Comment by fifticon
OSB wood?
OSB wood?
Advantech OSB will outlast conventional plywood by a mile in the rain. I exposed it, flat (the worst way possible) as subfloor, to rains for 1+ year while building my house with only maybe 1mm of fiber degrading on the surface a few places. Many modern OSBs use hydrophobic glues impermeable to water.
If it were going to be exposed to the elements, I would pick a pine and waterseal it or a marine ply and waterseal it.
It would fail eventually anyway, but either of those two options, depending on price, would be good and cheap enough to last.
OSB is not very nice either. Plywood is definitely the choice here.
I think MDF will easily last until his kids don't fit in it though. I don't think he's going to use it in the rain.