Bitumen, also known as asphalt is used to build highways, motorways and rail networks. Bitumen has exceptional water-proofing properties and is commonly used for making roofing products along with a range of other household and industrial applications. It is found in deposits such as oil sands and pitch lakes or is obtained as a residue of the distillation of crude oil. Bitumen is dense, highly viscous, petroleum-based hydrocarbon. Other than asphalt, bitumen is also frequently called tar or pitch—though, properly speaking, tar is a by product of the carbonization of coal and pitch is actually obtained from the distillation of coal tar.