As if the recent heavy snowfall hasn’t been challenging enough for Ontario residents, homeowners now have another pressing concern: ice damming. These thick ridges of ice most commonly form along the lowest edges of roofs and within gutters to create significant problems.
In this article, we’ll look closer at what causes ice dams, their risks to your home, and the best ways to prevent and address them before they result in costly repairs.
What Is An Ice Dam?
Whenever it snows, there’s a risk of ice dams—chunks of ice that block proper roof drainage. These ridges form when heat from a home’s attic or roof space causes the snow on the roof to melt, running to the roof’s edge. And if that occurs when the air and overhang are below freezing, the water freezes, creating an ice dam. The more water melts and refreezes, the larger the ice dam gets.
However, ice dams don’t just form when heat escapes from an attic or roof space. They can also develop when sunlight warms dark, south-facing wall siding, creating convection currents that rise into the eaves and roof area. This trapped warmth can cause snow to melt and refreeze at the roof’s edge, leading to ice damming.
Ice dams can develop even with minimal snowfall, not just during heavy storms. However, significant snow accumulation tends to speed up their formation.
Issues With Ice Damming
When ice dams block proper drainage, melting snow can’t flow off the roof as it should. Instead, the trapped water seeps beneath the shingles, increasing the risk of leaks, water damage, and even structural problems inside your home.
“Because of the pressure from an ice dam, existing cracks and leaks—like those in windows and doors—can worsen,” explains Chris Patrick, Kempenfelt Windows & Doors installation manager. “Moisture builds up in walls, window casings, and ceilings, potentially causing peeling paint, warped wood, mould growth, and even structural failure.”
Left unaddressed, this ongoing moisture intrusion can result in expensive repairs and compromise the integrity of your home.
The heavy ice formation also poses a safety risk. A piece that falls could break a window, injure a bystander, or cause damage to surrounding property.
How to Identify If You Have Ice Damming
Large ice dams are easily noticeable from the ground, but smaller ones—like those near skylights, dormers, and valleys—are more challenging to spot. Here are some potential signs of ice damming:
- Large icicles hanging from the roof’s edge or behind gutters,
- Ice or water on siding, exterior walls, or around window frames,
- Water dripping from the soffit or gutters,
- Visible leaks around windows or doors,
- Snow melting on the roof while ice or snow remains at the eaves,
- Shingles appearing worn or discoloured,
- Warped or damaged hardwood or laminate flooring,
- Damp, musty odours, and
- Water stains or damage on interior walls or ceilings beneath the eaves.
Removing Ice Dams and Ice Dam Remedies
If you suspect an ice damming problem, it’s best to call a professional water-intrusion contractor. And to prevent future costly damage, it’s essential to do so quickly.
Most professionals will use steam to remove ice dams without damaging the roof’s shingles. Professional steam equipment typically has an operating pressure of 240 PSI and uses water heated to around 300 degrees.
If you choose the DIY route, there are numerous ice-melting compounds available. However, corrosive substances like rock salt and magnesium chloride have risks, like damaging your roof.
How Do I Prevent Ice Dam-Related Leaks?
Although there’s nothing you can do about an impending snowfall, you can help lower your risk of ice damming by completing the following:
- Properly seal all attic air leaks,
- Insulate your attic thoroughly,
- Use ice dam prevention products, like heat tape and de-icing cable,
- Clear gutters and downspouts of all debris,
- Remove snow from flat or low-slope roofs using a roof rake, or push broom, being careful not to damage roof cladding, and
- Schedule a professional inspection of your roof and chimney flashing, and repair or replace any damaged areas as needed.
The Key Takeaway: Dealing with Ice Dams At Your Home This Winter
If you spot ice buildup on your roof during winter, you should address the issue immediately to prevent further damage.
If left untreated, ice dams can lead to leaks, water damage, and structural issues. Prompt action—such as removing the ice, improving insulation, or consulting a professional—can prevent costly repairs and protect your home’s integrity.
“While checking for ice dams, inspect your windows and doors for damage or potential leaks,” advises Patrick. “Look for gaps, cracks, or condensation problems which indicate compromised seals or insulation. Addressing these issues early can improve your home’s energy efficiency and prevent additional problems, such as water damage, from worsening during winter.”
If your windows or doors need replacing, the team at Kempenfelt Windows & Doors can help. If you are a previous customer with our products installed by us, you are protected against their failure by our 25-year transferrable warranty. Contact us today for a free, no-obligation estimate on new windows and doors, or garage doors – all manufactured in Ontario.
