Insulation, Radiant and Vapor Barriers - Ice dams

We get an ice dam in one section of our roof every winter. It is in the valley of a cross gable and faces east. Here, in Minnesota it doesn't get direct light in the winter and I wonder if that is the cause of the problem, or if a bypass is the more likely culprit. There are no pipes, etc. in that section. I hate to crawl through the fiberglass and vermiculite that's up there, especially since I'm not really sure I could identify a problem even if I was looking right at it! The house was built in 1958 and is stucco outside and plaster inside, if that helps.

Thanks for any advice!

A couple of things to check... Is the area of the ice damning near where your attic access is, if so It might possibly be you dont have the door or hatch insulated properly, or does a bathroom fan by chance exhaust into the attic in that area.

Good Luck

Jim

According to Resercon, ice dams are more often a result of inadequate ventilation.

http://www.resercon.com/Ventilation.html