We would like to section off a portion of a 30 year old hog barn into a coop for 25 chickens. The flooring is rubberized with a 4' pit underneath. Is that flooring ok to use for the chickens? We are using old Sow feeders for the nesting boxes, and will put a door in the wall so they can go outside during the day. My biggest concern is the flooring. Do I need to cover it with plywood, or is this ok?