Ok I ruined my edit by adding pictures.. but the TL/DR was:
I replaced a portion of my rear floor and interior wall on my Sonic 190VRB. Method was learned from YouTube university and involved a mold/rot killing with chlorine and then sistering rotted joists with new PT exterior ground contact lumber and new flooring also ground contact PT. And using 2-part epoxy off Amazon to strengthen/seal/waterproof the whole solution.
With the non-porous epoxy finish, laying down peel and stick was a great solution to the Linoleum removed. And the fix was rock solid.
Btw for rear wall repair, utilized FRP from Home Depot. Heavier, but totally waterproof required no finishing, and easy to work with.
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