What is an “Ice Dam?”

An ice dam is a ridge of ice that forms along a roof’s edge when three simple conditions coexist:

  1. Snow accumulates on a roof.
  2. Solar gain and interior building heat melts the snow. The melt water runs down the roof under the insulating blanket of snow.
  3. Sub-freezing outdoor temperatures cause the melt water to re-freeze at the roof’s edge, thus causing the ice dam formation and subsequent icicles. Without Summit Ice Melt Systems preventing the re-freezing, the ice continues to grow and build up the roof.

Ice dams and icicles pose significant threats:

  • When left unabated, ice dams will continue to grow up to the building’s wall line. A pool of standing water develops behind the dam above the wall line. It can then leak into the interior and cause water damage and dry rot.
  • Ice is very, very heavy. Ice formations stress buildings and overhangs, and damage roofing and underlying structures.
  • Ice formations and icicles eventually and unpredictably fall off roofs and damage decks, railings, vehicles, and break windows.  Worse yet, falling ice can cause personal injuries.

Click here to see a gallery of how and where ice dams form


Anatomy of an Ice Dam900x800