Roof Replacement & Installation in Ontario
Roof replacement is a full tear-off and reinstall: stripping old shingles, membrane, or metal panels down to the deck, checking and repairing sheathing, adding underlayment and ice-and-water shield along eaves and valleys, then installing new roofing material with proper flashing around chimneys, vents, and skylights. It's a different job from a repair or a re-roof over existing layers, and it's the point where a homeowner is most exposed to poor workmanship, since bad flashing or a rushed deck inspection won't show up as a leak until a year or two later. In Mississauga, this category lists 104 businesses that handle tear-offs and new installations on residential and light commercial roofs, working with asphalt shingles, metal, flat/membrane systems, and tile.
Before hiring, ask for a written scope that names the underlayment brand, the ice-and-water shield coverage, flashing details, and ventilation plan, not just "shingles installed." Confirm the crew is insured, pulls a permit where the municipality requires one, and offers a workmanship warranty separate from the manufacturer's material warranty. Get at least two or three quotes on the same scope so you're comparing like for like.
Our scoring weighs verified customer feedback, how consistently a company documents its work, and signals of licensing and insurance, so you can shortlist contractors faster instead of reading through every review yourself. See the full ranked list at Mississauga's best roofing contractors, and check our methodology for how we build these rankings.
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All roof replacement & installation, ranked by score and relevance
We found 818 businesses offering roof replacement & installation; 817 met the criteria for the scored directory. The order weighs each business's overall score by how much of its reviewed work is roof replacement & installation, so a lower-scored specialist can rank above a higher-scored generalist. Filter and sort below, or open the full map view.
Enquiries you submit through our forms may be shared with partner providers who can carry out the work, and we may receive a referral fee. Our rankings and scores are based only on our published methodology and are not influenced by referral fees.
Common questions about roof replacement & installation
- How much does a roof replacement cost in Mississauga?
- Most asphalt shingle replacements on a typical detached home run from around $8,000 to $16,000 depending on roof size, pitch, layers being removed, and material grade. Metal roofing, tile, or flat membrane systems cost more, and complex rooflines with multiple valleys or dormers push the price up further. Get itemized quotes so you can see how much is labor, tear-off disposal, and materials.
- How often does a roof need to be replaced?
- Asphalt shingle roofs in this climate typically last 20 to 25 years, though quality of the original install, attic ventilation, and hail or ice damage can shorten that. Metal roofs generally last 40 to 60 years, and flat membrane roofs often need attention or replacement every 15 to 20 years.
- What should I expect during a roof replacement?
- Expect the crew to strip old material, inspect and replace any rotten decking, install underlayment and ice-and-water shield, then lay new shingles or panels with new flashing. A full tear-off on an average home usually takes one to three days, with debris removal and a magnetic nail sweep at the end.
- How do I judge the quality of a roofing contractor's work?
- Look for straight, evenly spaced shingle courses, clean flashing lines around chimneys and vents with no visible gaps, and a ridge vent or other ventilation that matches the roof's needs. Ask to see photos of the deck before it was covered, since that's the part you can't inspect once the job is finished.
Guides to choosing roof replacement & installation
- What to expect during a roof replacement in Ontario, step by step
A walkthrough of a typical Ontario roof replacement, from the first inspection to cleanup, so you know what happens and when.