Originally Posted by Stoney
You should b able to take everything out of the room. Take a skill saw get it close as u can to the wall set it at 3/4 inch plywood cut it then remove .I have done it before but not no a airstream .Good luck post if it works. Stoney
Absolutely the wrong way to replace a floor in an A/S.
The floor is the main structural component attaching the shell to the frame on an airstream. It provides the rigidity to properly hold the shell to the frame and if you cut the floor like this you will seriously comprimise the strength of your trailer.
There are bolts inside the wall attaching the shell through the floor into the outriggers of the frame. The inner skins must be removed to access these bolts. You must also remove the belly pan(aluminium bottom) of the trailer to access the bottom of the bolts to tighten the new ones upon installation of your new floor.
First let's start with a little terminology. The body oy the trailer is called the shell. The interior walls are commonly refered to as the inner skins.
The walls in between rooms are called bulkhead walls. The aluminium covering the underside of the trailer is called the belly pan. Along the outside of the trailer at the lower edge of the shell there is a piece of aluminium that curves under the shell to transition from sides to the belly. I call them side wraps. On each corner of the trailer again at the bottom of the shell is a curved piece shaped somewhat like a banana, hence they are called the banana wraps. At the point where the shell and side wraps meet is a trim molding it is called the lower beltline trim. Inside the walls an extruded aluminium channel is used to attach the outer skins and inner skins to the shell. This C channel is also used to attach the completed shell to the floor and frame. There are two designs of this C channel. The curved ends of the trailer(end caps) use a single C channel and along the straight sides of the trailer use a double C channel. The single C used on the end cap area is vertical with the legs of the C pointed upwards and just sits on top of the floor. The double C channel is both vertical and horizontal, IE: the vertical part is the same as the end caps and the horizontal part forms a track for the floor to sit in.
I know that is a lot to take in but you can refer to this later and it will make discussion between members easier.
Moving on to your question. Replacing the last section of your floor is relatively easy compared to the rest of the floor due to the single C channel.
First remove all the furniture in the bedroom (2 single beds and the night table between them. they are just screwed down to the floor with wood screws.
Next using a drill with a #30 or 1/8" drill bit drill out all the rivets attaching the lower pieces of the inner skins. you should be able to roll the side parts forward into a coil still attached to the rest of the shell to expose only the area you are working on.
Remove all the insulation to see inside the walls. Now you will be able to see the C channel and the bolts.
Next go outside and using the same drill, drill out the rivets attaching the lower beltline to the shell. this beltline is in pieces remove enough to get at the area for repair. This will now expose the rivets attaching the side wraps and banana wraps,again drill them out.
Now go underneath the trailer and using a larger 3/16" drill bit drill out the rivets holding the belly pan to the frame. Once the belly pan is dropped far enough forward in your work area you can remove the insulation. you will find some very nasty surprises under there.
You are now ready to remove you rotten section of floor. There are several floor screws attaching the floor to the frame and as I mentioned earlier bolts called elevator bolts inside the wals attaching the C channel through the floor into the outriggers. Remove all these bolts and screws. There are also several small wood screws used to attach the C channel to the floor these need to be removed as well.
Last but not least at the rear of the trailer are two larger main hold down bolts and a steel plate calle dthe rear hold down plate. Before removing them support the frame from below with some jack stands. the frame is surprisingly flexible and will drop down quite a bit once you remove these bolts(ask me how I know).
That will get you started and I can go on later as how to replace the floor and the installation process.
I suggest you get all the materials you need first before doing any tear down.
Elevator bolts and floor screws can be purchased from fastenal and another place from which you can purchase them is Vintage Trailer Supply. They have exactly what you need and make it easy to source the correct ones. Vintage Trailer Supply - parts and supplies for vintage travel trailers and campers!