When we built the frame we used 2x4 along the bottom on the inside and placed a layer of fence and used fencing nails to attach
We also took 24” y’all HC and bent it at about 4 in and layed long pat along the ground and the four inches against the fence. Then took 2x6 on the outside and screwed it to the fame. Also poultry netting along top supported by 2x4 and 2x2.
The skirt we layed flat instead of digging. You can see vegetation will grow to help hold it in place along with ground staples. Picture probably explain it better. This at least for me has worked for raccoons. As long as they don’t sneak in there through door while chickens are out and hide till night.