I personally used pre-cut sheet vinyl flooring in top of pressure treated plywood.
I've read of many people trying vinyl / linoleum tiles in their coop and experiencing problem with dirt/poop getting in between tile seams to lift them up eventually. If you're going to actually lay tiles with grout for better moisture protection as in bathrooms, that'll probably hold up fine, but you might want to avoid linoleum tiles.
I have large dog kennel pans made of HDPE for easy slide out of my coop, as I don't think my vinyl flooring will hold up to chicken scratching in the long run. It all depends on the size of your coop, but HDPE sheet as ChickenCanoe mentioned sounds like a good idea.