Install This: Tiles of Different Heights

What do you do with tiles of different thicknesses?

It happens all the time: your main shower tile is 3/8" thick or thicker, and your glass accent tile or mosaic is 5/16" or less, with some as thin as 1/8". Combine that with the fact that larger tiles need more thinset, which will give them even more height, and you could have a height difference of almost 1/4"! 


Use a slice of 1/8" building material as an easy way to add height behind a thin mosaic or tile so it matches up to the surrounding material.


We recommend:

Cross Section showing use of JetBacker to add height to thin mosaic next to porcelain tile

In the above cross section, you can see how the larger trowel required for the thicker, larger tile adds 1/4" of height. To match this, we added our 1/8" board with a layer of thinset above and below. A thinner bed of mortar under the small mosaic tiles prevents it from oozing up and getting into the grout lines.


NOTE: After troweling your thinset for your mosaic, use the flat side of your trowel to knock down the ridges for smooth surface. You're not removing any thinset, just flattening it to get an even surface. This will prevent thinset from oozing up between your tiles and creating a mess.


Using this technique, you can achieve smooth, flawless floors, backsplashes, and walls, as seen below.


Wedi recommends this same technique with their 1/8" and 1/4" board, as seen in this video where they have pre-set and pre-grouted their mosaics:

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Comments: 7
  • #1

    Dee (Tuesday, 12 February 2019 10:31)

    THANK YOU! I found 2 different tiles to commingle and create a beautiful floor but one is .042 thick and one is .25 thick. Now maybe it can be done. I had about given up. thank you for your post.

  • #2

    Susan (Monday, 24 June 2019 17:36)

    I am doing small hot plates with tiles. I have chosen two different depth tiles for my pattern. Can I put some grout on the back of the thinner ones? only 8 x 8.

  • #3

    Tile Lines (Monday, 24 June 2019 19:52)

    Hi Susan,

    I wouldn't use grout, as grout is not designed as an adhesive and won't bond well. You can use a bit of modified thinset mortar to build it up, as long as you don't build it up more than 1/2". The thinset doesn't cure properly if it's thicker than 1/2".

  • #4

    Christy (Monday, 11 November 2019 12:18)

    Don’t laugh. I designed my backsplash by cutting apart 3 different glass mosaic tiles and then recombining those parts into tiles for my backsplash. Yes, one part is thinner. The tricky part is every other row has thinner tiles plus thicker tiles. I won’t be able to use a row of builder board every other row, I’ll have to cut it up further to help parts of every other row raise up to a single level height. Will this work?

  • #5

    Tile Lines (Monday, 11 November 2019 15:45)

    Hi Christy,

    You're certainly ambitious!

    Lots of people who do custom mosaic work are in the same boat: many different elements of different thicknesses.

    I've seen all sorts of solutions for this: glue a penny under a tile to raise it just a little bit, add more thinset behind some and less behind others, etc. You can definitely use a thin mat like the DCI mat or Schluter Ditra mat, or a thin board like 1/8" Wedi board or 1/8" Fiberock; whatever's available near you.

    Just make sure whatever you use isn't moisture-sensitive or water soluble, or the moisture in the thinset could cause problems.

    Good luck on your project!

  • #6

    Kathleen (Wednesday, 05 February 2020 19:44)

    I have found a porcelain 12x24 for my shower and the accent tile is 8x8 ceramic deco pattern. It’s beautiful! But thicker - can I make the bigger, thinner tile work with the accent tile? The whole shower will be the thinner tile with jutst the shampoo nock and accent band the thicker tile. Thx!

  • #7

    Tile Lines (Thursday, 06 February 2020 15:36)

    Hi Kathleen,

    Depending on how different the thickness of the tiles, you could do one of two things:
    Use a larger trowel (1/2x1/2" or larger) under the 12x24" tile and a smaller trowel under the 8x8" tile (1/4x1/4" or 1/4x3/8"). This will build the 12x24" up by about 1/8" to 1/4" more than the 8x8" tile.
    You could cover the entire area under the 12x24 tiles with an 1/8" membrane or board, but you'd want this layer to be completely dry before you start applying the tile. You would also want to add some sort of tall edge trim, like 1/2" Schluter Jolly or similar, *under* the 1/8" membrane so it hides the edge of the membrane and the tile.