I have a couple of questions about run construction that I haven't come across exact answers for in this forum: 1. Is there any concern about toxic chemicals in treated lumber, or are the new preservatives safe? I'd like to use treated 4 x 4s and 2 x 4s, but I don't want the chickens pecking at it and ingesting unsafe chemicals. 2. Is a 3' strip of hardware fabric buried a foot deep good enough? What would or would not be able to get through or around that? Thanks!