Schluter-DITRA is a polyethylene membrane with a grid structure of square cavities, each cut back in a dovetail configuration, and an anchoring fleece laminated to the underside. The anchoring fleece is embedded in thin-set mortar to provide a mechanical bond to the substrate. Tile is installed over DITRA using the thin-bed method in such a way that the mortar becomes mechanically anchored in the square, cutback cavities of the matting. Designed specifically for ceramic tile and dimension stone installations, DITRA serves as an uncoupling layer, waterproofing membrane, and vapor management layer that accommodates moisture from beneath the tile covering. Further, DITRA performs all these functions while still providing adequate support/load distribution for the tile covering. The combination of these four essential functions allows for the successful installation of tile over a wide range of substrates, including plywood/ OSB, concrete, gypsum, heated floors, etc. DITRA is 1/8" (3.5 mm) thick, which minimizes tile assembly thickness and reduces transitions to lower surface coverings (e.g., carpet, engineered wood, and vinyl). DITRA allows for ceramic tile application over single-layer plywood or OSB subfloors on joists spaced up to 19.2" (488 mm) o.c

1. Using a thin-set mortar that is suitable for the substrate, apply the thin-set mortar (mixed to a fairly fluid consistency, but still able to hold a notch). For DITRA use a 1/4" x 3/16" (6 mm x 5 mm) V-notched trowel, 5/16" x 5/16" (8 mm x 8 mm) V-notched trowel, or the DITRA trowel, which features a 11/64" x 11/64" (4.5 mm x 4.5 mm) square-notched design.

For DITRA-XL use a 1/4" x 1/4" (6 mm x 6 mm) square-notched trowel or the DITRA-XL trowel, which features a 1/4" x 1/4" (6 mm x 6 mm) square-notched design.

2. Apply DITRA or DITRA-XL to the floor, fleece side down. Solidly embed the matting into the mortar using a float, screed trowel, or DITRA-ROLLER*, making sure to observe the open time of the bonding mortar. If the mortar skins over prior to matting installation, remove and reapply.

*When using the DITRA-ROLLER, place a weight (e.g., bag(s) of mortar/grout or box of tile) not to exceed 75 lbs on the DITRA-ROLLER shelf. Slowly move the roller from one end of the matting to the other, slightly overlapping successive passes.

3. Lift up a corner of the matting to check coverage. Proper installation results in full contact between the fleece webbing and the thin-set mortar. Simply abut end and side sections of adjacent sheets. Note: Coverage may vary with mortar consistency, angle at which the trowel is held, substrate flatness, etc. If full coverage is not achieved, remove and reapply, making sure to verify proper mortar consistency and application.

4. Tile can be installed over DITRA and DITRA-XL immediately; no need to wait for the mortar to cure. Fill the cut-back cavities with Schluter SET, Schluter ALL-SET, Schluter FAST-SET, or unmodified thin-set mortar and comb additional mortar over the matting using a trowel that is appropriate for the size of the tile. Solidly embed the tiles in the setting material. Periodically remove and check a tile to ensure that full coverage is being attained. Back-buttering is a useful way to help ensure proper coverage, particularly when installing large-format tiles (e.g., 12" x 12" (305 mm x 305 mm) and larger).

Note: To bond DITRA to the substrate, using the DITRA trowel: Use one 50 lb. (22.68 kg) bag of mortar per 150 ft2 (10.7 m2). To bond DITRA-XL to the substrate, using the DITRA-XL trowel: Use one 50 lb. (22.68 kg) bag of mortar per 100 ft2 (9.3 m2). To bond the tile to the DITRA, using a 1/4" x 3/8" (6 mm x 10 mm) square- or U-notched trowel: Use one 50 lb (22.68 kg) bag of mortar per 40 - 50 ft2 (3.7 - 4.6 m2). To bond the tile to the DITRA-XL, using a 1/4" x 3/8" (6 mm x 10 mm) square- or U-notched trowel: Use one 50 lb (22.68 kg) bag of mortar per 35 - 45 ft2 (3.3 - 4.2 m2).