Installing electrical heat tape, or electrical cables, on a roof is safe and effective in preventing ice dams and ensuring proper drainage channels for water in the winter, if they are installed correctly. The drawback of electrical heat tape is that it is expensive to purchase, install and run.
Electrical heat tape uses about 5 to 8 watts of electricity per foot. Electrical heat tape is most effective for people with two-story homes who can't reach their roofs with snow rakes. Snow rakes are effective for single-story homeowners to use for pulling the snow off of the roof from the ground. If the snow is not removed from the roof and ice dams begin to form, the roof could suffer structural damage.