COMMERCIAL ROOFING · CHARLOTTE, NC
Built-Up Roofing (BUR) in Charlotte, NC
Built-up roofing — the classic “tar and gravel” flat roof — has protected commercial buildings for over a century, and for good reason. Its multiple layered plies and gravel surface make one of the toughest, longest-lasting flat roofs you can buy. 365 Roofs installs and repairs BUR systems on flat and low-slope buildings across Charlotte and North Carolina.
The Basics
What Is Built-Up Roofing?
Built-up roofing, or BUR, is the original flat-roof system — and it’s still going strong after more than a hundred years on commercial buildings. The name says it all: the roof is literally “built up” on site from alternating layers of bitumen (asphalt or coal tar) and reinforcing fabric plies, stacked one over another and topped with a protective surface. The more plies, the more redundancy and the tougher the roof.
That layered construction is why BUR earned the nickname “tar and gravel.” Each ply of felt or fabric is set into a mopping of hot or cold bitumen, and the assembly is finished with a top layer that shields it from sun and weather. The result is a thick, seamless membrane with no single point of failure — a proven approach we cover alongside other systems on our commercial roofing page.
The Layers
Multiple Plies for Built-In Redundancy
A BUR roof is defined by its plies. Instead of relying on one membrane, it stacks several reinforcing layers into a single thick assembly. If the top surface is nicked or worn in one spot, the layers beneath it keep the building protected — the same redundancy that makes a multi-ply roof so forgiving and so durable.
Those plies also add real puncture and weather resistance. A well-built BUR roof handles the everyday abuse of a working rooftop — foot traffic, service crews, and equipment — without the vulnerability of a single thin sheet.
The Surface
Gravel Ballast and Surfacing
The classic BUR finish is a layer of gravel or crushed stone embedded in a final flood coat of bitumen. That ballast does several jobs at once:
- UV protection — the stone shields the bitumen from sun damage, the number-one killer of flat roofs.
- Fire resistance — the mineral surface adds a protective, non-combustible top layer.
- Impact & weather — the aggregate helps absorb hail and foot traffic.
Some BUR roofs use a mineral cap sheet or a reflective coating instead of loose gravel — we’ll recommend the surfacing that fits your building.
The Payoff
Longevity and Best Uses
Longevity is BUR’s calling card. Because the system is thick, layered, and gravel-protected, a properly installed and maintained built-up roof commonly delivers around two to three decades of service — and its multi-ply redundancy means small surface issues rarely become sudden failures. It’s the kind of roof you install and largely forget, as long as drains stay clear and flashings are maintained.
As with any flat roof, that lifespan depends on installation quality, drainage, and routine maintenance — ponding water and neglected flashings are what cut a roof’s life short. BUR is an excellent fit for flat and low-slope buildings that want maximum toughness and a long service life, and where the weight of a gravel-surfaced system suits the structure. If you’d rather have a lighter, reflective membrane, ask us to compare BUR against TPO or EPDM single-ply for your building.
Already Have One?
Repairing and Extending a Built-Up Roof
Many of the BUR roofs we service are decades old and still have life left in them. Because the system is layered, a lot of issues — blisters, cracks in the flood coat, worn flashings, or bare spots where gravel has migrated — can be repaired without replacing the whole roof. Keeping the surfacing intact and the drains clear is often what buys a built-up roof its last several years.
When the membrane has genuinely reached the end of its life, a reflective restoration coating or a full re-roof may be the better value. Our free inspection will tell you honestly which stage your roof is at — we won’t push a replacement on a roof that just needs maintenance.
Questions, Answered
Built-Up Roofing FAQ
What is built-up roofing (BUR)?
BUR is the classic “tar and gravel” flat roof, built up on site from alternating layers of bitumen and reinforcing plies and topped with a gravel or mineral surface. The multi-ply construction creates a thick, seamless, redundant membrane that has protected commercial buildings for over a century.
Why does a BUR roof have gravel on top?
The gravel ballast protects the bitumen from UV damage, adds fire and impact resistance, and helps hold the surface layer in place. Sun is the number-one killer of flat roofs, and the stone surface is what shields the membrane beneath it.
How long does a built-up roof last?
A properly installed and maintained BUR roof commonly delivers around two to three decades of service. Its multi-ply redundancy means small surface problems rarely turn into sudden failures — but good drainage and maintained flashings are essential to reaching the longer end.
Can an old built-up roof be repaired instead of replaced?
Often, yes. Because BUR is layered, blisters, cracks, worn flashings, and bare spots can frequently be repaired without a full re-roof. When the membrane is truly worn out, a restoration coating or replacement may be the better value — our free inspection will tell you which.
Is BUR better than single-ply for my building?
It depends. BUR offers maximum toughness, redundancy, and a long service life, but it’s a heavier, gravel-surfaced system. Single-ply membranes like TPO and EPDM are lighter and reflective. We’ll assess your structure and give an honest recommendation.
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