Boat Storage Help.

Hi all, while we wait for the shed to be done I would like to build a temporary shelter in our field for the trailer and boats as the current tarpaulin system to keep the rain out is difficult to put on and is not terribly successful at keeping rain off. So if anyone has access to cheap or used building materials, timber or metal posts, timber framing, sheet steel, sheet plastic or heavyweight tarpaulin/truck side curtains or old farm building materials, that would be great and we can start making a collection.

Many thanks.
Gary