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The demand for mosaics is rising. More and more customers are requesting their pixelated beauty be worked into a variety of installations. Once reserved for ancient temples, places of worship and villas of the wealthy, today’s residential and commercial customers want patterns and images incorporated into backsplashes, shower floors, pools, accent walls and just about any other tile surface. For a lot of us tasked with installing mosaics for the first time, we tend to think along the lines of “small tiles, complicated installation methods, time-consuming project.”

Any ceramic, natural stone, glass, porcelain or metal tiles less than 2 inches are considered mosaic installations, and they are not as daunting as they initially seem. The process is rather straightforward, using many of the same standards applied to other tiling applications. There are also better products on the market that streamline the job and yield superior results. Let’s put this all together.


TILE 0322 Technical Focus: Mosaic slide 2

Because mosaic tiles are small in size and typically on sheets, a flat surface that meets TCNA requirements will prevent an undulated installation. Photos courtesy of Merkrete (Click on the image to enlarge.)


How Do I Install a Mosaic?

Substrate recommendations for mosaics follow those of other ceramic tile installations for the most part. However, extra attention must be given to substrate stability, rigidity and preparation. Because mosaic tiles are small in size and typically on sheets, a flat surface that meets TCNA requirements will prevent an undulated installation. Flat substrates also allow for uniform mortar coverage, avoiding extra thickness.

There are mortars specifically formulated for mosaics. As these installations tend to be more delicate than other surfaces, it is essential to choose a product that will not scratch the tiles. Some mosaic manufacturers require that installers use specific mortar when the tiles are backed by netting. For these, high-quality epoxy mortars like Merkrete’s Pro Epoxy may be a strong candidate, though be sure to consult and abide by manufacturers’ instructions to avoid damage.

Grout recommendations for mosaics differ based on aesthetics and joint size. While some mosaic tile manufacturers specify non-sanded grout to prevent scratches, others require sanded grout. Manufacturer recommendations vary regarding the acceptability of epoxy grout use, so it is essential to follow instructions carefully from project to project to ensure a pristine, long-lasting installation.


TILE 0322 Technical Focus: Mosaic slide 3

Manufacturer recommendations vary regarding the acceptability of epoxy grout use, so it is essential to follow instructions carefully from project to project to ensure a pristine, long-lasting installation. Photos courtesy of Merkrete (Click on the image to enlarge.)


Things to Keep in Mind When Installing Mosaics

Many mosaics, especially those made of glass or metal, should not be used as wear surfaces like floors. Also, as mentioned above, the netting on the back of some mosaics may present bonding issues, so it’s a very good idea to contact the manufacturer for adhesive suggestions. This netting may even need to be removed if it prevents the mosaic from mounting straight.

Something else to remember is that glass tiles expand more than ceramic, so additional movement accommodations will be necessary. Lastly, installers should be careful not to install mosaics with mismatched thinset and grout colors, as the thinset pigment may “bleed through” the grout and create a mottled appearance.


Are There Tile-Setting Products Designed for Mosaics?

Absolutely. The aforementioned “bleed-through” issues are easily avoided when using a single-product grout and thinset combination. Products like Merkrete’s Integra all-in-one thinset and grout serve this dual purpose while reducing overall installation time and eliminating mottling with its uniform color.

Mosaics will continue to be hot-ticket items. Whether it is a residential customer renovating with expressions of color and pattern or a large commercial client introducing a touch of grace to a stately space, you will be called upon to install mosaics with greater frequency. Stay within industry regulations, adhere to manufacturers’ instructions and assemble the right materials for the job, and you will easily be able to put all the pieces together.