Quick Answer
City Roofing & Exteriors installs and repairs flat roofing systems across Calgary, Alberta. We work with torch-on modified bitumen, TPO, EPDM rubber, and built-up roofing (BUR) systems for both residential and commercial properties. With 15+ years of Calgary experience and 158 Google reviews averaging 4.8 stars, we are SECOR certified and WCB Alberta registered. Call 403-608-9933 for a free flat roof assessment.
Flat Roofing Systems We Install
Torch-On Modified Bitumen
Torch-on modified bitumen is the most widely installed flat roofing system in Calgary — and for good reason. It is applied by heating the underside of the membrane with a propane torch, creating a seamless, waterproof bond directly to the roof deck. Modified bitumen performs exceptionally in Calgary's climate, withstanding freeze-thaw cycling, hail impact, and heavy snow loads. The multi-layer system is highly resistant to cracking and puncture, making it the top recommendation for residential low-slope roofs, garages, and commercial flat roofs in Alberta. With proper installation and regular maintenance, torch-on systems typically last 15–25 years. City Roofing installs both SBS (rubberized) and APP (plasticized) modified bitumen systems depending on your application and budget.
TPO Roofing (Thermoplastic Polyolefin)
TPO is a single-ply white reflective membrane that has become increasingly popular for Calgary commercial buildings and low-slope residential roofs. Its white surface reflects solar heat, reducing cooling costs during summer months. TPO is heat-welded at seams, creating strong, watertight joints that resist uplift and membrane separation. It is lightweight, UV resistant, and environmentally friendly. TPO is particularly well-suited for large commercial roof surfaces where energy efficiency and long-term performance are priorities. City Roofing installs fully adhered, mechanically fastened, and ballasted TPO systems depending on your building's structural requirements.
EPDM Rubber Roofing
EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane engineered to remain flexible in extreme cold — making it an excellent choice for Calgary's winters. Unlike some flat roofing membranes that become brittle and crack at low temperatures, EPDM retains elasticity well below -40°C. This flexibility allows it to accommodate building movement without developing stress cracks. EPDM is highly durable, resistant to UV degradation, and relatively simple to repair if punctured. It is ideal for residential garages, home additions, and low-slope commercial applications. City Roofing installs fully adhered EPDM systems with manufacturer-backed warranties.
Built-Up Roofing (BUR)
Built-up roofing is the traditional flat roof system — multiple layers of reinforcing felt alternated with bitumen (asphalt or coal tar), topped with a granule surface or gravel ballast. BUR systems are exceptionally durable and have been protecting buildings for over 100 years. The multi-layer construction provides outstanding waterproofing redundancy and resistance to foot traffic. While newer systems like TPO and torch-on have largely replaced BUR for new construction, it remains a proven and long-lasting choice for certain commercial applications. City Roofing installs and repairs BUR systems across Calgary.
Why Flat Roofs Need Expert Installation in Calgary
Calgary's climate presents unique challenges for flat roofing that don't exist in more temperate cities. Freeze-thaw cycling — where temperatures can swing 30°C in a single day during chinook events — puts constant stress on flat roof membranes and flashings. Improper installation leads to membrane cracking, seam failures, and water infiltration within a few seasons. Drainage is critical: flat roofs in Calgary must be designed with adequate slope (minimum 1/4" per foot) and unobstructed drains to prevent ponding water, which freezes and expands under the membrane in winter. Heavy snowfall creates significant dead loads that must be accounted for in system design. Ice damming at parapet walls and drain areas is a common failure point when installations lack proper insulation and vapour barriers. City Roofing's crews are trained specifically in Alberta flat roofing conditions and install every system to exceed National Building Code requirements.
Our Flat Roof Installation Process
Free Roof Assessment
We conduct a thorough on-site flat roof assessment at no cost and no obligation.
System Recommendation
Based on your roof slope, usage, and budget, we recommend the best flat roofing system for your property.
Material Selection
Choose from torch-on, TPO, EPDM, or BUR with detailed pricing for each option.
Installation
Our SECOR-certified crew installs your flat roof system with proper drainage slope and edge termination.
Inspection & Warranty
Final quality inspection, full site cleanup, and all warranty documentation handed over to you.
Flat Roofing for Commercial Properties
City Roofing & Exteriors has completed commercial flat roofing projects exceeding $3 million CAD across Calgary and surrounding areas. We install torch-on, TPO, and EPDM systems for warehouses, retail plazas, industrial facilities, and multi-unit residential buildings. Our commercial division works within your schedule to minimize business disruption, with project management from estimate through final inspection. All commercial projects are SECOR certified and carry full manufacturer and workmanship warranties.
View Commercial Roofing Services →Areas We Serve
City Roofing & Exteriors provides flat roofing services across all Calgary quadrants — NE Calgary, NW Calgary, SE Calgary, and SW Calgary — as well as surrounding communities including Airdrie, Cochrane, Chestermere, and Okotoks. Call 403-608-9933 to confirm service availability in your area.
Flat Roofing FAQ
How much does flat roof replacement cost in Calgary?
Flat roof replacement in Calgary typically costs $5,000–$15,000 for residential properties, depending on size and system. Commercial projects vary based on scope.
What is the best flat roofing system for Calgary weather?
Torch-on modified bitumen is the most popular choice in Calgary due to its performance in freeze-thaw conditions and resistance to hail damage.
How long does a flat roof last in Calgary?
Quality flat roofing systems last 15–25 years in Calgary conditions. Torch-on and TPO systems at the higher end with proper maintenance.
Can you repair a flat roof instead of replacing it?
Yes — if damage is isolated to less than 25% of the roof surface, repair is usually cost-effective. We assess this during our free inspection.
Do you handle flat roof insurance claims?
Yes. We document flat roof damage for insurance claims and work alongside Alberta adjusters throughout the process.
How do I know if my flat roof needs replacement?
Signs include pooling water, visible membrane cracking, interior leaks, or a roof over 20 years old. Our free inspection gives you a clear answer.
Do you install flat roofs on houses in Calgary?
Yes — we install flat and low-slope roofing systems on residential homes, garages, additions, and commercial buildings across Calgary.
Are you licensed for flat roofing in Alberta?
Yes. City Roofing & Exteriors is SECOR certified, WCB Alberta registered, and BBB Accredited.
Ready for a Free Flat Roof Assessment?
Free inspection. Honest estimate. No pressure.