Built-Up Roofing (BUR)The Original Flat Roofing Standard
Built-up roofing has protected commercial buildings for over a century. Its multi-ply construction creates a waterproofing system with exceptional redundancy — and when it's maintained properly, it can protect your building for decades.
What Is Built-Up Roofing?
Built-up roofing — often called BUR or a "tar and gravel" roof — is constructed by alternating layers of bitumen (asphalt) and reinforcing felts or fabrics directly on the roof deck. This process is repeated three to five times, with each layer bonded to the one below it. The top surface is finished with aggregate (gravel or mineral granules) or a cap sheet.
Unlike single-ply systems that rely on one membrane, BUR's strength comes from its multiple redundant layers. A weakness in one layer doesn't automatically mean a leak — the layers below continue to protect the building while the issue is addressed.
Many commercial buildings across Oklahoma still have BUR systems that were installed decades ago and are still performing well — because they were properly maintained. Regular inspections and minor preventative work are what keep BUR roofs in service long past their expected lifespan.
Why Building Owners Choose BUR
Decades of proven performance, exceptional waterproofing, and outstanding redundancy.
Multiple Redundant Layers
BUR is built up from three to five alternating layers of bitumen and reinforcing felt. This layered construction gives it outstanding redundancy — one layer's weakness is covered by the next.
Excellent Waterproofing
The combination of bitumen and reinforcing plies creates a seamless, watertight barrier across the entire roof surface. BUR has one of the best waterproofing track records of any commercial roofing system.
Built-In Insulation
BUR systems can incorporate multiple layers of insulation board, making it easier to achieve strong thermal performance alongside the roofing membrane.
Long Proven Track Record
Built-up roofing has been used on commercial buildings for over 100 years. It's one of the most proven systems in the industry, with a well-understood performance profile.
Resists Foot Traffic
BUR systems hold up well to the foot traffic that comes with HVAC maintenance, inspections, and other rooftop work — an important consideration for many commercial buildings.
Suited for Large Roofs
BUR is an especially strong choice for large commercial roofs where the redundancy of multiple layers adds meaningful protection across a big surface area.
Common Applications
BUR is particularly well-suited for large, complex commercial roofs where redundancy matters most.
Maintaining Your BUR Roof
BUR systems are durable, but they're not maintenance-free. The most common failure points are flashing failures, clogged drains leading to ponding water, and surface aggregate erosion that exposes the bitumen underneath. Catching these early — before they become leaks — is what keeps a BUR roof in service for 20, 25, or even 30+ years.
Our Preventative Maintenance Agreements cover scheduled inspections, minor on-the-spot repairs, drain clearing, and complete documentation — everything a BUR roof needs to stay healthy between visits.
BUR vs. Modern Single-Ply Systems
If your building has an existing BUR roof, you may be wondering whether to restore it or replace it with a modern TPO or EPDM system. The answer depends on your roof's current condition, remaining useful life, and your goals.
In many cases, a BUR roof that's still structurally sound can be restored with a roof coating that adds 10–20 years of life at a fraction of the cost of a full tear-off and replacement. We'll give you an honest assessment of your options.
Not sure what shape your BUR roof is in? Start with a free inspection. We'll evaluate your roof, tell you exactly what we find, and give you honest options — whether that's maintenance, coating, repair, or replacement.
Have a BUR Roof That Needs Attention?
We'll inspect your built-up roof at no cost, tell you exactly what we find, and give you clear options without any sales pressure.
