Commercial and Industrial Flat Roofing in Toronto
Low-slope roofing for building owners, property managers and plant managers across Toronto, the GTA and southwestern Ontario.
NorthCan Roofing is a commercial and industrial flat roofing contractor based at 425 Alness Street in Toronto. We install, repair, replace and maintain low-slope roof systems: SBS modified bitumen, TPO, EPDM, PVC, built-up roofing and low-slope metal. We work on occupied buildings across Toronto, the GTA and southwestern Ontario. Call 416-456-0777 to book a free roof assessment.
Who is this service for?
Our work is entirely commercial and industrial. We do not install residential sloped shingle roofs. The buildings we spend our days on are flat and low-slope, and the people who call us usually fall into four groups.
- Building owners who need a roof to last through a hold period, and who want the capital decision put in writing before it turns into an emergency.
- Property managers running multi-tenant office, retail and mixed-use buildings, where a leak becomes a tenant complaint the same morning. Our property manager services are built around that reality.
- Facility managers at schools, healthcare sites, community buildings and institutional properties, where access is restricted and the work has to fit around occupancy.
- Industrial and plant managers at warehouses, distribution centres and manufacturing sites, where production cannot stop for a roof. That work has its own page: industrial roofing in Toronto.
What these buyers have in common is that the roof is not a personal purchase. It is a line in a capital plan, a risk on an insurance file, and a source of complaints when it fails. We write our reports and quotes so they can be handed straight to an owner, a board or a head office without translation.
Which flat roofing systems do you install?
There is no single correct low-slope system. The right one depends on the deck, the building use, the interior humidity load, the amount of rooftop equipment, the drainage design and how the roof will be maintained. A full side by side comparison lives on our guide to flat roof types and systems. In short:
- SBS modified bitumen, a two-ply torch or self-adhered assembly with a granulated cap sheet. Redundant, tolerant of foot traffic and rooftop equipment, and forgiving in Ontario freeze-thaw cycling. It remains the workhorse assembly on GTA commercial buildings.
- TPO, a single-ply thermoplastic membrane heat-welded at the seams. Fast to install over large uninterrupted fields such as warehouse roofs.
- PVC, also heat-welded, and the usual choice where the roof sees grease, animal fats or chemical exhaust, such as restaurant and food processing exhaust zones.
- EPDM, a synthetic rubber single ply, seamed with tape or adhesive, and flexible in cold weather.
- Built-up roofing (BUR), multiple bitumen-saturated plies with a gravel or cap-sheet surfacing. Still found on many older Toronto buildings and still repairable.
- Low-slope and standing-seam metal, covered on our commercial metal roofing page.
Underneath the membrane, the assembly matters as much as the sheet on the surface: vapour barrier, mechanically fastened or adhered insulation, tapered insulation to move water to the drains, and a cover board to protect the membrane from hail, foot traffic and fastener back-out.
System choice is only half the specification. The other half is how the assembly is attached: mechanically fastened through the insulation into the deck, adhered in ribbons or full-spread adhesive, or held by ballast. Attachment is selected against the wind uplift demand for the building height, exposure and roof zone, with an increased fastener density in the perimeter and corner zones where uplift is highest. On a re-roof, the holding capacity of the existing deck is checked before the pattern is set, because a deck that has already carried two roofs may not take new fasteners in the same holes.
Should you repair, replace, or maintain the roof?
Most calls we take are really this question. The answer comes from the condition of the assembly below the membrane, not from the age on a file.
Repair
Repair is the right call when the field of the roof is sound and the failures are local: a split at a seam, a lifted cap flashing, a failed pitch pocket, a cracked base flashing at a curb, a drain that has pulled away from the membrane. Wet insulation, if any, is confined to a small area and can be cut out and replaced. See flat roof repairs for how we scope and price that work.
