This sand and gravel mix provides excellent drainage when used as a base material for interlocking stone. It compacts to 3/4's of the original depth once it is tamped. For patios with only foot traffic, we recommend 4-6" after compaction. For driveways, we recommend at least 12-16" after compaction. Keep in mind that when compacting Granular A and other compacting base materials, only 3 inches of material should be layed down at a time, running a tamper over in between each layer. This will greatly reduce sinking or shifting over the years.