I had a digger remove top soil from our backyard so that I could install raised garden beds with pebble paths between them. The soil was removed a few cm deeper than I'd planned, and the level of the pebbles needs to align with concrete paths/pads. If I use just decorative pebbles for the paths, I'll need substantially more of them than originally planned, and they aren't cheap.
There is woven weedmat on the ground ready for the pebbles to be brought in.
I consulted the local landscape supply business, and they suggested using a layer of scoria (a light, bubbly volcanic rock, excellent for drainage) underneath the pebbles. Scoria is substantially cheaper than the decorative pebbles.
Given that scoria is very light (as rocks go), will it rise to the surface and mix with the pebbles as the path is walked on, over time?