More About Ice Dams

I wanted to thank Mary Tate from Networx, for her recent guest post on Ice Dams, and to elaborate on the topic.

Ice/Water Shields

Here in Michigan, it is state building code to use ice/water shield where ice dams form on the bottom three feet of the sloped roof and in the valleys. Ice/water shield prevents the water damage caused by ice dams, it does not prevent ice dams. Ice/water shield is a rubberized material that comes in a three foot roll just like felt paper.

Typically one side of the water shield roll is extremely sticky and will adhere itself to the roof sheathing. The other side has a thin plastic backing that needs to be peeled off before applying. The upside of the ice/water shield roll has a sandy texture to it. When exposed to high temperatures, the material begins to flow, and it seals all the roof nail holes and any other small penetrations. Water still backs up under the shingles, but the water cannot penetrate the ice/water shield. Click here for more information from The rain gutter shop

Ice and Snow Removal

I have 12-14 inches of attic insulation and 150% of the required ventilation area. There is only one sure fire way to prevent ice dams. Remove the bottom 3 feet of snow off of the roof.

These are photos taken of my house at 12:30 PM, after it had snowed 8 inches the previous night. I'd removed the snow at 10 AM. Snow should be removed within 24 hours of a snow event exceeding 2 inches.