Setting different thicknesses of tile for inserts

by Roger

There are numerous really cool mosaics and liners which can be installed as an accent into your main field tile to add a unique touch to an otherwise standard tile installation. These are products such as glass and natural stone mosaics, individual painted tiles, or custom accents.

The biggest problem with these, however, is they are oftentimes not the same thickness as your main tile – they are usually thinner. This is especially true of most glass mosaics. I usually solve this problem with Schluter Ditra. Although I use ditra as my example in this post, you can also use regular 1/4″ backerboard if your inserts are significantly thinner.

glass mosaic insert

Photo 1

See that glass (and metal) mosaic right there? (Photo 1 – You can click on it for a size larger than a small dog) It’s setting inside the main linear mosaics I’m installing on a backsplash. See how much thinner it is than the surrounding tile? That’s what we’re gonna fix. When you have your tile installed you want it all to be on the same flat plane without either tile sticking out (or sinking back). The best way to do this is to have an additional substrate behind your thinner tile to bump it out flush with the rest.

You want to cut your ditra about 1/16″ smaller than the overall size of your insert. You want to make sure you have enough support behind the insert, but you don’t want it larger. (Photo 2)

glass mosaic insert with ditra

Photo 2

glass mosaic insert with ditra

Photo 3

 

 

 

 

 

 

 

In Photo 3 you can see where I’ve flipped the ditra upside down so the fleece side is out. You want to install your insert onto the fleece side rather than the plastic, dovetailed side. this is much easier, especially with smaller tiles, and gives the insert more adhesion on the backside once installed. The thinset will ‘lock’ it to the wall doing it this way.

Photos 4 and 5 show how the ditra bumps it up to the same height as the field tile. If your insert is a LOT thinner, it may be better to use the 1/4″ backerboard, although you can double-up the ditra to make it thicker.

glass mosaic insert with ditra

Photo 4

glass mosaic insert with ditra

Photo 5

 

 

 

 

 

 

 

Once you get your ditra and inserts cut to size (cut all of them at once) get your thinset mixed up and cover the entire fleece side of the ditra inserts. Make sure the entire surface is covered, most mosaics are fairly small and any uncovered areas may lead to just one or two pieces not being adhered well. Spread it just like these here:

glass mosaic insert with ditra

Photo 6

glass mosaic insert with ditra

Photo 7

 

 

 

 

 

 

 

 

Then place your inserts onto the ditra and press down slightly – only slightly! Before you firmly press the inserts and the ditra together you want to flip them upside down. Doing this ensures that the face of your inserts, the shiny part that makes people go ‘ooooh, pretty’, is completely flat. Flipping them upside down, then pressing down firmly, will get the entire face totally flat and get a full bond onto the ditra. It is always best to use a flat surface on the back, squeezing them between the flat surface and the flat countertop or bench – whatever your wife lets you use. Like these:

glass mosaic insert with ditra

Photo 8

glass mosaic insert with ditra

Photo 9

 

 

 

 

 

 

Once you get them all installed to the ditra, flipped, and pressed down firmly to ensure a full bond – leave them alone! Give the thinset at least three hours to cure and get a grab, ideally let them set overnight. Really, leave them alone. Stop staring at them. Go have a beer Pepsi and have some dinner. We’ll get to them later.

glass mosaic insert with ditra

STOP STARING! GO AWAY...

Once the thinset is cured you can fill the dovetails with the flat side of your trowel, then comb on the thinset with the notched side and install them into your design. You can cut your main field tile with spaces large enough for your insert (don’t forget the measurement for the grout line around the mosaics). And tile away. When you’re finished you should have two different tiles, with different thicknesses, installed flush on the same plane. Like this here:

glass mosaic insert with ditra

Finished

This method works for backsplashes, shower walls, even tile floors. As long as you have good contact with the insert to the ditra, and good contact behind the ditra to the substrate, you should have a nice, flush tile installation which makes people go ‘ooooh, pretty’. Like these here:

glass mosaic insert with ditra

Ooooh, Pretty...

Porcelain backsplash tile installation with glass mosaic inserts in Fort Collins, Colorado

Ooooh, Pretty < See?

 

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Michael

Do I use unmodified thinset to secure mosaic glass tile to the ditra and the ditra to the kerdi. The unmodified thinset will work with the glass tile?

Great site. Ive ordered a couple of your publications

Reply

Barb

Roger,
My mosaic is just 1/16th inch flatter then my other tile. Could we just use a deeper trowel to lay thin set or what do you recommend.
Thanks.

Reply

Sabrina

Can we use 1/4 inch hardiboard to raise the glass mosaic border in our shower floor?

