 Now, if you've been doing tile for 20 plus years, 30 plus years, you'll know where we came from. Back in the 70s, you'd see people putting up the green water resistant sheetrock and laying tile over the top of that. They'd go down and put down the hardy backer type concrete board or do a mud set pan. Or if you're in California, they'll do the hot mop one where they put liquid tar over it to waterproof it.