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How to prevent ice dams for good

Ice damming on your roof is a danger to your house. Here’s how to stop it.

Ice damming on your roof is a danger to your house. Here’s how to stop it.

While winter weather can be nostalgic and festive, most homeowners know it also can be the cause of some major issues—like icicles hanging from your house and roof.

Sure, icicles can be pretty.

But if you’ve got ice regularly forming, melting, and freezing on your roof in the winter, it’s likely that you have ice dams.

Roof ice dams are a symptom of a larger, more serious problem. (And damage caused by ice dams often isn’t covered by homeowners insurance.)

In this guide, you’ll not only discover ice dam solutions and prevention products, but you’ll also dig into how to tell if you have ice dams on your roof and what causes them.

Table of contents:

What is an ice dam?

Ice dams can look like icicles hanging from your roofline or gutters, or they might appear to be a block or ledge of ice on the roof that might be holding up, or damming, additional snow. 

ice dam on roof

Ice damming might seem like a normal display of winter weather, but they can actually cause major damage to your home and are a symptom of a larger problem. 

We’ll dive more into how they can harm your home’s structure (and how to fix them) later in this guide.

What causes ice dams?

Ice dams form on your roof because a portion of your attic is under-insulated and improperly air sealed.

As heat escapes from your house through the attic, it melts the snow on the roof line of your house too quickly. This snow then refreezes in an ice sheet at the bottom of your roof and expands underneath the shingles, causing them to break. 

Many homeowners assume that ice dams are caused by a problem with their roof, but they’re actually caused by heated air escaping through your attic and melting the ice and snow on top of your house.

Basically, your house’s airflow or ventilation systems are part of the issue.

But how does heat escape from your house through your attic to melt the snow, anyway? 

Most likely, you already have some attic insulation in your house. But over time, that insulation breaks down and becomes less efficient in keeping heated air inside and the cold air out. 

And in some houses, there are hidden attics that have been uninsulated the entire life of the house.

Or, even if you have newer insulation but that insulation was improperly installed, you’re likely losing heat through the attic.

Ice dams are caused by heated air escaping through your attic and melting the ice and snow on top of your house.

Another thing: Houses shift and move over the years, causing air leaks to form.

Air leaks allow outside air to be sucked into your home through a vacuum-like effect that building science pros call the stack effect.

Air leaks might be tiny and hard to spot, but they actually add up to quite a bit of energy waste in your home. ReadWhy is my house so cold? to learn more.

Combine insufficient insulation with air leaks, and you have the perfect recipe for heat to escape from your home right through your attic.

As the heat escapes through the attic and roof, the snow on your roof is warmed too quickly. It also refreezes repeatedly, causing an ice build up.

And that, dear readers, is exactly what causes ice dams on the roof.

ice dam preventions - air sealing

How common are ice dams?

Ice dams are fairly common in houses that have insufficient attic insulation and air sealing that are located in areas with significant snowfall.

90% of homes in the U.S. are under-insulated, so it’s likely your house is a part of this group (1).

And remember, they’re a serious issue that requires a remedy.

Ice dams are just one symptom of a larger problem, and they indicate that your house is wasting energy through heat loss. 

The worst part?

Ice dams can drip water slowly into your home through the attic—almost undetected—and cause moisture build up between drywall, within your insulation, and in unseen parts of your house. So preventing ice dams is your best bet to stopping long-term damage.

How to tell if your house has an ice dam

Here are a few signs that your house likely has an ice dam problem:

  • Snow and ice are damming up low on your roof, but your roof is clean and clear at higher points. 
  • Melting ice and snow is dripping along the underside of your roof.
  • Icicles that have taken up residency along the edge of your roof and gutters.
  • Ice is forming on the exterior siding of your home. 
  • Water is leaking into your home from the attic after a large snowfall. This is a sure sign!

3 common ice dam prevention myths

Myth #1: Ice dams are caused by roof problems 

Nope! Ice dams are not caused by issues with your roof. In fact, they cause roof issues, and preventing ice dams can keep your roof in healthy shape. 

Remember, ice dams are caused by ice and snow melting and refreezing quickly when heat escapes through your roof via improper insulation and ventilation. They’re not caused by your roof itself.

Myth #2: Gutters are the reasons ice dams form

While clogged gutters can sometimes cause drainage problems, they’re usually not the reason for regular ice dams forming on your roof. 

Myth #3: Regularly occurring ice dams aren’t a real problem

If ice dams are regularly forming on your roof, heat is already escaping from your attic—and that means higher energy bills and a colder house. And ice dams can cause big problems, like leaks and additional stress on your roof.

Should I worry about ice dams?

If ice dams show up consistently on your roof and eaves in the winter, it’s time to take steps to solve the problem. 

