I still say a solid roof is best but for those that don't/can't do a roof, plastic sheeting is really great to use on the top and sides (leaving some ventilation of course). I live in Iowa (more than enough snow and wind in the winter and plenty of rain in the spring and fall) and that's what I do on mine. I completely wrap the coop and run in winter then cut out the "people door" into the coop so I can get in lol then I poke a ton of nickel sized holes near the top of the run plastic for ventilation, works fantastic. I take the plastic sheeting off in the spring/summer/fall of the "roof" and replace it whenever it's going to rain but it stays on permanently in winter. (oh and in case it wasn't clear, I take the wrapping off the run and coop in the spring, I just use the plastic on the roof when it's raining in spring summer fall), I hope that made sense, I'm tired lol