In short
- One Ottawa firm's guide prices a roof leak repair at $500–$1,500, higher if the deck is wet.
- The same guide puts Ottawa roofer labour at $60–$120 an hour.
- The spot on the ceiling often sits well away from the hole in the roof.
- A written price that changes mid-job may rise 10% at most unless both sides sign a change.
- Water coming in during a thaw can point to an ice dam, which starts with heat in the attic.
Typical prices in Ottawa
| Job | Typical range | Notes |
|---|---|---|
| Missing or damaged shingles, small patch | $300–$700 | One Ottawa firm’s guide |
| Roof leak repair, locate, seal, replace damaged decking | $500–$1,500 | Same guide |
| Flashing or vent repair | $400–$1,000 | Around chimneys, vents, skylights; same guide |
| Deck or underlayment repair | $1,000–$3,000 | Major work under the shingles; same guide |
| Roofer labour | $60–$120/h | Ottawa contractors, same guide |
Sources. JDM Roofing, Roof Repair Cost: What Homeowners Need to Know, an Ottawa firm’s published list dated 16.10.2025, seen 29.10.2026. Ice dams: CAA-Quebec, seen 29.10.2026. Contract rules: Ontario, guide for home renovation and roofing businesses, seen 29.10.2026. The company that calls you sets its own price after it has seen the roof.
Where the stain is and where the hole is
Water follows the deck, a rafter or the vapour barrier before it drops through the ceiling. The stain can sit two or three metres from the opening. A roofer who prices a leak from the stain alone is guessing, so the first part of the visit is tracing: attic first, roof second.
In the attic, a roofer looks for dark streaks on the underside of the deck, wet or compressed insulation, rusted nail tips and daylight at a pipe. On the roof, the suspects are the same short list every time.
Usual suspects on an Ottawa roof
- Flashing. Metal strips at chimneys, walls, skylights and valleys. When the seal at the top edge opens, water runs behind the shingles. See flashing and chimney.
- Pipe boots. The rubber collar around a plumbing vent cracks in sun and cold. Water runs down the pipe and shows up in a bathroom ceiling.
- Lifted or missing shingles. Wind takes tabs from edges and ridges, which the wind damage page covers.
- Nail pops and exposed fasteners. Frost lifts nails; a hole opens under the tab above.
- Ice dams. Water backs up under the shingles at the eaves during a thaw. The cause sits in the attic, and ice dams explains the mechanism.
What drives the price
An Ottawa firm’s published guide prices a leak repair at $500–$1,500 and a small shingle patch at $300–$700. It lists deck or underlayment repair at $1,000–$3,000. The spread follows five things: how much wood is wet, how steep and high the roof is, how many materials the repair needs, whether the shingles can be matched, and whether scaffolding or extra safety gear is required.
Pay attention to the line about the deck. The roofer cannot see rot until shingles come off. Ask for a price per sheet of decking so a surprise has a number attached before work starts.
Rules that protect you
A leak repair is often a small contract, and Ontario’s rules still cover it. Anything over $50 goes in writing, with taxes, payment terms and dates. The bill may exceed a written estimate by a tenth, no more, unless you sign a change. If the roofer signs you up at your kitchen table, you get 10 days to cancel. The guide advises a deposit of a tenth of the job or less. The rest of the paperwork sits on the roofing contracts page.
If the cause turns out to lie in the rafters or trusses, the repair becomes structural, and that needs a City building permit. The permit guide lists what the City exempts.
Repair or bigger job
A single leak at a single flashing is a repair. Leaks in several rooms, shingles that crumble when touched, or wet deck over a wide area push the conversation towards replacement. The repair or replace page sets out how to weigh it, and a general overview of repair pricing is on the repair cost page. Ask the roofer to price both when the roof is old.
Timing
One Ottawa firm lists leaks after spring melt among the common problems here, and winter leaks often come with ice at the eaves. After a hard winter, the roof check after winter page lists what to photograph. Say in the request how long the leak has run, since wet insulation left for weeks grows mould.
Who you are dealing with
Your notes on the stain and the weather go to one independent Ottawa roofer. Its crew traces the leak, quotes the fix and does it once you say yes.
Questions to ask the company
- Will you go into the attic, or only look at the roof from outside?
- Does your price cover finding the entry point, or only sealing the spot I point to?
- If the deck under the leak is wet or soft, what is the price per sheet before you start?
- Will you photograph the damaged area and the finished repair for me?
- What do you do if the stain comes back after the next rain?
Have this ready for the call
- Photos of the stain from the ceiling, with a coin or ruler beside it for size
- A short log: date, wind direction, rain or thaw, and how long the drip lasted
- The age of the shingles, if you know it, and any earlier repair at the same spot
- A clear path to the attic hatch and a note on what is stored under it
- A bucket under the drip and furniture moved out of the way
Questions people ask
Where do I look first to see how the water gets in?
Start inside. Note the room, the position of the stain relative to outside walls, and whether it grows in rain or only after snow melts. The roofer uses those clues, then checks the attic for dark wood, wet insulation and daylight, before going up on the roof.
Can a leak be fixed in the rain or in winter?
A crew can usually make a temporary seal in poor weather, and a lasting repair waits for dry, workable conditions. Shingles stay brittle in deep cold. Tell the company the date the leak started and how bad it is, and ask what it can do this week.
Is a small drip an emergency?
A drip that stops after the rain can wait a few days for a visit. Water running steadily, a bulging ceiling, or water near a light fixture is urgent. Switch off the breaker for that room and use the emergency page.
Will the ceiling need work too?
Wet drywall and insulation are separate from the roof work. The roofer fixes the entry point. Drywall, paint and mouldy insulation belong to another trade, and your home insurance may respond if the cause was sudden. Photograph everything before it dries.
How can I tell flashing from shingles as the cause?
A homeowner cannot tell reliably from the ground. Leaks that trace to walls, chimneys, skylights and vent pipes usually involve flashing or pipe collars, and leaks in the open field of the roof involve shingles or nail holes. The roofer confirms it up close.