Built-Up Roofing
Built-up roofs BUR are roofing assemblies composed of alternating layers of bituminous sheets and viscous bituminous coatings.
Built-up roofs are a class of low-slope roof that consist of layers of reinforcing felt between either asphalt or coal tar bitumen.
The reflectivity of BUR depends on the color of the surface layer. Four BUR surfacing options are aggregate, smooth, mineral cap, and protective coating.