I am planning a paver patio, about 40'x20'. There is some 3/4" river rock in the area now. I am planning on removing the river rock and excavating and then placing the proper base material before paving. I am wondering if the 3/4" river rock could be used as a subbase ? If not I will just haul it away, but if it will work I would use it. How deep should I excavate, can the river rock be used and how deep should the sand be. ANy other tips or advice is welcome since this is my first paver project.