 And it's waterproofed because tile and grout are not waterproof generally. So you have to have something behind that for to stop that water from going down through the bottom, through the walls, whatever. And when you pop that tile off, generally speaking, if you did it correctly, you're going to take the waterproof again with it or you're going to have that mortar in there that you can't remove very easily without ruining that back.