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?

 

{ 418 comments… add one }

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  • Bryan

    Hi Roger,
    It might be too late for you to help me but i will give it a shot anyway.
    Just installed a mosaic tile insert with a marble border and then full 12 x12 tiles on my powder room floor. The mosaic sits too low, do you have any solutions without removing anything. I was even contemplating a clear epoxy for the insert to bring it up to the marble
    Thank you

    • Kris

      Bryan,
      The Ditra trick really works! Depending on where you live, you might be able to find a tile store that will sell you a small amount.

    • Roger

      Hi Bryan,

      Unfortunately once the mortar is cured there isn’t much you can do to fix it short of tearing it out and redoing all the mosaics. I would not do the clear epoxy. It is not uv stable and may yellow over time.

  • kris

    Hi Roger,
    Can I use vinyl tile to instead of ditra for a backing on glass tile to make up the difference in thickness? Will thinset work for this? I only need to do this for a few tile and don’t want to buy a whole roll of ditra.
    Thanks,
    Kris

    • Roger

      Hi Kris,

      Yes. And regular modified thinset will work. Rough up the surface of the vct with sandpaper first.

  • Laurie Hixon

    Roger,
    I would like to install an artsy mosaic design on my laundry room floor. A mix of glass tiles, broken ceramic, stones, misc. flat items. Is there a webbing product to glue the pieces to in small workable sizes to install later? I want to put together the entire floor design on 12×12 size sections and then install them all at once….over subfloor, ditra, thinset…maybe heated flooring (?). I’ve seen the sticky clear sheets that are placed over the top face of the design and then installed and then the sheet has to be removed after….don’t really like this option because the removal can also remove tiles. Thanks for your help. Laurie.

  • Kris

    I am installing 4 x 8 subway in a bath/shower surround. At about eye level I’ll be putting in a 6 in wide band of glass mosaic (total length about 12 feet in the surround). I’m afraid of installing segments of my glass tiles using the method of pre-setting on ditra. Even if I did a 6 x 12 inch section at a time I fear the mosaic will not appear to flow. It will look like a bunch of 12 inch segments put on the wall.
    Could I secure a long ditra strip waffle side down to the wall first, let it cure, then put more thinset on next day to the whole area (fuzzy side, I guess) and place my glass?

    • Roger

      Hi Kris,

      Yes, that’s how I do it with accent strips. The only reason these are pre-installed onto the ditra is because they are only 2×4 inch accent pieces.

  • Joe

    The advice you are giving about installing glass tile on the fleece side of the Ditra is wrong and will cause all tiles installed this way to eventually fall off. There is a reason the fleece side is installed against the wall/floor. After some time the thinset will eat the fleece and then allow the tile to uncouple from the substrate, thus the point of an uncoupling membrane. This is the way the product was designed. Any tile installed will fall off the wall after the Ditra has had a chance to uncouple. Bad advice. Very bad!

    • Roger

      Hi Joe,

      Thank you for your opinion, but your information is incorrect. The uncoupling ability of ditra is due to the tile not being chemically bonded to the substrate, the ditra is between it. The only thing that thinset will ‘eat’ is material which is not alkali-resistant, ditra’s fleece is. If it were not it would disintegrate within six months and all that tile would begin cracking.

      If thinset eats ditra fleece I would venture to guess that they would not use it on the bottom of ditra, seems to me it would cause a few problems. But thanks for your opinion. :)

  • Nancy

    Hi Roger,
    We have just had work done in the bathroom with glass tile detail. The inset is a strip of tiles which run horizontally around the 3 walls of the and bathtub/shower. The contractor obviously did not add substrate to make the glass tiles even with the ceramic tiles. The glass tiles curve into the wall and then back out to meet the edge of the ceramic tiles. It looks awful.

    The work has been grouted and to the contractor’s mind, finished.

    My question is how do I ask the contractor to fix this? How much work will it entail? And is it even a reasonable request to ask the contractor to fix this issue, now that all the work has been done?

    Any advice would be helpful…

    • Roger

      Hi Nancy,

      Just approach him and bring up your concerns with him. Ask him the same questions you just asked me. To my mind yes, it is absolutely reasonable to expect a flush tile installation. He apparently knows it should be which is why the bottom and top of the accent are flush.

