How Ice Dams form – Jeff’s December Update


Last winter a high majority of the homes in the North East were plagued by ice dams. You may wonder why you see icicles clinging to the eaves on homes but not on garages, sheds, or even dog houses. The reason being is that heat loss from air leakage and poor insulation in the home creates ice dams. Therefore buildings that are not heated, do not succumb to ice dams.

When heat escapes into the attic it melts the bottom layer of snow on the roof. The melting snow runs down the roof edge where it refreezes and backs up into the eaves or even into your shingles. This can lead to extensive water damage or even the possibility of mold.

Although some people install rubberized membranes, electric coils, and even place salty socks on their roof, none of these address the actual cause of ice dams. In order to prevent ice dams in the future a homeowner must correctly air seal and insulate their attic.