Home / Flat Roof Replacement
Replacement
Flat Roof Replacement in Toronto: Re-Roof, Recover or Repair
Full tear-off, recover over the existing roof, or a targeted repair. We will tell you which one your roof actually needs, and we will show you the photographs that led us there.
What you get from Flat Roofs Toronto
Straight Recommendation
If a repair will do, we will say so.
Free No-Obligation Quotes
Full written scope before you decide anything.
Manufacturer & Workmanship Warranties
Both handed over at the final walkthrough.
Residential & Commercial
Garages and row houses to plazas and warehouses.
Three Options, and Only One of Them Is Right for Your Roof
Almost every flat roof conversation ends up at the same fork. Repair the failure and buy time. Recover, which means installing a new roof over the top of the existing one. Or tear off everything down to the deck and rebuild the assembly. They cost very different amounts and they last very different lengths of time, and the difference between a good decision and an expensive one is usually just information.
The information that matters most is whether the insulation under the existing membrane is wet. You cannot tell from the surface. We find out by cutting small test cores through the assembly and looking, then patching the cores properly. If the insulation is dry and the deck is sound, a recover is often genuinely the right call and it saves you the entire cost of tear-off and disposal. If it is wet, covering it seals the water in against the deck, and the building quietly rots underneath a brand new roof.
Flat Roofs Toronto does nothing but low-slope work, so this is the conversation we have several times a week rather than once a season.
The second thing that matters is how many roofs are already up there. Layers add dead load the structure was never designed for, they make every future repair harder to diagnose, and a roof with several existing layers is generally a tear-off whether or not anyone wants it to be. We check that at the same time as the cores.
What a full replacement covers
- Core sampling to establish what is wet
- Tear-off of the failed assembly, down to deck
- Disposal of all removed material
- Deck repair or replacement where needed
- New insulation, tapered where drainage requires it
- Vapour control appropriate to the assembly
- New membrane system, fully detailed
- Drains, scuppers, edge metal and flashing
- Final walkthrough and warranty handover
Repair, Recover or Full Tear-Off
Here is how we actually decide, and what each route gets you.
Cheapest
Targeted Repair
The right answer when the field of the roof is sound and the failure is local: a lifted seam, a bad curb flashing, storm damage in one area. A proper repair on a roof with real life left in it is good value and we will recommend it where it applies. What it is not is a way to postpone a decision on a roof that is finished.
- Best when the field is sound
- Buys years, not decades
- Days rather than weeks
Middle Path
Recover Over the Existing Roof
A new membrane installed over the existing assembly. It removes the tear-off and disposal cost, which is a substantial share of a replacement, and it is a genuinely good option when the conditions allow it. Those conditions are specific: the insulation must be dry, the deck sound, and there must not already be too many layers up there.
- No tear-off or disposal cost
- Only valid over a dry, sound assembly
- Structure must take the added load
Full Reset
Complete Tear-Off
Everything comes off down to the deck, the deck gets repaired, and the whole assembly is rebuilt. It is the most expensive route and the only one that lets us see and fix what is underneath, upgrade the insulation, correct the drainage with taper and start the clock again from zero.
- Deck inspected and repaired
- Insulation and drainage can be corrected
- Full service life from new
Signs You Are Past Repairing
One of these on its own is a repair conversation. Several together usually is not.
- Leaks appearing in new places rather than the same place
- Widespread blistering, ridging or alligatoring across the field
- Seams failing in more than one area of the roof
- Wet insulation confirmed by core samples
- Ponding that no amount of drain clearing fixes
- A deck that feels soft or springy in multiple places
- Repairs that have not held through a full season
- A roof past its expected service life with no maintenance history
How a Flat Roof Replacement Runs
Five stages, and no surprises between them.
1
Inspection and Core Samples
We get on the roof, take cores where it matters and establish whether the assembly underneath is dry.
2
Written Recommendation and Quote
Repair, recover or tear-off, with the reasoning, the system, the timeline and the price. Free and with no obligation.
3
Tear-Off and Deck Repair
The old assembly comes off in controlled sections, and any rotten sheathing or framing is repaired before anything new goes on.
4
Insulation and Membrane
New insulation, tapered where the drainage needs it, then the membrane system laid and fully detailed at every edge and penetration.
5
Walkthrough and Warranty
We walk the finished roof with you, close out any punch items and hand over both warranty documents.
Deck and Structure Work on Replacements
Decks opened, structure put right and closed back in watertight.
