Building a Gravel Driveway: 5 Mistakes to Avoid ...
Pieces on the final, top layer should be no larger than a golf ball. The total thickness of your driveway with layers of various-sized gravel pieces should be about 12 inches. 5. Base Layers Not Compacted. Your driveway should be composed of various layers of gravel, but unless each layer is compacted, the driveway will not retain its shape.