KERDI-BOARD is the perfect substrate for creating both
standard and more intricate bathtub platforms. It is easily customizable and waterproof, making
it the ideal substrate for these applications. A variety of panel thicknesses can be used to
create a bathtub platform, depending on your design. You can also use the
KERDI-BOARD-V panels to add curved elements to your bathtub platform.
Check out our Working with KERDI-BOARD video for all of the details on cutting, fastening,
and waterproofing your KERDI-BOARD application. Once you have your design specifications,
the first step will be to cut the KERDI-BOARD to size.
We used a mixture of thicknesses for our bathtub surround ranging from
one inch to two inch thick panels. Using one and one-half inch or two inch
thick board, prepare your support blocking. We used a table saw since this gives us quick
clean cuts for the thicker boards. Let’s begin the installation.
Make sure the area is clean and free of any debris.
It’s a good idea to draw a level line and mark the floor for accuracy during installation.
The support blocking can be installed with KERDI-FIX or thin-set mortar.
We’re using a Schluter thin-set mortar, but others can be used for this application as
well. The mortar should be mixed to a consistency similar for setting tile.
Thin-set mortar allows you more adjustment during
the installation process, but KERDI-FIX is quick and simple to use as well.
All points of contact must have thin-set mortar or KERDI-FIX applied for proper support.
Make sure that you double up or run your supports perpendicular to one another at corners.
Support blocking is spaced at twelve inches on center
to ensure proper support of the decking. It’s also important to double up in any areas
of the bathtub surround that have seams where two panels of KERDI-BOARD meet.
Now that the end supports have been installed, begin assembly of the bathtub
apron using one inch thick KERDI-BOARD. We’re using thin-set mortar where the
panel meets the wall and floor and KERDI-FIX along the supports.
Installing the apron first will help stabilize the assembly for our next steps.
Two inch thick KERDI-BOARD is used as the decking for the bathtub platform. It is
best to use thin-set mortar for this part of the installation to allow for adjustment.
Continue with the installation of the front apron and decking.
Make sure to check that the assembly is level and plumb, with square corners,
throughout the installation process. When assembling the platform,
screws can be used as needed to help secure the board while the thin-set
mortar or KERDI-FIX sets. We will waterproof these penetrations in the next steps.
KERDI-BAND and KERDI-KERECK corners can be used to fully waterproof the bathtub platform.
The KERDI waterproofing accessories are installed with thin-set mortar.
Apply the mortar with one-quarter inch by three-sixteenths inch V-notched trowel a, or the
Schluter-KERDI-TROWEL, which features a one-eighth inch by one-eighth inch square notch design.
The mortar should be mixed to a fairly fluid consistency, but still able to hold a notch.
Embed the membrane using the flat side of the trowel or a dry wall finishing knife.
Two inch overlaps are maintained at all seams and penetrations in the KERDI-BOARD.
There are various sizes of KERDI-BAND to accommodate different bathtub platform designs.
KERDI-BOARD can be used to create custom designed bathtub platforms that are strong,
dimensionally stable, and waterproof. Installers have full control over the substrate, with the
ability to create flat, plumb, level, and square surfaces that are optimized for tile setting.