Have you or the BF looked into doing one of the self-finished epoxy coats? They are about $100 or so at Home Depot/Lowes, but you put them on over whatever is already on the floor. It's basically a really thick paint and it comes with little chips (like round sprinkles) to add traction. We were able to put it down in under 24 hours at our last house. It might not be the worst thing to check out!