Quebec winters put roofs to the test. Between ice storms, such as the one in 1998 and even more recent ones, and repeated freeze-thaw cycles, snow and ice accumulation quickly becomes problematic.
Roof de-icing is not a luxury, it is essential protection to prevent water infiltration and structural damage. AP Toitures et Fils explains why and how to monitor your roof safely.
When Do Ice Dams Form?
The phenomenon of ice dams is as variable, irregular, and unpredictable as our Quebec winters. Depending on what Mother Nature throws our way—snow, freezing rain, extreme cold, or milder periods—this problem can occur to very different degrees from one winter to the next.
The main causes:
Snow accumulation: A thick layer of snow on the roof significantly increases the risk. The more snow there is, the greater its weight and potential for melting.
Periods of cold and thaw cycles: This is the most problematic cycle. When temperatures hover around zero, the snow melts during the day and freezes at night, creating ice dams along the roof edges.
Inadequate ventilation: Lack of airflow in the attic, often caused by blocked soffits and vents with gaps, prevents the temperature from remaining stable and leads to moisture buildup in the attic.
Insufficient or uneven insulation: This is the real problem: during periods of extreme cold, you heat your home more, resulting in greater heat loss in the attic. This heat melts the snow from below.
Beware of gutter guards: While very practical during spring, summer, and fall to prevent debris and leaves from entering, these guards easily block the flow of water and snow during the winter. Ideally, they should be removed at the end of fall.
How does an ice dam form?
To understand the problem, you must first understand the role of the attic.
The attic: an essential buffer zone
It acts as a barrier between the comfort of your home and the outside, its purpose being to maintain a stable temperature inside. Insulation prevents heat from escaping your home, and ventilation ensures good air circulation to prevent humidity and condensation.
The ice dam phenomenon
When this area (the attic) is problematic and fails to perform its functions, the air or temperature in the attic is no longer adequate and causes the snow to melt from below, thus melting the first layer on the roof. Gravity causes this water to drain away, but as soon as the temperature drops, the water that couldn’t drain to the ground freezes at the bottom of the slope.
After several cycles, the ice accumulates in thickness, creating a barrier that traps new meltwater, preventing it from escaping and causing it to become stuck.
This water seeps under the overlapping shingles and finds its way into your attic. Despite all precautions and the installation of a membrane, a sloped roof is not designed to retain the small pool of water that forms. No shingle is designed to absorb significant amounts of water against the direction of the shingles.
The Risks of an Iced Roof
The consequences of an ice dam go far beyond aesthetics:
Water Infiltration: Stagnant water behind the dams seeps under the shingles and penetrates through any small opening it can find (a nail, a joint, etc.). This damages insulation, drywall, your walls, and your belongings.
Structural Overload: Ice is heavy and can exert dangerous pressure on the roof structure. Watch for signs: unusual creaking, interior doors that rub or stick, cracks in the walls, and sagging ceilings.
Gutter Damage: The weight deforms or tears off gutters.
Dangerous Icicles: Icicles pose a risk to people on the ground.
What to look out for on your roof?
Be vigilant and watch for these warning signs:
Compare with your neighbours
If your roof has an abnormally different accumulation of snow or ice, or if the snow melts faster than on neighbouring houses, it’s a red flag.
Areas that melt faster
Localized sections without snow while there is snow all around, uneven snowmelt could indicate a problem inside your attic (including heat loss).
Snow accumulation
Although our homes are designed to withstand a certain amount of snow, be mindful. Depending on the type of snow (loose, wet, icy), but if it’s between 1 and 2 feet, consider shoveling it.
Gutters filled with ice
If they no longer drain during thaws, it’s a problem. Also, check for icicles along the edge of the slope.
Inspect your attic
Go inside: look for signs of dampness, frost on the wood siding, and mold. Check that the insulation is evenly distributed. Verify that the pipes are properly connected, sealed, and insulated (stove hood, bathroom fan).
Too late, there’s an ice dam: what to do?
If you find an ice dam, here are the steps to follow:
1. Take photos.
Document the problem areas. These photos will be invaluable for a future inspection by a specialist.
2. Remove 3 to 5 feet of snow from the bottom of the slopes.
Focus on the section where the dam is forming and remove this section of snow to give yourself some leeway during the next thaw.
