Just started on our first coop. I was wondering about finishing the interior wood. Is there any reason to paint or seal the interior? It is exterior grade, but untreated, particle board. I was also wondering about lining the interior with tyvek. I thought it might make it easier to clean, but maybe they would be pecking at it all the time. Any thoughts? What size would you make a henhouse for 6 hens? I thought I would have a run for them for days that I wasn't home and let them free-range on days that I am home. Thanks!