A couple of days ago I had a past client email me a question about ice dams and what he can/should do about them. Then yesterday, my kitchen started leaking…FROM ABOVE!
Ice dams are caused when snow on the roof melts and then refreezes when it reaches the overhangs. It can be caused by warm sunny days followed by cold freezing nights. Or it can be caused by a warm attic, which causes a warm roof, which…you get the picture. That melted snow reaches the overhang where there is no attic below it, and then refreezes. That ice creates a dam that keeps new melt from reaching the edge. It sits behind the dam and can eventually find it's way into my kitchen. Roofs aren't meant to be submerged. They need the help of gravity to shed water.
I don't know if there is really a way to completely avoid them in this Minnesota climate, and it certainly doesn't help to live in a 90-year-old house. But here are some tips to help avoid them:
1. Seal your attic from the house. If your attic hatch isn't caulked shut…well caulk it shut!
2. Add some insulation to your attic to reduce heat loss from your warm house to your cold attic.
3. While you're up there, seal over any light fixtures. They can not only be a source of heat, but an access point for heat loss from the rest of the house.
4. Look for other "attic bypasses" that might be leaking hot hair air from the house. Around the chimney or duct work is another common place to find them.
4. Ventilate your attic. Attics should be cold in the winter. When you have a new roof installed, make sure the contractors follow guidelines for proper ventilation. Especially on old homes, they tend to ignore the problem of adding soffit vents on antique homes.
5. Remove the fuel. Removing snow from your roof will eliminate one of the necessary ingredients for making ice dams. A roof rake is a useful tool for getting snow off of hard to reach roofs. A long roof rake is a better idea than getting up on a ladder in icy snowy conditions. BE CAREFUL! Keep in mind that using the roof rake can damage your shingles and take years off the life of your roof.