Measure and Prep the Installation
With the tile backer board in place, begin by measuring the areas to be tiled (Image 1).
The tiles used here are pre-attached to mesh-backed mats. Each mat is a section of the overall pattern, and although the tiles in the pattern are different sizes, the mats are easy to install, which saves time.
On a flat surface, place the tiles as they would look installed and check their measurement against the layout (Image 2).
Cut the mats to fit the areas measured. In this project, the ceiling and floor are covered with square 2x2" tiles. On the shower walls, rectangular 2x4” tiles are used. The design also calls for a decorative 3” mosaic border on the walls between the second and third panel from the top.
If the mats can’t be trimmed to fit the space, tiles may have to be cut at one end or another – or at both ends, if you want the end rows to be symmetrical. Here, cuts will be less noticeable if they are made in the bottom row of tiles. Because vertical tile setting starts at the bottom up and works upward, this installation will begin at 72.5 inches down from the top of the shower (based on the mat width measured from the top). The bottom panel will be installed last.
For vertical installations, use a temporary starter board to ensure that the tiles go up straight and the rows stay even. Use a level to position the board and attach it with drywall screws directly onto the cement backing. The board and screws are removed after the tiles have set (Image 3).
Use non-sagging thinset mortar to set tile mats on vertical surfaces. This prevents the tiles from sliding down after they're placed.