  • Pratap Bhatnagar

    Namaskar Roger !

    Please help –
    (1) can laminate planks be used on walls in living – dining rooms ?
    like screwing the laminate planks on to the studs in place of drywalls ….
    or
    will it be better place the laminate planks over the drywalls.

    (2) what is the benefit of underpad beneath carpet other than cushioning ?

    Thank you and hv a nice day.

    Pratap

    • Roger

      Hi Pratap,

      I suppose they could be used on a wall, I would go over drywall. Cushioning is the only reason to have pad beneath your carpet.

  • Pratap Bhatnagar

    Roger !

    … one question about cement boards, 3/4 ( and 1/4 ) thick being set in bathroom for tilling.

    How to fill the gap ?

    With fibreglass tape and thinset ?

    There are two – three boards 3/4 thick.

    Will premixed thinset be good ?

    Thank you and hv a nice day !

    Pratap

    • Roger

      Hi Pratap,

      Yes, thinset and fiber tape. Do NOT use premixed thinset, you need to use the powdered type in a bag mixed with water.

  • Pratap Bhatnagar

    Namaskar !

    I am hoping you will take a question about hardwood flooring.

    The house is very old. The subfloor is lumber. There is a felt like material spread over the wood subfloor and the previous top floor that has been ripped.

    Can hardwood be installed over the felt ? It may not be possible to get rid of the felt.

    Thank you for your time.

    Pratap

    • Roger

      Hi Pratap,

      Yes it can. Normally you would use tar paper beneath your wood, but it can either go over the felt or just left out if the felt covers the entire floor.

  • Becky

    Hi Roger! In “Setting different thicknesses of tile for inserts”, you say to “fill the dovetails with the flat side of your trowel, then comb on the thinset with the notched side.” What are dovetails? And by “combing on the thinset” is that like buttering the back side of the insert? Thanks!

    • Roger

      Hi Becky,

      The dovetails are the indented waffle-like structures in the face of the ditra. Combing the thinset means using the notched side of the trowel to spread thinset.

  • shawna

    I wish I had your insight before setting accent stainless tiles in “extra thick” unmodified thinset. Those floor tiles are going to be taken up and replaced with your ditra trick!! My question is concerning the use of modified vs unmodified thinset to ditra. I used modified between the fleece side of the ditra and the subfloor. I undertand from the instructions that all tile types should be placed on the ditra with unmodified thinset. I’m placing slate tile and wondered if this is the correct method or if the slate will pull the moisture before the thinset cures? Sorry but I’m not entirely sure of the differences of thinset and their ideal usages. Thank you so much for your insight and entertaining delivery!!

    • Roger

      Hi Shawna,

      Unmodified is the correct choice over ditra with all tile and stone (according to schluter). If you backbutter the tiles it should be fine, or you can use an old-school trick and soak the slate in a bucket of water until right before you set them. Pull them out of the water, dry them slightly so they’re not dripping, and set them in the thinset.

  • Dave

    Hi Roger,
    I followed the instructions here and I laminated 6 of these strips and left them overnight. The next day I was installing them as part of an accent strip around the shower and I had just set the last one and I saw that the edge seemed to be delaminating from the ditra. I pulled it a little and the entire mosaic pulled right off. I looked at another of the peices and that one seemed better but still not a good bond and that one pulled off also.

    Four of the peices seemed to be ok and I left them up to dry overnight. They form a solid line (accent strip) on the back wall of the shower. The only issue I see is that one of the individual mosaic tiles (3/4″x3/4″) is a little loose.

    The only issue I had during the process of making the strips was that I mixed the Mapei P10 a little loose b/c I wanted to make sure the mosaics got a good sticky bond. So perhaps they had not fully cured when I started working with them (almost 24hrs later).

    My questions are:
    1. I’m concerned about the rest of the strips delaminating, any advice on whether I should leave them alone and let them cure or would it be better to be on the safe side and pull them out?
    2. Assuming I leave them in place and don’t pull them out, I guess I’d just pull off that one 3/4″x3/4″ peice that is loose and reset it? Or will grout hold it in place?

    Thanks, Dave

    • Roger

      Hey Dave,

      1. Leave it alone and let it cure. :D Your mosaics will never be put under the same condition of stress as you pulling them off, it never sees that movement on the wall, it’s sheer bond – can you ‘slide’ them off? (You can’t).
      2. Replace the one piece. Grout will not hold it in place long-term.

