Roof: Why Melt Away the Snow? Roof: Why Melt Away the Snow?
Should snow on the roof melt naturally or should it be aided in the process? This is a question that arises for homeowners in cold regions where heavy snowfall and extremely low temperatures are an annual occurrence. If the structure of the roof is strong and the attic is properly ventilated at the ridge and the under-eaves or soffits, there is not necessarily any reason to hasten the snow melt from the roof. However, there is one important reason to actively melt the snow off a roof: the formation of ice dams.
Ice dams are caused when melting snow refreezes around and in the gutters. This creates a thick dam that prevents other melting snow water from escaping. When this happens, the water is forced up underneath the shingles of the roof because it must go somewhere. The damage this can cause is extensive, ruining shingles, sheathing and possibly the entire eave structure of the roof.
Why Melt Snow
If a roof is not properly ventilated, ice dams may occur frequently in cold climates. Hastening the melting away of snow on the roof is a way to reduce the chances of ice dams. It should be done if you see ice dams beginning to form or if persisting freezing temperatures do not let the snow melt.