Southwestern Ontario
Flat roof repair in London
We repair, replace and maintain flat roofs in London: houses, garages and additions, condo and apartment buildings, plazas, offices and warehouses. Send photos and a few details for a written quote.
Flat roof services in London
London has many mid- and high-rise buildings, whose flat roofs are managed by condo boards and property managers. The usual work is drains, flashings at mechanical units and planned replacements. We find where the water gets in, fix that spot and tell you how much life the rest of the roof has.
When a roof is past repair, we replace it with EPDM, TPO, PVC or modified bitumen, and fix the drainage so water does not sit on the new membrane. Owners and property managers also book inspections and maintenance visits.
From London East to Masonville and Oakridge
London absorbed its neighbours over time: London West in 1897, London East, an industrial centre, in 1885, and London South, with Wortley Village, in 1890. Annexations in 1961 added Masonville and Byron, and later subdivisions such as Westmount, Oakridge, White Oaks and Stoneybrook were built around them. Western University was founded in 1924. Census data shows about 52% of homes were built before 1981.
So there are several different roofs in one city. In London West and around Wortley Village, small workers' houses and cottages often have flat-roofed kitchen or rear additions. London East carried factories and warehouses with big flat roofs. Western University, Fanshawe College and the large hospitals have extensive low-slope roofs on institutional buildings. The newer suburbs include townhouse and apartment blocks with membrane roofs, and about 32% of dwellings in the city are in apartment buildings, which means many shared roofs.
London weather and your flat roof
Ontario's Building Code sets the climate values used to design roofs in each municipality. They show what a flat roof in London has to handle.
- 1.9 kPaGround snow load (about 40 lb per sq ft)
- 0.4 kPaRain load added to snow (Sr)
- 28 mmRain in a 15-minute storm (design value)
- 103 mmRain in one day, 1-in-50-year storm
- -18 °CJanuary design temperature
- 3,900Heating degree-days per year
- 0.47 kPaHourly wind pressure, 1-in-50-year
That snow load is about 2.1 times the Toronto figure. Snow drifts against parapets, walls and rooftop units, and the weight sits on the roof for weeks. Drains that freeze shut leave meltwater nowhere to go.
A design storm can drop 28 mm of rain in 15 minutes. On a flat roof that water has to reach a drain or scupper quickly, so clear drains and sound drain flashings matter as much as the membrane.
Source: Ontario Building Code, Supplementary Standard SB-1, Table 1.2
Homes and buildings in London
The age and type of buildings shape the flat roofs we see. These are the 2021 Census figures for London.
- 52%Homes built before 1981
- 23%Homes built since 2001
- 52%Detached and semi-detached houses
- 13%Row houses and townhouses
- 21%Apartments in buildings of 5+ storeys
- 42%Households that rent
21% of homes in London are apartments in buildings of five or more storeys. Those roofs are looked after by condo boards and property managers, who need a written scope, photos and a plan that fits the reserve fund. See condo buildings and apartment buildings.
42% of households in London rent. Landlords and property managers can send photos and the tenant's description of the leak, and we reply with the scope and a quote by email. See apartment buildings.
Storms that hit London
- 21 May 2022: A derecho crossed London, where two tornadoes (an EF1 and an EF2) were confirmed within the storm. Source
Storms like these are when blocked drains, loose flashings and open seams show up. After a big storm, check the ceilings under the roof and send us photos of any new stain.
London: facts for property owners
- Population of London: 422,324 (2021 Census). Source
Rules and programs change. Confirm current details with the municipality before you start work.
Starting prices in London
| Item | Starting price |
|---|---|
| Commercial roof inspection and report | from $450 per roof |
| Roof drain or scupper repair | from $800 per drain |
| Commercial roof replacement | from $8 per sq ft |
Starting prices in CAD before 13% HST, based on typical Ontario contractor rates (mostly Toronto and the GTA). The final price depends on roof size, access, the layers to remove, the membrane, drains and flashings, and is confirmed in your written quote.
See all prices.
Roofs we work on in London
Nearby cities
Flat roofs in London: questions
How much does flat roof repair cost in London?
A small leak repair starts from $350 per repair and a new house flat roof starts from $8,000 per roof. Prices in London depend on access, layers to remove and the membrane. See pricing.
Why does my flat roof in London leak in late winter?
Melting snow refreezes at drains and edges overnight, then backs up under seams and flashings during the day. See ice and snow damage.
Do I need a permit to replace a flat roof in London?
Check with the London building department. Replacing the membrane alone is often treated differently from structural work, a new rooftop deck or added weight. See re-roofing permits in Ontario.
Do you work with condo boards in London?
Yes. We send a written scope, photos and a quote the board can compare, and can split work into phases. See planning a condo roof project.
Do you also work near London?
Yes, including Woodstock, Sarnia, St. Catharines and the rest of southwestern Ontario. See Southwestern Ontario.
Leak, damage or an old flat roof?
Send a few details and photos. We reply by email with next steps and a written quote.