I have a bunch of old hollow core inside doors that I lean up against the wall.
I have foam padding around the target on the floor but occasionally I get a flyer that hits the cement. I have one of the old good Carbon V tru flight throwers that can handle dozens of tip first hits into concrete. I just finished fixing up the dings in that old knife and redoing the edge and replacing the wrap with some coyote 550 wrapped Strider style. I even made a nylon sheath and it is like getting a new knife. It turned out so well that I have intended to take some pics of it for a while.