warm enough to melt the snow, while the roof edge remains below freezing. This is often the result of a warm attic. In most homes, heat escapes through ceilings into the attic and warms the wood and shingles directly above it. Although the outdoor temperature is below freezing, the snow melts over the warmed section of roof. When the melted water runs down the roof, it hits the cold edge not warmed by the attic. There it freezes, creating a rim of ice. This rim can grow, trap more water behind it, and bingo—you have a full-fledged ice dam.
The key to preventing ice dams is simply to keep your attic and roof cold. After a snowfall, a cold roof will have a thick blanket of snow. A warmer roof, however, will soon have clear spots where the snow has melted off, and may well have icicles hanging from the eaves.
In the average home, about one-third of the heat loss is through the ceiling into the attic. And most of that loss comes from air leaks caused by unblocked walls, gaps in drywall, and cracks around light fixtures, plumbing pipes, chimneys, access hatches.
At MGT we identify and seal those leaks, gaps, cracks and other attic openings. We use thermal imaging to test where the leaks are occurring. Then we seal those areas with caulk, spray foam, sheet metal, drywall or rigid foam to create a airtight seal.
Proper ventilation helps keep your roof system cool by mixing outdoor air with attic air
Give us a call today so we can make sure you don’t experience ice dams this winter.