Ice dams are formed when heat from the inside of a home escapes into the attic and warms the roof decking during the winter. This heat, combined with heat from the sun, can melt snow on the roof. Melting snow then runs down toward the eaves as water. When it reaches the cold eaves and gutters it refreezes. This continual thaw and re-freeze process creates ice dams. The result is water backing up under the roof shingles where it can soak through the roof decking or wall sheathing, causing damage to attics, ceilings and walls.
There are three ways to defend against the damage ice dams cause: attic insulation, attic ventilation system, and a water-proofing shingle underlayment (such as CertainTeed WinterGuard™). All three work together. Insulation keeps heat from escaping from your home's living space into your attic. Ventilation removes the heat and helps keep the roof deck evenly cool to help prevent snow from melting on the roof. Finally, waterproffing shingle underlayment, such as WinterGuard is laid across the roof before roof shingles are applied. WinterGuard is warranted against leaks from dams that do form on the roof.
Read more on how to Protect Your Home Against Ice Dams, by clicking on the brochure link under Helpful Resources.