Originally Posted by mtunderwood
What can be done about moisture that gets to the floor? Is there a way to allow the moisture to escape so there is less chance of rot or mold?
I had thought about this before putting in the subfloor and I don't think holes in the floor are a good idea. Not unless you feel like providing some sort of drainage space so the water can freely flow to the holes (say, lift the whole subfloor 1/4" an inch and leave dead air). Otherwise capillary action will keep the moisture trapped between the metal floor and the subfloor. With a tight fit between metal floor and subfloor the holes will _add_ to the moisture, not subtract from it. Luckily, rigid foam isn't entirely water proof. With that in mind, as long as the moisture isn't routinely going into the floor, my guess is that it will slowly wick it up and hopefully it will evaporate into the living space.
Now, if the bus is never to be driven I'd say it'd be worth leaving the holes. Otherwise, stop all leaks and seal it up the best you can. I would NOT put plastic vapour barrier between any layers in the bus since you DO want water to wick away from the metal and into your living space. The metal is a vapour barrier, after all. Two vapour barriers back-to-back seems like a bad idea. Hopefully the interior will never be wet enough for moisture to wick the opposite direction. Maybe if you drove off a boat launch...
My thoughts. I'm no engineer, but this is how I see it.