Mine boards are 24"x6'x 3" or 4" for the lip, and the roost is a 2x4 rounded off about 8 or 10" above that. I keep about a 11/2" to 2" deep in PDZ. That way I can scoop and not scoop the pdz out. The girls like to dust bathe before I'm done cleaning out and have even lay-ed an egg into the PDZ, which was not broken. I love it when it freezes-faster to scoop.