We put down lime, and sand, and a bit more lime and DE, then covered the whole thing with the thick woodchips, like landscaping bark. We use the big pieces tho....several people I know who have aviaries use this.
So, every year we mix it all up again and rake it out to remove most of the poop that we can, and add a little more sand, a little more lime, add fresh bark...and in fall we add ALL the leaves we rake up. The birds break them down quickly, but they help so much with drainage. We havent had a mud puddle YET in our chicken run, and that is something living here in the Pacific NW. And the nice thing is that with the bark and the leaves, in the spring lots of yummy bugs show up so the girls are loving it...then we redo the bark in the late summer, early fall.