Never rely on chicken wire for safety. Install a ¼ inch hardware cloth freely. Bury him or put on an apron. Close Coop and open the doors at dusk.
USE 2-STEP LOCKS ON THE LATCHES OF THE LATCHES Most people have some type of aerial predators. Whether it's falcons, owls, eagles or hawks, the best way to deter them and make your chicken coop predator-proof is to block the top of your chicken coop. Wherever you use chicken wire, such as window areas for ventilation, around the bottom, or for running, use a hardware cloth instead. Some raccoons will simply open the chicken wire and enter at will.
Wire cloth (the finer the mesh, the better) is more expensive but much more dissuasive. You can use mosquito net, chicken wire, snow fences, tarpaulins or shade nets. You might have some of this lying around and you can use. Bury chicken wire or wire mesh 12 inches deep along the run to add an additional barrier against digging predators.
Common chicken predators include birds of prey (hawks, eagles, owls), raccoons, possums, snakes, rats, skunks, foxes, coyotes, bears, weasels, minks, fishing cats, bobcats, and badgers. Set the trap near your chicken coop and lure predators with bait that is even more attractive than the chickens themselves. Another option to secure the bottom of the chicken coop is to use a single electrical cable close to the ground so that a predator, such as a rat or raccoon, will get a shock to the nose when trying to dig underneath. Make sure you go out and collect eggs every day so predators aren't tempted to visit your chicken coop.
I think the Advan Tech OSB subfloor is a great option considering that your chickens will put a lot of moisture in the ground from above. Flimsy and poor quality products, such as hinges, are easy for larger and more agile predators to destroy. Therefore, it's important that you research what predators your herd might be facing in your area. When designing this chicken coop, many predator protection techniques were included, such as predator proof locks, a hardware cloth apron buried around the perimeter of the entire run.
If you're building a predator-proof chicken coop, you don't want easy access from above or below. Mink, mice, rats and snakes can pass through chicken wire and fishing cats are strong enough to separate the cable and access. I know chickens don't care what it looks like, so I plant seeds by shedding them and covering them with soil. This is the best place to learn all about how to keep chickens safe from predators, both inside the chicken coop and on the run.
Have lots of low shrubs around the perimeter of your yard so they have a place to run for cover if there is a predator nearby. It's a great idea for your chicken coop to have windows because in winter the chickens will spend most of their time there, the light and the view from the outside will help a lot.