  • Deb

    Hi. Thank you for sharing your expertise.

    My contractor hired a sub and my shower was tiled. Horribly.

    The glass mosaic is the same thickness as my tile and yet when it was installed it was set in from the wall tile leaving a deep lip.

    Also, I noticed after the contractor tore out a few tiles that were installed poorly, that the remaining tiles are not evenly connected to the drywall ( yes drywall) and there are big gaps between the tile and drywall. It looks line he only put thinset in a few areas not consistently on the tile or wall. What am I in for if the contractor simply replaces the two tiles and air gaps are left between the tile and wall.

    I want to cry. The contractor is frustrated by my complaints. I’m worried bigger problems could arise.

    I would appreciate your advice.

    Any trips to canada planned??
    I would so appreciate your help to turn this around.
    :dance:
    Deb

    • Roger

      Hi Deb,

      If it’s drywall it needs to come out and be properly built – period. It sounds like he used a five-spot method which is just placing five big globs of thinset on the tile and placing it on the wall – absolutely not an approved method. The fact that he did this will allow your shower wall to become compromised much more quickly. His sub simply did not do it correctly, it’s a crap job and needs to be removed. There is no fix for it short of that.

  • Matt N

    Hi Roger,

    I have an opposite situation where the accent is thicker than the base tile. I looked through other people questions but nobody seemed to ask this question. I have plain white ceramic 1/4″ tile that will have a strip of bubble glass/stone accent that is 3/8 thick. I don’t want to use any transition pieces and would rather have one flat surface. Any suggestions on the best way to achieve this?

    Thank you,
    Matt

    • Roger

      Hi Matt,

      The only way to solve that is to build out the field substrate (behind the white ceramic). This can be done with 1/4″ backer, wall mud, kerdi-board (my choice), or any number of suitable substrates. But you need to build out the entire wall for that to work. Or you can pick a different ceramic.

      • John

        Using 6″x6″ tiles with an accent insert.
        1) Would ditra be a reasonable “build-out” material for this?
        2) (Shower) enclosure has been waterproofed with Redgard – unmodified thinset on both sides of the ditra?

        Thanks!

        • Roger

          Hi John,

          1. Yes
          2. I would use modified, but unmodified will work as well.

          • John

            You would use modified thinset on both sides?

            • Roger

              Yes.

              • John

                Roger, thanks for you patience with a noobie…

                Just confirming,

                Can I lay ditra (not kerdi) on the walls of my (bath) shower enclosure – the entire wall save for a 5 inch cut-out stripe where the insert will go? I’m very nervous that the waffles won’t provide retention for the tiles.

                • Roger

                  Hi John,

                  I apologize, my answer to your question as to whether or not ditra would be a suitable material to build out your wall tile was incorrect, it would NOT be suitable to build out your entire wall with ditra. You need to use a solid substrate such as 1/4″ backer with redgard, kerdi-board or wall mud. Ditra will retain water in the open areas between the waffles. While your substrate is waterproof, the issue is having that much water behind your tile. You need to have a solid surface.

  • MATT

    Roger,

    Should I attach multiple one foot sections of the mosaic to the ditra or do you find it easier to work with them in single one foot sections?

    Also, do I need to use unmodifed thinset at all or can I go strictly modified?

    Thank you in advance.

    • Roger

      Hey Matt,

      If you’re working with larger sections then it’s easier to install the ditra onto the wall first, then install the mosaic onto it. You can use either type of thinset.

  • Tracey

    The boyfriend has been hired to install new tile floor over existing 50s tile at the front door landing. The tiles I’ve chosen will be a rug pattern with 6 12×12 marble tiles (arranged 2×3) making the rug and sheets of 2″x2″ ceramic making the border. The marble tiles are quite thick and we will need to build up the surrounding edge. The total area is about 4’x6′. I’ve never tiled anything but sounds like the order should be thin set, cement board, thin set, ditra cut with a hole in the middle for marble tiles, then thin set between ditra and border tiles. Thy boyfriend is about ready to tell me to trash the marble tiles because he thinks this will be complicated… :bonk:

    • Roger

      Hi Tracey,

      Do thinset, cement board then install the marble. After the marble is install put in thinset with ditra (around the outside of the installed marble) then thinset and mosaics. Nothing complicated at all, just install the marble first, then there’s no guesswork with the ditra and mosaics.

