Built-up roofing (BUR)

Built-up roofing (BUR) is a type of roofing system that is made up of multiple layers of asphalt or bitumen, which are alternated with layers of reinforcing materials such as felt or fiberglass. The layers are typically applied in a hot-mopping process, with each layer being heated and rolled out over the previous layer to create a seamless and waterproof barrier.

BUR roofing systems are commonly used in flat or low-slope roof applications, such as on commercial or industrial buildings, and are known for their durability and long lifespan. BUR roofing systems are also relatively easy to install, and can be customized to meet the specific needs of a building, such as adding extra layers for added protection or insulation.

However, BUR roofing systems can be heavy and brittle, and may require specialized installation techniques, which can result in higher installation costs compared to other roofing materials such as asphalt shingles. Additionally, BUR roofing systems may require regular maintenance to keep them in good condition, and may have negative environmental impacts due to the use of petroleum-based products. Overall, BUR roofing is a cost-effective and versatile roofing option that provides many benefits over other roofing materials, but also has some limitations.