I went to a yard sale and said I was looking for a turtle sandbox with a cover for my chicken's dust bath. They had one out back that she didn't think to sell, perfect shape and I got it for a couple bucks. Then I asked if they had any lumber odds and ends. They had just built an addition and had a truckload of 1/2 sheet plywood pieces stored inside. Got that for $20 and it completely sheathed my coop.