Mixed building sand is the perfect product to use when a full bed of wet mortar is required, particularly when laying natural, concrete or porcelain paving. River sand, crushed sand, and pit sand are the three main types of sand used in building. River sand is typically collected from riverbanks, whereas pit sand is mined from deep trenches. Crushed sand, on the other hand, is made by strategically crushing rocks (to fine particles) in quarries.