bad paints and wood?

   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?

If you use a paint you must prime first. If you use a stain (exterior stain of course) you don't prime.

If a wood product is stained or painted it's sealed. The only down side to pressure treated is it doesn't accept paint well when new. You can stain it new though.

Also, avoid OSB at all costs where moisture is possible - that stuff is junk - even for a chix coop - if it stays dry its OK though.

It has been my experience that OSB will perform adequately, if primed and painted appropriately.

Pressure treated lumber is best for ground contact or repeated wetness.  On the other hand, pressure treated is sometimes cheaper than regular lumber.  In that case, price is a good guide.  Pressure treated wood needs to dry for about six weeks to be able to accept paint. Pressure treated wood requires specialty fasteners, else the ordinary ones will corrode rapidly.

Chris