Mosaic tiles, or tiles that are smaller than 5 cm (two inches) in size, are frequently used in tile designs. Shower floors, Victorian-style bathroom floors and contemporary designs all make use of mosaic tiles on a regular basis. Mosaic tiles are typically mounted on sheets of either mesh or paper to make them easier to install. Mosaics can be installed by the full sheet or in strips, provided the mortar beneath them has been smoothed out to keep it from coming up through the many grout lines.
Without putting down any mortar, lay out your mosaic tile sheets over the area you wish to install them, to get a feel for how they fit together. Line up the sheets so the grout lines between the sheets are uniform with the grout lines within the sheets, and ensure that patterns interlock in the correct direction.
Cut the netting or paper of the sheets with a razor blade to get the sheets as close to size as needed to fit the edges of the installation. If needed, cut individual tiles with tile nippers, or use a tile wet saw if cutting multiple tiles at once.
Remove the mosaic sheets from the surface being tiled and spread a small amount of thin set mortar over the area. Key the mortar with the notches in the trowel to produce ridges, and then smooth these ridges out with the flat edge of the trowel to produce a smooth, level surface.
Press the sheets of mosaic into the flattened mortar one by one in the layout you predetermined. Place a 5 x 10 cm (2 x 4 inch) board over each sheet and hit the board with a wooden mallet to beat the sheets into the mortar. This will produce a level installation.
After the mosaics have set up for one hour, remove any paper from the face of the mosaics by soaking the paper with warm water. Peel the paper away from the mosaics and allow the mortar to finish drying overnight.
Grout the mosaics by spreading grout over all the tiles at once with the flat edge of a grout float. Pack the grout evenly between each joint and wipe the surface of the tiles clean with a damp grout sponge.