No matter what you’re building with Schluter-KERDI-BOARD, there are some basics that you need to know.
Let’s take a look at cutting, fastening, and waterproofing methods in particular…
There are options for cutting KERDI-BOARD. Regardless of the method used, please observe
all safety practices.
A utility knife can be used to cut any thickness of KERDI-BOARD. The gridlines printed on the
surface of the panels help guide cuts, though a straight edge can be used if required.
When cutting the thicker panels with a utility knife, don't attempt to cut through all at
once. Take your time and make multiple passes.
When building countertops, shower benches, or similar applications that require more
precise cuts, we recommend the use of a circular saw or table saw.
Cut outs for sinks or other fixtures can be made simply and easily using a jigsaw.
After cutting KERDI-BOARD, you can use a Knife or rasp to remove any of the fleece webbing
that may have frayed or pilled along the edges if desired.
There are a number of ways KERDI-BOARD can be installed, depending on the application.
For example, panels are attached to stud framing with appropriate screws and corresponding
KERDI-BOARD-ZT washers
The minimum KERDI-BOARD thickness for installation over wall framing is one half inch for studs
spaced at sixteen inches on-center and three quarter inch for studs spaced at twenty four
inches on-center.
Keep in mind, that any bathroom fixtures such as grab bars or wall-mounted toilets must
be anchored into the structure or solid blocking behind KERDI-BOARD.
KERDI-BOARD can be mounted horizontally or vertically on the framing.
When installing over wood framing, use KERDI-BOARD-ZS course thread screws, reaching a depth of
at least three-quarters of an inch in the studs.
For applications over metal framing, use self-tapping screws reaching a depth of at least three-eighths
of an inch in the studs in conjunction with the KERDI-BOARD-ZT washers.
Keep in mind, the vertical edges of each panel must be positioned over a stud or other solid
backing.
Make sure that your fasteners are slightly indented into the board. This will ensure
minimal interference during waterproofing and tile installation.
The maximum allowable on-center fastener spacing is twelve inches.
Screws may be placed between adjacent panels so that the washers fasten both panel edges.
KERDI-BOARD can be spot-bonded to existing wall surfaces to correct substrate variations
or fully embedded in thin-set mortar where walls are sufficiently even and plumb.
When spot bonding, place mortar spots on the KERDI-BOARD panel or directly onto the substrate
approximately 12 inches apart.
Make sure that the surface is clean and free of any contaminants that could weaken the
bond between the board and the existing wall.
When creating custom building elements, thin-set mortar or Schluter-KERDI-FIX is used for KERDI-BOARD
installation.
Thin-set mortar provides for adjustment to make sure surfaces are level and plumb, but
KERDI-FIX is a quick and simple option, particularly when stronger initial tack is desired or mixing
mortar is inconvenient. KERDI-BOARD is waterproof, but joints and
corners must be sealed with KERDI-BAND and KERDI-KERECK in wet areas.
The KERDI waterproofing accessories are installed with thin-set mortar.
The mortar should be mixed to a fairly fluid consistency, but still able to hold a notch.
The membranes are embedded using the flat side of the trowel or a dry wall finishing
knife.
Two inch overlaps must be maintained at all seams and penetrations in the KERDI-BOARD.
There are various widths of KERDI-BAND to accommodate different KERDI-BOARD elements
and designs.
KERDI-BAND can also be used for sealing connections to fixed building elements such as door and
window frames.
Since thin-set mortar will not bond to some of these surfaces, KERDI-FIX is used as the
adhesive and then the KERDI-BAND is embedded into both the thin-set mortar and KERDI-FIX
to ensure it is fully waterproof.
Any protrusions through the KERDI-BOARD, such as showerheads, tub spouts, and mixing valves,
are treated with Schluter-KERDI-SEAL waterproofing accessories.
KERDI-FIX or other suitable sealant can be used in lieu of the pipe and mixing valve
seals.
Tile can be set immediately over KERDI-BOARD using thin-set mortar.
Now that you know the basics of working with KERDI-BOARD, you’re ready to get creative.