Not a bad idea. I would just think it would get baked pretty easily depending on the stain/finish from sun/rain, but I bet it would look nice.I'm looking at using composite fence pickets for the floor in my rack once it gets the extension and added floor braces. I read a post from a guy in Arizona on a different forum thats had it in his rack in a redwood color for over two years and no warping or discoloration or any other problems. I thought about the coop flooring too but I think I like the composite better.
You would have to come up with a way to mount them. Do you know how he mounted them?
The sheets of polymax flooring happen to be almost perfectly sized for my roof rack and are made to interlock, so it made the install very easy.