L/897 Deflection - Seek Specifics on Building Subfloor for Stone Tile Installtion

[bradesp]

I know there are many ways to do this, however I want advice on how YOU would build the subfloor for this stone tile installation. BTW, I'm NOT doing this install, I'm hiring a professional tile contractor to do the work. I just want to be educated about how to collaborate with my tile installer when the time comes.

I'm completely tearing out an existing master bath down to floor joists. My deflection is L/897 (2x10" Fir Joists, 12" O.C.).

I'm installing Radiant Heat Wire and then Travertine Stone in either 18" or 24" squares. The Stone is 1/2" thick for the 18" and 5/8" thick for the 24".

I want to avoid an excessivly "thick" subfloor to avoid an awkward transition to the adjoing bedroom area. So, given that I'm planning the use of the MasterHead radiant wiring and stone tile what would you recommend?

I can screw/glue any plywood base I choose (5/8" or 3/4"). Then I plan on putting down the wire and then thinking that we'd pour SLC. Is there a way to build the plywood and SLC such that when the SLC is poured, All I have to do is thinset the stone tiles on top of the slc?

Again, tell me how you would install this if it were your bath with the need to minimize the total build-up of the floor thickness while still ending up with a quality finished product.

Thanks!!!!

bradesp

[bbcamp]

You are going to need a double wood subfloor because of the stone. The reduce the apparent thickness of the subfloor, you can install cleats along the sides of the joists, 3/4" down from the top edge, then cut pieces of 3/4" plywood to fit between the joists (remember that the face grain must be perpendicular to the joists for maximum strength) and screw to the cleats. The install 5/8" plywood over the joists, making sure that you screw into the lower plywood only

[bradesp]

BBCAMP,

Very interesting approach! Not something I had thought of, duh.

Now, what if I decide not to go to this extreme, can I possibly use a very high grade 1/2" play over the joists followed by a 1/4 or 3/8" ply and then the SLC? Or is this pushing it?

Thanks,

bradesp

[bbcamp]

You need thickness. High $ plywood is still plywood. Not having enough thickness will kill your stone.