Ice dams can cost you thousands in repairs.
Fortunately, homeowners have a few different prevention strategies at their disposal.
The most well-known approach to warding off ice dams involves insulating and ventilating your attic. Other ice dam prevention solutions include metal roofing, installing heat cables, and routine roof snow removal.
While these options each have their own merits, keep in mind they merely prevent ice dams – they do not get rid of existing ones.
As luck would have it, we highlight two ways to liquidate ice dams before they can wreak havoc on your home.
Read on to learn more about how ice dams form, why they cause damage, and what steps you can take to melt them away for good.
On this page
- Ice dam definition
- Ice dam causes
- The problem with ice dams
- Getting rid of existing ice dams
- Preventing future ice dams
What are ice dams?
Ice dams are a buildup of ice that forms along the eaves (edge of the roof) that block meltwater from draining.
Ice dam causes
Ice dams form when roof snow melts and refreezes upon reaching the eaves. As more water flows down to the eaves, the ice dam builds in size.
The roof's surface must exceed freezing temperatures (above 32 degrees Fahrenheit) while outdoor temperatures need to clock below freezing for ice dams to develop.
This temperature disparity arises when heated internal air gets into the attic space with no place to escape – often a product of poor insulation and ventilation.
The warm attic air heats the roof deck, which then transfers to the shingles, which melts the snow. As attic heat does not affect the eaves, they maintain the same temperature as the outside.
Heavy snowfall only aggravates the dilemma because of how well snow insulates. Essentially, the snow traps the heat directly above the shingles, which leads to more meltwater and faster ice dam development.
Get in touch with a respected contractor about replacing your roof.
Why are ice dams bad?
Image source: IKO
Ice dams prevent meltwater from draining off of the roof.
Eventually, the ice dam will grow large enough to envelop the beginning of the eave, where the roof meets the attic and water stays liquid.
As standing water collects behind the ice dam, it will have nowhere to go except beneath shingles. Water underneath roof shingles may refreeze and expand as temperatures cool, which can break them off even worse. Water can pour into your attic, drywall, framing, insulation, and other interior components – a catalyst for mildew and rot.
Apart from detaching shingles and costly water damage, icicle formation also poses a substantial structural burden on your gutters and a danger to people below.
How do I get rid of ice dams on my roof?
Chemical ice melter
Image source: Structure Tech
Pros: Inexpensive, DIY-friendly
Cons: Potentially corrosive to metal, concrete, and landscaping
Cost: $20-$70 per bag
As their name may suggest, ice melt products like calcium chloride provide a relatively quick means to melt ice. Avoid rock salt, which can damage shingles, landscaping, and concrete as it runs off your roof.
Climbing up on your roof to apply the ice melt poses safety concerns. Therefore, you may want to consider using easy-to-toss ice melt tablets to keep your boots on the ground.
Another DIY strategy employs filling a pantyhose or sock with ice melter and placing it over the ice dam, overhanging the gutter.
Eventually, the ice melt will work its way through the ice and create a channel for water to drain off your roof.
This approach may not totally eliminate the ice. Simply, it clears the water – the prime culprit damage.
Image source: Ice Dam Guys
Pros: Effectively eliminates entire ice dams
Cons: Expensive, requires a professional
The most intuitive method to melt ice involves heat.
Before you bring out the flamethrower, we recommend looking into a far more practical and less destructive pressurized steamer.
Ice dam removal specialists use steamers to directly melt ice dams. With the ice dam eliminated, nothing obstructs snowmelt from draining.
Unfortunately, steamer machines cost thousands of dollars, so this approach doesn't suit one-off jobs. The process also involves the hazardous task of navigating an icy roof.
You're better off hiring a professional who owns and has experience with removing ice dams via steamer, though this also doesn't come cheap.
Ice dam specialists charge anywhere from $250 to $600 per hour of service. For removing particularly large or tough-to-reach ice dams, the job can take several hours.
How to prevent ice dams for good
The most reliable way to prevent ice dams is to properly insulate and ventilate your attic.
If you don't know the condition of your attic insulation and ventilation, you can pay for or perform your own home energy audit to find out.
Alternatively or in conjunction, you can opt for other ice dam prevention methods like heat cables, metal roofing, and diligent roof snow removal.
We explain each of these practices below.
Image source: Standard Insulating Company
Pros: Can reduce energy bills, can be DIY
Remember that ice dams start with internal heat loss. By keeping the roof below freezing, snow won't melt. No melting snow means no water to freeze into ice dams.