Lumbered Slope Build and Two-Ply System, Toronto
A lumbered slope framed over a flat roof deck to move water toward the drains, with a two-ply system installed over it.
Flat Roof Application Detail, Toronto
A detail from a flat roof membrane application, showing the finished surface of the system.
Attic Inspection and Blown-In Insulation, Toronto
Inspection of a flat roof attic space followed by blown-in insulation. The cavity is checked before any insulation is added.
What a Flat Roof Replacement Costs in Toronto
Full flat roof replacement in Toronto typically runs $8 to $15 per square foot. That is a genuinely wide band because the roof itself is only part of what you are paying for. Here is what moves a job from one end of it to the other.
- Tear-off versus recover. Removing and disposing of an existing assembly, particularly a multi-layer built-up roof with gravel, is a real share of the total.
- Number of existing layers. One layer comes off quickly. Three layers is days of labour and several more disposal bins.
- Deck condition. Nobody knows what is under the old roof until it is off. Rotten sheathing and failed joists are repaired before anything new goes down.
- Insulation and taper. Upgrading R-value, and building tapered insulation to correct chronic ponding, is frequently the largest single line item after the membrane.
- System choice. Modified bitumen, cold-ply, EPDM, TPO and PVC carry different material and labour costs, and the right one depends on the building rather than the budget alone.
- Details and access. Parapets, curbs, skylights, drains and penetrations are where the hours go, and how materials get onto the roof matters as much as what they are.
Every quote is free, in writing and carries no obligation. If the honest answer is that a repair buys you five more good years, that is what the quote will say.
Flat Roof Replacement Questions
The decisions people are actually weighing up when they call us.
How do I know whether to repair or replace?
The short version: a local failure on an otherwise sound roof is a repair, and widespread failure or wet insulation is a replacement. The way to tell them apart is core samples, which show whether the insulation under the membrane is dry. We take those during the inspection and show you what came out, because that is the single piece of information the whole decision turns on.
Can I just put a new roof over the old one?
Sometimes, and it saves the entire tear-off and disposal cost, so it is always worth asking. A recover only works if the existing insulation is dry, the deck is sound, the structure can take the added load and there are not already too many layers on the building. If the insulation is wet, a recover traps that water permanently against the deck, and you get a rotting structure under a new roof.
How long does a replacement take?
A straightforward residential roof, for example a rear roof or a garage, is commonly one to three days. A larger or more complicated residential roof runs to the better part of a week. Commercial work is phased and quoted with a timeline attached. Weather is the variable nobody controls, and we will not open more roof than we can make watertight before the end of the day.
Will you find problems once the old roof is off?
Sometimes, and we would rather tell you that up front than pretend otherwise. The deck is the usual one: sheathing that has been quietly rotting under a leak for years, or a joist end that has gone soft where it sits in a brick wall. We photograph anything we find, tell you what it costs to put right, and get your agreement before doing it.
Can you fix the ponding while you are up there?
Usually yes, and it is the best possible moment to do it. Tapered insulation built into the new assembly creates fall on a dead-level deck and moves water to the drains without touching the structure. It adds R-value at the same time. If the ponding is caused by a sagging deck rather than a lack of slope, that is a framing repair and we will price it separately.
Which system should I choose for the new roof?
It depends on the deck, the exposure, the access, the traffic the roof will take and how long you plan to hold the building. Two-ply modified bitumen and cold-ply are the residential workhorses, and TPO, PVC and EPDM cover most commercial situations. Our flat roofing systems guide compares all six on lifespan, seams, fire behaviour, cost tier and what each one is actually best at.
Areas We Cover
Toronto and out through the GTA. Open the plan to find your area, or call and ask about somewhere we have not named.
Select a region on the plan
Free, No Obligation
Request a Free Quote
Tell us what the roof is doing and we will come and look at it. No charge, and no obligation to proceed.
Call Us
Office Hours
Open 7 days a week: 7:00am to 11:30pm
Emergencies
The line above is answered 24/7 for anything that cannot wait, including weekends and statutory holidays.
Related Flat Roofing Services
Three more places our crews spend their time. Every one of them touches the same roof.
Google Reviews
Flat Roof Replacement Reviews
These come straight from our Google Business Profile. We cannot edit them, reorder them or take one down, and the rating in the header is whatever Google is showing today.
Free, No Obligation
Find Out Whether You Need a Repair or a Replacement
We will get on the roof, core it where it matters and give you a straight answer in writing. Free, and with no obligation either way.