  • Louis

    New topic, I have just read that they have change the vapor or moisture numbers for steam showers and that 4mil kerdi no longer meets them. kerdi DS is recommend.

    • Roger

      Hi Louis,

      Actually what they changed is the steam shower specs in the book are now based on commercial applications. Like steam showers in health clubs that run all or most of the day. Residential steamer specifications haven’t changed, but now every one is treated and built to commercial numbers. DS is a very good product and is surprisingly robust. Definitely a better choice for a steamer.

  • Louis Vattuone

    I WAS PLANING ON USING DITRA ON BATHROOM FLOOR AND STEAMSHOWER WALLS.CAN I BUILDUP GLASSTILE INSERTS WITH DITRA ON DITRA TO FLUSHOUT WITH FIELD TILES.

    • Roger

      HI LOUIS,

      YES YOU CAN BUILD THEM UP WITH DITRA TO GET THEM FLUSH.

      Why are you yelling? :D

  • Ed

    Hi Roger,

    I’ve got a different type of inlay tile. It is glass tiles, with the occasional aluminum tile. Each tile is about 1/4″ or so wide with varying lengths all attached on a mesh backing. The 1 square foot assemblies are not square on the ends meaning that the smaller 1/4″ tiles vary in their height above and below the top and bottom. The pattern is the same in terms of above and below dimensions on each assembly so that the tiles can be stacked nicely.

    It appears that the use of Ditra with these tiles will be a problem unless I make up the whole inlay section which is 8″ x 7′ to run vertical in the shower. Do you have any other suggestion on how to inlay these tiles?

    • Ed

      Once the surrounding tiles have been laid, what about installing a layer of Ditra upside down onto the wall over the whole 8″ x 7″ area and let dry. Then install the glass tile onto the fuzzy side of the Ditra. My only concern is will the orange colour show through the glass tiles?

      Sure would be nice to be able to post pictures.

      • Roger

        Hi Ed,

        Sorry for the delay, been out of town at the new Schluter facility all week.

        Provided you have proper coverage behind your tile then no, the orange will not show through.

        Sure would be nice if someone would write a program which allowed me to allow you to post pictures. :D

    • Roger

      Hi Ed,

      Sorry for the delay, been out of town at the new Schluter facility all week.

      I don’t understand why you think that would be a problem. You can cut the ditra with scissors at the ends of the mosaics or you can install the ditra on the wall, then the mosaics to it. It doesn’t need to be attached beforehand. Or is it something else you’re concerned with?

      • Ed

        I’ll have to put the ditra on the wall first as the weight of the mosaic tile and filled ditra will make it hard to manage an 8″ x 7′ piece and get it perfectly in place. Also, given that the Ditra is somewhat flexible between the cavities and not all that rigid, I would worry that when trying to move this large piece around that I might end up damaging of popping out some of the filled cavities.

        Other concern:

        Setting these linear mosaic tiles vertically onto the installed Ditra and until the thinset is dry, having some of the weight of the tiles all coming down on the first row of mosaics. This works fine for full tiles as you can add spacers to transmit the load but these tiles that have lots of spaces in between them vertically and thus the need for backing mesh. Can’t do that on this as there is about 25 – 30 spacers needed per sq ft to do that. This leads me to wanting to lay the tiles on the Ditra beforehand. That would definitely resolve this problem but create the above mentioned handling problem.

        Breaking the size of what I have to install in one shot is not an option as the tile ends are all not even. If i cut the Ditra to match the uneven ends, that’s a lot of work, I could install each of the seven pieces individually but still have to deal with about 10 spacers between each tile. There are 10 small glass vertical lines in 8″ of width of this tile.

        Not sure if you understand the type of tile I’m using. I hope I’ve explained it better.

        • Roger

          I understand perfectly what tile you’re using. The confusion, I think, derives from the manner in which those mosaics actually work when being installed. While the mesh on the back is used to keep them consistent and holding them together, while being installed and before the mortar cures it will actually also hold them apart. They will not crush down to the first one when hung vertically – they’ll stay put. You’ll need to let them cure overnight before installing tile ABOVE them, but once placed they won’t go anywhere.

