depending your predators me for instance I have mt lions , bears , fox , coyotes , the big guys 2x8 strips of plywood with many sharp screws or nails placed around the coop will stop them in their tracks.
for the smaller predators racoon, squirrel , skunks , rats ect a electric fence will ward them off . just don't build one like I did. see details below
as for snakes a bunch of 24 inch pieces coiled sheet metal
so the snake can;t get over it .
back to electric fence I set up my own using 12 old 6 volt battery's from old trucks . actually watched a bear fall down from the jolt . it hit him so hard . I didn't think was going to be that strong ,
I disconnected the battery's as it was just to over powering . I went and bought a electric fence box so far it works good nothing cooked just deterred sorry Mr bear lol