Melt pucks can work in some situations, but there are problems when relying on them for thawing ice on a larger area or up high. For instance, the pucks are lightweight so they can easily be blow away. They melt ice, but only in a small perimeter around the actual puck. The pucks may also discolor shingles 1 or roofing, and if they reach the ground they can harm your landscaping as well as the environment.