Built-Up Roofing consists of layers of asphalt or coal-tar pitch, (bitumen) hot or cold applied using mops, machines or squeegee applied in between layers of a reinforcing plies, fabric, felt or mat. The reinforcing is rolled into the bitumen for stability and reinforcement. There can be 3, 4 and 5 layers, of bitumen and plies used to provide a thick, redundant, long lasting assembly. Each layer adds waterproofing and longevity.
Also, known as the 'Tar and Gravel Roof', the built-up roof membrane (BUR) assembly was invented in Chicago shortly after the Great Fire of 1871 by a CRC Contractor Member family who is still in business today.
The asphalt type Built-Up Roofing (BUR) membrane assemblies can be protected with gravel, pavers, vegetative garden covering or left as a smooth surface with a reflective coating or granules. Coal tar pitch BUR membranes are only graveled.
Multi-layer BUR membranes provide redundancy through multiple plies of felt and bitumen. The BUR provides longevity and a long history of performance and continues to be one of the most durable and cost effective roofing systems.
Coatings over BUR's can provide reflectivity and also some fire resistance. Smaller round river washed gravel provides UV protection in addition to fire-resistance from flame spread or flying burning objects from other burning buildings nearby. And, vegetative rooftop gardens and photovoltaic panels can be used over these roofs.
The built-up roof 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.