Ice dams, the ridge of ice that collects on roof eaves, are a frequent winter season problem for residents of the rockies. They can cause expensive damage to the structure each year. The icicles hanging from the gutters are apparent. What isn’t so obvious is what causes the ice dam to form.
What causes the ice to dam?
2.Heat (Enough to melt the snow)
3.Cold to refreeze the snow that has melted
Colorado’s winter weather in the rockies will generally supply the snow and freezing conditions. It only takes as little as 1 to 2 inches of snow on a roof and sub-freezing temperatures, are the conditions that can help create ice dams.
The heat that melts the snow comes from the warm air inside a home or apartment. The snow that melts runs down the roof until it reaches the cold edge of a roof, where it freezes. Ice begins to accumulate along the eaves, composing a dam that can manipulate water backwards and under roofing shingles and ultimately back into the home.
How does warm air get inside a cold attic?
Inadequate or missing insulation is one major reason for this. Although, warm air can find many pathways from heated areas into an attic. These pathways are usually referred to as an attic bypass. Insulation made up of fiberglass or cellulose can slow the air movement in these bypasses, but does not stop it.
Some of the common attic bypasses include:
Chaseways (Chimneys, Garbage Chutes)
How to prevent ice from damming
The most effective method of preventing an ice dam would be to keep the roof cold. This can be achieved by insulating improperly insulated areas, as well as finding and sealing the places where air leaks into the attic.