Home Inspections 101

Ice Damming and Icicles

I noticed that this winter produced a tremendous amount of icicles and ice damming had become a big problem for many homeowners .

What is Ice Damming?

Heat escapes from improperly sealed or poorly insulated portions of the roof, melting the snow above. As the snow melts, it runs down the roof until it encounters un-melted snow over an unheated space on the roof. There, it will stop and refreeze. This process will continue until an ice dam is formed.

Why is Ice Damming Problematic?

These dams cause the water that runs down the warm portion of the roof to pool behind the dam and back up under the shingles. Once the water from the ice dam gets under the shingles it is free to leak into the ceiling and the wall. While it is periodic, (eventually the weather will warm up, thus stopping the leak), this water intrusion can become costly. If left uncorrected, water damage will occur to at least the ceiling or wall finishes, and at worst, there is a potential for structural rot.

How can Ice Damming be Prevented?

There are two major preventative measures to consider when approaching the issue of ice damming.

1. Adding attic insulation: This will work well depending on the attic in question. However, some attics have so many warm air leaks that it would be impossible to add enough insulation to fix the problem.

2. Sealing the air leakage paths into the attic space: In many cases, with proper sealing tools a homeowner can take care of this task themselves. However, some instances require a specialist to find and fix the issue. Common air leakage paths include attic access hatches, ceiling light fixtures like pot lights, and plumbing stacks.