Why not an apron around the outside of the pen/coop. I did that, using the rabbit type fencing (2x3 graduating down to 1x3 I think). I was only trying to keep out predators and larger digging pests, not mice with this type of fencing. I used available rocks to hold it down, and wire to fasten it to the bottom of the kennel-run type of coop/run I had. I held the apron down with pavers once, but I think they attracted mice. My birds could walk over the apron but wouldn't try to dig. Of course, they only had access to that because they were free ranging.Did anyone else deal with caliche when they were building a coop? Our yard has a thick layer of caliche right under the surface dirt/sand. We want to construct a hoop coop similar to this one. Since we can't dig down we have to build it all above ground.
That means the bottom of the coop would be hardware cloth sitting right on top of the dirt. We could try to cover it with a few inches of dirt or mulch or something. How would that affect the hens? They wouldn't be walking right on the hardware cloth all the time but it would get exposed. When scratching they'd scratching right down to it.
I did put hardware cloth on the dirt floor inside a coop once, but put in a flooring of pallets covered by paneling so there was no way the birds could get at the hardware cloth. I sure don't recommend that approach!