Karam RoofingFlat and low-slope roofs are everywhere in Toronto — on additions, garages, row houses and modern homes — and they have their own set of problems. The good news: most flat-roof leaks are very fixable once you find the real source. Here's what goes wrong, what repairs cost, and your options.
Common flat-roof problems
- Ponding water. Flat roofs should drain; standing water after rain means a drainage or slope issue that ages the roof fast.
- Cracks & blisters. Sun and freeze-thaw cause the membrane to crack, bubble or split.
- Failed seams. Where two sheets of membrane meet is the most common leak point.
- Flashing failures. Around drains, walls, vents and skylights — the usual leak culprits.
- Punctures. Foot traffic, debris or dropped tools can puncture the membrane.
Typical flat-roof repair costs
| Repair | Typical GTA range |
|---|---|
| Small patch / seam / puncture repair | $300 – $900 |
| Flashing or drain repair | $500 – $1,500 |
| Larger section / ponding fix | $1,500 – $4,000+ |
| Emergency leak sealing | $250 – $800 |
Estimates for planning only — send a photo on WhatsApp for a tighter number, or book a free on-site inspection.
Flat-roof systems (and when to replace)
EPDM (rubber) is durable and cost-effective; TPO is a light-coloured, energy-efficient membrane; modified bitumen is a tough torch-down system common on Toronto homes. If your flat roof is old, ponding badly and leaking in several spots, re-membraning the whole roof is often better value than chasing leak after leak. We'll tell you honestly which stage yours is at.
Got a leak? Get a fast, honest answer.
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