Roofless. We always used a ear corn elevator under a hopper trailer.  Silage blower works. Years ago, we couldn't get truck around to the big shed door because of snow banks. slid a silage blower hopper under the trailer, slid blower band around so it would blow horizontal, 3 or 4 sections of pipe through the walk in door, didn't plug. Quite a bit of lint hanging around the shed when we were done.