8 signs your roof needs replacing — a GTA homeowner's checklist

July 20, 2026 · Well Roofing · 5 min read

On GTA roofs we look for granules in the gutter, shingles that have started to lift, and stains that show water has already got in. Those are the clues that separate a repair from a replacement.

First, the age question

In Ontario's climate, a typical asphalt shingle roof lasts roughly 15 to 20 years — some premium shingles longer, some builder-grade roofs less. Freeze-thaw cycles, heavy snow load, ice buildup, and strong summer UV all age shingles faster here than in milder climates. If your roof is past 15 years, the signs below matter more: at that age, chasing individual repairs often costs more over five years than replacing once and being done with it.

The 8 signs, from the ground up

1. Granules in your gutters and downspouts. That gritty coating protects shingles from UV. When you find it collecting in gutters or washing out of downspouts after rain, the shingles underneath are ageing fast. Bald or dark patches visible from the street mean the same thing.
2. Curling, cupping, or buckling shingles. Edges that turn up, centres that dish inward, or wavy rows across the roof plane. Curled shingles can't seal against wind-driven rain — and in a GTA winter they're where ice gets under the roof first.
3. Cracked or missing shingles. One or two blown-off shingles after a windstorm is a repair. Cracking spread across whole slopes means the material itself has dried out and become brittle. Replacing patches of a brittle roof is a losing game.
4. Ceiling stains or attic moisture. A brown ring on the ceiling means water is already getting past the roof system. Check the attic after a heavy rain: darkened sheathing, damp insulation, or daylight through the boards are all signs the leak has been active for a while.
5. Moss and algae holding moisture. Dark streaks are mostly cosmetic, but a mossy carpet keeps shingles damp for weeks at a time, which lifts edges and rots what's underneath. Common on shaded, north-facing slopes.
6. A sagging roofline. Look down the ridge from the street — it should be straight. A dip or sag suggests deck or structural trouble underneath, and that's beyond shingles: get it inspected promptly.
7. Flashing that's rusted, lifted, or improvised. Chimneys, valleys, vents, and skylights are where most leaks start. If the metalwork is rusting or was patched with roofing tar, water is finding its way in, sometimes far from where the stain shows up inside.
8. Ice dams every winter. Recurring thick ice at the eaves usually points to poor attic insulation and ventilation, not just bad luck. It shortens shingle life and forces meltwater under the roof. A replacement is the right time to fix the ventilation and insulation so the new roof doesn't inherit the old problem.

Repair or replace?

Rules of thumb from our GTA projects — an on-site inspection is what turns this into a real answer for your roof.

Don't forget the skylights

If your roof has skylights, replace or reflash them when you replace the roof. The roof around them is already open, so most of the flashing labour is already being done. A 15-year-old skylight sealed into a brand-new roof is the first thing that will leak. As VELUX® certified installers, we quote roof-plus-skylight work as one job so you're not paying for the same labour twice.

What to do next

If you have spotted two or more of these signs, it is still a planned project. The Customize Your Roof tool measures the roof on satellite imagery and gives an estimate range. For the roof itself, book a free on-site assessment. We will check the shingles, flashing, attic, and skylights, and give you a written, itemized quote within 48 hours. If a repair is all you need, that is what we will tell you.