how deep to dig for a driveway
So if you are paving a driveway with 2 1/2-inch thick bricks, you need to dig a level hole that is 8 1/2 inches deep.. For vehicular traffic, excavate 9 to 11 inches deep to allow for base material and 6 to 8 inches of gravel.. ...need to excavate 12+ inches deep for driveway that parks cars (7 inches deep for walkway).  We typically dig a 12â base under patioâs and walkways, and then 18â-24â deep for driveways in Ottawa.The weight of a car will destroy any interlock with an insufficient base installation and you will be doing the levelling again in 2-3 years.. have received four different suggestions about how deep that I need to excavate, as follows: Driveways should be at least 6 inches deeper than the thickness of your brick.