Flashing failures cause more roof leaks in Winnipeg than any other single issue, more than worn asphalt shingles, more than hail damage, and more than roof age. Flashing is the thin metal or rubber boot that seals every intersection where your roof meets something vertical: a chimney, a sidewall, a skylight, or a vent pipe. When that seal breaks, and in Winnipeg's freeze-thaw climate it eventually will, water finds the gap and follows it straight into your attic, your insulation, and your ceiling. The good news: flashing repair is often one of the cheapest roof fixes you can make, and it's the first thing we check on every leak call.
What Flashing Actually Does (and Why It Fails)
Your asphalt shingles are designed to shed water downhill. They overlap each other like fish scales, and as long as the slope is adequate, water runs off the surface and never has a chance to work its way up and under. But a roof is not a single flat plane. It has penetrations, places where something pokes through the shingle surface, and intersections where two different surfaces meet. Those are the weak points.
Flashing is the material that bridges those gaps. On a typical Winnipeg home, you'll find:
- Step flashing along sidewalls where a roof meets a vertical wall (like a dormer or a two-storey wall)
- Chimney flashing, a base flashing plus counter flashing that locks into the mortar joints
- Pipe boot flashing (also called vent boots) around plumbing vents and exhaust stacks
- Skylight flashing, a full perimeter system that channels water around the opening
- Valley flashing where two roof slopes meet and form a valley
Flashing fails for a few reasons. The most common is age: the sealant that bonds the flashing to the shingle or the wall dries out, cracks, and pulls away. Another is corrosion, galvanized steel flashing will eventually rust through, especially in areas with standing water or where ice dams hold moisture against the metal. And a third is physical damage: hail can dent or dislodge flashing, and wind can lift the edges.
But in Winnipeg, the biggest killer of flashing is the freeze-thaw cycle. And that deserves its own section.
Why Winnipeg Is Especially Hard on Flashing
Winnipeg sits in one of the most extreme climates in Canada. Our winters see stretches of −30°C, and our summers push past 30°C. That's a temperature swing of more than 60 degrees, and it happens every single year. No other building material feels that cycle more than flashing.
what happens. Flashing is metal. Metal expands when it's hot and contracts when it's cold. Over a single year, a piece of flashing on a Winnipeg roof goes through hundreds of these expansion-contraction cycles. Each cycle stresses the sealant, the fasteners, and the joints. After a few years, sometimes as few as five or six on a south-facing roof, the sealant cracks and the flashing starts to lift.
Then comes the freeze-thaw cycle itself. Winnipeg gets warm spells in January and February. Snow on your roof melts, runs down to the eaves, and refreezes when the temperature drops. That's an ice dam. And an ice dam does two things to flashing: it holds a pool of water against the flashing for days at a time, and when it expands and contracts, it physically pries at the flashing edges. A pipe boot that was fine in November can be leaking by March because an ice dam worked it loose.
And then there's hail. Winnipeg's hail season runs roughly May through September, and we get storms that produce hail the size of golf balls, sometimes bigger. Hail impacts can dent metal flashing, crack the sealant, and knock pipe boots loose. Even if the shingles survive, the flashing often doesn't. That's why a hail damage inspection should always include a close look at every penetration on the roof.
The Six Most Common Flashing Failure Points on Winnipeg Roofs
In our leak repair work across Winnipeg and the surrounding communities, from River Heights to Transcona, from Charleswood to St. Boniface, we see the same flashing failures over and over. Here are the six most common.
1. Pipe Boots (Plumbing Vents)
The rubber boot around a plumbing vent pipe is the single most common flashing failure we repair. The rubber dries out and cracks, usually within 8 to 12 years. When it cracks, water runs down the pipe, under the boot, and into the attic. The fix is straightforward: replace the boot and the flashing collar. It's one of the cheapest roof repairs you can make.
2. Chimney Counter Flashing
Chimney flashing has two layers. The base flashing sits under the shingles, and the counter flashing is embedded in the mortar joints of the chimney itself. When the mortar cracks, and it will, after Winnipeg winters, the counter flashing pulls loose. Water gets behind it and runs down the chimney, often appearing as a leak in the wall beside the fireplace, not on the ceiling. This one is frequently misdiagnosed as a chimney problem when it's actually a flashing problem.
3. Sidewall Step Flashing
Where a roof meets a vertical wall, step flashing is installed in overlapping layers, one per shingle course. The problem: if the flashing was installed without proper overlap, or if the wall was stuccoed or re-sided over the flashing, water can work its way behind it. This is common on older Winnipeg homes that have had siding replaced without re-flashing the roof-wall intersection.
4. Skylight Flashing
Skylights are basically a box with a hole around it, the flashing is what keeps the water out. On Winnipeg roofs, skylight flashing fails when the sealant between the skylight frame and the flashing dries out, or when ice dams build up around the skylight and push water up under the edge. A skylight leak is almost always a flashing issue, not a skylight issue.
5. Valley Flashing
Valleys collect a lot of water, they're a gutter built into the roof. If the valley flashing is narrow, or if the shingles are cut too close to the center line, water can work its way under the shingles and into the roof deck. In Winnipeg, valley flashing also takes a beating from ice dams, which form in valleys and hold water against the metal for weeks at a time.
