Hi J: Thanks for your views. I tend to agree with Steve. Unless you expect stiff winds this winter, 3-tabbing a shed is probably safe. Because you will likely not have a heat source in the shed, ice daming will not be a problem. If you absolutely feel you must wait until spring, I'd keep the tar paper off, put your plastic on and nail down with strips of wood lath, lest the wind whip it all over the place.