Ottawa Ice Dam Removal
When an ice dam is pushing meltwater under your shingles, Ottawa Roofing Pros sends a crew with a low-pressure steamer to cut it away without breaking shingles. We clear ice dams and heavy roof snow for Ottawa homeowners 24/7, all winter long.
More than 17 years of Ottawa winters have taught us that the dam is only the symptom. Every visit ends with a plain explanation of why your roof is icing, whether that is attic heat loss, weak ventilation or missing eave membrane.
We are roofing specialists, licensed, insured and WSIB-covered. The person on your roof knows how frozen shingles, flashing and eavestroughs behave, and how easily the wrong tool damages them.
A standard visit covers three things: steaming open the ice dam and the eavestrough behind it, clearing the snow that feeds it, and stopping any active leak. Most Ottawa homes are finished in one visit of 2 to 4 hours.
It suits homeowners with water dripping at a window head, icicles thicker than a forearm, or a frozen gutter pulling away from the fascia. It is also for anyone who would rather not stand on an icy ladder in January. Ice dam removal is one part of our residential roofing services, so a roofer, not a snow contractor, is the one assessing your shingles.
We use a purpose-built ice dam steamer that heats water to roughly 300°F and delivers it at low pressure, around 100 psi or less. Steam melts through the ice instead of blasting it, so shingle granules and tabs stay intact.
We cut the dam into blocks, open a drainage channel to the eavestrough and steam out frozen downspouts so meltwater has somewhere to go.
We clear the lower 1 to 2 metres of roof above the eaves, or the whole roof when weight is a concern. A thin layer of snow stays on the shingles so no shovel blade ever scrapes the surface.
Snow comes off in balanced passes and lands in a marked area away from walkways, vents and gas meters.
If water is already inside, we open a channel through the dam first to stop the inflow. We note the entry point and photograph the damage for your insurer.
Lifted shingles, soaked decking or torn flashing are then handled by our emergency roof repair crews, often on the same visit.
We never chop ice with hatchets or hammers, run a 3,000 psi pressure washer over shingles, or spread rock salt. Each of these shortens roof life, and chipping in particular cracks frozen, brittle shingles and dents eavestroughs.
Ice dams form when heat escaping from the house warms the upper roof deck above 0°C while the eaves, which hang past the heated walls, stay below freezing. Snow melts on the warm section, runs down and refreezes at the cold edge into a ridge of ice. Meltwater then pools behind that ridge and backs up under shingles that were designed to shed water, not hold it.
Ottawa's climate makes this worse than in much of Ontario. Deep snowpack, long cold stretches and repeated mid-winter thaws melt and refreeze the same roof many times. A thick blanket of snow also insulates the roof surface, so attic heat can melt the underside of the snow even on a -15°C day.
The houses we steam most often share a few traits:
We see the bungalow pattern constantly on the 1960s and 1970s streets of Nepean, while the complex rooflines of 1990s and 2000s two-storeys in Kanata trap snow in valleys above garages. Older split-levels in Orléans often combine both problems. Our guide to ice dams covers each cause in more depth, including the checks you can do from inside your own attic.
Low-pressure steam is the only method that removes a thick ice dam quickly without damaging the roof. Most other methods either harm shingles and eavestroughs or only work on small dams over several days.
| Method | How it works | Risk to your roof | Our view |
|---|---|---|---|
| Low-pressure steam | Hot, low-pressure steam cuts the dam into removable sections | Very low with trained operators | The right tool for an active dam or leak |
| Hammers, hatchets, chisels | Ice is chipped and pried off | High: cracked shingles, torn flashing, dented eavestroughs | Never on a shingle roof |
| Pressure washer | High-pressure water blasts the ice | High: strips granules, forces water under shingles | Not safe on shingles |
| Rock salt (sodium chloride) | Melts a channel through the ice | Moderate: corrodes metal, kills plants, stains siding | Avoid |
| Calcium chloride socks or pucks | Slowly melts a drainage channel | Low to moderate: runoff can damage lawns and gardens | A stopgap on small dams |
| Heat cables | Electric cable keeps a melt path open | Low if installed correctly | Prevention for problem spots only |
| Roof rake from the ground | Pulls snow off the lower roof | Low with a rake that has rollers or a plastic blade | Good homeowner prevention after storms |
Steam is also the only option that works on the day you call. Calcium chloride and heat cables need time and conditions on their side, and neither does anything for water already running down your wall.
