Preventing Ice Dams Without Tearing Up Your Roof

Ice dams form when warm air leaks into the attic, melts snow on the roof, and lets it refreeze at the cold eave. Water then backs up under the shingles.

Three fixes do most of the work: seal attic bypasses, insulate to R-49+, and keep gutters clear of leaves before the first freeze.

If a dam forms, don't chip it off — you'll damage shingles. Calcium chloride pucks placed in a tube across the dam open a melt channel safely.