Replace
Replacement earns its place when moisture has spread through the insulation, when the membrane has lost its surfacing across the field, when repairs are being repeated in the same areas season after season, or when the deck itself is deteriorating. A wet assembly cannot be dried in place, and every additional patch is money spent on a roof that is already finished. Details are on flat roof replacement and, for the broader capital project, commercial roof installation and replacement.
Maintain
Maintenance is what keeps the first two decisions from arriving early. Clear drains, sound seams, intact flashings and a documented file are the difference between a roof that reaches the end of its service life and one that fails halfway there. Our commercial roof maintenance program sets that on a schedule.
If you do not know which of the three you need, that is what the roof condition report is for. It is the lowest-friction way to start, and it produces a document you can act on.
How does a commercial roofing job run on an occupied building?
Almost every roof we touch has people underneath it. The sequence below is how we keep the building running.
- Site attendance and assessment. We walk the roof, open test cuts where the assembly is unknown, check the deck type, measure the insulation, photograph every failure point and confirm access.
- Written scope and quote. You receive the assembly specified by layer, the tear-off or recover approach, the flashing and drainage work, the disposal method, the site logistics and the price, in writing. A workmanship warranty and the manufacturer system warranty are quoted with the job in writing.
- Pre-start logistics. Crane or hoist placement, parking and lane occupancy, material staging, dumpster location, tenant and neighbour notice, fire watch procedure where torch work is involved, and hours of work agreed with the property manager.
- Phased work. On an occupied building we open only what can be made watertight the same day, and we phase the roof section by section so no area is ever left exposed overnight.
- Daily control. Debris contained, drains kept open through the work, temporary water cut-offs at each stop point, and a foreman on site who talks to your building contact rather than to no one.
- Close-out. Final walk with your representative, photo record of the completed details, warranty documents issued, and the roof handed back with a maintenance schedule.
WSIB coverage and certificates of insurance are provided on request before we mobilise, which is usually what a property management office needs on file first.
What does the Ontario climate do to a flat roof?
Southern Ontario is a difficult climate for low-slope roofing, and most of what we repair traces back to four local mechanisms.
- Freeze-thaw cycling. Toronto crosses zero repeatedly through the shoulder seasons. Water sitting in a seam, a lap or a crack expands as it freezes and opens the defect a little further each cycle. This is why ponding water is not a cosmetic issue.
- Snow load. The Ontario Building Code sets ground snow load Ss and rain load Sr by location in Supplementary Standard SB-1, and drifting against parapets, mechanical screens and adjacent higher walls concentrates that load well above the field value. Any structural concern goes to a professional engineer rather than to a roofer.
- Ice damming at parapets. Meltwater runs to the cold perimeter, refreezes at the parapet and around the drains, and backs up behind the ice until it finds the base flashing. Parapet and cap flashing detailing is where a Toronto flat roof usually leaks first, which is why we treat it as its own trade on the roof flashing and siding page.
- Thermal movement. A dark roof surface swings through a wide temperature range in a single summer day and again across the seasons. Expansion joints, cant strips at wall junctions and correctly relieved membrane terminations absorb that movement; rigid, unrelieved details tear.
What about code, safety and site compliance?
Re-roofing work in Ontario is regulated at two levels, and both affect your scope and your schedule.
Building Code. When a roof is torn off and rebuilt, the new assembly is designed to current Ontario Building Code requirements, including the insulation and thermal requirements applicable to the building, wind uplift resistance for the roof zone, and drainage capacity. A recover over an existing membrane is limited by the number of existing membrane layers already present and by the condition and load capacity of the deck. Permit requirements are confirmed with the local municipality before work begins.
Occupational health and safety. Roofing is high-risk work. Our crews follow the Occupational Health and Safety Act and the Ministry of Labour, Immigration, Training and Skills Development working-at-heights requirements: guardrails or a travel-restraint or fall-arrest system at every open edge, controlled access zones, anchor points selected for the deck, and a documented rescue plan. Where torch-applied work is used, a fire watch is maintained after the torches are shut down. On industrial sites we coordinate with your own health and safety representative and follow your site orientation.
