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.
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)
Photo 2
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.
Photo 4
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:
Photo 6
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:
Photo 8
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.
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:
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:
Ooooh, Pretty...
Ooooh, Pretty < See?
Add a Brilliant Retort
Hello Roger,
Your website was incredibly helpful when I did my kitchen floor, which turned out fantastic. My father in law is an old school contractor and I kept fighting with him because my dogs were running around on fire.
My question is about a new project I am starting. I am going to tile my fireplace with glass mosaic tile. I have figured out that I need to use that cement board with the metal mesh in it so I can use the cement screws to attach it to the wall. I think the regular cement board is too brittle to support that kind of screw.
Where I need the help in this project is an uneven surface. The face of the fireplace has a recessed portion which is about 1/2 inch deep and 1′x3′ in size. I thought about putting thicker backer board in the void but it will not make up the difference. I don’t think i should stack the backer board.
Suggestions?
Max
Hi Roger:
This site is the greatest!
I have question about mosaic tile being used for a shower floor. The tile I would like to use is 2″x2″ in sheets 12″ square and they are only about 3/16″ thick. Can I use them or look for something thicker? How thick?
Also, can I build up the area around my drain with thinset (3/8″ let it dry) to bring the thin tile up to the right height? Even with the added thinset the slope would still be 1/2″ per foot since I made the pan slope steeper than needed.
Does it hurt anything to sift the sand out of the thinset for really tiny tile setting?
Thank you,
Dave
I love the idea of mating mosaics to Ditra….I have a ‘detail tile ‘ that is like a mosaaic, however they are a bunch of 1/2″x4″ tiles glued to a mesh backer. On the sides, every other row sticks out from the row above, so when you place it beside each other they interlock…(God, I hope that makes sense).My question is, how to cut out the Ditra so it catches these ‘mini tiles’ that extend to the sides??? In your photos above, the mosaic is perfectly rectangle….
Hey Kevin,
I normally just cut the rectangle out and offset the ditra so there is an open area for the piece from the next row that locks in. That part gets stuck to the ditra as you’re putting it up on the wall. (God, I hope that makes sense).
I’m (kinda) confused. When you say “offset the Ditra”, do you mean that the tiles that extend (every other row) beyond the main group of tiles would not be thinseted to the Ditra, as in Photo 8 above? What size trowel do you use for the Ditra backed mosaic tile?….
Hey Kevin,
Yes, when you initially bond it to the ditra leave the part that locks into the pattern overhanging the ditra. Then as you install it on the wall just bond that overhanging piece to the open piece on the pattern before it. KnowWhatIMean?
I use a 1/4″ v-notch trowel to install mosaics to ditra.
What do you think of 1/8″ vinyl floor tile being used as a backer for mosaics? Also, does your mosaic/ditra combo have to be supported on the wall, or does it stay in place on its own?
Hey Kevin,
As long as you have a good thinset which will bond to the vinyl – guaranteed – then it will be fine. The biggest problem is that most of these tiles have a shiny or waxy coating on them which makes it very, very difficult to get a long-term bond.
Hi Roger,
I stumbled across your site and love it. I had my entire bathroom gutted (60 year old bathroom). I am unhappy with the tile job. I am a picky person
I took some pic’s, I’m just not sure how to get them to you.
I am not sure if Ditra was used for the glass accent tiles. The problem is thinset is around some of the tiles, not grout. The thinset has peaked out in other places too.
At first the border was set and was obviously not square in the corner. I was told the wall wasn’t plum; however, they were new walls. I had them “fix” that issue but now I see even more thinset and not grout. Note I think it’s epoxy grout and we did not caulk the tub, just used grout.
Thanks,
Sherri
Hi Sherri,
You can upload photos here: FloorElf’s photo upload page. There are many substrate that can be used to bump out the glass, it doesn’t have to be ditra – that’s just what I use. Thinset will always ooze through mosaics, it just needs to be cleaned before grouting – it sounds as if that just wasn’t done. Whoever did your tile is responsible for fixing that. Any change of plane, including the tile/tub transition, needs caulk or silicone – not grout.
I want to use 12 x 12 marble tiles half way up my shower walls and 3 X 8 glass tiles the rest of the way. Also, the shower ceiling will be covered with the marble tiles. The marble tiles are thicker than the glass tiles. Do the tiles need to be flush with each other? If so, what do you suggest?
Hi Jayne,
You need an additional substrate behind the glass. I use ditra a lot to create flush tile – as I’ve described above. You can also use 1/4″ backerboard, which would probably be a better option with as much as you need to shim out.
Hi
Great site! I have learned a lot but I still have a bunch of questions. I am remodeling a small 5′X7′ bathroom with a tub/shower on the 11th floor of a Coop apartment. We want to use large glass tiles on the walls (pattern of 9×18, 4×12 & 3×6 tiles) and frosted oval glass mosaic tiles on the floor. Is it just a stupid idea to try and DIY with such large glass tiles?
I have demolished the floor down to the concrete slab (which is flat but not level) and the walls down to the studs (1 5/8″ metal lattice studs). I plan to double up the studs, plumb the walls, add cross bracing and Hardie or Durock backerboard. Would it be a good idea to put a bead of polyurethane construction adhesive on both faces of the new studs to stiffen up the wall?
For a crack isolation/waterproofing membrane would Durock tile membrame be good? I thought since its vapor permeable the thinset behind the glass tiles might set faster/better. Is Laticrete 254 a good thinset to use or do you have another recommendation? Should I use the quickset thinset? Kerdi seems like a great product but is there a thinset that will work with it and large glass tiles?
I was thinking of using a urethane grout. Is Starglass really needed or can the cheaper Starquartz be used without scratching the glass? Since urethane grout is somewhat flexible can it be used at a change in plane instead of caulking? Do you prefer urethane or epoxy grout? Would you recommend using a grout release with frosted glass and are they compatable with urathane/epoxy grouts?
