Because it is starting to get warmer here in Michigan and we get rain or it snows and melts, my chicken run is getting to be a muddy mess! Is there something I can put down over it so my chickens don't have to walk in it?
I fix mine with nothing really. If you grass is growing and if it is time for a cut, cut it and then bag it up. (If your lawnmower has bags on it.) Then throw it into the run. If I don't want to cut my grass, get like some long weeds wherever you can find them. Then throw them into the run. It really helps me, and the chickens love scrathcing through it!
I like the sand myself. Be careful with pea gravel some have posted on here that when they put that under the sand it didn't do so well. You may want to do a search on here for sand and pea gravel.
The chickens will dig down deep to take dirt baths. They'll be able to dig up the pea gravel if the sand isn't deep enough. Don't skimp here because it'll be tougher to fix. You can lay some 4 x 4's or 4 x 6's on their side, drill holes in them, and stake them down with rebar. Then fill with sand. That will raise the floor of you run. I did this in my horse stables and it works great!!! Never any water in them.
A farmer friend of mine suggested getting wood chips, and we've been very happy with that. Our run was muddy, and the wood chips worked great. They composted a bit over the winter and now that the snow is melting and it is really wet out there, I plan to get another batch delivered. Here you can get them for free. Just call a tree service company and they're more than happy to drop off a load of wood chips after a job of theirs for FREE.