How to make specific tile flush with hardwood

[ballaw]

Hi, I am preparing to do my first tiling job and I'd like to make my bathroom floor flush with hardwood. The tile I have chosen is 9.5mm but I could have just as easily chose ones that were 8mm or 10mm. The first question I have is is there a general method for how you flush up tile when there are variations down to .5mm (1/25").

For my specific application I have 3/4" hardwood on 3/4" plywood subfloor so I think I have to use 1/8" schulter membrane, and my 9.5mm (3/8") tile, and 3/16" worth of mortar and I should have my 3/4". But this only works because my tile happens to be very close to 3/8". How would you do this if you had, say, 8mm tile? Even if you use Schulter (5/16") the total thickness would be 3/16" + 1/8" + 5/16" = 10/16" and if you use Schluter XL, 3/16" + 5/16" + 5/16" = 10/16" = 13/16". In both cases you are not exactly flush for 3/4" hardwood.

Any advice about how to do this or maybe aspects I'm not getting correctly would be appreciated!

[cx]

Welcome, Stuart.

Schluter also makes a Ditra XL and advertises that one of it's features is that it allows you to match up with traditional hardwood flooring using nominal 3/8ths" tiles. How well that actually works, I cannot testify from personal experience.

You have evaluated your joist structure and subflooring to determine that you qualify for a ceramic tile installation without improvement?

My opinion; worth price charged.

[jadnashua]

Keep in mind that the notch size is NOT the ultimate thickness of the mortar if things are installed properly...during that process, ideally, you will collapse the notches so that it is a single, even layer. While Ditra may be 1/8" or so, it will end up thicker once you've added the thinset to attach it to the subfloor.

The notch size on a trowel needed primarily depends on how flat the surface is and how flat the back of the tile is...you need enough mortar to get full contact on both surfaces- the tile and floor. Your technique on spreading the thinsest, the angle you use, and the notch size can vary to achieve different results. As long as you get good coverage, and you've not exceeded the min/max thickness of the mortar you select, you should be good.

[Tiger Mountain Tile Inc]

Ditra XL or 1/4 inch cement board. I've used 1/2 inch cement board for really thin tiles like penny rounds.

Sometimes I've even used 1/4 inch cement board with 1/8 inch Ditra over it. But that can get expensive doing it that way.

[smifwal]

I have used 1/4" fiber rock on occasion where none of the other 1/4" stuff lined up.

[ballaw]

Thanks for the help everybody. I will always make sure my subfloor is adequate. I am more asking about in an indeal scenario how you are supposed to get the surfaces flush.

I'm not following how you end up with a flush surface with these approaches.

Ditra XL (5/16") + tile (3/8") + thinset (3/16") = 14/16"
cement board (1/4") + tile (3/8") + thinset (3/16") = 13/16"

Which is greater than 12/16" = 3/4" of the hardwood

Ditra (1/8") + tile (3/8") + thinset (3/16") = 11/16"

Which is less 3/4".

Am I supposed to tune the height via the amount of thinset? Sounds like you are only allowed to make it so thick or thing without breaking installation guidelines.

[cx]

Stuart, the only way you're gonna know for sure what your tile height will be is to make up a test board using your materials, your trowels, your techniques, and measure the results.

The industry standard minimum for thinset mortar thickness under the tiles is 3/32nds of an inch and the maximum for standard mortars is 1/4-inch. Under the membranes with be less than that. If you made up a test board with your materials, and I made up a test board with your materials, the result would theoretically be the same. But there's frequently a difference between the theoretical and the practical. You just hafta try it for yourself. The Ditra manufacturer says you can match 3/4-inch hardwood with 3/8ths-inch tile using their Ditra XL. We've had reports here of a lot of people doing so. How well it matched, I cannot say. And I've never tried it.

I'd want my tile to finish out about 1/32nd of an inch above my wood. With a rectified tile you may want a little less.

My opinion; worth price charged.

[ballaw]

Alright, thanks. That's very interesting to know there is not cut-and-paste way to do this. I guess the mortar specs you mentioned are what let installers make up for the small differences in tile thickness.

[RichVT]

Ditra XL is what I normally use. 1/4" cement board can work if you are generous with your thinset.

[Tiger Mountain Tile Inc]

Ditra XL (5/16") + tile (3/8") + thinset (3/16") = 14/16"

This is the one that you want but the thinset won't be 3/16. More like 1/8th with a 1/2 x 1/2 inch square notch trowel.

However, it may still feel a bit low if your tile has a factory bevel or 'shoulder' on the edge that rounds down.

[Dan Marvin]

Seems like you've gotten some good advice on using our DITRA-XL for this purprose. I'll also mention that we make a variety of transition pieces that are designed to help one floor covering transition to the next without an unsightly edge. The store where you bought your Schluter uncoupling membrane should be able to help you or you contact our customer service department for details.