          • Ed

            “You’ll need to let them cure overnight before installing tile ABOVE them, but once placed they won’t go anywhere.”

            When you say installing tile, do you mean full size tile or the next layer of mosaic? If mosaic that really makes it hard to get thinset down between the jotting upper edge of the mosaic the day after curing.

            • Ed

              BTW, these tiles will run floor to ceiling in the shower. Just like this one.

              http://www.houzz.com/photos/80778/Jason-Ball-Interiors-Bathroom-Designs-bathroom-portland

              This is where I got the idea.

              • Roger

                I mean the full-size tile. You can install all the tile below the insert, install the insert all in one shot, then the next day install the tile above the insert.

                • Ed

                  Hi Roger,

                  Tiling going good so far in shower. I put in 80% of the tiles with Mapei Kerabond / Keralastic modified thinset. I have about 2 square feet of small thin tiles in one corner to do…couldn’t fit them in with the last batch due to the leveling system being in the way. I also have the mosaics left to do and decided instead of the Ditra to just build out the thinset with the scaps left in the bottom of each pail. That is about 75% done.

                  Question 1:
                  The K/K system is modified generally for larger and difficult tiles if I understand correctly. The largest tile that I have left in porcelain is about 3″ x 24″ in the corner. Can I get away with just using unmodified Kerabond?

                  Question 2:
                  I need about 1/2 a gallon of thinset to finish the final build out of thinset before using the Mapei Adesilex Glass tile mortar to install the Mosaics. Can I just use unmodified for that last portion on top of the modified that already is there and before using the Adesilex?

                  The reason I’m asking is that the Keralastic additive is about $70 per container here and all I need is about $15 worth of it. If I can get away with using unmodified for the build out and the small tiles that’s what I’d like to do.

                  thanks again Roger.

                  • Roger

                    1. Yes

                    2. Yes

                    • Ed

                      Why did Mapei recommend the K/K for the wall tiles in the first place then?

                    • Roger

                      Because they make money on it. :D

                      Having a modified mortar is normally a better option in most cases because you have a bit more flexibility, buildup ability, a little stickier, retains water longer so cures stronger (in most cases), but unmodified works also.

          • Ed

            Roger,

            For these mosaics, I won’t be using a grooved trowel as the grooves will show through the glass so I’ll just be putting down a bead of thinset and then sink them into it. How thick of a bed of thinset should I use? Don’t want to be too thin as to not provide enough thinset to hold them but don’t want to have too much as then I may end of with too much between these small tiles (the gap between the tiles is about 1/2 the width of the tiles themselves) as that would result in quite a bit of work to get the thinset out from between the tiles given the number of grout lines and the thin grout lines.

            Was thinking about 1/8″ of depth.

            • Roger

              You do not want to put down a ‘bead’ of thinset. That isn’t the correct way to do it. What you want to do is comb your thinset onto the wall as you normally would then take the flat side of your trowel and flatten down the ridges so you have a flat, consistent layer of thinset on the wall, then place your mosaics into that. You’ll have full coverage on the back so nothing but white shows through and still have the proper amount of thinset behind your tile.

              • Ed

                Any suggestions on the size of trowel to use? Each mosaic is about 5/16″ wide x 6″ long x 1/4″ deep on a backing.

                I’m trying to line up the front of these mosaics with the surrounding tiles that are already installed and that are 3/8″ deep versus the mosaics that are 1/4″ deep. Trying to figure out how far to build out the base thinset (to compensate for the large 1/2 x 1/2 trowel used on the surrounding tiles and for the difference in the tile depths) that I will allow to harden before using the Adesilex at the end.

                Maybe I’m not explaining this clearly.

                • Roger

                  If they are 1/4″ deep then using a 1/4″ trowel will give you a flat bed of 1/8″. That should give you the needed depth to flush with the wall tiles. If you want to put down a layer to harden first in order to build them out then use a 1/8″ trowel. Or ditra, as I’ve explained above.

                  • Ed

                    Ok, let me explain this in more detail,

                    3/8″ tile is already installed with 1/2 x 1/2″ trowel. It looks that with the back burning of the tiles that the cured thinset depth is 1/4″ or so. That means a total depth of 5/8″ from the DenShield to the front of these tiles.

