Built-up Roofing (BUR)
Roof Online Staff
Last updated June 25, 2020
Basic Information: A built-up roof is a type of “flat” or low-sloped roof made up of multiple layers of bitumen (asphalt or coal tar pitch) and reinforcing felts.
Typical built-up roofs have three to five layers, called “plies”. Built-up roof systems typically have a layer of insulation under the waterproof bitumen membrane, as well as some sort of protective surfacing, most commonly gravel. A built-up roof is frequently called a “BUR” in technical literature. The colloquial term “tar and gravel” refers to built-up roofs.
1. General: For an informative, in-depth general article about various roof systems, see this page at the Whole Building Design Guide site, which is maintained by the National Institute of Building Sciences.
3. Inspection and Maintenance of built-up roof systems: ROOFER: An Engineered Management System (EMS) for Bituminous Built-Up Roofs is an extremely detailed and valuable resource put together by the US Army Corps of Engineers' Engineer Research and Development Center, and available at the Defense Technical Information Center website.
4. Safety: See this material safety data sheet for health and safety information about the roofing asphalt used in built-up roof systems at the Owens Corning website. This is only an example and other products and brands may be different.
6. Safety: See this material safety data sheet for health and safety information about the interply felts used in built-up roof systems at the Johns Manville website. This is only an example and other products and brands may be different.
8. Manufacturers: A list of built-up roof system manufacturers can be seen here.