I have a new asphalt roof- replaced when I moved in four years ago (not by your crew- but you helped us out on a vinyl siding replacement so I thought I’d reach out). 

Last December I had problems with ice dams. With Christmas right around the corner, I don’t want to spend a lot of money on something new. Plus, my roof is almost brand new….it doesn’t seem right that this should be a problem at all.  

A friend of mine recommended deicing cables. What do you think? Easy solution or not worth the money?

I appreciate your response!

God Bless, 

John from Tamaqua. 

John, that’s a great question. 

Ice dams can be a serious problem here in Schuylkill County. De-icing cables seem like a DIY option to give a roof an extra edge against our heavy snowfall. But do they really work…and at what cost?

First, let’s look at this question:

What is a de-icing cable? 

These cables were invented over 50 years ago to keep pipelines from freezing over in oil fields. Overtime, they moved from pipelines to roofs.

Today, they are used to regulate roof temperature. Their main purpose? To help homeowners like you get rid of or prevent ice dams. The cables run along your roof’s eaves, in the gutters, and downspouts like this:

The cables melt nearby ice, allowing water to flow through your gutters…that’s the idea, anyway. 

It might sound like an easy fix, but deicing cables are just a band-aid solution to a much bigger problem. They don’t solve the real issue and the “help” they give your roof now can come at a big cost to you as a homeowner. 

Before you head out to the hardware store and buy a few hundred feet of these cables to install, here are my three big issues with using de-icing cables to prevent ice dams:

Issue #1: History of Fire Damage

In recent years, improperly installed deicing cables have put these ‘solutions’ in the spotlight for all the wrong reasons.

In 1996, deicing cables caused a fire at the Philadelphia zoo. 

As of January 2000, deicing cables led to an estimated 2,000 fires and 100 related injuries. 

And in 2018, a fire caused by deicing cables completely destroyed a roof in Leavenworth, Washington.  

These accidents aren’t as common they once were- but the hazard is still there. Deicing cables are marketed as a DIY fix, but in reality? They should always be handled by a professional. 

Proper installation is key in fire prevention- but that’s not the only reason to hire a pro. 

When cables aren’t installed well, they can damage your roof- and causing leaks and early failure.

In short: don’t DIY a de-icing cable installation. 

If you’re trying to save money and protect your roof? De-icing cables might not be the best answer to begin with. Which leads me to my second issue…

Issue #2: They’re Cost Ineffective

John, you’re looking for a budget friendly solution to your ice dam problem. With deicing cables costing $1-$6 per square foot, they seem like a good fit, right?

Well- not exactly. 

De-icing cables don’t have a large initial investment but they can cost you in the long-run. 

A typical cable uses about 5 watts per foot to keep the ice from forming on your roof. This number stays the same, no matter the outdoor temperature. That means whether it’s 30 degrees or -10,  for every foot of cable, you’re using 5x that foot-length in energy.

So if you’re using a 100 foot cable (a small cable installation), it’ll cost an average of $14.40 a month to run your cables. If you use them 5 months out of the year, that’s an additional $72 – plus the upfront cost of the cables, installation, and any yearly repair/replacement needs. 

Need more than 100 feet of cable? You can calculate the cost here. 

The real issue here isn’t the extra cost on your electric bill. It’s this:

If ice dams are forming- you have a ventilation problem, 

Poor roof ventilation is costing you money and deicing cables only add to that expense. So…why not just address the real problem head on? 

That’s why my BIG problem with de-icing cables is this:

Issue #3: De-Icing Cables are A Band-Aid Solution to a Larger Roofing Problem

Ice dams can cause serious damage to the inside and the outside of your home (we cover ice dams in depth here). Here’s a quick refresh on why:

Ice dams happen when melting snow refreezes at the edge of your roof. This buildup keeps water from draining properly. Melted snow is pushed into your shingles- instead of draining- destroying your roof and leading to interior water damage. 

By melting the buildup by your gutters, de-icing cables are meant to help with good drainage.

The problem? 

Deicing cables only melt ice around where they’re placed. Ice dams may not form around your gutters and edge of your roof, but they can still happen on other parts of your roof. This means:

• • Extra weight on your roof 
  • Backed up water 
  • The risk of water damage to your home’s interior

In short, deicing cables are only a temporary- and incomplete- fix. 

So, what should you do instead?

Improper Ventilation and Your Winter Roof

You mentioned your roof was replaced within the last five years- and wonder why you’re still seeing ice dams. 

Ice dams aren’t necessarily caused by a bad roof installation. They usually happen when you don’t have the right level of ventilation in your attic. 

Good attic ventilation regulates your roof’s temperature- whatever the age of your roof. If your asphalt shingle roof isn’t all the same temperature, ice melts irregularly and you’ll have ice dams. 

Good news though- if your roof is solid, fixing your attic ventilation will put a stop to your ice dams…and the cost? It may be less than installing those de-icing cables to begin with. 

Some ventilation systems, like box vents, are an inexpensive way to increase ventilation in your attic. But again, you need a professional to take a look and make sure you aren’t just needlessly cutting holes in your roof. 

So what should you do? Call my team at 570-345-0436. Any one of us can come out, climb up in your attic, and take a look at what you have going on before the snow starts to fall. It’d be a pleasure to give you a bid on how to get your roof working the right way to protect your home. 

Until next time, 

Vern

The post Ask Vern: Do Deicing Cables Work? appeared first on Martin Roofing & Siding.