Flooring Tile - Floor Height - Ditra On Top of Durock

Hi! I'm hoping someone can help me with this question. I am in the midst of remodeling my ensuite and am about to work on the floor which is 4'x6'. It was originally small porcelain tile on a mud bed and metal lathe and cleavage membrane. I removed all of this and am down to the plywood. The height from the top of the plywood to the top of the sill plate is 1 3/8".

The plywood looks to be 5/8" and in good condition and since it did support the previous tile floor without cracking I believe it should handle the new tile floor as well.

My plan was to put down thinset, 1/2" durock, thinset, and 3/8" ceramic tile. I figured with the 2 thinset layers, durock and tile the total height would be 1 1/8". That would leave a 1/4" difference in height between the new floor and sill plate.

I was ok with this until I realized the top of my closet flange sits another 1/2" above that. It is somehow cemented to the pipe and does not move.

My question (finally) is can a put Ditra on top of the Durock to make up the height difference? I would also benefit from the anti-fracture properties...an added bonus.

Thanks,

Mike

I'd do it this way.

3/4" exterior glue bc or better plywood, then ditra, then tile. should come pretty close to the 1 3/8" you need.

Ideally, the closet flange should sit on top of the finished tile floor. A little lower is ok, higher might be too high.:)

Plywood will strengthen and stiffen the floor. Cement boards only purpose is to provide a substrate that thinset will bond to. It provides no structural strength to speak of. Thats why the plywood will be better.:)

Hi HeresJohnny:

Thanks for the reply! I failed to mention that I had already purchased the Durock. For the 3/4" plywood, do you need any adhesive or just screw into existing plywood? And would you avoid the joists?

Thanks again,

Mike

Mike

Plywood underlayment gets screwed to the plywood subfloor only. Yes, avoid the joists, and no adhesive needed.

If you use cement board, make sure you set the cement board in a fresh bed of thinset, and then screws, according to manufacturers instructions.

Thanks again for your help!

You are welcome. Keep us posted on your progress. Finished picture of your masterpiece would be appreciated.:)