Roof snow load becomes a concern when snow is deep and dense, when rain soaks into an existing snowpack, or when the structure starts showing distress such as sagging, cracking or interior doors that suddenly stick. Most sloped Ottawa roofs handle a normal winter, but some roof types deserve a closer look after every major storm.
Ontario's alert on snow loading and roof failures notes that snow can weigh about 7 lb per cubic foot when fresh and dry, and about 30 lb per cubic foot when old and compacted. That means 2 feet of fresh powder adds roughly 14 lb per square foot, while the same depth of settled snow can add about 60 lb. Rain on top makes it heavier still.
The roofs we watch most closely:
The Ontario alert recommends an engineer's assessment where a roof shows distress, avoiding uneven loading during removal, and keeping people away from the drop zone. We work the same way: balanced passes, fall protection as Ontario law requires, and a stop to call for an engineer if we see cracking or deflection.
Ice dams stop when the roof deck stays cold, and that comes from keeping house heat out of the attic. Steaming solves this winter's problem, while the four fixes below solve next winter's.
We usually recommend them in this order, because air sealing and insulation remove the heat source, and the other measures manage what is left.
Most ice dams start with warm, moist air leaking into the attic through gaps around pot lights, top plates, hatches and stacks. Sealing those gaps, then topping up insulation toward the roughly R-60 level that new Ontario homes are built to, keeps heat where it belongs.
Our attic insulation and ventilation upgrades start with exactly this.
Cold outside air should enter at the soffits and leave at the ridge, carrying away any heat that does reach the attic. Blocked soffit vents and too few exhaust vents are common on Ottawa homes built before the 1990s.
Clean, open soffit panels matter too. We cover soffit and fascia alongside seamless eavestrough installation.
Ontario's Building Code (O. Reg. 163/24) requires eave protection on most shingle roofs in a climate as cold as Ottawa's. The membrane must run at least 900 mm up the slope and reach at least 300 mm past the inside face of the exterior wall.
Self-adhered products such as Grace Ice & Water Shield or IKO StormShield seal around nails and stop backed-up water from reaching the deck. We fit them during a roof replacement, with extra courses on deep overhangs and low slopes.
Self-regulating heat cables can keep a drainage path open over a chronic valley or a north-facing eave. They treat the symptom rather than the cause, so we suggest them only where the roof design itself makes dams unavoidable.
Ice dam steaming in Ottawa is billed hourly, and most homes take 2 to 4 hours to clear. Your assessment is free, and we give you the hourly rate and a time estimate before the steamer starts.
What moves the time, and the price:
Any repairs found during the visit are quoted separately. Minor roof repairs in Ottawa typically run $350 to $1,200, and an attic insulation top-up runs $1.50 to $3.50 per square foot. Repairs and installations carry our 1-year written labour warranty, and materials carry their manufacturer's warranty.
These are the questions we hear most on winter calls, often while water is still dripping at a window. If yours is not here, call and a roofer will answer it directly.
Yes. Low-pressure steam melts through ice without impact or high-pressure water, so shingles, flashing and eavestroughs are left intact.
The damage people associate with ice dam removal comes from chipping and pressure washing. Frozen shingles are brittle, and one hatchet strike can crack several.
Raking snow from the lower roof with a long-handled roof rake, while standing on the ground, is reasonable after big storms. Climbing onto an icy roof is not, and most winter roof falls happen on low, familiar roofs.
Leave a thin layer of snow on the shingles, keep away from power lines, and never chip at ice from a ladder.
Many Ottawa policies cover sudden interior water damage from an ice dam, though coverage for the roof itself and for repeat events varies. Photos taken before removal help your claim.
Our page on roof insurance claims explains how we document damage for adjusters.
No. Heat cables keep a small melt path open but do nothing about the attic heat that creates the dam.
They are useful on a problem valley or a low-slope porch roof. On most homes, air sealing and insulation solve the problem for less money over the life of the roof.
We dispatch 24/7 from our Centretown base, and inner neighbourhoods are a short drive away. Outer suburbs such as Stittsville and Barrhaven are roughly 25 to 40 minutes out in normal conditions, longer when the Queensway is snow-covered.
During heavy thaws, active leaks are prioritized first, so tell us if water is coming inside.
Our crews dispatch from Centretown to every Ottawa community and anywhere within about 30 minutes of the city.
Free roofing estimate
Call (343) 504-9753 day or night and we will ask about the leak, the roof height and access, then give you an arrival window. Steaming slots fill quickly after a thaw, so call as soon as you see water inside.