Goderich · Stratford · Sarnia · St Thomas · Chatham · Leamington
Chatham gets 79 cm of snow. Stratford gets 218.
Both are in southwestern Ontario and they do not need the same roof. Everything above the deck — how far the membrane runs, how the attic vents, how many nails go in a shingle — is an answer to a number that changes across this corridor by a factor of three.
- Written findings whether or not you hire us
- Storm damage documented before it is tarped, for the claim
- Ice dams removed with steam, never with a hammer
- Shingles The only layer anyone sees, and the last one to fail. Uplift rating is earned by the nailing pattern, not by the box. 5 mm
- Underlayment A secondary barrier over the field. Cheap, and the reason a lifted shingle is not immediately a leak. 1 mm
- Ice & water membrane Self-adhering, at the eaves and in the valleys. How far up it runs is the single biggest snowbelt decision. 2 mm
- Deck Plywood or planks. Nobody can assess it without a tear-off, which is why going over old shingles hides the one thing worth seeing. 11 mm
- Ventilated attic Soffit to ridge. A warm attic melts snow from below, and that is what makes an ice dam — not the weather. —
What are you seeing?
Start with the symptom, not the roof
Almost nobody calls a roofer about a roof. They call about a stain, a noise, a pile of shingles on the lawn or a letter from an insurer. Find yours below.
- Brown stain spreading on a ceiling Leak trace Call now
- Shingles on the lawn after a storm Storm damage Call now
- Ice building along the eave in winter Ice dams Call now
- Water coming in during a thaw, not during rain Ice dams Call now
- Damp patch around a bathroom vent pipe Leak trace Call now
- Granules collecting in the eavestrough Replacement Don't wait
- Shingles curling or cupping at the edges Replacement Don't wait
- Roof is over twenty years old Inspection Don't wait
- Insurer asked how old the roof is Inspection Don't wait
- Buyer or lender wants a roof report Inspection Don't wait
- Eavestrough overflowing in ordinary rain Eavestrough Don't wait
- Trough pulling away from the fascia Eavestrough Don't wait
Not sure? Send a photograph from the ground of the elevation you think is affected, and say which town the property is in. Between the roof age and the local snowfall, that is usually enough to tell you what you are looking at. (519) 555-0143
What we do
Six jobs, and half of them arrive on somebody else’s deadline
An insurer, a storm or a sale decides most of this work. Prices are the measured 2026 Ontario ranges rather than numbers we picked.
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Roof replacement
The one job where the same house needs a different roof at each end of this corridor. Snowfall here runs from 79 cm a year to over 200.
$8,250–$19,000 Full tear-off, deck inspection, ice-and-water membrane, new shingles -
Storm damage
This is the most tornado-prone corridor in Canada. Wind claims here are ordinary events, and the insurance clock starts before the tarp comes off.
$450–$4,500 Emergency tarp, documented assessment, repair; full replacement quoted separately -
Ice dams
An ice dam is a heat problem wearing a roof problem. In the Huron snowbelt it is the single most common cause of winter leaks.
$650–$5,500 Steam removal, cause diagnosis, ventilation and insulation remediation -
Repairs & leaks
Most leaks are not where the water shows up, and most are flashing rather than shingle. Tracing costs less than replacing what was not wrong.
$350–$1,800 Leak trace, flashing or shingle repair, written findings -
Eavestrough
The roof sheds the water and the eavestrough decides where it goes. Undersized trough on a snowbelt roof is a foundation problem waiting.
$1,200–$4,800 Removal, fascia repair where needed, new trough, downspouts and extensions -
Inspections
Booked because an insurer asked, a sale is closing, or a storm went through. Usually on a deadline, usually on a roof nobody has been on in years.
$275–$650 Inspection, photographs, written report and remaining-life estimate
Why the number matters
One corridor, two completely different roofing problems
North and east of London the roof has to survive snow that sits for weeks, which is an argument about membrane, ventilation and the eave. Along the Erie shore it has to survive wind in the most tornado-active corner of Canada, which is an argument about uplift rating, nailing pattern and the starter course. A quote written for one and used in the other is under-specified in a way that takes years to show.
