Asphalt or coal-tar pitch, (bitumen) cold applied built-up roofs (BUR) are spray or squeegee applied, with a fabric, felt or mat rolled into the cold bitumen for reinforcement. There can be 3, 4 and 5 layers or plies of felt used to provide a thick, redundant assembly. Gravel or a coating can be applied over the membrane for protection
The cold asphalt type BUR membrane can be either protected with a reflective coating or graveled while coal tar pitch is only graveled. The gravel used is the small round river rock. When gravel is applied, it is a small round washed river rock broadcast into a layer of cold adhesive or bitumen to help keep it in place. The gravel or coating can provide fire resistance.
The cold applied version of the built-up roof provides the advantage of no hot kettles and smoky fumes. There may be some chemical smell as the material cures. And, there might be some application temperature limitations.
The system has to be installed to the manufacturers installation instructions, the listing, where applicable, and the building code.
Visit the specific build up membrane pages for more information.
Professional Chicagoland Roofing Council contractor roofing technicians understand the complexity of all types of roofing and get the installation done right the first time. Contact a CRC Contractor that has the equipment, workforce and technology to get your roof done right.