Im a first time chicken mom and im planning to start building this run pretty soon. My mom says a roof is unnecessary but we have hawks and i disagree but since im a chicken amature maybe im being overly cautious? I was just thinking of buling a basic frame and using chicken wire or hardware cloth as the walls and roof and adding a door. Were buliding right next to concrete so im hoping this will help keep out digging predators. Any suggestions? Does this sound safe for my babies? Also how big should it be if i have 3 chickens?