There are a lot of ways to deter digging predators. Rather than digging into the soil to make a wire skirt barrier extending from the coop walls into the ground, we just placed our little feed store custom coop on a paver stone patio and left a little 2x4 dirt floor in the middle of the coop. We eventually raised the coop just a couple inches on treated lumber to divert rain water and it basically worked well to keep the dirt floor dry especially when we used a tarp and a pop-up canopy over the little coop - sorry, no photo of the canopy. This little 4x6 custom coop came with chicken poultry hex wire which I adamantly oppose because stray dogs broke our fence gate and attacked the coop mangling the chicken wire beyond repair. I strongly recommend 1/2" hardware cloth as opposed to this weak chinsy poultry hex wire!!!!!! It keeps chickens inside but doesn't keep predators OUTSIDE!!!!! Our neighbors saved our chickens when they heard the commotion and chased the stray mutts off. TG for good neighbors.
The little feed store coop served us well for almost 5 yrs and now we have the little Barn Coop I always wanted which has a 4x8 heavy kennel run extension (not attached yet) to extend under the coop. Our chickens free-range the yard all day and only use the coop for laying eggs or roosting for the night. The rest of the day they snooze under makeshift plywood lean-to's, several large doghouses placed around the yard, and a pop-up canopy for shade and protection from the visiting Cooper's Hawk.