Really? This sounds like someone forgot what they learned in second grade science class but it really is true. Keeping the roof cold can prevent ice dams from forming at the edge of the roof.
To make this clearer, let’s look at how ice dams form. When snow is on your house roof, a warm roof will melt the snow. The melted snow runs down the roof, hits the cold roof above the eaves and freezes. Ice builds up into a dam, water keeps collecting behind this dam and is pushed back and up under the shingles. The water seeps into the house, damaging wood and insulation and causes mold and mildew. What a mess!
The solution is insulation that keeps the house warmth in the house and away from the roof. You also need ventilation moving cold air from the eaves to the peak of the roof. Check here for more information. If your house has ice dams, call some home remodelers for quotes on fixing the problem. The solution for ice dams can also keep your house warmer this winter.