Commercial Flat Roof Replacement in Toronto & the GTA

A commercial roof replacement is one of the biggest capital items a building will see, which is why it gets deferred — until the repair invoices and the tenant complaints start arriving faster than the budget cycle. Whether it is a plaza roof over six storefronts or a warehouse roof the size of a football field, the decision usually lands on a property manager or owner who needs real numbers and a defensible plan, not a sales pitch.

The first technical question is tear-off versus recover. The OBC permits a second roof over one existing system if the deck can take it and the insulation below is dry — a moisture scan and core cuts tell you which situation you have. Wet insulation must come out; covering it just seals the problem in. From there it is membrane choice, tapered insulation to fix chronic ponding, and careful phasing so sections are never left open overnight.

We quote replacements with the options priced separately: recover where it is legitimate, full tear-off where it is necessary, and drainage corrections listed on their own line so the board or ownership group can see what each decision buys. If part of the roof has years left and only one section is failing, we will quote the section. Replacing roof that does not need replacing helps nobody but the contractor.

• Moisture scan and core sampling to map wet insulation before pricing
• Full tear-off to the deck, or recover over the existing system where code and conditions allow
• Deck inspection and repair — steel, wood or concrete — once the old roof is off
• New insulation to current OBC energy requirements, tapered to drains where ponding is chronic
• New membrane installation: TPO, EPDM or modified bitumen to suit the building
• New flashings at every parapet, curb, drain and penetration
• Phased scheduling so no section is left exposed overnight and tenants keep operating
• Daily site cleanup, magnetic sweeps and disposal of all tear-off material

• Total area — a warehouse roof replacement is priced very differently per square metre than a small plaza roof
• Tear-off versus recover, which the moisture survey largely decides
• Quantity of saturated insulation; it is priced as a unit rate because nobody knows the true number until the roof is open
• Deck condition — rusted steel decking or rotted wood adds structural work
• Insulation thickness needed to meet current energy code, which is often double what the old roof carried
• Rooftop units that must be lifted, disconnected and re-flashed, and whether cranes are needed
• Phasing requirements around tenants, loading docks and business hours

Every home is different, so we don’t publish flat prices — the quote is free and based on your actual job.