How Much Does Roof Heating Cable Installation Cost?
Last Updated: January 26, 2022
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When snow begins to melt on the roof due to escaping heat from the attic, it often refreezes upon reaching the eaves, which are cooler than the rest of the roof. Ice accumulation on the eaves eventually results in an "ice dam" that can deform roofing and gutters and cause meltwater to pool behind the dam. The possible consequences of this backed up water include not only roof damage, but also exterior and interior wall, ceiling, floor, and insulation damage.
One way to prevent ice dams is to install roof heating cables, also known as deicing cables or roof heat tape. They're relatively inexpensive to install, especially compared to the cost of cleaning up the destruction wrought by ice and water.
Installing Roof Heating Cables #
Because ice dams form on the eaves of roofs, that's where roofing cables are installed, typically in a zigzagging pattern. By heating the roof edge, deicing cables prevent solid sheets of ice from forming, and thus prevent water from backing up on the roof.
Don't forget, though, that proper roof drainage is dependent upon functioning gutters and downspouts. If they remain trapped in ice, meltwater can still back up and cause problems. That's why it's a good idea to also install heat tape within gutters and downspouts.
Homeowners should temper their expectations for roof heating cables. While they melt enough snow and ice to keep water flowing, heating cables aren't designed to keep roofs, gutters, and downspouts completely clear. That is, heat tape isn't a substitute for roof shoveling and shouldn't be counted on to melt large piles of snow. During a winter with heavy snow accumulation, a roof shovel/rake or snow removal service should still be used. When removing snow from the roof, take care not to damage or rip off the heating cables.
Types of Deicing Cables #
Standard roof heating cables plug in to an electrical socket. They can remain plugged-in throughout the winter for continual melting, but this can cause a significant increase in electricity bills. A more efficient way to use heating cables is to turn them on as needed. There is no exact formula for determining when the cables should be switched on, as temperature, the time of day, and the sun all come into play. A good rule of thumb is that if it's warm enough to melt snow on the top of the roof but cold enough for refreezing to occur on the eaves, the cables should be on. Often, this occurs during the late afternoon. The manufacturer instructions should provide more details on when (and when not) to use the cables.
More sophisticated heating cables come with a thermostat that switches the cables on when the temperature drops below freezing. Such models eliminate the guesswork associated with manual plug-in cables and can promote greater energy efficiency. Even more advanced deicing cables are "self-regulating," meaning they get proportionally warmer as the outside temperature drops. Basic thermostatic cables only have a single heat setting.
Preventing Ice Dams #
Just as heating cables aren't a substitute for roof snow removal, they also aren't an effective solution to the improper insulation and sealing that can cause excessive ice damming. In other words, using heat cables might be treating the symptoms of the problem, not the problem itself. Resources on preventing ice dams include the following:
Roof Heating Cable Average Costs #
- Basic de-icing cable (no thermostat) costs less than $1.00 per linear foot. Numerous lengths are commonly available, including 30, 60, 80, 100, 120, and 200-foot. The clips and screws needed for installation are included. The actual amount of cable needed depends on the size of your roof and where you intend to install it. To cut down on costs, install heating cables only in the most ice dam prone areas (such as the northern exposure). Certain parts of the roof, including those with a steeper pitch or under trees, may not require heat cables.
- A heating cable thermostat can be purchased separately for $75 to $200 or more.
- Self-regulating heating cable costs $2 to $6 per linear foot.
- Knowing which type of heating cable to use as well as where and how to install it are necessary for proper melting and drainage. Consider professional installation for the best results.