caravans?

You can but it sounds to me like the frame or flooring edge is rotten and sides have come loose because of the rot. You will have to either check the underside floor edge for rot and or remove side panels to check the state of the base of side framing.
But first get in touch with manufacturer if they still exisst and ask if they can advise where the side panel mounting points are where it meets the floor and if they would be kind enough to send a diagram of the construction.

Bob
March 2011