Roof Repair in Thornhill
Brittle flat sections over garages, shingles past a first cycle, flashing at additions that were built quickly. We trace Thornhill leaks and repair the cause.
Roof Repair in Thornhill, what we fix.
Roof leak repairs
Emergency tarping
Storm damage repair
Shingle repairs & replacement
Flat roof repairs (EPDM, TPO, Mod-Bit)
Flashing repairs
Why Blue Knight finds it when others don't.
We trace first
Written reports
25+ years experience
No upsells
60-min emergency
Permanent repairs
We trace first
Every job starts with a full trace from interior stain back to the roof. We find the source before touching anything.
Written reports
You receive a written diagnostic report with photos, suitable for insurance, lenders, and property management files.
25+ years experience
Two and a half decades on GTA roofs means we've seen every failure mode across every building type in the region.
No upsells
We don't sell replacements when repairs are appropriate. Our invoice reflects what the building actually needs.
60-min emergency
Active leaks get same-day priority dispatch, around the clock, including nights and weekends.
Permanent repairs
We use manufacturer-matched materials and test the repair before we leave. No waiting for the next rain.
“We trace the leak from the stain back to the source. That's how leaks get fixed permanently.”
“We trace the leak from the stain back to the source. That's how leaks get fixed permanently.”
Rated 5 out of 5Blue Knight was, by far, the best. Responsive, ethical, totally professional — and their crew went above and beyond at no extra charge.
Rated 5 out of 5They installed a full new roof in one day. The crew worked around the house without us hardly knowing they were there.
Rated 5 out of 5I emailed at 4 a.m. and spoke with someone that same day. Estimate and completed work all within one day. Pricing was fair, work was excellent.
Blue Knight was, by far, the best. Responsive, ethical, totally professional — and their crew went above and beyond at no extra charge.
They installed a full new roof in one day. The crew worked around the house without us hardly knowing they were there.
I emailed at 4 a.m. and spoke with someone that same day. Estimate and completed work all within one day. Pricing was fair, work was excellent.
Luciano did not try to sell me a new roof. Appreciated the honesty — he showed up when he said he would.
We had a leak diagnosed by two other contractors who could not find the source. Blue Knight found it on the first visit and fixed it the same week.
Flat roof replacement on a commercial unit. Clean, fast, no surprises on the invoice. The crew left the site cleaner than they found it.
Called after a storm damaged our roof. Someone was on site within hours, tarped everything, and had us fully repaired before the next rain.
Had a slow basement leak for years. Every other company just caulked it. Blue Knight found the actual source and did a proper waterproofing job. No issues since.
Our neighbours recommended them for a valley repair. Small job, but they treated it like it mattered — showed up on time, matched the shingles perfectly, and charged exactly what they quoted.
Featured Projects.
Rooftops across the GTA.
From downtown Toronto to the 905 and beyond, one crew, one warranty, twenty-five years of GTA rooflines.
Service availability may vary. Call (647) 383-8664 to confirm coverage for your area.
Rooftops across the GTA.
From downtown Toronto to the 905 and beyond, one crew, one warranty, twenty-five years of GTA rooflines.
Service availability may vary. Call (647) 383-8664 to confirm coverage for your area.
Roof Repair questions for Thornhill.
Localized repairs run $350 to $2,000 depending on the failure and the access. A flat section membrane repair over a garage typically sits in the lower half of that range unless ponding has undermined a larger area. Full replacement on a typical Thornhill home runs $9,000 to $22,000.
Usually because there is not enough fall for it to drain, so water sits on the membrane rather than running off it. Any patch on a ponding roof is temporary. Where that is the situation the honest answer is that the slope has to be built before a membrane will hold, and we say that rather than selling another repair we expect to fail.
Sometimes, and it depends what you are buying with the money. A repair that carries a sound roof another five or eight years is good value. A repair on a roof with two years left is deferring the replacement at extra cost. We open a section and tell you which of those you are looking at rather than guessing from the age.
Always, itemized and after the diagnosis rather than before it. The estimate names what failed and what the repair involves, so you can compare it against another proposal on substance rather than on the total at the bottom.
Yes, on every job as standard. The report includes dated photographs of the condition before and after, the failure described by mechanism, and the materials used. That record settles the sudden versus gradual question an adjuster will ask, and it answers a buyer's inspector at resale.
Flat section membranes at seams and wall junctions, followed by ordinary end of life failures on the sloped shingles, followed by flashing at additions that were built after the original house and tied in quickly. Knowing that order is why our diagnosis is fast.
Roof repair in Thornhill divides between the sloped roof and the flat section, and they are different trades. On the sloped roof the housing is at or past a first full cycle, so the failures are the ordinary end of life ones: sealant strips gone, nail line working loose, pipe boots cracked, and wind loss on whichever slope takes the weather.
The flat sections are where the surprises live. Early modified bitumen and EPDM over garages and rear additions has gone brittle after three decades, and it fails at seams and at the junction where the flat meets the wall of the house. A roofer who only does slope will patch that with sealant and be back next spring.
The Flat Section Nobody Quotes Properly
A great many Thornhill houses are not entirely sloped. The subdivisions of the 1980s and 90s frequently put a flat or near flat roof over a garage, a rear addition, or a porch, and thirty years on that is the part of the building most likely to be leaking.
It matters because it needs a different trade and a different quote. Membrane work is not shingle work, and a roofing quote that treats the flat section as an afterthought is a quote that will need revisiting. We price it separately and explain what we found, including the awkward answer when the problem is drainage rather than the membrane.
Repair or Replace on a Thirty Year Old Roof
Most Thornhill owners at this point have been told by somebody that the roof needs replacing. Often that is right. Frequently it is a conclusion reached from a driveway on a roof that has eight good years left in the field and one failed detail.
We open a section before recommending replacement, photograph the deck, and put the finding in writing. If the roof is finished, the photographs show why. If it is not, you have evidence to hold up the next time somebody knocks on the door after a storm.
We also cover nearby cities.
Ready to schedule your estimate?
We come to you, assess the roof, and give you a written quote. You are not obliged to proceed. Most estimates completed same week.