We are building round retaining walls into the hill in our backyard for an Intex pool. We were going to install a permanent pool, so my landscape contractor (my wife's uncle) was going to put down 3-inches of sand on top of 6-inches of compacted gravel. Now that we are moving to the Intex, I'm thinking we should change the top layer material from sand to dirt or something else. I have not read much here but enough that installing on top of foam sounded interesting.
What should we use for the top layer, just under the pool?
If we go sand, should I install concrete patio blocks to support each vertical pool support?
Advise please. I will post some more recent photos of our progress with the walls shortly.