Thanks,
Sabrina

Reply

Roger

Hi Sabrina,

Yes you can.

Reply

Jared

Hi Roger – I am installing a paper backed mosaic over kerdi. I’ve built up the low area with unmodified – b/c I couldn’t find a small amount of ditra. Can I use modified for the glass mosaic or will the unmodified hold the glass well?

Reply

Roger

Use the modified – still. :D

Reply

Camille

Great post! Can this be done with a tile butting up to a wood floor? I am installing a wood floor and in the entry, have an octagonal tray ceiling. To add interest, I want to follow that tray ceiling shape on the floor and add a glass border tile. The engineered wood floor is 13/32 in thick. Thank you for your input!

Reply

Roger

Hi Camille,

Yes.

Reply

Jared

Roger – Love your tip on spacing out the mosaic with ditra.

I am working on a glass accent strip in a shower. I didn’t have a small amount of ditra so I built up the area with unmodified thinset over the kerdi membrane to get the tile and mosaic the same height. Is this acceptable??
Is unmodified good enough for 3/4 x 1 1/2 glass mosaic? Some folks seem to think modified is need for glass mosaic. Could I use modified for the mosaic over top of my unmodified leveling/build up bed?

Reply

Roger

Hi Jared,

Yes, it is acceptable. Normally yes, unmodified is fine, but modified is always a better choice for glass. Yes, you can use modified over the unmodified.

Reply

kevin

12×12 porcelain tile which is plain grey, no pattern at all. Yet on the back of the tile are directional arrows. I guess tiles should be placed so the arrow faces the same direction, but with no pattern is there another reason?

Reply

Roger

Hi Kevin,

Yes, that is the direction in which the tiles are placed on the conveyor while being manufactured. If there is no pattern they mean nothing.

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Jerrod

we had a tile guy install our shower with two rows (different heights) of mosaic tile. He did NOT grout yet and we have two different thicknesses of tile now installed on backer board.

What is the best way for me to remove the mosaic tile and retile using the backer system you showed in this article?

Reply

Roger

Hi Jerrod,

Tell your tile guy ‘remove those mosaics and put a backer behind them’. :D I don’t know that you’ll be able to remove them intact enough to reuse them. Prying the mosaics out is the only solution to remove them, there is no easy way.

Reply

Ryden

Hi Roger,

I have installed 24″ x 24″ porcelain field tiles on my bathroom floor over Ditra heat. I used a 1/2″ x 1/2″ trowel and MLT system. I will be installing a 6″ accent strip that comes in at about 29″ long. The tiles in the strip range from 1″ to 2 1/2″ wide and are roughly 12″ long. the accent strip tiles are the same thickness as the field tiles. Would I use something like 1/8″ Ditra as a backer and then a smaller trowel to install the accent strips? What if 1/8″ Ditra is too thick?

I installed the same mosaic strip vertically on one shower wall (field tiles 12×24, same thickness as floor tiles), however I installed it as I was doing the field tiles. I realize now that it was a mistake to do all in one go and did the floor tiles with a plywood placeholder for the accent strip. I did get the strip on the walls very flat (definitely not perfect though), but it took me a long time and a lot of patience. It seemed as though the thinset was never going to stop coming through the accent strip grout lines as I flattened it with a level. I would prefer to not go through that again, Ever.

Bonus question: I found that even with the 1/2″ x 1/2″ trowel and back buttering, I was having a heck of a time achieving 100 percent coverage. Is there a different trowel that I should try in this scenario? Perhaps its because of my inexperience installing, but I was surprised I had to go that big, considering that the floor was flat enough that I had less than 1/8″ variation when checking with a 6 foot level before installing anything.

Thanks for any insight you can provide!

Reply

Roger

Hi Ryden,

Ditra would be good. If it is too thick try bonding the mosaic to kerdi, let that cure, then install it. It’ll prevent the thinset from coming through the mosaic. You can also grout the mosaic first, let that cure, then install them, but you still need to be aware of the spaces between each mosaic strip.

Reply

Roger

Sorry, missed your second question. If your floor actually was flat then it’s an issue with the tiles being overly-cupped. In that case you should comb your thinset onto the substrate as well as the back of the tile (rather than using the flat side of the trowel).

