My View: Tips for using heat tape
Vail, CO Colorado
Vail Fire and Emergency Services has recently responded to several calls, including one structure fire, involving heat tape. Heat tape is used to form channels in the snow and ice that have built up along the edges of the roof. This allows the melting snow to drain off the roof instead of building up and potentially leaking into the home. It is also used in gutters and drainpipes to keep them ice-free during the winter.
Ice dams form on the eaves of a roof when either the heat escapes from the home through the roof or from the solar activity warming the roof. The water then drains off the roof until it hits the cooler portions of the eaves, where there is less heat. As the ice freezes, it builds up a dam which prevents the remaining water from dripping off the roof. As the dam size increases, more water builds up.
Then water does what it does best. It finds the lowest point and starts a leak. If that point is inside the house, it can soak the insulation and start causing mold and mildew problems. It also can find its way to the interior ceiling, staining the drywall or wood. If the leak gets bad enough, the drywall will absorb the water until it becomes so heavy that the ceiling starts falling down in large pieces. It also can find its way into electrical wiring, causing circuit breakers to trip or, worse, causing short circuits that can create sparks.
Back to heat tape. Heat tape is installed in a zigzag pattern along the eaves where the water tends to freeze. As the wires heat up, they melt the snow and ice, creating a channel for the additional water to drain. If the home has gutters, it is usually installed along the gutters and drainpipes, as well. A 100-foot section of heat tape can use 500 to 600 kilowatts of electricity monthly if it’s run 24 hours per day, and that can cost between $35 and $50 per month. That is a small price to pay if it saves the roof, but if multiple sections of heat tape are needed, the cost can rapidly increase.
The best solution is to only use the heat tape at a time when most of the snow will be melting. Because of the solar activity and warmer temperatures, heat tape is usually only needed from 6 a.m. to 6 p.m. It also would be wise to keep an eye on the ice dams throughout the winter. The wires and surrounding channels should be visible from the edge of the roof. Occasionally, a section of heat tape will fail and an ice dam will start to accumulate once again. As the season comes to an end and ice dams are less of a problem, the heat tape should be turned off all together.
Prior to use, heat tape should be carefully examined to ensure the product is functioning as designed. Ice dams can weigh several hundred pounds in the spring and, as they slide off, can take portions of the heat tape with them. Sun degradation is also a possibility. After being exposed the entire summer in the sun at high altitude, the rubber casing on the wires can wear out and crack, exposing the bare wires to moisture. As we all know, water and electricity don’t mix. If you have any questions regarding the installation of heat tape, consult a licensed electrician.
The bottom line: If you currently use, or are considering using, heat tape, follow these simple suggestions to keep your home safe and well-protected.
Al Bosworth is a fire engineer with Vail Fire and Emergency Services.