You only need a 1/2 - 1" inside the coop and it's spread over a large area so weight shouldn't be an issue unless you have a very flimsy floor. Mines 24" off the ground and no problems. I contain my sand in large dog crate pans. Simple, Clean, Fast!
I recently changed to "sharp" sand (builders coarse sand) inside the coop. Have it in the pen area over pea gravel. Also, have a sand box out there for dusting. Use DE and PDZ in all areas and I can't say enough about how easy it is to do a quick cleanup after 6 birds. No smell. I made a scoop...