2 questions

[Gary and Karla]

#1 Does the toilet flange screw to the sub-floor(1/4 inch hardy) or does it sit on the ceramic tile. #2 When you are going to tile around a spa tub is it ok to prime and seal the green board or leave it uncoated.

There is a friendly wager on both questions Thanks

[roger61611]

1) Screwing anything to hardyboard is oxymoronic, it won't hold unless you screw it to something that will hold a screw, like the subfloor. 2) N/A - the backing should be cementous backer board, not green board.

[B]

1. screws to the subfloor
2. Even a pro will not have heard of trying that, so nobody will be able to say exactly what goes wrong (other than the tiles failing to adhere, perhaps?).

[calhoun]

#1 both. Flange should sit on the finished floor (tile) and be secured to the sub floor. (Hardi board is not a subfloor, flange should be secured into the wood subfloor)

#2 - priming green board is not needed but should be OK if you want.

[Rudy]

I hope this is a "typo". Subfloor should be a minimum 5/8" T&G but some prefer 3/4". Then in the areas to be tiled, you should glue and screw another layer of

3/8" ply over top .. before tiling.