If you really want to go all the way in building a saferoom or armoring your house against the mutant zombie cannibal welfare bikers, you need to check out ArmorCore.
Even if you decide not to buy, the videos (that’s one of them) are worth watching. This must be some tough stuff.
You know, if they had it 1/2″ thick and smooth on one side, you could put a 4′ sheets all the way around the outside walls of your home in place of the sheetrock….