Schluter-DITRA-XL provides the same four essential functions as Schluter-DITRA, i.e., uncoupling, waterproofing, vapor management, and support/load distribution, but is 5/16" (7 mm) thick, whereas DITRA is only 1/8" (3 mm) thick.  The increased thickness allows for even transitions between typical ceramic tile and 3/4" (19 mm)-thick hardwood flooring.  It also increases the movement accommodation capabilities of the product, allowing for the installation of ceramic tile over single-layer wood subfloors on joists spaced at 24" (610 mm) o.c.

Even Transitions to Hardwood Flooring

In many thin-set ceramic tile applications, one of the goals is to minimize the thickness of the assembly to reduce height transitions from the tile to other floor coverings such as carpet, engineered wood, or vinyl.  At 1/8" (3 mm) thick, Schluter-DITRA accomplishes this goal while providing the four essential functions for successful tile installations.  However, where ceramic tile meets 3/4" (19 mm)-thick hardwood, minimizing the thickness of the tile assembly can result in a height transition up to the hardwood.  Schluter-DITRA-XL is 5/16" (7 mm) thick, which allows for even transitions between typical ceramic tile and 3/4" (19 mm)-thick hardwood flooring.

Ceramic Tile Installation over Single-Layer Wood Floors on Joists Spaced up to 24" (610 mm) o.c.

Since the uncoupling function is based on the geometric configuration of the membrane, the increased thickness of Schluter®-DITRA-XL results in increased movement accommodation.  DITRA-XL and 12 x 12 porcelain tiles were installed over a single layer 3/4"-thick plywood subfloor on joists spaced at 24" (610 mm) o.c. and tested according to the ASTM C627 “Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson Type Floor Tester.”  The assembly passed cycles 1 through 12, thus achieving a Heavy rating per the TCA Handbook for Ceramic Tile Installation.  This high performance rating is particularly impressive considering the bending and deflection of the single-layer subfloor under loading.