I use hay on the floor and in the nestboxes. I hardly ever have to change it out (quarterly at worst) and I think it's because of the poop boards.
I have my nestboxes set up 2 high and the tops of the top layers is a 24" wide, waist-high countertop, with a 2x4" across it, wide side up, about 8" above the top.
This shows it with the roost up in a different position than where it is now, down at the level of the boards across the side, and back, centered over the countertop (poop board).
The light layer of hay on the poop board allows me to use a hand broom to sweep the whole thing, poop and hay, into a 5 gallon bucket every few days, which I dump into a composter- it's a perfect ratio for fast composting, too! Some don't use anything on top of the poop board, but I don't want to scrape!
This leaves almost zero poop to hit the floor in the coop, so there isn't any smell, ever, on the floor hay. I do have to fluff it up a bit occasionally, so the heavy birds have a soft landing.
I prefer hay by far, and without having to change the floor, I only have to buy 2 bales a year, max. I do use food grade DE I get at the ritzy dog food store on the floor, because it prevents hay mites. I use it on the roosts, too, once a year.
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