Natural stone border depth

[LeroyMakins2018]

I'm looking at options to edge my residential driveway project. One option I particularly like is a tumbled stone border. If laid for the edging, the stone would be 8" wide, 4" or 8" deep, and of varying lengths. These are chopped, not cut, so sizes would not be precise.

The project site slopes ~6' over 300', and the bottom of the slope is at the bend in the teardrop.

The frost line in my neck of the woods is 2' below the surface.

The pavers are 2 1/4 inches thick.

Dirt would be brought in and leveled with the top of the edging on the outside of the drive, then seeded with grass.

Now to the questions:

Q1: would 4" be a suitable depth for retaining the driveway pavers in the level sections of the drive
Q2: Would I need to bump it up to the 8" depth at the base of the teardrop (where presumably turning pressure from vehicles would be at its highest)?
Q3: Would I need to use staked metal reinforcement for either of the depths?

[Tony McC]

The system you propose is not used in Britain and Ireland. We don't need to construct for frost heave due to our maritime climate. You'd be better off seeking local advice - even in the US, the advice varies with latitude, so different systems/practices are used in, say, Missouri to those used in Montana.