                    So now I have to install the mosaic that are 1/4″ deep. To match up with the front of the existing tiles I’ll need to have a final thinset depth of 3/8″ behind these tiles.

                    My thoughts were to build out a bed of thinset and let it cure say 1/4″ to match the thinset depth on the thicker tiles. Then use the Adesilex on top of that to adhere the glass mosaic tiles. That would mean a finished Adesilex depth of about 1/8″. My concern is that would mean most likely be a flattened down 1/4″ square trowel. Is that going to be able to hold these sheets properly or given the weight and depth of these tiles, will they sag down the wall?

                    If thinset too thick the tiles will sag and might get too much thinset between the tiles and if too thin I won’t get enough bonding.

                    This would be the same problem with the Ditra from my understanding. How far out from the wall to install it so that the Adesilex is not too thin or too thick.

                    thanks for being understanding in this discussion.

                    • Roger

                      I understand what you are trying to accomplish. This is the easier and easiest way to do it. Install the mosaics to ditra (or 1/4″ backer, ditra, etc.), no matter which size trowel you use, you can let it cure then install the ditra/mosaic combo onto your wall with as much thinset as you need behind it to build it out and it won’t sag down the wall or squeeze thinset through the lines. What you’ll essentially be doing is creating a 3/8″ deep mosaic tile with no open spaces behind the mosaic. It will also allow you to adjust the mosaic in or out without making a complete mess.

                    • Ed

                      Roger,

                      I would do it that way if I thought that would work. See my explanation way above. I cannot break the mosaic install into pieces so I’d have to deal with a piece (of tile and Ditra) that is 8″ x 7′ tall. Not easy to deal with. A bit unmanageable I would think especially if you get it in place and you need to add additional thinset.

                      What size trowel would you use to mount the thinset on the Ditra?

                    • Roger

                      Then comb the thinset onto the front of the ditra, install it on the wall then install your mosaics. I would use a 1/4″ x 1/4″ v-notch for the mosaics.

                    • Ed

                      Ok, I’m installing the glass tile using Mapei Adesilex P10 and water only. The mixture seems very thick; almost like plasticine. Is that how it is supposed to be? I do know it should be thicker than regular thinset.

                    • Roger

                      It should be a bit thinner than that, but yes, it’s a fairly thick mortar.

  • Lisa

    I just found your post about building up tile inserts using ditra. My strips are 4 inches by 12 inches and my question is about the thinset. I see you install the tiles to the fleece and the waffle side to the wall. My wall has kerdi on it. Does that mean I should fill waffles and adhere to wall with unmodified thinset? I’m worried about two waterproof surfaces with thinset between them or am I over thinking this?

    • Roger

      Hi Lisa,

      I install it with modified all the time. You can use either.

  • leeda

    Hi Roger… I hope this post in the right place.. I am reading your advise to use Ditra to level irregular size tiles. I am laying a marble floor .. the tiles are 12×12 and about 3/5 ” thick. I am using a medium bed mortar. I want to do a border tile that is much thinner than the marble tiles.. my question is, can I use Ditra on the border tiles with a medium bed rather than a thin set? Or should I use thin set in the area that I am putting the border tiles and ditra?
    I am using the medium bed because the marble tiles are irregular in thickness.. and also I think that a heavy marble wears better in a medium bed.
    I have absolutely no working knowledge of ditra, having never used it.
    Grateful for any help you can give me
    L

    • Roger

      Hi Leeda,

      Yes, you can use medium-bed mortar with ditra. It’s normally modified, so you won’t have your warranty from Schluter, but it works fine.

  • Rachel

    Hi. To start off, your website is great. Thank you for compiling all your knowledge and posting it publicly. :) I saw this post a little late. I installed an accent border (almost the same as the ones in your example) and there is a noticable difference. After it was installed we liked the look of it but now I’m second guessing myself after seeing this post! My question is, will it be okay? We used a membrane and I’m worried of damaging the membrane if I try and take the accent tiles off now. We used 12 x 24″ tiles with Megalite thinset. Your advice would be really appreciated!