6. Roof Edge Flashing (Drip Edge)
The drip edge is the metal strip along the eaves and rake edges. It's supposed to direct water away from the fascia and into the gutters. When it's missing or improperly installed, water runs back under the first course of shingles, and that's a common cause of rot in the roof deck at the eaves. We see this on a lot of older Winnipeg homes where the drip edge was never installed in the first place.
How to Tell If Your Flashing Is Failing (Without Climbing Up There)
You don't need to get on your roof to know you have a flashing problem. Here are the signs to look for:
- Water stains on the ceiling, especially under a chimney, skylight, or vent pipe
- A musty smell in the attic, that's damp insulation, often caused by a slow flashing leak
- Wet spots on attic insulation, check after a heavy rain or during a thaw
- Cracked or crumbling sealant, visible from the ground on pipe boots and chimney flashing
- Loose or lifted flashing edges, visible from the ground if you know what to look for
- Ice dams at the eaves, a flashing failure is often the secondary damage caused by an ice dam
If you see any of these, don't wait. A small flashing leak becomes a big roof leak quickly, and the longer it runs, the more it damages the roof deck, the insulation, and the ceiling drywall. In Winnipeg, a flashing leak in the winter can also lead to mould growth in the attic, which is a much more expensive problem to fix.
What Flashing Repair Looks Like: Process and Pricing
how we handle a flashing failure at Roof Repair Winnipeg, start to finish.
Inspection
We start with a full roof inspection, not just a look at the obvious spot. We check every penetration, every flashing point, and the condition of the asphalt shingles. We also look for signs of ice dam damage and hail impact. The inspection is free for leak calls, and you get a written report with photos
Diagnosis
We tell you exactly what's failing and why. If it's a cracked pipe boot, we show you the crack. If it's chimney counter flashing that's pulled loose, we show you the gap. You'll know what the problem is before we quote you a price
Repair
The repair itself depends on the failure
- Pipe boot replacement: Remove the old boot, replace it with a new rubber boot and metal flashing collar, and seal it properly. Usually 1 to 2 hours.
- Chimney flashing repair: Re-seal the counter flashing, replace any corroded base flashing, and re-embed the counter flashing in fresh mortar. Usually half a day.
- Step flashing replacement: Remove the lower courses of shingles, replace the step flashing, and re-install the shingles. Usually half a day to a full day.
- Skylight flashing repair: Remove the sealant, re-flash the perimeter, and re-seal. Usually half a day.
- Valley flashing repair: Remove the shingles in the valley, replace the flashing, and re-install the shingles. Usually a full day.
Step 4: Verification. We run water over the repaired area if possible, or we do a visual inspection to confirm the repair is watertight. We also walk you through what we did and why.
Pricing. Flashing and vent boot repair typically runs between $150 and $800, depending on the scope of the repair. A single pipe boot replacement is usually at the low end; a chimney re-flash or a valley flashing replacement is at the high end. A full roof leak repair, if the flashing failure has already caused damage to the deck or the interior, runs between $200 and $1,200. And if the flashing failure is part of a larger hail or storm damage claim, the repair may be covered by insurance. these are typical ranges, not firm quotes, the final cost varies a lot depending on job size, scope, and site conditions. We'll give you an exact number after the inspection.
Why Winnipeg Homeowners Choose Roof Repair Winnipeg
Flashing repair is the kind of work that most roofing companies don't want to do. It's small, it's fiddly, and it doesn't sell a new roof. That's exactly why we built our business around it.
We quote the fix, not the replacement. If your flashing is failing but your asphalt shingles have 10 years of life left, we'll tell you that. We repair the flashing and you keep your roof. We only recommend a full roof replacement when it makes financial sense, and we'll show you the math.
The person who quotes is the person who repairs. We don't have a sales team. We don't have account managers. if you call Roof Repair Winnipeg, you talk to the same person who will be on your roof. That means the quote is accurate, the repair is done right, and there's no disconnect between what was promised and what was done.
We know Winnipeg roofs. Our crew has worked through every season this city has to offer, the January deep freezes, the March thaws, the May hail storms, and the August heat. We know how freeze-thaw affects flashing. We know how ice dams form on Winnipeg roofs. We know what hail does to different shingle brands. That local knowledge means we catch problems that a generalist roofer would miss.
We're fast in a storm. When a hail storm rolls through Winnipeg, we respond within 24 to 48 hours. Every inspection comes with an adjuster-ready damage report, so if the flashing failure is part of a larger storm damage claim, you have the documentation you need for insurance. We don't bill the insurance and disappear, we do the repair and stand behind it.
Small crew, fair prices. We run deliberately lean. No call centre, no showroom, no twelve-truck fleet. That low overhead shows up in our pricing. Flashing repair starts at $150, and most leak repairs come in well under $1,000. You're not paying for our marketing budget, you're paying for the repair.
Get Your Flashing Checked Before the Next Storm
If you've noticed a water stain, a musty attic smell, or ice dams at your eaves, don't wait for the next rain or the next thaw to find out how bad it is. Call Roof Repair Winnipeg and book a free inspection. We'll check every flashing point on your roof, identify the source of the leak, and give you a straight answer on the best fix, whether that's a $200 pipe boot replacement or a more involved repair. You'll get a written report, honest pricing, and a repair done by the same person who quoted it. Small crew. Honest repairs. Fair prices. That's how we've built our reputation across Winnipeg and the surrounding communities.