What is a Built-Up Roof System?
BUR commercial roof systems consist of multiple layers of roofing felts and roofing asphalt (bitumen) or coal tar pitch that provide redundancy of durable protection. These installations can be fabricated in a variety of ways. Typically, a base sheet is positioned over a suitable insulation board and serves as a foundation for additional plys to be mopped. Then, this layered roof system is covered with gravel, a mineral sheet cap or a coating.