I was going to say the other day when people were talking about using the plastic feed sacks for shade or for growing things in, if you will roll some regular acrylic house paint(white usually but your choice) it will slow down the ultra violet rays of the sun that helps to deteriorate them faster, and way back when i was raising lots of game fowl for sport, we used to make 4'x4' round top pens from 2"x$' welded wire 4' tall, using a 12' long piece I think, with a 2"x6" board from for the bottom, then on the ends use the 2"x4" welded wire, some trimmed it ti fit some don't, some put doors in some don't, then I used paper feed sacks laid out flat on the back half over a roost pole centered under them, I would take the feed sacks and lay one out on the sides and see where I needed to tie off long pieces of baling wire, usually centered one and one on each end in about 6 inches, then I would layer the feed sack up both sides like shingles over lapping the about half a sack for better insulation and then when they met on the top I'd use one for a ridge cap like on a house roof, pull the wires up as you go and tie them snug in the middle, you could paint them with house paint also but we didn't, usually replaced them once a year, usually in the spring!!! Sounds complicated but it really isn't, I put cut out bleach or detergent bottles on the front inside corners for waterers and tossed feed on the ground, we didn't enclose the ends so that you had good air flow for ventilation. If I had problems with wind Id use re-bar stakes at an angel on the corners, usually moved the pens at least once a week or more. These pens work great for one or two large chickens, i have made some longer to accommodate a trio or quad of chickens also. Maybe this will help someone. Lynn