    • Roger

      Hi Rachel,

      It will be just fine. Flushing the two different tiles is only an aesthetic thing, it has nothing to do at all with the integrity of the installation or the waterproofing itself. It is extremely difficult, if not impossible, to remove tile from a waterproofing membrane without damaging it, especially with megalite. I’d just leave it if you like the look of it.

      • Rachel

        Phew! Thanks for that. :dance:

  • Mike Nickau

    Hey Rodger…Wow! What a great idea to use the ditra as a spacer! I was having the same problem with the different thicknesses of tile and was concidering changing tiles. Thank you so, so much! Now I can make accents ahead of time and set them as I go along! Damn man, great idea! I will be using 12×12 marble tile with glass accents. I know marble is porous and I am concerned about it leaching color from the grout. I thought about sealing the tile and the edges before I grout to prevent this but, will I have issues with the grout bonding to the tile and the Kerdi afterwards? I will use a non sanded grout similiar in color to the marble. Once again, thanks for all your help and this site, I have learned so much….Mike.

    • Roger

      Hey Mike,

      The marble will not leach color from the grout. Do not seal the sides. When you’re finished the edges may look a little darker, but that’s just water from the grout causing ‘picture framing’, it will dissipate.

      • Mike Nickau

        Okay Roger, thanks a lot. I won’t worry about it then. Mike.

  • Vivian

    Hello Roger,

    I have thoroughly enjoyed reading through your articles and comments from others doing similar projects. My project is to redo the master bath that is about 5’6″ x 5’4″ (hope I have the right markings). I am at the stage where I have done the demolition, put down a 1/4 inch hardie backer board, and have the tiles laid out and cut. The basic design is a border of 1x1x1/8″ glass mosaic tiles bordering 8x8x1/4″ tiles. Reading this article helped a ton!
    Questions:
    1) Can I use that Ditra backing like you described for much larger swaths, like 5inx20inches? 6inches by 30?It would help if I could do the mosaics in a larger chunk cause I’ve had to piece a few squares here and there while doing the dry run.
    2) If I can, when I am ready to lay the tile down with modified thinset, I fill the waffles first then set it onto a combed thinset on the floor right?
    3) What do you think of the already mixed up acrylic thinset? Preferences on the powdered stuff to use?
    4) I have a 1/4 x1/4 x1/4 inch trowel, I plan on using it to put the thinset on the floor. What are you using to put the thinset on the fuzzy side of Ditra to stick the glass mosaic to?
    5) is there anyway I can send you a picture of what I plan on doing so you could let me know whether the ditra leveling thing would work?

    Thanks so much!
    Viv
    Ps – dancing banana at the bottom really distracting!

    • Roger

      Hi Vivian,

      1. Yes, you can use as large a strip as you need.

      2. Yes.

      3. I think it’s absolute garbage. Use powdered thinset. I prefer laticrete, but customs (versabond) and mapei are very good also. Any good modified thinset will work fine.

      4. 1/4″ x 1/4″. But you can use any size you want. A v-notch trowel works easier, it minimizes squeeze-through.

      5. Yes. You can upload it to the photo upload page. Be sure to attach your name to it so I know what I’m looking at. :D

      Please tell me you put thinset under your backer board.

      Sorry about the dancing banana – we’ve asked him to tone it down a bit but he has a bad attitude. :dance:

      See? :D

      • Vivian

        Hi Roger,

        You are a awesome as the other postings have mentioned!
        I did about 2 months of research, you tube watching, and harassing the people at Lowes, Home depot, friends, and neighbors before I decided that this is/was a project that I could realistically do. I knew that once demolition started, the job must be done.

        Yes, I used thinset under the backer board, used an entire bucket of the premixed thinset (not the acrylic) stuff and was peeved that I had to go and get one more bucket to achieve full coverage! I went back with the partially used bucket and complained that the mixture was more doughy than creamy. So they pointed to another bucket, acrylic, and said use this!
        I used the hardie backer approved screws and, since my piddly little firestorm drill did not have enough power, rented a more powerful drill to put them in. The first few went WAAAAY below the surface and had to be backed out.
        Picture sent, and since then, the missing sections have been filled in, tiles cut and fitted.
        Thanks so much for your time!!!

        –Vivian
        PS The dancing banana is smiling like he knows something we don’t and one of your smiley’s is seizing. May want to get that checked out.