Reply

april

:whistle: :corn: waiting to see kortnees project(pictures please) :dance: :evilb:

Reply

Josh

I’m almost to tile tiling part of the shower. I was thinking about it and i wanted to ask you if when setting this tile design, do I put the 12×24 tile then the mosic and let it set before I put another row on top because of the weight? I’m thinking it might crush the mosaics or push them down if i put another row of tiles on top before each row sets. Your thoughts? and any extra advice I might forget when setting this design? I have your package with the tile tips but just making sure I don’t miss something and mess it up. The link to the design I am doing is below.

http://www.houzz.com/photos/1131571/Glass-Tile-Shower-contemporary-tile-chicago

Reply

Roger

Hi Josh,

Yes, only set up to the mosaics, let that cure, then install the rest. Or you can create a placeholder out of wood or backer the same size as your insert and stack all your tile, let it cure, remove the placeholder and install your mosaics.

Reply

zoran

Hi Roger . My boss is insisting on me installing strips of glass tile mosaics btwn large format tiles diferent thiknes only in grout . They are on paper and it is very hard to find the right time to take paper down and fix them , cause grout is drying fast and sudden . Lot of it stay btwn little glass tiles and next day is hard to clean joints . I dont agree . I think it always has to be white thin set aplayed very thin on a dry and hard flat surface prepared day earlier , or on hardybecker that is inserted prior btwn large formats or glass can be put on the bord before , dried and then inserted btwn large formats . I prefer prepering space btwn large formats perfectly with special thin set first , letting it to dry and leaving just enough space for glass tile plus just 1/16 for the same thinset and glue them so there is nothing btwn glass tile joints , so that grout looks better cause its surrounding them completly . I am in this for a long time and mostly high end jobs and have never seen or heard that they can be installed ussing only grout . Is it posible ?

Reply

Roger

Hi Zoran,

No, they can not be installed using only grout. There is, however, a system from Laticrete in which grout is mixed with white thinset, giving the color of the grout to the thinset, then the mosaics are set and embedded into the colored thinset. Once they are set the paper is removed and the grout/thinset wiped down. This essentially uses the thinset as grout also. It is called the one-step method. You would be setting the mosaics with grout-colored thinset.

Reply

Janet Cassady

We just had our shower remodeled. We had a 4″ band of accent tile installed near the top of the engineered stone (marble) walls. The accent tile is thinner than the sone walls.

The contractor did not install the accent tile flush with the marble wall. It is almost flush in one area and recessed as much as 3/16″ in another. They insist this is standard and that it’s impossible to get the accent tile flush with the marble.

I say they’re nuts and that, with little extra work and time, it could have–and should have–been installed flush.

Your opinion, please?

I say

Reply

Roger

Hi Janet,

My opinion.

It can be done, it should be done and I do it every week. :D

Reply

Kortnee

okay, Roger, so what do we do with this challenge…
We are creating a tile “river” set into a wood floor.
there will be blue pebble mosaic tile with ceramic art tile fish and turtles swimming along in the river and a few floating leaves. (Super cool, right!!!)
We already have our river cut into the wood floor.
We are planning to line the river path with hardi-backer (placed over the subfloor) and then lay the tiles onto it.
However, the problem is we need the REVERSE answer to what your post describes…
The main tile (blue pebbles) are thinner than the art tiles. So we need to figure out how to set our turtles LOWER than the surrounding blue pebble river tiles.
The other issue is that our tiles are not square (or any predictable shape)… as they are pebbles and leaves and fish and such. (All the art tiles are of a consistent depth)
Should we simply lay a thinner type of hardibacker so the thicker turtle tiles are even with the floor… But then how do we build up the blue pebbles???
It’s a decent size area… the river is 15 inches across and about 20 feet long.
Please help!

NOTE: The blue pebble tile is a 1/2 centimeter in depth
The art tiles are 1cm in depth.

THANK YOU.

Reply

Roger

Hi Kortnee,

I would install all the art tiles first, let them cure, then put an additional membrane such as kerdi (upside down), install it around the art tiles then install the blue pebbles on them.

And you better send me a picture when you’re done! :D

Reply

Kortnee

Thanks Roger! So would the kerdi board be better than using ditra? Our art tiles are installed … woot woot!!! Do we use the same mastik mud to attach the kerdi or ditra to the floor? Should we place the ditra and then place the blue pebble on top.. or should we attach the blue pebble to teh membrane and THEN place it… ?????

Reply

Roger

Yes, kerdi-board would be better, it’s a solid surface without the inconsistencies of the waffles. I would cut it to the shape first, bond the pebbles to it, then install it to the floor. Yes, same thinset.

Reply

Loren

I’m about to do a kitchen back splash, with 3×6 field tile and 1×2 accent tile, horizontal stripe, 2/3 of the way to the top.
12″ (four rows brick pattern) of field tile, then 2″ (2 rows brick pattern), then about 6″ more field tile.

