What Do You Put on a Roof to Melt Ice?

Heating Cables

• Electric heating cables can be used, if electricity is available, to melt drainage paths through ice dams or remove ice from a larger portion of the roof. Attach loops of de-icing cables to a long board near the lower edge of the roof and tie ropes to the board that can be thrown over the roof and secured to another board or a stationary object. The cables can be drawn up as high on the roof as desired, but the cables must extend beyond the roof's lower edge to ensure adequate drainage of melt.

Chemical De-icers

• Chemical de-icers can be used to remove roof ice. Clear the snow from the roof, and break the ice crust above the ice dam along the roof edge every few feet. Place a small amount of de-icing agent in each hole. Repeat, small applications are more effective than a single, heavy application. If corrosion is a concern, choose de-icing agents that do not contain oxidizing agents. Calcium magnesium acetate, urea and potassium chloride are safer options while sodium chloride and calcium chloride may harm roofing materials, so use these with caution.

Roof Sock

• A roof sock consists of a leg cut from a pair of pantyhose filled with de-icing agent. Lay this roof sock on the roof so that it overhangs the roof edge and gutter and crosses the ice dam, eventually creating a drainage channel.

Hot Water

• Hot or warm water can be an effective means to remove ice or create ice channels that allow the drainage of any built-up water. Ideally, thin slices of ice should be cut away from the gutter to as high up on the roof as possible. Spray hot water on the ice from as short a distance as possible. This technique is best performed on a warm day and is only a temporary solution, generally requiring repetition every few days.

Physical Removal

• Physical removal of snow and ice can be used to temporarily resolve the ice problem or to make other methods of ice removal or melt more successful. Mechanical ice removal can be dangerous and may harm roofing materials. Snow can be pushed off of roofs with a snow rake designed for the task. Eliminating the snow will prevent an increase in roof water or ice and will allow easier access to the ice. When removing ice from a roof, use a tool like a sledgehammer that will not cut into the roofing material and work from the top of the roof downward.