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Built Up

Commercial Roofing systems

Built Up systems

A built-up roof (BUR) is one of the oldest, most traditional flat and low-slope roofing systems. These commercial roofs consist of waterproof layers of thick compounds, durable fabrics, and roof gravel, glass fiber, or a coating. They’re durable and completely protected from water penetration, making them an excellent choice for commercial roofing businesses.


  • Built-up roofing (BUR) is one of the oldest and most durable systems available.
  • Built-up roofing systems consist of three components:
  • Bitumen (asphalt or coal tars) provides the water proofing and adhesion.
  • Reinforcement with Ply Sheets (felts) provides tear strength, puncture resistance, multiple layers of waterproofing, span caps in the substrate and improve fire ratings.
  • Layers or plies of roofing felts are laid between asphalt or bitumen. The surface of the roof can have a gravel application, or a mineral cap sheet.


  • Its multiple layers provide extra protection and perform well in extreme weather conditions.
  • BUR surfacing materials can be coated to reduce UV radiation, which can degrade other roofing materials over time.
  • These coatings provide the additional benefit of protecting the roof system from premature aging as well as reducing building interior cooling and heating costs.
  • The multiple layers of a BUR system provide redundancy, meaning if one layer is compromised, the other layers continue to provide protection.
  • If the appearance of your roof is important, the gravel texture of BUR is a great choice.
  • The gravel layer in a BUR system helps to evenly distribute the pressure from foot traffic or large debris, reducing potential damage and enhancing safety.
Built Up Roofing Systems

Frequently Asked Questions

  • Is built-up roofing still being used?

    Absolutely, yes! Built-up roofing systems are still one of the best ways to protect a low-sloped or flat roof against water penetration. They’re also quite durable, making them still a popular choice today.
  • What is the life expectancy of a built-up roof?

    The life expectancy of a built-up roof ranges from around 20 to 30 years. Several factors affect the life expectancy, including the quality of the materials used, installer expertise level, and ongoing maintenance.
  • What is a built-up roof made of?

    A built-up roof is made of layers of bitumen (an oil-based, tar-like substance), roofing felts or fabrics, and a top layer of gravel or a protective coating. There are several layers of bitumen and fabric, creating a built-up design worthy of the namesake.
  • How many layers are there in a built-up roof?

    It depends on the design but there are typically three to five layers of materials used to create a built-up roof. If necessary, additional layers can be installed to level the surface.
  • How do you maintain a built-up roof?

    Built-up roofs are tough but they do require a little bit of maintenance to get the most durability out of them. Maintenance requires inspecting the roof regularly, cleaning debris, keeping drainage systems clear, replacing missing gravel, and keeping records of all the maintenance performed. Promptly call for service if any repairs are necessary.
  • What does the process of installing a built-up roof look like?

    When our crew arrives on site to install a built-up roof, they’ll start by ensuring that they’re wearing the proper safety gear and that the roof and their tools are safe for work. Then, we clean the roof and install flashing around penetrations and any walls. Next, we apply a base layer of bitumen, then a layer of roofing felt or fiberglass mat, continuing to sandwich these layers until the roof is built up. Finally, we apply a surfacing coat of bitumen and gravel to finish the roof.
  • What are built-up roofs designed to do?

    There are several purposes to a built-up roof. They’re designed to be extremely waterproof thanks to their layers of bitumen. They’re also designed to be flexible to shift with the building and not create leaks. They’re also fire-resistant and low maintenance and can even add to the energy efficiency of the building.
  • How much does a built-up roof weigh?

    A built-up roof can weigh between 2 and 5 pounds per square foot. Thick roofs with several layers of bitumen and roofing felts will be heavier than thinner roofs made of fewer layers of material.

Our Roofing systems

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