Okay - even though I have read much more info on how today's PT lumber is so much more safer these days for animals than it used to be, I'm still going to side with trying to use non-PT lumber to build my next coop. I figured out how the majority of the lumber in the coop will be covered from rain, but the corner posts will not. I'm thinking of going with non-PT 4x4s from a lumber yard near by. If I take this route, is there something that I can paint over the 4x4s that would seal them off from rain with no possibility of contamination to the soil or chickens?? Or is there another type of corner post (non-PT) that you would recommend I use? Thanks so much in advance!!