If tile is to be set on floors adjacent to bathtub surrounds, we strongly recommend use
of the Schluter-DITRA or Schluter-DITRA-HEAT uncoupling and waterproofing membranes.
The floors can be made fully waterproof by sealing joints in the membrane with
the Schluter-KERDI-BAND waterproofing strips. The result is a comprehensive waterproofing system
that protects today’s moisture-sensitive substrates like plywood or OSB.
Please refer to the Schluter-DITRA Installation Handbook for complete
details before beginning your DITRA project.
Schluter-DITRA is installed simply and easily with modified thin-set mortar,
such as Schluter ALL-SET or FAST-SET, in this application since there is a plywood substrate.
The mortar is mixed to a fairly fluid consistency, but still able to hold a notch
A 1/4 inch x 3/16 inch V-notched trowel or the Schluter-DITRA-TROWEL, which features a 4.5
millimeter x 4.5 millimeter square-notched design, is used to apply the mortar.
Clean any dust or other debris from the substrate.
Apply a thin layer of the mortar with the flat side of the trowel to produce solid
contact with the surface and then comb additional mortar using the notched side of the trowel.
Apply the DITRA, fleece side down.
Leave a 1/4 inch wide gap between the DITRA and the bathtub apron.
Solidly embed the matting in the mortar using a float.
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. Re-embed the matting.
After the DITRA has been installed, Schluter-KERDI waterproofing accessories
are used to seal joints in the DITRA matting and connect the matting to the
walls and bathtub surround. KERDI-BAND is used to seal
the DITRA matting to the bathtub. The banding is installed using any
of our Schluter® 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 1/4 inch x 3/16 inch V-notched trowel or the Schluter-KERDI-TROWEL, which features
a 1/8 inch x 1/8 inch square-notched design, is used to apply the mortar.
Place painter’s tape to protect the face of the tub.
Fill the cut-back cavities in the DITRA adjacent to the bathtub
and comb additional thin-set mortar on top.
Remove any thin-set mortar from the gap between the DITRA and the tub. A 1/4 inch
backer rod or similar may be used to keep the joint clean during thin-set mortar application
and subsequently removed prior to KERDI-FIX application.
Completely fill the gap between the DITRA and
tub with Schluter-KERDI-FIX or other suitable sealant.
Apply KERDI-BAND to the joint.
Embed the banding in the thin-set mortar and KERDI-FIX using the flat side of the trowel
or a drywall finishing knife to ensure full coverage and remove air pockets.
KERDI-BAND is also used to seal floor-to-wall transitions.
The banding may be creased prior to installation to help maintain
tight corners and make subsequent tile setting as easy as possible.
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 or a drywall finishing knife.
Install Schluter-KERDI-KERECK preformed corners using thin-set mortar.
Apply the mortar to the area where the KERDI-KERECK is to be installed.
Embed the KERDI-KERECK into the thin-set mortar using the flat
side of the trowel or a dry wall finishing knife.
Corner installation may be simplified by holding one side of the corner in place
while embedding the other side of the corner in the mortar.
Repeat this process at all remaining joints ensuring that the minimum 2 inch overlap is
achieved at all transitions. Sealing seams in the DITRA and
connections to the bathtub surround assembly improves the overall utility of the bathroom
by providing comprehensive waterproofing in an area that is repeatedly exposed to moisture.
For all of the details on the different features and benefits of using DITRA
and how it can enhance your tile installation, check out our complete video
“How to install Schluter®-DITRA Uncoupling and Waterproofing Membrane”.
If you still have questions, please contact our Customer Support Specialists. For more information
on Schluter products, visit schluter.com or check out our YouTube channel to view our videos!