Industrial Roofing for Warehouses, Plants and Distribution Centres
Large-area low-slope roofing on operating industrial sites across Toronto, the GTA and southwestern Ontario.
Industrial roofing covers the large low-slope roofs on warehouses, manufacturing plants and distribution centres. The differences from a small commercial roof are scale, wind uplift across a big open field, dense rooftop plant, process exhaust, and the fact that production cannot stop. NorthCan Roofing works on operating sites across the GTA. Call 416-456-0777.
What makes an industrial roof different?
Everything that is a detail on a small building becomes a system on a large one.
- Area. A distribution centre roof can be several hectares. Logistics, staging, material handling and daily watertight stopping points matter more than crew speed.
- Structure. Long-span steel joists and deep steel deck deflect more than a concrete deck, which changes fastener selection, insulation layout and where ponding develops.
- Rooftop plant. Dozens of units, make-up air, dust collectors, process exhaust, refrigerant lines, gas piping and conduit runs, each of which is a penetration and a potential leak.
- Process exhaust. Grease, oils, solvents and chemical discharge land on the membrane downwind of the stack, and membrane chemistry has to suit that exposure.
- Interior humidity. Wet processes, washdown areas and heated production spaces drive vapour into the assembly, which makes the vapour barrier selection a design decision rather than a formality.
- Consequences. Water lands on racked inventory, packaging lines, electrical panels or machinery. The value under the roof usually exceeds the value of the roof by a wide margin.
Scale also changes how a roof is owned. Nobody walks a five-hectare roof casually, so problems go unseen for far longer than on a small commercial building, and the first symptom is often water on the floor rather than a defect on the roof. That is why large sites benefit most from a mapped roof plan with numbered areas and a documented inspection history, so a condition is tracked rather than discovered.
How is wind uplift handled on a large-span roof?
Wind does not load a roof evenly. Pressure is highest at the corners, next highest along the perimeter, and lowest in the field, and the difference is large. That is why the fastening pattern is not uniform across an industrial roof.
- Zoned fastening. Corner and perimeter zones receive an increased fastener density or additional adhesive, sized to the design wind load for the building height, exposure and location.
- Perimeter securement. Edge metal and coping are the first line of defence. Most wind failures start at a loose or under-fastened edge that lifts, admits air under the membrane and peels the field back from there.
- Deck attachment. Fastener holding depends on the deck gauge and condition. Corroded flutes and elongated holes from a previous roof reduce pull-out values, which is one reason a tear-off is preferred where the deck is suspect.
- Ballast. Ballasted assemblies rely on stone or pavers for securement and have their own perimeter requirements. Ballast also complicates leak tracing and adds load, so it is usually reviewed at replacement.
- Snow. Ground snow load Ss and rain load Sr are set by location in the Ontario Building Code Supplementary Standard SB-1, and drifting against parapets, mechanical screens and higher adjacent roof levels concentrates load well above the field value. Structural questions go to a professional engineer.
How do you work over live production?
We assume the plant runs. That assumption shapes the plan before anyone is on the roof.
- Pre-start walk with your team. We map what is under each roof area: production lines, electrical rooms, server rooms, clean or food-handling areas, and anything that cannot tolerate dust or water. Those areas set the phasing order.
- Intakes and exhausts. Fresh-air intakes are identified and shut down or filtered during hot work and tear-off. Nobody on your line should smell the roof.
- Hot work control. Where torch-applied work is used, we follow a hot work permit process, coordinate with your fire safety plan, keep extinguishers at the work face and maintain a fire watch after the torches are shut down. On some sites we specify self-adhered or mechanically fastened assemblies specifically to avoid open flame.
- Vibration and noise. Fastening over sensitive operations is scheduled to shift changes or planned downtime.
- Containment. Debris is chuted and binned, not swept over the edge. Deck openings and cut-outs are covered and guarded so nothing falls into the plant below.
- Daily close-out. No area is left open overnight. Every stopping point gets a temporary water cut-off tied into the existing membrane.
The same phasing discipline applies to a full roof replacement on an occupied building.
