[59toaster]

It's been refered to Clam shell repair.
DO NOT remove exterior pannels unless it's the last ditch effort. The body is mostly assembled when it is dropped o nthe frame and deck at the factory. The rivets are bucked and it's very noticable when they have been replaced. The lower rivets will hide under the rub rail so not noticable.

Once you drill out the rivets to the first rib under where the rub rail attaches and remove everythign above the bumper then lower the belly pan pan to get at the bolts. You will need to remove the inner lower pannel.
Once everything is free you can put about 200lb on the ends of the bumper and cause the frame to drop about 1-2 inches from the body. This is just enough room to slide in a new peice of deck.


You can only get away with this to the first rib . At the First rib the U-channel has a second lip that wraps under the deck and makes it near impossible to slide wood in and out.

If you hit the search buttom at the top right you should be able to find quite a few posts on how to do this. Many ofe these folks have some pictures if you hit the Photo button at the bottom of their post. use key words like rot, floor repair, clam shell, etc.

I would also look at the posts about Sag or trail droop. Many longer coaches have this problem and there are repairs for it that would be easy to do as your replacing the flooring.