I'd wait on the predator proofing until you come here and see what VF did on our run; it's awesome and MUCH easier than what you just said. It's just a hardware cloth apron all the way around the run so that nothing can dig under. Super easy and since predators aren't smart, they don't think to back up 12" and dig under away from the run. DummiesI think the dog attack has left us feeling a little uneasy with the whole predator thing. Today, DH decided that we will dig the run down, lay in some chicken wire and encase the chicken wire with concrete. Then we'll fit it back in with dirt, and put whatever top layer we want. I'm considering large bark chips. I bought concret mix this evening. Getting the run complete will be a bit more work, but it will be nice knowing we did our best to keep our girls safe.
