Schluter®-DITRA Installation over Wood
Schluter
-DITRA is specifically designed to allow theinstallation
of ceramic and stone tile over  any even and load bearing substrate. The first step in a successful project is planning.  TheSchluter
-DITRAInstallation
 Handbook includes comprehensive Âinstallation
guidelines and warranty criteria. The planning process starts by searching for  the detail applicable to your project based on the substrate, tile type, and other factors.  All requirements in the Handbook are important. Please pay close attention  to the setting materials and movement joints requirements when planning any DITRA project  After finding the applicable DITRAÂinstallation
handbook detail and  confirming that all requirements can be met, we can create a list of materials and quantities.  When installing DITRA, the following tools are commonly used:  - A Tape measure, - A Marker,  - A Utility knife or scissors, - Buckets,  - One-half inch electric drill and mixing paddle suitable for thin-set mortar,  - A Margin trowel, - A DITRA-TROWEL or one-quarter-inch  by three-sixteenths V-notched trowel, - AWood
or magnesium float  - A Chalk line reel, - Hairspray,  - A Notched trowel for tile setting - And a Grout float  Project planning is now complete.  Now we re ready to prepare for theinstallation
.  It is important to have a perimeter movement joint throughout the tile assembly. One option,  as shown here, is to fasten a strip of Sill ...
Seal, a compressible polyethylene gasket,  to the surrounding walls to ensure a consistent joint along the perimeter.  The substrate must be clean, even, and load bearing. Any leveling of the subfloor must  be done prior to installing DITRA. Sweep the floor to remove any debris.  For
wood
substrates, verify that subfloor panels are properly fastened to framing members.  Measure and cut the matting using a utility knife or scissors.  Clean any dust from the substrate with a damp sponge.  Now we re ready to begin theinstallation
. DITRA is installed simply and  easily with thin-set mortar. In this case a modified thin-set mortar is used,  because the matting is being installed overwood
. Always verify the proper type of mortar required  to install DITRA based on the substrate. The mortar is mixed to a fairly fluid consistency,  but still able to hold a notch. A one-quarter inch by three-sixteenths inch  V-notched trowel or theSchluter
-DITRA-TROWEL, which features a four-point-five millimeter by  four-point-five millimeter square-notched design, is used to apply the mortar.  Apply a thin layer of the mortar with the flat side of the trowel to produce solid contact  with the substrate and then comb additional mortar using the notched side of the trowel.  Apply the DITRA, fleece side down and solidly embed in the mortar using  a float or the DITRA-ROLLER. When using the DITRA-ROLLER,  place a weight on the shelf...
and slowly move the roller from one end of the matting to the other,  slightly overlapping successive passes. Bags of thin-set mortar or grout or boxes  of tile can be used as weight, provided the total weight is kept under seventy-five pounds.  Make sure to observe the open time of the thin-set mortar. If the mortar skins over,  remove and reapply fresh mortar before installing the membrane.  The risk of skinning is increased when installing a longer run of DITRA. Applying  the mortar and embedding the membrane in shorter sections will help avoid this problem.  Lift up a corner of the membrane to check coverage. Proper
installation
results in  full contact between the fleece webbing and the thin-set mortar. Re-embed the membrane.  Coverage may vary with mortar consistency, angle at which the trowel is held, membrane application,  and other factors. If full coverage is not achieved, remove and reapply, making sure to  observe properinstallation
techniques. For DITRA-XL, it may be beneficial to use a  trowel with larger notches, such as a one-quarter inch by one-quarter inch square-notched trowel.  This process is repeated over the entire floor.  Since we ll be installing a movement joint profile at the floor-to-wall transition,  we need to cut the sill seal above the DITRA. Otherwise we would leave the gasket in place  until after the tile was set and grouted. Theinstallation
of the DITRA membrane  is...
now complete. Floors can be made fully  waterproof with DITRA if desired by sealing seams and floor-to-wall transitions with Â
Schluter
-KERDI waterproofing accessories. The KERDI accessories can be installed  using any of our thin-set mortars or an unmodified thin-set mortar.  The mortar is mixed to a fairly fluid consistency, but still able to hold a notch.  A one-quarter inch by three-sixteenth inch V-notched trowel or theSchluter
-KERDI-TROWEL,  which features a one-eighth inch by one-eighth inch square-notched design,  is used to apply the mortar. Apply thin-set mortar to the  area where theSchluter
-KERDI-KERECK corners are to be installed. Fill the cavities in the  DITRA matting and comb additional mortar using the notched side of the trowel.  Embed the KERDI-KERECK into the thin-set mortar using the flat side  of the trowel or a dry wall finishing knife. Cornerinstallation
may be simplified by holding  one side of the corner in place while embedding the other side of the corner in the mortar. ÂSchluter
-KERDI-BAND waterproofing strips are used to seal seams and floor-to-wall connections.  The band may be creased prior toÂinstallation
to help maintain tight  corners and simplify subsequent tile setting. Apply thin-set mortar to the area where the  KERDI-BAND is to be installed. Embed the KERDI-BAND in the thin-set  mortar using the flat side of the trowel to ensure full coverage and remove air pockets.... Note that a 2 inch overlap can be achieved at KERDI-KERECK corners without continuing the  KERDI-BAND all the way to the corner. This will limit build-up of the membrane in these areas.  This process is repeated at remaining floor-to-wall transitions and DITRA  seams. Always ensure that a minimum two inch overlap is achieved at all locations.  The waterproofing application is now complete. Tile may be installed immediately over  DITRA using thin-set mortar . We have already figured out our  tile layout and have applied chalk lines to guide our
installation
. Hairspray helps  ensure the chalk doesn t easily wipe off the membrane. The hair spray will not act  as a bond breaker because the thin-set mortar is mechanically locked into the top of the membrane.  Fill the cut back cavities with thin-set mortar . Then comb additional mortar over  the matting using a notched trowel that is appropriate for the size of the tile.  Back-buttering large-format tiles is a useful way to help ensure proper coverage. The skim  coat can fill in the concave area on the back of the tile and improve  contact with the mortar combed on the substrate. Solidly embed the tiles in the setting material,  making sure to observe the open time of the mortar. Slide the tile back  and forth to collapse the mortar ridges and transfer the mortar to the back of the tile.  Periodically remove a tile to check coverage. Run a margin trowel...through the bond coat  and slide the tile before pulling up to avoid creating tension on the surface of the DITRA;  this is especially important soon after the matting
installation
. Â Properinstallation
results in full coverage of the mortar to the back of the tile. Industry  standard guidelines for ceramic tile require a minimum of eighty percent coverage in dry areas  and ninety-five percent coverage in wet areas. Tile edges and corners must be fully supported.  If sufficient coverage is not achieved, remove the tile and reapply, making sure to verify  proper mortar consistency, application, and tile embedding techniques. Consider  back buttering large format tiles. Continue setting the remaining tile.  Profiles are a useful tool to enhance any floor tileinstallation
.  DITRA does not eliminate the need for movement joints within the tile  covering. This includes perimeter joints at restraining surfaces such as walls.  As an alternative to sealant,Schluter
-DILEX movement joint profiles accommodate movement  and protect tile edges, resulting in a permanent, maintenance-freeinstallation
.  DILEX-EKE creates a discreet, uniform joint at floor-to-wall transitions.  DILEX-BWS matches common grout joint widths and is available in a variety of colors,  allowing it to blend into the tile field. Because ceramic and stone tiles are inherently  brittle, their exposed edges can chip and crack if left...unprotected. Transitions  between floor surfaces and at thresholds are particularly vulnerable to damage. Â