They will damage your roof over time, including the underlayment of your roof. And a new roof is an expensive fix that won’t resolve the core issue.

Insulation and air sealing are the right fix to trap warm air inside in the winter.

When you have proper insulation installed and your home professionally air sealed, it stops heat loss from causing the ice that dams up on your roof and roof eaves. (More on how attic insulation and professional air sealing is the permanent fix later in this article!)

Even if ice dams don’t cause visible damage, they can cause invisible mold and mildew issues in your house, which can lead to respiratory problems (2).

Learn more about how professional air sealing and proper insulation can increase your home indoor air quality (in addition to stopping ice dams).

Do ice dams always cause damage to a house?

Ice dams don’t always cause damage every time they form, but if they’re left untreated, they can cause permanent damage to your home over time. And that damage can be really expensive to fix.

Did you know? Damage caused by ice dams isn’t often covered by your home insurance policy. It’s considered a routine maintenance issue. The best thing to do is prevent ice dams in the first place!

Here are a few ways ice dams cause lasting damage to your house:

  • Ice dams can lift roof shingles as they form and expand, causing shingles to have trouble resealing. This reduces your house’s protection against future ice and water exposure. 
  • The weight of ice dams can cause stress and damage to your roof and your gutters. In fact, the weight of an ice dam can rip the gutters right off your house.
  • Ice dams can force water to seep in underneath damaged shingles, causing serious moisture and water damage to the rest of your house.
  • Ice dams can cause water to back up under the shingles of your roof—and even force it beyond your roof and into your attic.

When water intrudes into your house because of melting ice, it does so slowly and quietly. This can soak interior insulation and get in gaps and spaces between drywall, all while going unnoticed.

But here’s the good news: When you take steps to permanently solve your ice dam problem, not only are you stopping moisture intrusion and stress on your roof, but you’ll also be stopping drafts and your home will finally feel comfortable year-round.

How to get rid of ice dams: Temporary and permanent ice dam solutions

So if you’re wondering how to get rid of ice dams on your roof, you’re in the right place.

Now that you know those sheets of ice and sparkling icicles on your roof aren’t a good thing, what’s the next step?

We’ll start by diving into short-term fixes.

Short-term ice dam solutions

Here are a few things you can do in the short-term to help prevent ice dams from camping out on your roof in the winter.

  1. Keep the roof valley (the place where two roof slopes meet) clear of falling leaves and twigs throughout the year. This is how to prevent ice dams in roof valleys. That way, these spots are less likely to collect snow and ice in the winter. 
  2. Regularly clean your gutters. This helps melting ice flow off your roof more efficiently, lessening the chance you’ll have ice damming.
  3. Use a salt brick, rock salt, or a calcium chloride brick to prevent ice build up. (More on these below.) 
  4. Keep your attic cold in the winter. While this seems like an odd thing to do, this can prevent ice from melting too quickly and then refreezing. You can help your attic stay cold through proper attic ventilation, including using a box fan to keep air circulating as a short-term solution.
  5. Remove snow with a long-handled tool. If you can remove snow on your roof (with a roof rake, for example) that’s ideal until you get a permanent fix.

What if my house has a metal roof? How do I prevent ice dams on my metal roof?

The same tips apply to ice dam prevention for metal roofs with a couple extra considerations.

Homeowners with metal roofs should install snow guards on their roof, and you may want to ask your roofer to apply a special coating to your metal roof that can help. 

But the long-term fix for ice dams, no matter your roofing material, is proper weatherization of your home, including insulation and air sealing.

Ice dam prevention products (quick fixes)

There are a few things you can do to temporarily fix or remove an ice dam on your roof. 

But remember, the list of ice dam prevention products below are temporary fixes designed to help you reduce the chance of ice dams or melt them away after they’ve formed.

These suggestions below aren’t able to solve the underlying problem that causes ice dams to form.

  1. Use electric de-icing cables or a snow-melting system. This heated cables work to melt snow and ice build-up using electric heat.
  2. Use a roof rake (also called a snow rake) to pull fresh snow and debris off your roof to prevent build up.
  3. Hire someone to professionally remove the ice dam by using steaming machines. If you live in a colder region, we bet there are some ice dam removal companies near you who can help in the short term.
  4. Install metal ice belts or ice belt panels on your roof. These can help protect your roof and cause ice to slide off, but ice dams can still form around them. 
  5. De-icer bricks that include a safe solution for your roof, lawn, and garden. They work to gradually disperse calcium chloride on your roof to keep ice dams from forming.
  6. Soffit vents can also help your attic ventilate to reduce ice damming on your roof, but they do require an installation. (But if your attic is properly insulated and air sealed, you won’t need to install extra soffit vents.)