Break up the ice, BUT…
Caution: Leave a thin layer to avoid damaging the shingles. Never break the ice forcefully. You risk damaging it and having to replace your shingles in the spring.
DO NOT touch the gutters
We strongly suggest leaving the ice in the gutters. Breaking it can cause them to crack or be seriously damaged.
Ensure future drainage
Check that, during the next thaw, the water can reach the ground.
What to absolutely avoid
Metal tools: Rigid picks and shovels will puncture the shingles.
Ordinary de-icing salt: Corrodes gutters and damages vegetation.
Climbing without equipment: Never climb onto an icy roof without a harness and crampons.
Blowtorch: Risk of fire and damage to the roofing material.
Hitting violently: Risk of weakening the structure.
Recommended Safe Methods
Telescopic Roof Shovel or Snow Rake
The safest method is to use a snow shovel with a telescopic handle or a roof snow rake. These tools allow you to remove snow and ice from the ground without going onto the roof. Gently pull the accumulations towards you.
Roof De-icer
Products specifically designed for roofs help melt ice without damaging shingles. Calcium chloride or magnesium chloride tablets are less corrosive than regular salt. Place them strategically on icy areas to create drainage channels.
Heating Cables
To prevent long-term ice dams, heating cables installed in a zigzag pattern along eaves or in your gutters keep a clear path for meltwater. Important: Plug them in at the beginning of winter and leave them running throughout the season.
When to Call in Professionals
Some situations require the expertise of a specialized team (like AP Toitures et Fils).
Warning Signs
- Significant icicles along the eaves
- Completely clogged gutters
- Damp patches on the ceiling or walls
- Ice accumulation exceeding 5 cm in thickness
AP Toitures et Fils’ Expertise
Our teams of certified roofers have the experience and equipment to safely remove ice from your roof. We use proven techniques and appropriate equipment, and offer emergency service during freezing rain events.
Our technicians assess the situation, identify critical areas, and remove ice from your roof according to a rigorous protocol that guarantees your safety and keeps your shingles intact.
Long-term solutions
Every situation is different, but here are some long-term solutions:
Attic inspection
Have your attic inspected by a building inspector or an insulation/ventilation company. It’s often the source of the problem.
Adding heating wires
Install them either in the gutters or at the bottom of the slopes. Plug them in at the beginning of winter and leave them running for the entire season.
Proper insulation and ventilation
A cold roof is less likely to cause ice dams. Make sure your attic is well insulated and properly ventilated. The main cause of ice dams is heat loss in the attic.
Gutter Maintenance
- Clean your gutters before winter
- Check the slopes for optimal drainage
- Repair damaged sections
- Remove gutter guards at the end of fall
Fall Inspection
Have your roof professionally inspected before winter to identify damaged shingles, check the flashing, and pinpoint vulnerable areas. AP Roofing & Sons offers comprehensive inspections and personalized recommendations.
The Benefits of Being Proactive
By acting before problems arise, you benefit from:
- Extended roof lifespan
- Significant energy savings and consistent home comfort (in case of heat loss)
- Preventing damage and breakage, as well as the associated repair costs
- Peace of mind throughout the winter
Frequently Asked Questions (FAQ)
When should you de-ice your roof? You must act as soon as you observe large icicles, ice dams at the bottom of your roof slopes, clogged gutters, or signs of leaks. Don’t wait for the situation to worsen.
Does roof de-icer damage shingles? Specific roofing products based on calcium or magnesium chloride are formulated to be safe. Avoid regular salt (sodium chloride).
Can I de-ice my roof myself? You can remove light snow from the ground with a telescopic shovel. For heavy accumulations or steep roofs, call professionals.
Are ice dams covered by insurance? Damage caused by water infiltration is often covered, but preventative de-icing generally is not. Consult your insurer.
Protect your investment with AP Toitures & Fils
Roof de-icing is a delicate operation that requires expertise and appropriate equipment. By entrusting this task to professionals, you protect your home and your safety.
At AP Toitures et Fils, we understand the challenges of Quebec’s climate. Our teams respond quickly to protect your roof. We also offer preventative maintenance programs to minimize the risk of ice buildup.
Don’t let ice compromise your roof. Contact AP Toitures et Fils today for a free assessment or to schedule a service call. Our expertise is your best protection against Quebec winters.
