Type 8 Sub Base
Type 8 sub base is a mix of rock, gravel and clay. It is processed through a screener to become no larger than 1 and 1/2 inch, a grade lower than the type 32-33 gravel. The material is still considered a well compacting material.
As its name suggests, it is typically used to build the load bearing sub structure under the base layer for roads, driveways and gravel parking lots. It is not required when only foot traffic is expected, but is necessary for surfaces intended for vehicles.