WSIB clearance and certificates of insurance are provided on request.
What happens if the roof is leaking right now?
Call 416-456-0777. Active water entry is handled as its own service, not as a scheduling item. We stabilise first: locate the entry, dry in the area with a temporary membrane or a mechanically fastened patch, protect the interior, clear the drain if the water has nowhere to go, and photograph the condition for your insurance file. Permanent repair follows once the assembly is dry and the cause is confirmed, because a permanent detail installed into wet insulation fails again.
Full detail on what to do before the crew arrives is on the emergency roof repair page. Between events, the least expensive protection is a drain and flashing check before the fall rain and before the spring melt.
Where do you work?
We operate out of 425 Alness Street in North York and work across Toronto, the GTA and southwestern Ontario. Core coverage includes Toronto, Mississauga, Vaughan, Brampton, Markham, Scarborough, Etobicoke, Richmond Hill, Oakville and Burlington, extending to Hamilton and Barrie. The full list is on our service areas page.
Portfolios of completed low-slope work are in the project gallery.
How do you start?
Start with a free roof assessment. We attend the site, walk the roof with you or with your building contact, document what we find and return a written quote for the work that is actually needed. If you want a fuller document for a capital plan, ask for the roof condition report instead, which sets out remaining service life, deficiencies by priority and photographs.
If you are budgeting before you are buying, the flat roof cost calculator shows the range that the main variables produce. It is a planning range only, not a quote.
Call 416-456-0777, email info@northcanroofing.com, or use the contact page.
Bring whatever you already have to that first visit: previous roofing invoices, the original specification if the building still holds it, a roof plan, and a note of where leaks have appeared and when. A history of where and when water arrived tells us as much as the walk does, and it shortens the diagnosis considerably on a large or multi-area roof.
Frequently asked questions
Do you work on residential roofs?
No. NorthCan Roofing works on commercial and industrial buildings only, and specifically on flat and low-slope roof systems. We do not install or repair residential sloped shingle roofs. If your building is a low-rise multi-unit residential or mixed-use property with a flat roof over a commercial ground floor, that is work we do handle.
Can a commercial roof be replaced while the building stays open?
Yes, and that is how most of our replacements run. The roof is phased into sections, and we only open the area that can be closed in and made watertight the same day. Interior protection, tenant notice, crane or hoist scheduling and agreed working hours are all set before mobilisation so occupants are not surprised.
How do you know whether the insulation under the membrane is wet?
Test cuts and a moisture survey. A test cut gives a physical sample of every layer of the assembly at that point. Infrared or capacitance moisture scanning maps the wet areas across the whole roof so the drawing shows what has to come out and what can stay, rather than guessing from the surface.
What is a recover, and when is it allowed?
A recover installs a new roof over the existing membrane instead of tearing it off. It is possible only when the deck is sound, the existing insulation is dry, and the number of existing roof layers permits another. It saves disposal and time, but it is not appropriate on a saturated assembly and it hides the deck from inspection.
Do you provide insurance documentation?
Yes. WSIB coverage and certificates of insurance are provided on request, normally before mobilisation so your property management office can put them on file. For water damage events we also supply dated photographs and a written description of the failure and the temporary repair for your insurer.
Which system should we choose for our building?
It depends on the deck, the interior humidity, the amount of rooftop equipment and how the roof will be maintained. SBS modified bitumen suits traffic-heavy roofs with lots of mechanical units, TPO suits large open warehouse fields, PVC suits kitchen and process exhaust exposure. Our comparison of flat roof types walks through each one.
Ready for your free roof assessment?
Tell us the address, the roof size and what you are seeing. We will book a time to get up there and put it in writing.
Call 416-456-0777 for anything urgent. Our emergency line is answered around the clock.
Call 416-456-0777