How to Prevent Ice Dams on a Roof
Ice dams on a roof can cause a lot of damage. Knowing how to remove ice dams and how to prevent them is an important part of winter maintenance for your home. The first step is to understand what ice dams are and how they form.
If the winter is severe and your roof isn’t insulated enough to keep the snow from melting, ice dams can form: The snow on the roof melts, and the water runs down and freezes over the eaves to create the ice dam. Melting snow continues to run down the roof but then backs up behind the ice and under the roofing shingles. When all that moisture refreezes and then starts melting again (including the ice that’s under the shingles), water seeps in through the ceilings and walls.
Over time, ice dams can cause considerable damage to your roof and walls. But there are a few simple tricks that can help you prevent them from ever occurring.
Keep your gutters cleared of debris and ice so that the melt water has a place to go.
Remove the snow from the edges of your roof. Hardware and home improvement stores sell long-handled roof rakes. You also might see neighbors on the roof shoveling the snow off. This isn't the best approach for two reasons: You might cut into the shingles or fall off the roof!
A thick layer of insulation in the attic or crawl space provides an effective barrier, trapping warm air in the house where it belongs and keeping the roof itself cooler so the snow doesn’t melt quite as fast. Use insulation with an R-value of R-30 to R38.