The Roof Ice Dam
Ice dams are a pervasive and damaging winter roofing problem caused by poor roof ventilation and a warm attic space. Left untreated, ice dams can cause serious damage to your roof, gutters, paint, insulation, drywall, structure and even contribute to mold. Dam! (Pun intended, sorry).
Ice dams form when melting snow on a roof runs off and refreezes at the edge of a roof. This condition occurs when the snow is melted by a warm roof, creating water running between the snow and the warm roof surface, then freezing and turning to ice when it gets past the exterior wall and hits a cold unheated roof edge or gutter. As the bottom of the snow pack continues to melt, water continues to flow down the roof surface until it hits the ice, thereby creating a larger and larger ice dam.
Ironically, ice dams occur most commonly after a heavy snow because snow is a great insulator. I’ll discuss why in the next section “What Causes Ice Dams?”
In this tutorial we’ll address the following Issues:
- What causes ice dams?
- How to prevent ice dams.
- Determining proper roof ventilation areas.
- Battling ice dams before winter.
- Battling ice dams during winter.