Read our blog post, Ice Dams: A Winter Challenge for Homeowners for some great tips on preventing ice dams and what to do in the case of ice dams on your roof. Ice dams are more than just an inconvenience—they can cause significant damage to your home. While prevention is the best strategy, ice dams can still form despite your efforts, so having a response plan is crucial. Ice dams occur when attic air warms to above freezing, causing snow on the roof to melt. As the water runs down the roof and reaches the colder edges, it refreezes, creating an ice dam. These dams block water from draining off the roof, causing it to pool and seep under shingles, into the attic, or along exterior walls.