While I have not redone my RT’s floor, in my home I’ve put in an “engineered” wood floor (stabilized thin layers glued together with last veneer made of wood species of choice; ½” total thickness) that is prefinished. The edges are “tongue-n-groove” to achieve snug and locking fit. Had to buy an inexpensive crow-bar like tool that you hit with a hammer to snap the boards together. This was a floating system (not nailed) which helps floor from buckling during contraction/expansion of wood (all materials will do this). After 9 years still looks good, no splits or checks nor shrinkage. Key is solid sub-floor, perfectly flat no dips or valleys to prevent creeking noise.
Having said that, a “true” wood floor in a moving van seems tricky – constant movement suggests unstable sub-floor and possibly some bending when the van hits bumps. It would seem to make sense to use a floating system, but I think since the area we are talking about is small (about 30” wide x 10 ft long?) maybe glue-down system may work better. If I were to do mine, I would use a solid plywood sub-floor on top of the bare metal floor with ridges filled (metal rate of expansion is too different from wood). I would want to secure the plywood to the metal floor – not sure if glue or screw. I would leave gaps, maybe 1/8” at edges of plywood to adjacent vertical surfaces for expansion – maybe seal it. Before I glue the finish wood floor I would acclimatize it inside the van at least overnight so that it is as stable to its environment as possible. If you can park your van in a covered area (no sun nor rain) – garage is better – to do the work. Hopefully no extreme humidity.
If you are not a purist, then consider LVT – luxury vinyl tile (try Mannington.com for pics) – with the wood look. There’s wide range of quality but some really look good. You would still need a sturdy sub-floor but not losing that extra half inch of height.
Whichever method you use, good luck…keep us posted.
