Heat trace, or more commonly known as heat cable, is a form of ice dam and gutter freezing prevention. The cable is installed where ice dams build up, typically at the eaves and in the gutters. The cable heats up like a heating pad to prevent the ice dam from forming.
Heat cable comes in two basic varieties: heavy duty and light duty. The heavy duty heat cable is designed for continual use. It is the “industrial strength” heat cable. The typical install for heavy duty heat cable is extreme weather winter environments where the cable will be “on” all day, every day. Raychem makes an industrial strength heat cable for residential use.
The light duty is designed for intermittent and as-needed usage. It is less expensive than heavy duty and is sold in pre-cut lengths at box stores like Lowes and Home Depot. When the snow starts to fall, plug it in to prevent the ice dam or frozen gutter. When the weather clears simply power it off until the next storm.
Roof heat cable is installed in a zig-zag pattern along the edge of the roof, generally at the eave or bottom of the roof where ice dams form. For extra protection the heat cable can be run up valleys or in other problem areas into the gutter and downspout. If not installed properly the heat cable will not prevent ice dams. Depending on the weather environment and the type of cable installed, the heat cable is either run all winter long or used on an as-needed basis.
Excel Roofing will install heat cable. The cost is $12 per foot of the heavy duty cable and $5 a foot of the light duty cable. When installing the zig-zag pattern, two feet of cable is required for each foot of roof line. If a gutter is present, it must be heated as well. This means it takes three feet of cable to heat each foot of combined roof and gutter.
The downside of heat cable is the relatively higher cost involved and an additional expense to your power bill. Heat cable is more of a last resort solution. The preferable method for prevention is proper insulation and ventilation in your attic.
Ice dams are a wintertime threat to your home and heat cable can be an effective measure to prevent them.