Coatings continued pitch

Built-up roofing n. 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. Harris CM (2005) Dictionary of architecture and construction. McGraw-Hill Co., New York. 

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