I've seen people using pretty varied materials in their chicken run and I'd love to hear why you love what you use - or hate it ;)
We are building "The Garden Coop" on an area that right now is mulch over weed barrier with some plantings. So ripping that out and then we'll have bare dirt.
I'm looking for something easy to maintain - we are in an urban area and the coop will be relatively close to both our house and our neighbor's - so I want to make sure that it can be kept as smell-free as possible with the minimum amount of effort.
Chickens will be allowed to free range during the day to whatever extent they can without becoming predator-bait. If it doesn't work to have them out without supervision they should still get several hours each day in the afternoon.