I'm building my first coop. It will be small (4'x4') with a shed roof framed and covered with plywood. I got some asphalt shingles from freecycle, but wonder what kind of material--if anything--I should use underneath them. I think I read somewhere that the felt-like roofing paper was a mite magnet and thus bad news for chickens. I'm also wondering whether asphalt shingles are such a good idea anyway. The shed roof has to slant down toward the run area because the coop will be attached to another small outbuilding. I can put a little gutter on the edge to redirect run off, but should I worry about those little rubber specks that tend to wash off of shingles? It seems too cold here (in CT) to use the corrugated vinyl roofing unless it was on top of the plywood. If asphalt isn't a good idea, what about cedar shingles? Same questions about what to put underneath. Any advice welcome!