Flat roof repair in Mississauga

Flat roof services in Mississauga

Mississauga 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.

Postwar subdivisions and the Argentia Road industrial belt in Mississauga

Mississauga was mostly farmland and lakeshore villages until after the Second World War. The Queen Elizabeth Way opened in 1935, Malton Airport followed in 1937, and Applewood Acres became the first major planned development near the QEW and Dixie Road. The new towns of Erin Mills and Meadowvale were started in 1968 and 1969, and Square One opened in 1974. Census data show about 38% of homes were built before 1981 and 23% since 2001.

That mix explains the roofs. Older pockets such as Port Credit, Streetsville, Cooksville and Applewood have houses and low-rise plazas from the 1950s to 1970s, where you often find flat roofs over additions, garages and small commercial strips. Erin Mills, Meadowvale and Lisgar hold later subdivisions and townhouse blocks, which commonly carry membrane roofs over balconies and podium sections. Around Malton, the airport and the Meadowvale Argentia Road industrial park, large warehouses and head-office buildings have wide low-slope roofs, and Mississauga City Centre adds condominium towers with terraces and podium decks.

Mississauga 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 Mississauga has to handle. Figures are for Mississauga; SB-1 also lists Pearson Airport and Port Credit.

• 1.1 kPaGround snow load (about 23 lb per sq ft)
• 0.4 kPaRain load added to snow (Sr)
• 25 mmRain in a 15-minute storm (design value)
• 113 mmRain in one day, 1-in-50-year storm
• -18 °CJanuary design temperature
• 3,880Heating degree-days per year
• 0.44 kPaHourly wind pressure, 1-in-50-year

That snow load is about 1.2 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 25 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.

Environment and Climate Change Canada climate normals (1991–2020) record about 115 cm of snowfall a year at the Toronto Lester B. Pearson Int'l Airport station.

Source: Ontario Building Code, Supplementary Standard SB-1, Table 1.2

Homes and buildings in Mississauga

The age and type of buildings shape the flat roofs we see. These are the 2021 Census figures for Mississauga.

• 38%Homes built before 1981
• 23%Homes built since 2001
• 48%Detached and semi-detached houses
• 14%Row houses and townhouses
• 27%Apartments in buildings of 5+ storeys
• 30%Households that rent

27% of homes in Mississauga 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.

14% of homes in Mississauga are row houses or townhouses. Flat sections often run across several units, so a leak can start on a neighbour's part of the roof or at the joint between two units. See townhouses and row houses.

Source: Statistics Canada, 2021 Census Profile

Storms that hit Mississauga

• 8 July 2013: Two thunderstorm systems merged over southern Ontario on 8 July 2013 and caused widespread flooding and power outages in Mississauga and the rest of the Greater Toronto Area. Source
• December 2013: The December 2013 ice storm caused major damage in Mississauga. 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.

Mississauga: facts for property owners

• Population of Mississauga: 717,961 (2021 Census). Source
• Mississauga is part of the Regional Municipality of Peel.
• City of Mississauga: re-shingling a roof needs no permit; 'roof extensions or alterations to increase the height or change the slope' and rooftop HVAC replacements do need a permit. Source
• Stormwater charge: Charge on Region of Peel water bill based on property type and amount of hard surfaces. 2026-27 fee schedule effective April 1, 2026. Source
• Basement flooding prevention rebate: Rebate of up to $7,500 for installing basement flooding prevention measures (detached, semi, duplex, townhouse owners). Source

Rules and programs change. Confirm current details with the municipality before you start work.

Starting prices in Mississauga

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.