I have a small deck (10 by 12) that is going to be up for 2-5 years.
I've priced composite decking, and even 2 by 6, but they are "costly",
and the 2 by 6 is poor quality.

I was wondering about 4 by 8 panels, 5/8 or 3/4 inch (joists are 16" oc)
as a "temporary" surface. Maybe chipboard or outside plywood. What could
I do to it to have it last that long?

I thought about priming and then a rubberized coating, especially on the
edges, leaving the bottom bare. Then thought about treating the bottom
side as well, but couldn't come to a conclusion. Also thought about
raising the plywood off the joists by using angle iron so there was no
wood/wood contact.

What does the collective intellect think?

--
charles