I noticed, too late (during install), that the mosaic tile my wife chose for accent in our shower is a different depth than the regular tile we're using. The mosaic tiles are about 1/8-3/16" thinner than the other tiles. I tried using a piece of backer board, but that made the mosaic tiles push past the regular tiles. I wound up trying to build up using thicker glass mortar, but that resulted in less-than-perfect mosaic...so I need to rip this out.

My question is...how should I build this up so I don't need to make a thick mortar base for the mosaic? Should I built it up slowly with layers of mortar? Is there some thinner material I can use to build this up in this (wet) environment?


2 Answers 2


Wire lath has been used as a base for plaster walls and stucco for decades.


It is made from an expanded mesh of metal. You should be able to:

  1. cut a piece that is the size of your mosaic
  2. check to make sure that the lath + thinset + mosaic will be flush with the remainder of your tiles
  3. attach it to your backerboard (or whatever the substrate is for the rest of the tile) with screws or staples
  4. cover the mesh completely with thinset, making sure it fills the gaps under the mesh and adheres to the backing material
  5. place your mosaic on the thinset.

The wire lath should be available at tile stores and possibly home centers. See, e.g. this

  • This approach seems like it will give a much more solid base than simply building it up. I'll use small pieces of scrap sheet metal in various gauges to make sure I have the right thickness before purchasing the wire I need. Great advice! Thanks. Aug 4, 2012 at 19:22
  • ~2yrs later now..I took this advice and not only did it initially come out looking great, but it's standing up to time. Thanks again! Oct 25, 2014 at 4:53

If the mosaic accent tiles are thinner than the field tiles, I think building up extra thinset behind the accent tiles and carefully pushing them into it so they are flush with the surrounding field tiles is a decent approach.

If the mosaic accent tiles are thicker... I don't have a good solution for that. That is the situation I had in my shower and I just have a bit of a lip that is grouted. The transition is not too bad.

How different are the tile thickness'?

  • I've used showers with this "situation" and it's hardly noticeable unless you're special needs / older and need to lean against the shower wall for whatever reason.
    – Aarthi
    Jul 31, 2012 at 16:42
  • The delta is about 1/8~3/16 of an inch...just too little for 1/4 backer to be too much...and too much for my 1/4 mosaic trowel to be effective. I blame myself to both putting a coat of thinset on the well and back-buttering as well...that added a bit of thickness, enough to ruin my day. Perhaps the answer is for me to be more patient and get it perfect. I thought I had...perhaps it "drooped" as it dried. It's amazing how much respect one gets for professionals when it becomes evident how much artistic skill is involved. Jul 31, 2012 at 23:18

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