Need to insulate the house to help avoid ice dams


We have had some leaking this past winter due to ice dams. After we get everything dried out, we would like to put up some insulation to help prevent this in the future. Is insulating the ceiling enough or do we need to insulate along the actual beams of the house (we have easy access to a crawl space along part of the roof but not for an addition to part of the house which was where the main problem was)?

Best Answer

Ice damns are caused by heat rising to the underside of the roof, heated it and melting the snow, where it refreezes as ice.

You need to make sure no hot air is leaving your house - insulate thoroughly.

Airflow is also crucial - make sure you leave baffles to provide airflow from the eaves to every part of the attic. If you have a "one and a half" or similar you need to provide that channel of air between the corner (of roof) crawl spaces and the proper attic.

A well ventilated attic, with no heat bleeding into it, will not ice dam!