Are you Ready for Ice Storms? 3 Key Steps to Help Stop Ice Dams.
Ice dams and icicles form when snow melts, runs down your roof and refreezes near the edge. This only occurs when part of your roof warms to above 0 degrees celsius, warm enough to melt the snow, while the roof edge remains below freezing. So with the changing weather, the key to preventing ice dams is simply to keep your attic and roof cold.