If you look a few back on this thread to post #44, it talks about how to lay the hardware cloth. This is also how we did it and no mink problems. I have literally seen a mink run past the run about 5 feet away from it, and saw one in the barn which is maybe 15 ft from run, so I know they are around but have never gotten in.I hear about chickens, but what about ducks? I can't imaging laying down concrete in the run. My husband was planning on burying hardware cloth all across the bottom. Concrete seems like a fine idea, but ducks are so wet and messy, i see drainage problems....