gravel roofing

built-up roofing, composition roofing, felt-and-gravel roofing, gravel roofing

built-up roofing
A continuous roof covering made up of laminations or plies of saturated or coated roofing felts, alternated with layers of asphalt or coal-tar pitch and surfaced with a layer of gravel or slag in a heavy coat of asphalt or coal-tar pitch or finished with a cap sheet; generally used on flat or low-pitched roofs. Also see tar-and-gravel roofing.
References in periodicals archive ?
Currently, one third of the roofing market is comprised of tar and gravel roofing, which uses fiberglass reinforcements almost exclusively, another third is unreinforced rubber membranes and 25% of the market is held by modified bitumen roll roofing, which is growing more than 10% a year at the expense of the other two.
The most frequent concern with built-up gravel roofing is the need for periodic maintenance to retain gravel coverage on all surfaces.