The floor design in your Trail Mite is similar to most of the Boler
clones. I am describing a Scamp
. Yours may have some slight differences, but the basic process is the same.
The floor is attached to the frame, probably with screws, a lot of them, then the shell is attached to the floor with those fiberglass strips, or tabs. There’s another one under the floor which you will leave in place. The shell is not attached directly to the frame anywhere.
So the shell doesn’t shift, it’s best to work on one section of the floor at a time. Carefully cut through the fiberglass tab around the edge of the floor, one section at a time.. A multi-tool with an oscillating blade works well. Use good PPE when cutting fiberglass. Then remove all the screws, drilling or cutting as needed. .
Once the board is loose, remove it and use it as a template to cut the new one. The cheapest option for replacement is OSB, available at Home Depot and other building supply stores. That’s what Scamp
uses now. Marine plywood is a nice upgrade, but pricey and hard to obtain in some markets. Seal the bottom with fiberglass resin. Cut and seal the freshwater tank drain hole if you plan to reinstall it.
Before reinstalling the new flooring section, this would also be a good time to wire brush and paint
the exposed frame with a rust inhibiting paint
Lay the new floor section in place, mark the location of frame members, apply epoxy to the bottom tab, and screw it down with self tapping screws. Then lay in new fiberglass tabs along the edge of the floor.
Repeat for each damaged section. Some people seal the top after installation, either with more fiberglass resin or paint
. Others leave the inside unfinished to allow the wood to breathe.
If you remove the closet and galley during this process, you should add vertical supports to hold up the roof. Interior cabinets are part of the structure of the trailer Lengths of 2x4 with squares of plywood at the top to distribute the pressure will work. If you don’t support the shell during the rebuild, it will sag and nothing will fit right when you go to put it back together. One good snow and the whole thing could collapse..
There’s a great primer on working with fiberglass right here on this forum.