I did a bathroom once but it was really easy. This time I was given marble tile. Not fake or polished marble. It's mostly very light tan with lots of streaks even some shallow holes. I think there is enough to do the bathroom floor by using the big squares and judiciously using the cut of broken pieces. The full tiles are 12"x12" and about 3/8' thick. Do I have to put in a water barrier board? Can a plastic or other barrier work? The bathroom open floor is about 12'x7'. It did have carpet but I pulled that out so now it's just OSB.