Commercial and Industrial Flat Roofing in Toronto

NorthCan Roofing is a commercial and industrial flat roofing contractor based at 425 Alness Street in Toronto. We replace, repair and maintain low-slope roofs on the city's mid-rise, brick-and-beam and industrial stock, and we work inside Toronto's own permit and green roof rules because this is where our yard is.

What kind of commercial roofs does Toronto actually have?

Toronto is not one roof market, it is at least four. The King-Parliament and King-Spadina areas hold the city's brick-and-beam stock: late nineteenth and early twentieth century warehouse buildings with heavy timber decks, low-slope roofs and tall masonry parapets that were never designed to carry a modern insulated assembly. Many of these buildings have been converted to offices and studios, and the roof is usually a modified bitumen or built-up assembly laid over whatever was there before.

North of the core, the mid-rise commercial and institutional stock along Yonge, Eglinton and St. Clair tends to be concrete deck with a two-ply SBS modified bitumen system, often with mechanical penthouses, elevator overruns and a dense population of rooftop units. In the older industrial pockets, from the Port Lands through Leaside and out to south Etobicoke, we still see steel deck with tar-and-gravel built-up roofing under decades of patch work, and increasingly single-ply TPO or EPDM where an owner has already done one full replacement cycle.

The detail that separates a Toronto roof from a suburban one is the parapet. Downtown parapets are frequently shared, tall, and built of soft brick with cut-stone or metal copings that have moved with a century of frost. On a downtown re-roof, more of the budget and more of the risk sits in the parapet, coping and counterflashing than in the field membrane. We treat flashing and coping work as its own scope on these buildings rather than as a line item inside the membrane price.

Two further Toronto conditions are worth naming. The first is the roof that is also a terrace or amenity deck. On mid-rise and mixed-use buildings across the core, waterproofing sits beneath pavers, planters and insulation in a protected membrane assembly, so the roof cannot be seen without dismantling what is above it, and a leak investigation begins with a lift-and-reinstate plan rather than a ladder. The second is the shared or abutting roof. Downtown blocks are built wall to wall, so a Toronto roof frequently terminates against a neighbour's higher wall rather than at a free edge, and the counterflashing into that wall belongs, legally and physically, to someone else's building. Sorting out access and responsibility at that junction is often the first real task of the project.

What does the Toronto Green Roof Bylaw mean for a re-roof?

Toronto has a green roof requirement written into Municipal Code Chapter 492. The City states that it applies to new building permit applications for residential, commercial and institutional buildings with a gross floor area of 2,000 square metres or greater, on a graduated scale of required coverage that rises with floor area, and that industrial buildings instead provide a green roof covering the lesser of ten per cent of available roof space or 2,000 square metres, or cool roofing across the available roof space.

For an existing building doing a straight membrane replacement, the trigger is the permit application, not the roofing work itself. The City's own guidance is that a building permit is required for the construction of a new green roof or the material alteration of an existing green roof, and that the review checks the Toronto Green Roof Construction Standard contained in the bylaw alongside the Ontario Building Code and zoning. If you already have a green roof and you are replacing the waterproofing under it, that is a permitted alteration and needs a designer of record. If you are adding one, you need a structural engineer to confirm the deck can carry the saturated weight, and you need to plan the root barrier, drainage layer and overflow before anyone orders membrane. Check the current requirements on the City's green roof permit guide before you budget.

Where do Toronto crews and materials come from?

From 425 Alness Street, in the industrial block near Keele and Finch. Toronto is our home city, so material staging, kettle and equipment moves, and same-day returns to site are simply shorter here than anywhere else we serve. That matters most on downtown jobs, where the real constraint is not distance but access: a King Street roof is reached through a lane closure, a hoist window and a delivery slot, and the crew size has to match what the street permits allow that morning.

We are also on call for water entering an occupied building. Our 24/7 emergency line takes the call, and the roof gets a temporary watertight repair before we quote the permanent one. See emergency roof repairs for how that call is handled. Elsewhere in the city, the same crews cover Scarborough and North York, and the full list of places we reach is on the service areas page.