Commercial roofing
Commercial roofing for commercial and industrial buildings in Oshawa.
Commercial and Industrial Flat Roofing in Oshawa and Durham Region
Oshawa is our Durham base of operations on paper only: the crews come from Toronto, and from Oshawa we also cover Whitby, Ajax and Pickering.
NorthCan Roofing handles commercial and industrial flat roofing across Oshawa and the wider Durham Region, including Whitby, Ajax and Pickering. The stock here is anchored by large automotive plant and supplier buildings and by substantial institutional campuses, both of which bring complex rooftop mechanical arrangements and long-span decks.
What does Durham's industrial roof stock consist of?
Oshawa's building fabric was shaped by the automotive industry. Large-format assembly and component buildings in the south end near the harbour and along Bloor and Park, and a wide supply chain of stamping, moulding, machining and logistics buildings distributed through Oshawa, Whitby and Ajax, produced a stock of very large single-storey industrial buildings, many with long-span steel decks, extensive rooftop process ventilation, and roofs installed and re-covered in successive waves from the 1960s onward.
Alongside that sit two other groups. Institutional campuses, including post-secondary and health facilities and a large public school stock, contribute flat roofs with complex geometry, stepped levels, atria and dense mechanical plant. And the newer distribution and commercial development in Whitby, Ajax and Pickering along the Highway 401 and 407 corridors adds a layer of modern single-ply warehouse roofs closer in character to what we see in Brampton.
On the older plant roofs the recurring pattern is layers. Fifty or sixty years of re-covering means multiple membranes, uncertain insulation condition, and process penetrations that have been cut, moved and abandoned without record. On these buildings a roof survey is genuinely investigative work.
How does the Durham lakeshore affect these roofs?
Oshawa, Whitby, Ajax and Pickering all front Lake Ontario, so this is a lakeshore climate: moderated winter temperatures compared with inland Durham to the north, frequent crossings of the freezing point, and persistent humidity. The Ontario Building Code publishes climatic design data for each municipality in Supplementary Standard SB-1, and the Durham lakeshore municipalities take values reflecting that position rather than the higher inland ones further north in the region.
The specific consequence on a large industrial roof here is the combination of freeze-thaw with process moisture. Plants that vent humid process air onto or through the roof push moisture into a cold assembly, and where a vapour retarder is discontinuous, that moisture condenses inside the insulation and stays there. Wet insulation is heavier, conducts more, and rots the deck from above. Many of the wet areas we map on Durham plant roofs did not come from the sky.
Which areas does this page cover?
Oshawa is our anchor for Durham Region, and from it we serve Whitby, Ajax and Pickering as well. Those are separate municipalities with their own building departments and their own permit processes, so if your building is in Whitby, Ajax or Pickering, apply to that municipality rather than to Oshawa. What is common across all four is the building stock, the lakeshore conditions, and the way we mobilise to reach you.
Work in the Durham lakeshore corridor includes industrial roofing on plant and supplier buildings, phased replacement on institutional campuses, moisture surveys on multi-layered roofs, flashing and metal work on process penetrations, and maintenance programmes for owners with several buildings across the region.
What we do on Oshawa's plant and campus roofs
Investigation first, then targeted work.
- Core sampling and moisture scanning to map how many layers exist and where the assembly is wet.
- Deck condition assessment where wet insulation has been sitting on steel for years.
- Rebuilding and consolidating process penetrations, including capping abandoned ones properly.
- Full tear-off and reconstruction where layer count and moisture rule out an overlay.
- Phased replacement on institutional campuses, scheduled around academic and clinical calendars.
- Repairs and interim measures to hold a roof through to a budgeted replacement year.
Institutional clients in particular need the work to fit a calendar rather than a season, which shapes how we phase. For an initial budget figure, the flat roof cost calculator is a reasonable starting point, and the commercial roofing page sets out the wider scope.
How crews reach Durham Region
From 425 Alness Street in Toronto, east along Highway 401 or 407. We keep no Oshawa, Whitby, Ajax or Pickering office, yard or local phone line; every enquiry across Durham comes to 416-456-0777. Pickering and Ajax are the shorter runs and Oshawa the longer one, and we plan larger Durham jobs as multi-day mobilisations with a full crew rather than a series of short visits.
On a running plant, the more important scheduling variable is the production calendar, not our travel: shutdown weeks and maintenance windows determine when the roof over a process area can actually be opened. We plan around those. Urgent water ingress goes through the 24/7 line to emergency roof repairs. Our neighbouring coverage is Scarborough and Markham, and the full list is on the service areas page.
Permits for roof work in Oshawa and across Durham
The City of Oshawa publishes guidance on when a permit is required, listing replacement of roof shingles or non-combustible siding, and non-structural repair of a chimney, porch, deck or roof, among the work that does not require a permit, while alterations generally do. The distinction, as everywhere in Ontario, is structural. Start with Oshawa's building permits page and confirm your scope with the City.
On Durham plant roofs the structural question comes up often. Decades of wet insulation on steel deck produces section loss, and replacing deck is structural work. So is adding or relocating heavy process equipment, cutting new openings, or reinforcing for a heavier assembly. Expect engineered drawings for any of that. And if your building is in Whitby, Ajax or Pickering rather than Oshawa, the application goes to that municipality's building department, not to Oshawa's, even though the technical work is identical.
What we do in Oshawa
Flat roof repairs
Flat roof repairs for commercial and industrial buildings in Oshawa.
Emergency roof repairs
Emergency roof repairs for commercial and industrial buildings in Oshawa.
Flat roof replacement
Flat roof replacement for commercial and industrial buildings in Oshawa.
Roof installation & replacement
Roof installation & replacement for commercial and industrial buildings in Oshawa.
Roof inspections
Roof inspections for commercial and industrial buildings in Oshawa.
Roofing in Oshawa: questions we get asked
Do you cover Whitby, Ajax and Pickering as well as Oshawa?
Yes. Oshawa is our anchor page for the Durham lakeshore and we work across Whitby, Ajax and Pickering on the same terms, with crews travelling from Toronto. Note that each is a separate municipality with its own building department, so a permit application goes to the municipality your building sits in rather than to Oshawa, even though the roofing work is the same.
Our old plant roof has been re-covered several times. Can it be covered again?
Rarely. Repeated re-covering leaves multiple membranes, uncertain and often saturated insulation, and flashing heights that no longer allow another layer. On Durham plant roofs of that history we take cores across the area and scan for moisture, and the usual finding is that the assembly has to come off, partly because the steel deck beneath needs inspecting.
We vent humid process air through the roof and keep getting wet insulation. Why?
Because the moisture is coming from inside. Humid process air migrating into a cold roof assembly condenses in the insulation and stays there, particularly where the vapour retarder is discontinuous or has been cut by later penetrations. The fix is assembly design rather than membrane repair: a continuous vapour control layer, adequate insulation, and properly sealed process penetrations.
Can you re-roof a campus building during term time?
We would rather not, and we plan around it. Institutional roofs in Durham are usually phased into summer periods, reading weeks and other low-occupancy windows, with noise and odour restrictions during any work that must happen while buildings are in use. On health facilities, infection control and mechanical intake protection add constraints that have to be agreed with facilities management first.
Free roof assessment in Oshawa
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 to book. Roof leaking right now? Our 24/7 emergency line is 416-450-1818.
Call 416-456-0777