How Much Does It Cost to Operate a Roof De-Icing Kit?

In this article, we will talk about Roof de-icing kit let you use electricity to prevent snow and ice accumulation on your roof, but at what cost? Here’s how to calculate the cost of operating a kit on your house.

Roof de-icing kit

Why Use a Roof De-Icer?

There’s a strong probability that you’ve never heard of Roof de-icing kits if you reside somewhere where there isn’t much snowfall (or none at all!). However, if you reside somewhere with severe winters, there is a strong probability that even if you don’t have a kit of your own, you have at least observed them on other people’s homes.

Electric cables that resemble extension cords are called roof de-ice cables. The de-icing cable’s function, however, is to act as an electrical resistor, producing heat in the process, similar to the wires in a toaster or an electric space heater, rather than to transport power from point A to point B like an extension cord.

You hook the wire to your roof in a looping W pattern along the first few feet above the eaves (as well as down your gutters, too) (as well as down your downspouts, too). You switch it on when the snow starts falling. Snow is removed from the eaves by the cable’s heating and snow melting action.

The goal is to safeguard the roof, the inside structure of the house, and the home’s inhabitants rather than for aesthetic reasons; most people like the cosines of snow-covered roofs. Snow accumulation along a roofline can result in “ice dams,” when melting runoff freezes at the edge due to the temperature difference between the warm roof and the cold eaves.

That can result in massive ice chunks that break loose and fall off the roof, damaging the roof and perhaps causing serious property damage and human injuries. The melting snow might lift the shingles and roofing membrane when it meets the edge and freezes. When this happens, water may readily enter the wall hollow, destroy the drywall, and cause structural damage and mould.

Some individuals use roof rakes to remove snow from roofs after significant snowfalls to prevent these issues, then wait for the sun to warm the roof to finish melting the remaining snow and ice. Roof raking, however, may not be possible or efficient depending on your location, the solar orientation of your roof, how much snow you get, and the design and insulation quality of your roof.

Related: What Are The Common Causes Of Roof Leaks?

What Is the Cost of Running a Roof De-Icer?

You would be right if you assumed that melting snow off your roof with a massive electric line in the dead of winter couldn’t possible be inexpensive. Snow and ice melting consume a lot of energy, but depending on how frequently you use the system, it might not be as awful as you might think. Let’s go over a basic calculation, and you may modify it using our formulae to meet your home’s size, the area you need to de-ice, and the cost of electricity in your location.

How to Calculate Your Need for De-Icing Cable

The amount of roof you have and the depth of your eaves will determine how much cable you require. You need as much cable as the depth of the eave plus enough to reach roughly a foot back on the roof. Therefore, to achieve the required zig-zag setback on a roof without an eave overhang, just around 2 feet per linear foot are required. However, you need increase the overall cable length by about 1.8 feet for each additional foot of eave overhang. A house with 2-foot-deep eaves will require almost twice as much cable as a house without an overhanging eave.

Downspouts must also be taken into consideration since it is useless to melt the water on the roof only to have it freeze solid while it is being carried away from your house by the downspout. Although many people quadruple the wire to provide adequate heat to keep the downspout flowing smoothly, you’ll need at least as many feet as you have downspouts (especially if the downspout leads into a drain run buried beneath the yard).

We suggest reading this Frost King guide to designing and installing your roof de-icing kits cable system as well as this excellent King Electric guide if you want to plan out a de-icing system more accurately than simply with a rough estimate. Consider a roofline of 100 feet with a 1-foot overhang. You would require 280 feet for the eaves alone (100 ft. * 2.8). For a total of 352 feet of cable, add four downspouts that are 12 feet above the ground and have a 6-foot run at the bottom.

This adds an extra 72 feet. Feel free to modify your calculations to include anything from the entire roof edge around the entire home to just the part by the back door that receives very little sun in the winter. Some people choose to only apply the cable to the portion of the roof that gets the least sun or has the worst problem with ice dams.

Related: What Tools Are Used in a Roof Replacement?

Cost Analysis for Running De-Icing Cables

Now that we have a general notion of how much cable our hypothetical house would require, we can think about how much energy it will consume. Roof de-icing kits cables consume between 5-8W of electricity per foot of cable, depending on the brand and cable thickness. Please be aware that the power consumption is determined by the actual cable length, not the distance the wire travels over the edge of the roof. For the purposes of our calculations, let’s choose 5W as that is the amount that the almost universal Frost King cables consume.

We just multiply the number of feet (in this example, 352) by the wattage per foot (5W) to get the total load for our cable run, which comes to 1,760W. Now that we have the watts, we can calculate how much the Roof equipment will cost per hour of use using the same techniques described in our guide to evaluating your energy use.

First, since your electric provider bills you in kilowatt hours, we must convert the 1,760W operational load into those units. To convert, we’ll increase the load by the number of hours and divide by 1000. Operating our Roof de-icing kits system costs 28 cents per hour. Now that we have that knowledge, we can calculate how much it would cost us depending on our anticipated consumption.

Imagine that you are forced to use your Roof cables day and night because you live in an ice post-apocalyptic hellscape from The Day After Tomorrow. With our fictitious 1,760W system, you would have to pay $6.74 per day and a staggering $202.12 per month to de-ice your roof.

It would cost $2.25 per day and $67.37 per month to use a powerful timer to turn on the de-icer for 8 hours each day. Speaking of timers, you can also get plugs that are thermostat-driven and only turn on when the temperature drops.

You would spend much less money if, for example, there was significant snowfall interspersed with extended sunny spells that allowed you to operate your de-icer during the snowstorm itself but otherwise leave it off. Your cost for a given month would be $13.47 if you could get by with only 12 hours of runtime.