Preventing your roof from heating up begins with sealing the attic, which should stop warm air from the living space from penetrating the attic. This process involves using a sealant like spray foam around perforations, including recessed lights, ductwork, HVAC units, and so on.
Sealing air leaks helps significantly, but you can further keep the roof cool by insulating the attic floor. Popular roof insulation options include spray foam, fiberglass, and blow-in insulation.
When insulating the roof sheathing, use baffles between trusses to avoid blocking airflow from soffit vents. This is another crucial component of ice dam prevention.
Image source: AirScape
Pros: Can prolong shingle lifespan, reduce attic moisture
Cons: Difficult for some roof types, usually requires a professional
Even with quality insulation, heat can still diffuse into the attic and potentially warm up the roof.
This is where roof ventilation comes in.
Proper ventilation allows heated air to escape your attic before it can substantially warm your roof's surface. Effectively, venting keeps your roof cold during the winter, which prevents uncoordinated temperatures between the surface and the overhang.
There are many ways to go about attic ventilation. However, most ventilation systems include soffit vents beneath the eaves to draw in cool air and ridge vents at the top of the roof to exhaust hot air.
Beyond ice dam prevention, ventilation can increase asphalt shingle lifespan and prevent attic moisture problems. Some manufacturers, like Certainteed, reduce their warranty for unvented attics because they can cook shingles in the summer.
As for costs, you can expect to pay between $100 and $900 for professional attic ventilation. Pricing depends on several variables, including ventilation type (soffits, ridge vents, gable vents, etc.) as well as the roof shape and size.
You can save money by doing it yourself, although installing ventilation requires ample time, know-how, and equipment.
Stay on top of snow removal
Image source: Don’t Waste Your Money
Cons: Manual labor or calling a professional following every snowstorm
With no snow on your roof to melt, you eliminate a key factor of ice dams.
You can easily remove roof snow with both feet on the ground by using a roof rake. Alternatively, you can pay a roof snow removal company to take care of this arduous task for you.
To minimize ice dam formation, act quickly after a snowstorm.
Ice dams take shape soon after roof snow starts melting, so any delay may render this approach futile. Additionally, snow removal only gets more challenging after melting and refreezing.
Using a snow rake may prove the fastest, safest, and cheapest way to remove snow from a roof. However, it's likely the most labor-intensive, time-consuming, and temporary of the options at your disposal.
Image source: IntegriBuilt Roofing
Pros: Minimal maintenance, 50+ year lifespan, durability
Among their many benefits, metal roofs boast a reputation for shedding snow exceptionally well compared to shingles.
This is because metal roofs have a sleek surface and because they reflect solar heat, even with snow on top. When a metal roof emits solar heat back onto the bottom layer of snow on a sunny day, it starts to melt and quickly slides off the roof.
Removing or installing on top of perfectly good shingles isn't the most cost-effective ice dam removal option, however, especially when you consider metal roofs cost double that of shingles.
Image source: Heat Trace Specialists
Pros: Convenient, can be DIY
Cons: Electricity costs, requires proper installation, safety and damage concerns
Plug-in heat cables sit in a zig-zag pattern along the roof eaves and through gutter downspouts to heat ice dams from below.
For ice dam problem areas, like valleys, heat cables offer a convenient solution. Just turn on the cables once the ice dams form to melt them away.
For even more ease of use, look for "self-regulating" cables. You can keep these plugged in because they turn off as temperatures rise.
Although you can set up heat cables yourself, we recommend considering a contractor. Yes, it will cost you more, but installation requires caution and diligence because fasteners, adhesives, and localized heat can damage a roof system.
For this reason, among others, the National Roofing Contractor Association advises against using heat cables altogether.
Leading industry opinions aside, you may also want to avoid heat cables to keep your electricity bill from rising.
Prevent ice dams before it's too late
Image source: St. Cloud Times
The longer you wait to dispose of ice dams, the greater your odds of encountering expensive problems increase.
The best way to remove existing ice dams yourself is with chemical ice melt. If you don't fancy your salt-spreading skills, look towards hiring an ice dam removal specialist equipped with a pressurized steamer.
Preventing ice dams long-term is often as simple as bolstering your attic insulation and ventilation. However, metal roofing, roof snow removal, and heated cables can also prove effective ice dam prevention measures.