Built-Up Roofing (BUR) is the original roofing system that Industrial Roofing Services Limited began installing when we opened our doors in 1973. Today, we successfully install thousands of square feet of built-up roof membranes of all kinds annually. Our certified contractors have the hands-on experience to deliver a watertight, highly durable roof for your commercial property.
Built-up roofing is a time-tested, multi-layer flat roof system. The traditional method consists of a 4-ply system built using 15 lb organic felt layers adhered with hot asphalt, finished with a top flood coat of asphalt and embedded pea gravel. This multi-ply approach creates a redundant, heavy-duty barrier against the elements.
Over the years, BUR technology has advanced significantly. While traditional hot asphalt systems remain effective, modern commercial roofs often utilize organic and glass felts paired with modified bitumen membranes.
To improve job site safety and reduce odors, these systems can now be installed using cold adhesives. This completely removes the need for hot kettles and open-flame torches, relying exclusively on high-performance adhesives to secure the modified bitumen membranes and embed the pea gravel. These modern, flame-free installations are referred to as hybrid built-up roof systems.
☑ 2 Hours Response Time
☑ A repair crew is dispatched to immediately stop the leak
☑ Attempt to perform a permanent repair first
☑ Temporary stopgap measures are implemented if necessary
☑ Cease the water infiltration
☑ Provide recommendations for permanent repair
Installing a Built-Up Roof is a multi-step process that requires precision and heavy equipment. Here is what you can expect when our crews arrive on-site:
When you’re considering to replace your roof, it’s important to weigh your options. Here is a quick look at the advantages and disadvantages of BUR systems:
| Pros | Cons |
| Multi-Layer Protection: Multiple plies create a highly waterproof and durable barrier. | Finding Leaks: The gravel layer can sometimes make tracking down the exact source of a leak more difficult. |
| High Traffic Resistance: Excellent for roofs requiring regular access for equipment maintenance. | Slower Installation: The multi-step process takes more time than single-ply systems (like TPO or EPDM). |
| UV & Weather Resistance: The top layer of gravel naturally deflects harsh UV rays and withstands extreme weather. | Odors (Traditional Only): Hot asphalt installation produces strong fumes (avoidable by using cold-adhesive hybrid systems). |
| Low Maintenance: Highly resistant to punctures and tears, requiring fewer emergency repairs. |
While Built-Up Roofs are incredibly durable, their lifespan relies on your roof being properly maintained. Because the membrane is hidden beneath a layer of gravel, spotting minor issues before they become major leaks requires a trained eye. To get the maximum 30-year lifespan out of your BUR system, we recommend bi-annual inspections to:
IRSL offer quality flat roof services throughout Ontario. With 45+ years of industry experience we are the favourite flat roofing company in the province. Please see our commercial roof repair services below and please do not hesitate to call our team if you have any questions.
Industrial Roofing installs thousands of square feet of BUR membranes annually. Clients continually trust us with these complex, heavy-duty commercial installations because:
Traditional BUR uses hot asphalt to adhere layers of organic felt, finishing with a gravel flood coat. A hybrid BUR system uses organic or glass felts with modified bitumen membranes, often applied with cold adhesives to eliminate the use of hot kettles and open flames on the job site.
A properly installed and maintained BUR system typically lasts between 20 and 30 years. Regular inspections and prompt maintenance can help maximize the lifespan of your roof.
Yes. Despite the gravel surface, experienced roofing contractors can isolate damaged areas, remove the gravel, patch the membrane, and reseal the area. We also offer roof restoration services to add years to your existing BUR system without a full replacement.
Not anymore. While traditional hot asphalt systems are still used, we can install a hybrid built-up roof using cold adhesives. This eliminates the need for hot kettles and torches, making it a safer and less disruptive option for occupied buildings.
Built-up roofs are heavy due to the multiple layers of asphalt and the gravel top coat. Before recommending a BUR replacement, our commercial roof inspectors will assess your existing roof deck to ensure it has the structural integrity to support the weight.
