We use the washer/screw system as it's the easiest method to replace the wire as needed. We use a few staples to pull the screen tight, then use the screws and washers. Plus, seems to be largely secure, even with big peafowl. We make a bit of a sandwich with the wire.
First inside layer is 1/2" mesh, it's either 18 or 20g. Keeps the less the bright ones from getting caught in the larger grid or babies from getting out, and keeps smaller predator feet from getting in.
Between that and the wood frame is 14g 1" x 2" wire. 18 and 20g is too thin to keep most things out to me, but the bigger grid doesn't keep feet out, or all predators, and heads can get caught (peafowl being the main problem there). It's probably way overdone, but it's how we feel most comfortable. That is dug down 3' and goes out flat 3' also.
Then the wood/PVC frames.
Then the outside is electrical wired for the various predators. It's not so much a list of what we have here, the list of what we don't have would be shorter. The coons/opposums/birds of prey/fox/coyotes were all more/less respecting the fence set up (the coons liked to try to see if they could take apart the latches), but the new idiot from Hades neighbors had the worst stupid small terrier who was NOT respecting the fence set up or the guard dogs. So we wired up the fence, and now the dog is staying far away and the silly little hawk who was trying to find a way to break in for a chicken dinner hasn't come back.
This may be Fort Knox of Chicken Coops.