When installing tile adjacent to thicker materials, with the intention of the two tiles finishing in the same plane (flush), the substrate must be brought up to a level such that the tile can be installed with the recommended amount of thin-set. This should be accomplished in one of three ways depending on the amount of variation between the uninstalled tiles and installed surrounding material.
For Variation between 1/8″- 1/4″
Step 1 Apply a build-up layer of a recommended thin-set, screed to the desired substrate depth and cure for a minimum of 48 hours.
Step 2 After the build-up layer of thin-set has cured for a minimum of 48 hours, install and grout the tile per the installation instructions.
For Variations between 1/4″- 3/4″
Step 1 Using a recommended thin-set, install a piece of ¼” or ½” cement board. Use a notch trowel size and cement board thickness that will render the desired substrate depth. Cure a minimum of 24 hours.
Step 2 After the installed cement board layer has cured for a minimum of 24 hours, install and grout the tile per the installation instructions.
For Variations between 3/4″- 1 1/2″
Step 1 Apply a thin layer (bond-coat) of a recommended thin-set.
Step 2 While the bond-coat is still tacky, apply a cement mortar bed (4:1 sand & cement mixture per ANSI A108.1B). Screed the cement mortar bed to the desired substrate depth and cure a minimum of 7 days.
Step 3 After the cement mortar bed has cured a minimum of 7 days, install and grout the tile per the installation instructions.