It's my understanding that pressure treated wood isn't the best wood to use around chickens or food.
The newer stuff may be a little less toxic than the old Penta-wood. Someone enlighten us.
What I've been using is Eastern Red Cedar harvested and milled locally. It repels most bugs that would eat
it and lasts a lot longer than untreated spruce-pine-fir.
I've built the last 2 coops out of Western Red Cedar. It's very expensive compared to pine or white wood,
but needs no finish to protect it, lasts many times longer,and doesn't contain any toxic chemicals.
Plywood, OSB, and particle board contain formaldehyde and glue solvent residue. I would guess a good
semigloss exterior latex would seal the plywood and stop the off-gassing. Any one know anything about that?