Ice Dams: Signs of Trouble

 

    While icicles hanging from your eaves may look beautiful, anyone who understands houses well knows icicles are a sign that something bad might be going on under the roof. Ice dams form when the upper section of the roof is warm enough to cause the snow to melt and the bottom overhang and gutters are cold enough to freeze the runoff into icicles. The typical cause of a roof being too warm is air from inside the house seeping into the attic and
heating it up. When water from melting snow gets to the bottom exposed section where the eaves begin, it re-freezes and creates a dam, and then the water accumulates behind it. The two most important factors in preventing ice dams are insulation and ventilation. For more detailed information please read the article below.

http://bct.eco.umass.edu/publications/by-title/preventing-ice-dams/