Vinyl flooring that runs up the sides about 6 to 8 inches is what lots do here. I personally used a thick layer of Patio Paint on the floor, in the nesting boxes, and up the walls. Painted inside of my coop
I laid down a cheap sheet of linoleum flooring on the coop, it has lasted so far for 7 years. And it still looks great. I didn't glue it down but I used trim to hold it down. I just painted the coop before moving the flock into the coop.