Rotten floors are only one area of concern. If you are looking at a '85 vintage trailer these are now 30 years old and some have had at leadt parts of floors replaced. On my 1985 16" the rear floor has bad spots aroung the back where the main stress from holding the shell is located and the front had been replaced.
I decided to pull the front first since I want to move the side bath to the front. The frame had repairs made to the tongue and this did not particulatly concern me when I bought the unit.
Upon removel of the front floor I found that the holes from the sheet metal screws and been the starting place for cracks that extended across the frame members and the area where the tube is bent to form the VEE had numerous cracks. Also the door entrance tubse that tie the front to the back on the right side were cracked and split.
These had been "patched" poorly.
Also the dead axle
is a prime contributor to the cracking frame and it is estimated that by 20 years the rubber in the axle
is dead and the main suspension is the tires
at that point.
I plan to replace the frame in the damaged areas with the 11 gauge material used in the later scamps and reinforce the areas that have failed, extending the square part of the frame forward of the egg.
I am also going to add bracing made of either angle iron or sone square tubing to carry the loads along the side of the egg that are now barely supported by the floor from the frame to the wall. These can support very little since they are really only cabaple of supporting themselves and any weight
added in these areas is really suspended between the wall and frame by the floor.
Actually the entire weight
of the trailer is supported by the contact aref of the front and rear floor in the area where the frame passes under the shell.
This concentrates the stress in these areas and makes the floors more cirtical here. The sides just serve to close out the bottom and carry a very small part of the total load.
The above may not apply to the Casita
with its fiberglass bottom, but I have not looked at one all apart yet. The loads still have to be carried from th egg to the frame.
My plan is to add as light weight
supports for the shell around the bottom of the shell with the above mentioned angles and tubing so that the floor really only closes out the bottom. Then I can fabricate the floor from a sandwich of fiberglass sheeting like is used in bartroom remodeling and 1" foam board. This will be epoxy glassed to the walls to seal and insulate the bottom.
The reinforcements may add some weight to the trailer, but as I see it these eggs have had the weight more or less continually increase during their progress from their inception.
Before you buy a trailer look carefully at the area on the inside if the bends at the front ant at the area around the transition from the door beams to the rectangular tubing on the right.
Also look carefully at the age of the axle
and get someone heavy to jump up and down in the trailer and look to see if the suspension movement is in the tires
or the axle.