Commercial and Industrial Flat Roofing in Richmond Hill

NorthCan Roofing services flat and low-slope roofs on Richmond Hill's office buildings and retail plazas, concentrated along the Yonge Street and Highway 7 corridors. Most of our calls here start as a leak in one tenant's unit, and most of them end somewhere other than directly above that tenant.

What does Richmond Hill's commercial roof stock consist of?

Richmond Hill has comparatively little heavy industry and a great deal of multi-tenant commercial. Along Yonge Street from Elgin Mills down to Highway 7 you find strip plazas and small commercial blocks, many built between the 1970s and the 1990s, typically single-storey with steel or wood deck, a low parapet on the street elevation, and a modified bitumen or built-up roof that has been patched by successive owners.

Along Highway 7 and around Leslie and Highway 404 the stock shifts to low-rise and mid-rise office buildings and business parks from the 1990s and 2000s, with concrete or steel decks, SBS or single-ply membranes, mechanical penthouses and screened rooftop equipment. There is also a band of smaller multi-tenant industrial and flex units in the Newkirk and Beaver Creek areas.

What links them is the tenancy pattern. A plaza roof is one continuous membrane over eight or ten separate businesses; an office roof serves multiple floors of separately leased space. Nobody owns a piece of the roof, everybody experiences it, and the party who reports the leak is rarely the party under the hole.

How we trace a leak in a multi-tenant building

Methodically, and starting further away from the stain than most people expect. Water entering a roof travels along the top of the vapour retarder or the underside of the deck until it finds a fastener, a seam or a penetration, and only then drops. On a plaza with a continuous deck across several units, that path can cross two tenancies.

1. Map the interior evidence: every stain, its position relative to the deck flutes and the joists, and when it appears relative to rain.
2. Survey the whole roof area above and upslope of that zone, not the nearest suspect.
3. Inspect and record every curb, drain, scupper, parapet joint and equipment penetration in the zone.
4. Flood test or water test a defined section where the source remains ambiguous.
5. Report with a marked-up roof plan so the landlord can allocate the repair fairly between the roof and the tenant's own fit-out.

Then we carry out the repair, or set out the case for replacement if the roof has stopped being repairable. Landlords with several plazas usually want that in a portfolio format, which is what the property manager service provides, and the flat roof cost calculator helps set the reserve fund number.

Permits and approvals in Richmond Hill

Richmond Hill handles non-residential work through two streams: a tenant permit for businesses operating within an existing space, and a non-residential building permit for a new ICI building or an alteration to an existing one. Notably for roofing, the City's non-residential materials include a mechanical unit data sheet to be completed by the design engineer for all rooftop unit installations, which is directly relevant if your roof project includes swapping equipment while the membrane is off.

Whether a straight membrane replacement needs a permit turns, as everywhere in Ontario, on whether structural work is involved. Check the City's non-residential permits page and confirm your scope with Richmond Hill Building Services. Plazas along Yonge may also carry site plan or sign bylaw conditions affecting the parapet and sign band, so confirm before you change the front elevation's appearance. See the commercial roofing page for how we scope this work.