I have a large concrete slab upon which our new coop can be built. I see some sites mentioning not having concrete flooring for a coop. I plan to have a "back door" to open up when I need to clean out the coop. Are you all for or against concrete flooring? Would you use it if you had the chance and was already there. Frankly, I would be happy to have it covered up so I don't have to look at the slab the rest of my life. Also, I am looking for coop plans for 30+ birds. Any ideas? Is it possible to convert a steel building into a chicken house? BTW, The chicken run will have a covered top over a dirt run.