The accent tile are 3/16″ thicker than the field.

My first thought was metal plaster’s lath (because I’m familiar with using it with manufactured stone). Looks like I was on the right track, just going in the wrong direction.

What thicknesses is Ditra available in?

This probably isn’t the right place for this question, in fact I’m sure it could be an entire post someday, but, I haven’t found it here.
What are your thoughts on self adhesive mats?
I have been to SimpleMat and MusselBound websites, I don’t see a Schluter product yet.

Reply

Roger

Hi Loren,

Ditra is available in 1/8″ (regular) or ditra XL which is about 1/4″. You can use either, and if it’s a bit thin you can always build up the thinset behind it to get it where you need it. I hate the self-adhesive mats. I can nearly guarantee you’ll NEVER see one from schluter. :D

Reply

Robert K

Roger,

First…Thank you for doing what you do for us DIYers. I have a question regarding Ditra. Can I key in all of the Ditra, let it dry, and then come back and lay my tile? Will the thinset bond correctly to the keyed and dried Thinset?

Thank you,
Bob

Reply

Roger

Hi Bob,

Yes you can, and yes, it will bond just fine.

Reply

Lynn Cleek

I’m a novice. You speak of Ditra. What is Ditra?

Thanks

Reply

Lou

Roger
We picked a large format rectified porcelain tile 12×24, you and the manufacture says no more then 33% off set. But i see running bond brick pattern in buildings and on all the tv home shows. I looked on line and saw boyertile.com and he agree with the TCNA no brick pattern because of lippage,warping and grout lines no less than 1/8″, 3/16 recommended. So whats the deal. P.S. I have all your books and yes its sill the same project from a year ago.

Reply

Roger

Hi Lou,

The deal is with large format tile the cooling process of the tile makes it ‘cup’, where the center of the tile will sit higher than the ends. The edges of the tile will cool faster than the center, causing the center to expand ‘up’ as it cools. Placing the corner of the tile (the lowest point) next to the center (the highest point) causes lippage issues. Offsetting it by 1/3 makes it much easier to get flat.

Reply

paul roman

Sorry for the repeat. I was just reading a different thread and saw your comment about posting updates as a reply.

Figured out my problem with mosaics coming off. Enough blue tape, but not in the right places. I had covered near the cut, but not across it and not the rest of the sheet. I cut some tonight that I had put on some Kerdi. I placed them on top of a piece of plywood (second “Aha!” moment) and did not lose a single piece. Learning is fun!

Unrelated issue/comment. With a glass blade in, I found the glass and marble mosaics had a tendency to be pulled strongly into the blade. A couple of times the saw raced through two or three pieces before I could either get the feed under control or reach the off switch.

Reply

paul roman

Your tip worked great. One issue I did have is where I had to trim off about 1/4 inch from a three-tile row for a band of mosaic at the ceiling. Shower is about 99″ high and we used 6″x24″ porcelain set vertically with another mosaic band just above the niche. I could trim a few inches off the bottom row of tiles, but we did not want to increase the width of the band above the niche and I could not stretch the top row of tiles! (hence the 3″ gap). We were going to use PVC crown molding, which is in the main area of the bathroom, but liked the mosaic look better. Anyway, the flimsy backing on the mosaic did not like the wet saw (even after I used a bunch of blue tape) and about 20% of the row that I trimmed came off the backing. I will be patching them in. Because I had unmodified thinset (Kerdi membrane), I used it for the mosaics on the Ditra. Would I have been better off with modified thinset or would the result (losing tiles) most likely have been the same?

Reply

paul roman

Double repeat. I posted my reply to my follow-up. I think I have it now.

Figured out my problem with mosaics coming off. Enough blue tape, but not in the right places. I had covered near the cut, but not across it and not the rest of the sheet. I cut some tonight that I had put on some Kerdi. I placed them on top of a piece of plywood (second “Aha!” moment) and did not lose a single piece. Learning is fun!

Unrelated issue/comment. With a glass blade in, I found the glass and marble mosaics had a tendency to be pulled strongly into the blade. A couple of times the saw raced through two or three pieces before I could either get the feed under control or reach the off switch.

Reply

Roger

Hi Paul,

It likely would have been the same. For some ridiculous reason they use water soluble glue on most mosaics.

Reply

Michele

Roger,
I want to put a full 12 inch strip of mosaic set in field stone in our shower. Can I put the Ditra on the wall first and then apply the mosaic tile? The strip will be 11 feet long when it is wrapped around the shower.
Thank you!

Reply

Roger

Hi Michele,

Yes you can.

Reply

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