The floor will have a suntouch radiant heating mat. I need to raise the floor about 3/4″ before tiling. I was planning on attaching 1/4″ cork with thinset to the slab as a thermal break. Then embedding the heating mat in ~1/2″ of thinset or self leveling concrete followed by an crack isolation membrane and tile. Should the slab be acid etched or primed with latex before applying the thinset? What do you recommend to use for embedding the heating mat? Should I use the same membrane I use on the walls on the floor?
Sorry for the long winded questions. Take a break and have a beer.
Any advice you can provide is greatly appreciated.
Lawrence
Hi Lawrence,
To be honest yes, it is kind of a stupid idea.
Not so much stupid at all, more an issue of misunderstanding. Not to be an ass, I’m not trying to be, but professionals, including myself, need to research each particular glass we work with. There are literally hundreds and hundreds of different glass tile manufacturers out there and every one of them has their own installation requirements. So regardless of what I tell you about the installation there are certain to be aspects of it that will differ. Each installation differs, techniques, setting materials, acceptable applications, etc. Every one is different. If you indeed want to do all that you need to contact the manufacturer. It can be done, but it requires specific techniques.
The durock membrane is good, but may not be approved for your glass. Starglass is good as is starquartz, but either may scratch your glass. Glass tile can be manufactured with one of three techniques, the specific glass may be easily scratched or not, I dunno. I have NEVER seen a glass manufacturer that would accept a non-modified thinset – kerdi is out. Urethane grout can not be used in lieu of silicone. If you don’t allow for proper movement your glass will crack.
Laticrete’s 254 is great stuff, their glass tile adhesive is better for most glass – not all. Do not use quickset with glass – it may crack. I prefer epoxy grout – but you can’t use it with all glass – it may crack. Radiant heating under glass? Nope, it’ll crack. Catching a theme here?
I prefer using thinset and ditra over heating elements. I think I’ve answered most of the questions I could and most in regards to regular tile – glass, not so much… Sorry.
Thanks for the quick response. I was afraid that would be the general gist of your response. Even though its stupid I still love the look of the glass tile and haven’t completely given up on it. I will check with the manufacturer about more specific installation instructions. The website that has the affordable glass wall tile we are looking at only gives very general installation instructions on their website (I know that probably is not a good sign
) The manufacturer of the oval glass mosaic is very reputable. Would it still be stupid to use them if they claim the 1 1/4″ x 3/4″ tiles can be used with radiant heat?
I have another question about the substrate. There is an approximately 15″ wide ceramic vent pipe running inside the wall near one corner. There are no studs in this area and no room to add any. Directly attached to the vent is approximately 3/4″ of chicken wire reinforced cement with about 1/4″ of gypsum plaster. These layers cannot be easily removed without damaging the vent. The plaster is approximately even with the new backer board. Where the new cement board abuts this area can I just tape the seam and skin coat it with thinset to even it? Would it be a better idea to then cover the entire wall with an additional 1/4″ of cement backer? Do you have any other specific suggestions for transitioning to this area?
Thanks again for the great site. I loved your detailed instructions on creating a nitche.
Lawrence
If the manufacturer says it can be used over radiant heat it’s fine – they take the risk. Just be sure to follow their installation requirements to the letter.
It would be better on that wall to install a continuous membrane of some sort over that area. This can be 1/4″ backer, kerdi, any crack-suppression membrane or any membrane which will create a continuous surface on that wall. It needs to be tied into the rest of the wall behind the tile. Skimming thinset will simply float it out, not tie it in. It may still crack at the transition.
I’m hoping to use 4 x 16 subway tiles with a 2 x 2 marble tile for an insert in two small bands in the shower.
1. Can that be done as the subway tile is thinner than the marble.
2. If it can be done (fingers crossed!) should I use a marble pencil tile in between the subway tile and 2 x 2 marble tile.
Hope to hear from you soon.
Hi Melissa,
1. Yes, you can do that. If you want all the tile to be flush, however, you’ll either need to build out the substrate behind the subway tile or inset the marble.
2. That would actually be the ideal technique – because the pencil rail will hide the fact that the tile is not flush. Do that.
You rock!
Not only did you tell me what I wanted to hear (which always raises people in my esteem,haha), but you were uber fast doing it!
Can you use the same sanded grout if doing a tub surround with big, 12X12 or 12X24 slate-looking tile and putting a glass tile accent strip? Will sanded scratch the glass?
Hi Cece,
Some glass will scratch and some won’t, it depends on the glass. Test it on an extra piece before you try. As long as it doesn’t scratch then yes, you can use the same grout. I’ve only had four or five glass tiles that would scratch over the course of nineteen years, so it’s fairly rare.
Good morning,
Bet you are already up?
On the above tiling method can I use something else besides Ditra, if I don’t have it? and if so how? I am using RedGard for waterproofing instead.
Thank you,
Anita
Hi Anita,
Yes, you can use a cement backerboard or any substrate suitable for we areas. Note that they must be water stable – that is, they don’t deform or break down when wet. While denshield is acceptable as a shower substrate only the face of it has the waterproof aspect, it can break down if the core of it is left wet.
Since you are using redgard you can also flip your mosaics over and place the alkali-resistant mesh tape on the back of it (ummm, you have that, right? Because you put walls up and taped and mudded them – right???
) then redgard over that. The idea is to get a full layer on the back of the insert so you can build up the thinset behind it to make your insert flush without it squeezing through the smaller grout lines.
I just used this method (Redgard over mesh on the back of Mosaic) and It’s a fantastic way to go. It makes the Mosaic more stiff and doesn’t allow any thinset through the smaller grout lines..