
How to Install Asphalt: 10 Steps (with Pictures) - wikiHow
May 01, 2011· The composition of the rock should be coarse and jagged. This type is usually called '3/4" minus' or 'Road-base' mix. If your underlying soil is clay-based, you will need 8 inches (20.32) of crushed rock. If your underlying soil is sandy, you will need 4 inches (10.16 cm) of crushed rock.