Asphalt, also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product; it is a substance classed as a pitch. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs. Common usage often refers to various forms of asphalt/bitumen as “tar”, such as at the La Brea Tar Pits.