Most of these short-term solutions are things you can do before a snowfall to make ice dams less likely and attempt to prevent ice dams in roof valleys, gutters, near soffits, and more. 

But it’s important to know that they may not work, because they don’t address the real cause of ice dams.

You can fix ice dams permanently by getting your home properly insulated and air sealed, which you may be able to do for NO upfront cost.

Take the quiz to see if your home is eligible.

Next, let’s talk about permanent solutions and how they work to stop ice dams.

All other ice dam fixes are temporary—including a new roof.

Ice dam remedies: Permanent solutions

If you’ve done any prior research on the problem of ice dams on your roof, you know that your home and attic need to be properly insulated and air sealed.

Getting your home professionally air sealed and properly insulated has a three-part reward:

  1. Solving the problem of ice dams 
  2. Making your home feel more comfortable year-round 
  3. Reducing your energy waste

And it’s true: Insufficient insulation and unsealed air leaks are the core issues that cause destructive ice dams to regularly form on your roof in the winter. And fixing those issues is the only permanent solution.

All other ice dam remedies are temporary—including a new roof.

Here’s why home insulation and professional air sealing solve the ice dam problem for good.

upgraded attic insulation helps prevent ice dams

Upgrading your home insulation 

Home insulation works by creating a thermal boundary between the interior of your home and outside.

When a home is under-insulated, or when older insulation starts to wear down, that thermal boundary decreases, causing your home to feel uncomfortable—even drafty or damp.

In the winter, insufficient insulation can allow heat to escape through the walls, ceilings, and attics of your home into the great outdoors.

Basically, you’re spending money to warm your home, but that precious heat is being lost due to insufficient insulation and home air leaks. And when that heat escapes through your attic and the roof of your house, snow and ice on the roof melts and refreezes, causing ice dams to form.

With the proper home and attic insulation in place, you’ll trap heat inside your house where it belongs—and that will help stop ice dams in their tracks (as well as keep everyone inside your home much more comfortable).

Professional air sealing

Professional air sealing is also a must to prevent ice dams for good. 

Insulation and air sealing work together to create your home’s thermal boundary, and when the two work together, they allow healthy airflow and proper ventilation throughout your home.

Upgrading your home’s insulation without getting your home professionally air sealed leaves room for heat loss to continue. 

How does air sealing work? Basically, a professional home performance contractor will assess where your home is losing heat through gaps and holes that form around doors, windows, plumbing and lighting fixtures, and even your foundation.

Then, the professionals do the highly technical work of sealing up your home’s air leaks, while still allowing room for proper home ventilation. (Learn more about air sealing here.)

When your home is properly insulated and air sealed, you have the right solutions in place to stop ice dams once and for all.

But getting your home professionally sealed and insulated has a lot of other benefits, too.

Here’s how these permanent ice dam solutions have a lasting effect on your whole home:

You’ll feel the effects of proper air sealing and insulation throughout your home pretty quickly. Here are the three biggest things you’ll notice:

1. Your home will feel so much better inside.

Everyone knows drafty houses are uncomfortable, but they don’t have to be a normal part of daily living. You can love your home and make it feel like new again. You’ll also improve your indoor air quality, too. 

2. Your heating bill will go down.

Upgraded home insulation and professional air sealing increase your home’s energy efficiency and reduce energy waste. Your HVAC system will no longer need to work twice as hard to maintain comfortable temperatures, and you’ll benefit from lower energy bills throughout the year.

3. Your home’s marketability and value can go up.

According to the National Association of Homebuilders (NAHB), 57% of buyers “are willing to pay $5,000 or more on top of the price of the home in order to save $1,000 a year in utilities” (3).

Not only can energy-efficiency upgrades like insulation and professional air sealing increase home value, but they can also increase the overall marketability of your house in today’s unique market.

And these three effects are just the easy to see and feel benefits. 

You’ll also be:

  • Protecting your home’s structure from excess moisture
  • Increasing your roof’s longevity
  • Lessening the overall stress on your HVAC system throughout the year.

All while saying sayonara to ice dams once and for all. 

Say goodbye to damaging ice dams for good 

Ice dams can cause lasting damage to your house.

But the good news is that home insulation and air sealing provide a permanent ice dam solution and long-term remedy—one that can have a positive effect on your whole home.

And depending on where you live, you can get your home professionally insulated and air sealed at no upfront cost

Yep, you read that right. 

With Sealed, we help you find the right contractor, negotiate pricing, manage the work, and get the work done right—and you pay us back a little at a time.

That means you keep your cash on hand while getting rid of ice dams (and the damage they cause).

And your home will feel amazing after the work is done, too.

Contact us to learn how to get rid of ice dams permanently for no upfront cost.



February 7, 2022