Built-up roofing is a centuries old roofing practice that utilizes more than one layer of water-proofing membrane to keep the water out of your building.

Built up roofing systems, often referred to as BUR, have been utilized in the U.S. for over 100 years. These systems are an incredibly reliable waterproof membrane that is field fabricated with layers of bitumen alternated with reinforcing felts. Commonly referred to as “tar and gravel” roofs, built-up systems redundant layers give it exceptional resistance to water and weather. Johns Manville has been a leader in BUR with 150 years of experience, and offers a complete line of fiber glass felts, including ply and base felts, and mineral surfaced cap sheets.

The bitumen typically used in built-up roof systems is asphalt, coal tar or cold-applied adhesive. The asphalt or coal tar is heated in a kettle or tanker and then applied by mop or mechanical spreader. Cold-applied adhesives do not have to be heated to be applied since these adhesives are solvent-based asphalts.

There are options for built-up roof surfacing’s that include aggregate, such as gravel, slag or mineral granules, as well as glass-fiber or mineral surfaced cap sheets. Other options are hot asphalt mopped over the entire surface, aluminum coatings or elastomeric coatings.



    Advantages of Built-Up Roofing

    • Built-up roof surfacing materials can be coated with paint or other reflective materials to reduce the effects of UV radiation. These coatings provide the additional benefit of reducing heating and cooling costs for the business owner.
    • Multiple layers of bitumen provide a redundancy of protection that is very sound and durable.
    • These systems are known for being easy to repair should the roof be damaged.
    • Having been utilized for over 100 years, built-up roofs have a proven history of being effective and a top choice for businesses.
    • These roofs have the ability to withstand strong foot traffic due to the durable materials used to construct built-up roofs.