The flooring we did. I hope this works for us. We tacked up chicken wire covering the bottom so no critters could get under it. Then we put a layer of gravel down. Our soil is not that well draining so we thought this might help. Then my Dad dug me up some nice well draining sand. Once the sand is in and we get ready to move the chicks we will put pine shavings in and use the deep litter method. When we clean it we will just clean down to the gravel and add more sand and pine shaving and compost the poo for next years garden.