Mine is a raised coop. The inside walls and floor are just untreated plywood. I use a good layer of wood shavings on the floor, a poop board under the roosts. By keeping the poop board cleaned off and the wet clumps regularly scooped off the floor, plus mixing in some DE to dry things out, the floor and walls still look great after a year. The only thing stained with poop is the roost.
