Installation Guide
Ceramic and Porcelain
In general, ceramic and porcelain tiles are excellent choices for shower applications. They are not adversely affected by moisture and are easily 
cleaned. Furthermore, they can be installed using unmodified thin-set mortar within the Schluter
®
-Shower System. However, some specific 
categories of these materials require special consideration.
Mounted Mosaic Tiles
Schluter Systems does not specify a minimum tile format for use over the KERDI-SHOWER 
series of prefabricated foam trays, but when using small tiles with heavy loads a mortar base is 
recommended. 
Mosaic tile are typically mounted and sold as sheets for ease of handling and installation. There 
are various methods used to mount the tiles, some of which can present installation or application 
challenges. 
Back-mounted and edge-mounted tile assemblies may have paper, mesh, resin, polyurethane, 
or other bonding material on the back or edges of each tile, which becomes part of the tile 
assembly. In some cases, the adhesive used to mount the tiles is moisture sensitive and may lead 
to debonding once the shower is put into service. According to the TCNA Handbook for Ceramic, 
Glass, and Stone Tile Installation, mounted tile assemblies must feature sufficient exposure of the 
bonding surface of the tile to allow for 95% contact with the setting material in wet areas. Confirm 
with the tile manufacturer that the back- or edge-mounted tile is suitable for use in wet areas and 
never use paper back-mounted mosaics in shower applications.
Face-mounted tiles may use a clear film that is removed after final set or paper that is removed 
during the installation process before adjustments are made and final set is reached. In general, 
this approach is superior because the back of the tile is in full contact with the bond coat. 
Pebbles
Pebble tiles have been used on shower floors for years, but due to their irregular shape there are 
some items to address with installation. For example, rounded pebble tiles can create barriers 
to drainage in showers since the grout is typically not flush with the surface of the pebbles. 
Maintaining sufficient slope for drainage is essential, perhaps even in excess of the typical 1/4" per 
foot. Rounded pebble tiles may also require a relatively thick bond coat to ensure proper coverage 
and bond to the shower base. Pebble tiles with flat surfaces can be easier to install with respect 
to the issues described above. Grout joints in pebble tile applications are typically wider than 
those in square or rectangular tile applications. Follow the tile and setting material manufacturer’s 
instructions for grout selection. 
Large Porcelain Tile Panels
Large porcelain tile panels are growing in availability and interest in North America. Some of these tile panels feature resin or urethane 
backings, which require special setting materials, such as modified thin-set mortars or epoxy adhesives. Panel manufacturers may require 
modified thin-set mortars to install panels without backings as well. Often, these manufacturers have tested and recommend specific mortars 
to install the panels, not just any mortar within a category or meeting an ANSI specification. Contact the panel manufacturer and setting 
material manufacturer to obtain a recommendation for a specific setting material to install the panel over a bonded waterproofing system.
The Schluter
®
-Shower System is an integrated family of products that creates a sealed system for showers, steam showers, steam rooms, and bathtub 
surrounds. The Schluter
®
-KERDI/-KERDI-DS membranes and Schluter
®
-KERDI-BOARD substrates are waterproof and provide a bonding surface for tile 
coverings. Typical covering materials include ceramic, porcelain, and natural stone tiles. The following information is intended to be used as input for tile 
selection in shower applications.
TILE SELECTION CONSIDERATIONS
Discussion of different tile types in shower applications
TILE SELECTION CONSIDERATIONS — Discussion of different tile types in shower applications 41