Communication is the part that most often fails on an industrial site, so we fix it before mobilising: one named foreman, one named contact on your side, a short daily note of what area is being worked and what is planned for the following day, and immediate notification if anything is found that affects the plant below. On multi-shift sites that note goes to the shift supervisors as well, because the crew arriving at seven in the morning did not hear yesterday's conversation.
What about roof access and fall protection?
Industrial roofs are worked on constantly, by us and by your own trades, which makes access and edge protection a permanent facility issue rather than a project one.
Our crews work under the Occupational Health and Safety Act and the Ministry of Labour, Immigration, Training and Skills Development working-at-heights requirements: guardrails or travel restraint at every open edge, fall-arrest where restraint is not practical, anchor points selected for the deck type and capacity, controlled access zones around openings and skylights, and a written rescue plan on site. Crews complete the site orientation your plant requires and work to your permit systems.
We also report on the permanent provisions during any inspection: the condition of hatches, fixed ladders and stairs, whether existing anchor points are documented and inspected, whether skylights are guarded or screened, and whether service routes to rooftop units have walkway protection. Unguarded skylights are the hazard most often missed on an industrial roof, and they are covered on commercial skylight installation.
Where your own staff and contractors regularly access the roof, documented anchor points and a clear designated walking route are worth having in place before the next trade arrives rather than after an incident.
Which systems suit industrial buildings?
Large open fields with few penetrations favour heat-welded single-ply membranes: TPO for general warehouse and distribution roofs, and PVC where grease, animal fats, oils or chemical exhaust land on the membrane, because PVC resists that exposure better. EPDM remains flexible in cold conditions and suits roofs with long uninterrupted runs. SBS modified bitumen earns its place where the roof carries heavy foot traffic and dense mechanical plant, because two plies give redundancy and it takes abuse well. Low-slope and standing-seam metal is common on older industrial buildings and is covered on commercial metal roofing.
Below the membrane, the decisions that matter are the vapour barrier for the interior humidity load, insulation to current code in two staggered layers, tapered insulation and crickets to move water off a deflecting long-span deck, and a cover board that will survive the traffic. Full comparisons are on flat roof types.
How do industrial roofs get planned and maintained?
Large roofs are rarely replaced all at once. Most industrial clients work from a documented plan: a mapped roof with numbered areas, a moisture survey showing where the assembly is wet, a deficiency schedule by priority, and a phased replacement over several budget cycles while the sound areas are maintained. That plan starts with a roof condition report.
Between phases, a maintenance program keeps drains clear before the fall rain and catches damage from the other trades who work on your roof. Water entry over a production line is handled through emergency roof repairs at 416-456-0777, and targeted work is covered under flat roof repairs.
We work across the GTA and southwestern Ontario, including the industrial belts in Mississauga, Brampton, Vaughan and Hamilton. WSIB coverage and certificates of insurance are provided on request.
Frequently asked questions
Can you re-roof a plant without shutting down production?
In nearly all cases yes. The roof is phased area by area against what sits underneath, hot work is controlled or eliminated by specifying self-adhered or mechanically fastened assemblies, intakes are protected, and no deck is left open overnight. The areas over sensitive processes are scheduled around your downtime.
Our roof leaks over racked inventory. What should we do first?
Call 416-456-0777 for an emergency attendance to dry the area in and clear any blocked drainage, then move product out from under the affected bay. Once the make-safe is done, we survey the assembly to find whether it is a detail failure or wet insulation, which decides between a repair and a phased replacement.
Does process exhaust really damage a membrane?
Yes. Grease, animal fats, oils and some solvent exhausts degrade certain membranes and their seams, typically in a plume downwind of the stack. PVC is normally specified for those zones. Where exhaust is a known issue we also detail the surrounding area for cleaning access and check it at every maintenance visit.
Who is responsible for damage caused by our mechanical contractor on the roof?
Commercially that is between you and that contractor, but practically it becomes your leak. We document any third-party damage found during maintenance visits with photographs and location, which gives you what you need to raise it, and we quote the repair separately.
Can solar panels or new rooftop units be added to our existing roof?
Sometimes, and it needs checking first. Added load, new penetrations, altered drainage patterns and the effect on an existing manufacturer warranty all matter. Structural capacity is a professional engineer's call. We assess the roof assembly, detail the supports and penetrations properly, and advise whether it is wiser to schedule the addition with a re-roof.
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