Pros and Cons of Installing Heat Cables to Combat Ice Dams


As the weather grows colder, it’s a good time to perform some routine maintenance on your home, such as cleaning out your gutters, to get ready for the winter season. Is your roof in good shape and ready for another snowy, icy winter in the Midwest?

One of the difficulties of living in a climate that is prone to snow and ice storms is ice dam formation on your roof. Ice dams are the buildup of ice and snow on the edges and eaves of your roof. This can cause beautiful icicles—and damage to your roof, broken gutters, and water infiltration.

What causes ice dams?

After a significant snow with sustained sub-freezing temperatures, your roof may be covered by a thick layer of snow. Your roof should ideally be the same temperature or colder than the air outside, so snow would melt from the outside layer and evaporate or run off the top of an outer, icy crust. Often, however, a home’s heat seeps through your ceiling into the attic and through the roof. This makes the roof warmer than the outside temperature and melts the bottom layer of the snow sitting atop it. On sloped roofs, the melted snow trickles down the roof—under the snowpack. But the edges of the roof are colder, since they hang over cold air rather than sitting on top of the heat-leaking home. When the runoff gets to the colder edges, it freezes, blocking further runoff like a dam.

Over time, this mound of ice builds up; it can happen extremely quickly, especially if your gutters are obstructed. As the ice dam grows, it prevents water from flowing off the roof, giving it a great opportunity to seep between the seams of your roof shingles and into your home. This can cause damage to your roof structure and insulation, water infiltration, and harmful mold growth. The ice blockages can also damage gutters and create hazards for people and animals below.


How Can Heat Cables Help Ice Dam Prevention?

Heat cables, also known as heat tape, heat wire, or roof ice cables, are heated cables that can be attached to your roof. If you have problems with ice building up on the eaves of your home and forming ice dams, running heat cables in problem areas may seem like a great solution to help melt the ice.

Heat cables melt channels through already-formed ice dams to minimize ice buildup. Ideally, they can help provide a path for snowmelt to drain off your roof rather pooling behind the dam. This may help prevent water infiltration into your roof deck and home. They are usually installed in patterns along the eaves, in valleys on the roof, around chimneys and skylights, and in gutters or downspouts. They can be a helpful tool when used as part of a comprehensive snow and ice removal plan to combat roof leaks. They are especially useful for very limited problem areas where you are unable to address the underlying cause of ice dam formation. If you have widespread ice dams on your home, however, you likely have issues with your attic insulation, ventilation, or roof.

The most common areas of the home for ice dams to form are 

  • In valleys of the roof
  • On low-angle roofs
  • Around chimneys and skylights
  • At the eaves of the roof (by far, the most common spot)

Heat cables are often the first things that come to mind for homeowners attempting to deal with ice dams. First and foremost, it is very important to understand that heat cables do NOT prevent ice dams from forming or get rid of them altogether. They merely melt channels through the formed ice dams to minimize the amount of buildup and partially remove snow from the area. In order to prevent ice dams, you need to target the source of the problem.


Advantages of Installing Heat Cables 

If heat cables are correctly and professionally installed, they can be very useful in minimizing water buildup behind ice dams. While they are not a permanent solution, they are a great choice if you need a quick fix. They are also much less costly than sealing air leaks in the attic, installing adequate insulation, and creating proper ventilation systems. The biggest advantage is the simple fact that heat cables will protect your gutters from filling with ice, breaking off, and harming your roof.


Disadvantages of Installing Heat Cables

Heat cables take electricity to operate. If you leave them running all winter long, your electric bills are sure to increase. You will also need to monitor them to make sure they don’t overheat or use more power than necessary. Heat cables may protect your home from ice damage, but they aren’t pretty and can detract from its curb appeal. Because they don’t address the underlying problem, this approach could end up being more costly in the long term.

Most often, ice dams form due to poor attic insulation or ventilation, improper roof installation, or roof damage. All of these factors contribute to a roof that stays warmer than 30°F during freezing weather. Have a roofing professional perform an energy audit before freezing and snowy weather sets in. Following their recommendations for reinforcing specific areas of your attic or roof insulation can make a big difference in preventing ice dams.


Contact our team to see if heat cables are right for your home.