Ice doesn’t just cause a slipping hazard on your roof. It can also lead to the formation of ice dams, which can be dangerous. These occur when snow toward the top of your roof melts and freezes again near the eaves due to attic heat. This can block melting snow and ice from flowing into your gutters and cause it to seep under your roof, raising the risk of water damage and mold growth. These blockages can also ruin your gutters and cause roof shingles to become loose.