There are many different built-up and hot-mop roofing variations, with more or less layers and different types of rock and/or cap-sheets.
This type of commercial roofing is generally used on low-pitched or flat roofs.
A continuous roof covering made up of laminations or layers of saturated roofing felts, alternated with layers of asphalt, and surfaced with a layer of rock in a heavy coat of asphalt or finished with a cap-sheet.
