We got the bottom of the flooring on (pictured below). I went with plywood (3/8″, which is very reasonably priced) instead of the aluminum flashing because this thing isnt going to be on the road, and because the floor needs to breathe. If I do end up taking it on the road for some time or find that it needs more protection I will either seal it or put flashing on the bottom side of the trailer. Either way, for now it will be OK.
We were sure to leave 1/8″ (a nail’s width) between each sheet for expansion space.
Then we had to flip the thing. The middle section between the wheels proved to be a weak point, and the thing is very very very heavy. Once we had it vertical, I was verrrry sketched out about how to get it over without it sliding out from under us and breaking all of our necks. Rusty and Mike kept their cool and we did it without incident:
Once it was flipped we lined it up and it looks good. Next: put in the insulation, foam where the insulation meets the “joists,” add the poly 4 mil membrane and then cap it with some 1″ rough cut hemlock boards as the flooring.