Ice dam removal in Ottawa: steam at the eaves, then the cause in the attic

How an ice dam forms on an Ottawa house

NRCan describes the sequence. Deep snow acts as insulation. An attic above freezing warms the roof deck and melts the snow touching it. The water runs down to the overhang, where the air is below freezing, and freezes. Each melt adds to the ridge, and water behind it backs up under the shingles.

CAA-Quebec, drawing on CMHC, ties ice along the roof edge to poor attic and soffit ventilation. NRCan names the usual hot spots: the knee-wall line of a 1½-storey house, and the roof above a roof-ducted exhaust fan, a plumbing vent, a skylight or a leaky attic hatch.

Steam, chipping or salt: how the methods compare

A US cost guide lays out the methods side by side, in US dollars:

• Steam: US$800–$2,400, about 2–4 hours, US$400–$600 an hour. The guide says steam melts ice without harming shingles.
• Chipping with chisels or hammers: US$800–$1,800, 4–6 hours, risking roof damage.
• Pressure washer: US$400–$2,000, which can harm some roofing materials.
• Salt or melt tablets: US$200–$300, for minor ice only.

Canadian sources add to this. NRCan says an axe or ice pick damages the roof surface; CAA-Quebec warns against sodium chloride on roofing and says the goal is to let water drain. Ask whether the price covers opening channels or clearing the whole eave.

What moves the price

With no published Canadian price, the company sets the figure from your photos or a visit. Five things move it:

• Thickness and length of the ice.
• Height and access. Two-storey eaves, steep pitches and tight side yards add time.
• Snow above the dam. The US guide notes crews may need to clear it first. HomeStars puts residential roof snow removal at $200–$1,000+ across Canada.
• Price basis. HomeStars lists Ottawa one-time snow work at $60–$120 an hour. A crew may bill by the hour or per job.
• Timing and distance. The Canada-wide guide lists emergency call-outs as a higher-priced service and travel fees for properties outside a provider’s standard area.

Other winter prices: snow removal cost guide.

What the quote should list

A useful ice quote names the method and the stretches of eave included. Snow above the ice, cleanup of fallen chunks and any after-hours charge go on separate lines.

Ontario’s consumer guidance names snow removal services among transactions over $50 that should have a written contract. If a written estimate is part of that contract, the final price can go at most 10% above it unless you sign a change. A contract signed at your home carries a 10-day cooling-off period.

Under the eaves: icicles, the gas meter and the steps

CAA-Quebec lists ice breaking off onto people below and, on metal roofs, large sheets sliding off at once. Section 5 of the City’s Property Maintenance By-law requires every owner or occupant to keep roofs and the land around them free of snow or ice accumulations that might create an accident hazard.

Enbridge asks owners to remove large icicles hanging above the gas meter and vents and to leave ice on the meter itself alone. If ice buildup cannot be removed safely, Enbridge asks you to call 1-866-763-5427. For ice on the steps below, see walkway and step clearing and salting.

After the ice comes off: the leak and the cause

Removal ends the backup for now, and the cause stays in the attic. NRCan’s prevention advice is to seal attic air leaks, insulate thoroughly and keep vents clear.

If water reached the ceiling, a roofer may need to check the sheathing and shingles. HomeStars’ Ottawa guide reports roof repairs from a lowest reported $300 to a highest reported $10,000, averaging $1,800.

Who you are dealing with

Ottawa Snow Desk takes your request and passes it to one independent local company that removes roof ice. That company calls you back, looks at the roof or your photos, prices the work and does it.