Southwestern Ontario conditions
Six facts that decide what your roof has to be
Snowfall figures are Environment Canada 1981–2010 normals at the nearest reporting station to each town. None of this appears on a roofing page written for all of Ontario and swapped across forty markets.
| Condition | Where it bites | What it does | When |
|---|---|---|---|
| The snowbelt | Goderich, Listowel, Stratford, Strathroy | Snow sits for weeks rather than days, which is what an ice dam needs; 170 to 218 cm a year and more inland | Dec–Mar |
| The Erie shore | Leamington, Chatham, Simcoe | Least snow in the province at 79 to 86 cm, and almost no upwind shelter from storm wind | Year round |
| Tornado corridor | Chatham-Kent, Essex, Elgin, Norfolk | The most tornado-active region in Canada; far more common is the straight-line wind from the same storms | May–Sep |
| High annual rainfall | Tillsonburg 900 mm, St Thomas 874 mm | Volume at the eave rather than weight on the roof; trough sizing and valley detail decide the outcome | Apr–Nov |
| Freeze-thaw cycling | The whole corridor, 94 to 107 days | Works every lap and seam on a roof, and ages a shingle mat faster than cold alone does | Nov–Apr |
| Flat farmland | Lambton, Chatham-Kent, Essex, Oxford | No upwind obstruction, so a roof sees close to the full wind speed the storm is carrying | Year round |
Where we work
Twelve towns, and the snow load triples across them
Chatham averages 79 cm a year, Leamington 86, Sarnia 112, Woodstock 120, Tillsonburg 145, Strathroy 170, Listowel 192, Stratford 218 — and the country inland of Goderich more again. Every figure is from Environment Canada normals at the nearest reporting station.
What customers say
No reviews yet, and we are not going to invent any
This site is new. There is nothing here yet.
Reviews will appear here once there are real ones, with the town beside each so you can weigh whether it came from somewhere like yours. Until then, judge the site on whether it tells you something a company two hours away could not — how much snow your town actually gets, which of the two failure modes applies to you, and what that changes above the deck.
FAQ
What people ask before booking roofing work
What does a roof replacement cost in southwestern Ontario?
A full asphalt shingle replacement runs roughly $8,250 to $19,000 in Ontario in 2026, with most houses in the middle of that. What moves it is roof area, pitch, the number of junctions — valleys, dormers, chimneys — and whether the deck needs work once the old shingles are off. A simple post-war roof in Sarnia and a Victorian in Stratford with five dormers are not the same job at the same rate per square.
Why does the spec change between towns here?
Because the climate does. Environment Canada normals put Chatham at about 79 cm of snow a year and Stratford at 218, with the country inland of Goderich and Listowel higher again. The snowbelt end needs membrane coverage, ventilation and eave detail; the Erie shore end needs shingle uplift rating and nailing pattern. A quote written for one and used in the other is under-specified.
Do I need a permit to replace my roof?
It depends on the municipality and on the scope. Replacing shingles like for like frequently does not require one; changing the roof structure, the deck or the material generally does. Requirements genuinely vary across the twelve municipalities in this service area, so it is confirmed with yours before work starts rather than assumed either way.
Can I put new shingles over the old ones?
Sometimes, and it is usually a false economy. A second layer is cheaper on the day, adds weight in the part of this corridor that already carries the most snow, and hides the deck — which is the one part of a roof nobody can assess without a tear-off. Where the deck is known sound and the snow load is low it can be defensible. In the snowbelt it rarely is.
What should I do first after storm damage?
Photograph it from the ground before anything is touched, then get it tarped, then start the claim. In that order. A roof made watertight before it was documented is a roof whose damage now has to be argued from memory. Do not go up to look, and do not let anyone tarp it before there are photographs.
How do I stop ice dams coming back?
Find where the heat is getting into the attic. A dam forms because snow on the warm part of the roof melts and refreezes at the cold overhang, so the cause is almost always air leaking up — around light fixtures, a bathroom fan ducted into the attic, a hatch with no weatherstrip, insulation blocking the soffit vents. Removing the ice without fixing that buys one thaw.
Is it worth repairing a twenty-year-old roof?
It depends on the deck and on how many things are wrong. One failed plumbing stack boot on an otherwise sound roof is a cheap job worth doing at any age. A third leak in a year, with curling shingles and granules in the eavestrough, is a roof being repaired past the point where repair is the cheaper option — and the findings will say so.
Do you charge for a quote?
No. Quotes are free and the written findings come either way, including when the finding is that the roof is fine and the water is getting in somewhere else. If a repair solves it for a tenth of a replacement, that is what the report says.
Talk to a Woodstock roofing contractor
Tell us the town, roughly when the roof was last done, and what you are seeing — a stain on a ceiling, granules in the eavestrough, shingles on the lawn after a storm. Those three things usually decide whether this is a repair, a claim, or a roof that has reached the end, and they are enough to say so without anybody driving out.