        • Vivian

          NOt sure what happened, I clicked the “click here to reply to this comment” and it posted new. Sorry!

          • Roger

            No worries, sometimes the banana sabotages comment threads. :D

            I would stay completely away from premixed ‘thinset’ of any type. It is not thinset, it is mastic with sand in it. That’s whether it is the acrylic type or not, it shouldn’t be used on floors. I think yours will be fine, I just don’t know how the stuff acts under backerboard.

            Yes, the ditra should level out your insets just fine.

            • Vivian

              Hello,

              Thanks again for all your help!

              So I made the mistake of talking to yet another worker at Lowe’s. That guys says that I must use acrylic thin set to bond the glass and that the latex kind will not do the job well. Lowe’s no longer sells the Laticrete but has replaced it with a “better” brand named Tech and the Tech Ceramic is similar but better than the Laticrete 253 (or some number like that)

              Now I’m just plain confused. Acrylic vs Latex modified thin set?
              Mix the powdered stuff till creamy? I’ve read the directions, and I have not found the proportions at which to mix powder to water. 1 part powder to 1 part water?

              I plan on starting the ditra to glass sections this weekend. then tackle the actual sticking tile to floor later next week.

              –Viv
              :dance:

              • Vivian

                I attempted to include dancing banana but I’ve apparently messed up or he just doesn’t want to be associated with me

                • Roger

                  He’s an asshole sometimes. :D

              • Roger

                The guy has no idea what the hell he’s talking about. Tec ceramic is a good thinset and will work for what you need, but it is nothing near 253 – just sayin’. Powdered thinsets, to my knowledge, are not modified with acrylic polymers, it is all done with latex polymers, albeit different ratios and chemical makeups. Mix it until it’s creamy and fairly thick, like creamy peanut butter.

                • Vivian

                  Hello Roger

                  So what might happen if the mixture is creamy but not quite thick but someone (ahem, me) did not realize it till she was halfway thin setting the glass tiles to the fuzzy ditra side? I don’t plan on touching them till Wed (next day off).

                  I tried powder then water and later water then powder but ended up with lumps that I had to work out with my hands. Any suggestions? I do not have that nifty mixing bit for my drill

                  Does dried thinset come off of the glass tiles easily? Do you have a favorite tool to remove said thin set from between the tiles? That stuff is just messy, I thin set-ed the floor about as much as the fuzzy ditra. I think I even got some in my hair.

                  Thanks for your help.
                  Viv
                  PS – tried ordering you tile tip for the rich and famous, I could not get it to go past the ordering page. I clicked order now/get it now but nothing happened. :eek:

                  • Vivian

                    Sigh, never mind the PS. I just tried it again and it worked. I am now the proud owner of the Tile tips.

                    • Roger

                      Okay. Thanks. :D

                  • Roger

                    No worries on the mixture, fairly wide window there. Always do water first, then thinset. Mix only a little powder at a time and mix until smooth, then add more. Dried thinset does come off of glass easily unless it has surface texture. I normally use a grout saw (the hand type) to remove thinset in the grout lines.

  • Karen

    Hi Roger,

    First, thank you for sharing your wealth of knowledge with the rest of us.

    Now, I want to create a tile “rug” in our jack and jill bath. The field of the
    rug will be made out of a tile mosaic (which looks kind of like a flower)
    which is 12″x12″ with a possible border created with 4″x4″ around the
    mosaic parts. The “rug” would be 2′ 8″ x 4′ 8″ (that would be 8 of the
    12″x12″ mosaic tiles plus the border). The rest of the floor will be
    12″x12″ porcelain tile possibly in a running bond pattern.

    I want to use Ditra but got worried that the mosaic would not be
    supported – the pieces that create the picture vary but are as small
    as a dime (perhaps less). Can I use this technique of reversing the
    Ditra in just this “rug” section to be able to use the Ditra with
    success? Also, if I do this, then there will be no waterproofing – since
    I would not be able to use the KerdiBand over the seams in the
    Ditra – correct?

    Thanks for any assistance.

    • Roger

      Hi Karen,

      I wouldn’t install it upside down. I’d just install it regularly and fill the cavities, let it cure, then install the mosaic. As long as you get the waffles completely full you should have no problems with it.

      And yes, I know what schluter says. :D