Installation Guide

STEAM SHOWER ASSEMBLY — Schluter
®
-KERDI waterproofing membrane 15
Areas of Application
Interior intermittent use steam showers (e.g., residential applications).
Over wood or concrete subfloors.
Areas requiring disabled access/barrier-free applications; see detail
K-SHBF on page 12.
Limitations
Not intended for continuous use steam rooms (e.g., applications in spas,
fitness centers, etc.); see detail K-SR on page 18.
Certain glass tiles may not be compatible with bonded waterproof
membranes and/or may require special setting materials. Consult glass
tile manufacturer and Schluter
®
-Systems for more information.
Certain moisture sensitive stones, e.g., green marble, or resin-backed
tiles may not be appropriate for use in wet areas such as steam showers
or may require special setting materials. Consult stone supplier and
Schluter
®
-Systems for more information.
Do not use sawn lumber curbs on concrete subfloors subject to
moisture migration.
Requirements
Plywood, OSB, or concrete subfloor must be clean, even, and load bearing.
Provide insulation in wall and ceiling cavities to reduce moisture
condensation on the tiled surface.
Solid backing – gypsum wallboard, cementitious backer unit, fiber-
cement underlayment, fiber-reinforced water-resistant gypsum
backerboard/underlayment, coated glass mat water-resistant gypsum
backerboard, Portland cement mortar bed, concrete, or masonry.
Base – KERDI-SHOWER-ST/-L/-LS or Portland cement mortar bed.
Curb – KERDI-BOARD-SC, KERDI-SHOWER-SC, KERDI-BOARD,
concrete, masonry block, or sawn lumber sheathed with solid backing
(see above).
Bench – KERDI-BOARD-SB, KERDI-SHOWER-SB, KERDI-BOARD,
concrete, masonry block, or sawn lumber sheathed with solid backing
(see above)
KERDI-DRAIN/-LINE shall be properly supported.
KERDI-DRAIN/-LINE shall be connected to the waste line; use ABS
cement for ABS drains, PVC cement for PVC drains, a no-hub coupling
for stainless steel drains with no-hub outlets, and thread sealing
compound or tape for stainless steel drains with threaded outlets.
Slope ceilings 2" (50 mm) per foot minimum to avoid condensation from
dripping onto occupants (may be sloped to center to minimize rundown
on walls).
Install KERDI waterproofing membrane on all surfaces, including the ceiling.
Any protrusions through the KERDI membrane (e.g., showerhead, mixing
valve, steam inlet, etc.) must be treated with KERDI-SEAL-PS/-MV seals,
KERDI-FIX or suitable sealant.
When using the stainless steel KERDI-DRAIN integrated bonding flange,
use KERDI-FIX to bond KERDI to the drain.
Movement joints shall be provided at all changes in plane, including floor/
wall, wall/wall, and wall/ceiling transitions. Schluter
®
-Systems prefabricated
movement joint profiles (e.g., DILEX-EKE) provide a maintenance-free
alternative to sealant; see page 38.
Substrate Preparation
Verify that subfloor panels and solid backing are properly fastened to
framing members.
Any leveling of the subfloor must be done prior to installing
KERDI-SHOWER-ST/-L/-LS/-SC/-SB/-SR and KERDI-BOARD-SC/-SB.
Solid Backing Materials
Gypsum wallboard – ASTM C1396/C1396M
Cementitious backer unit – ANSI A118.9 or ASTM C1325
Fiber-cement underlayment – ASTM C1288
Fiber-reinforced water-resistant gypsum
backerboard/underlayment – ASTM C1278
Coated glass mat water-resistant gypsum backerboard – ASTM C1178
Portland cement mortar – ANSI A108.1B
Concrete
Masonry
Setting and Grouting Materials
Unmodified thin-set mortar – ANSI A118.1
Grout – ANSI A118.3, A118.6, A118.7
Installation Specifications
Solid backing panels – follow manufacturer’s directions
Portland cement mortar bed – ANSI A108.1B
Tile – ANSI A108.5
Grout – ANSI A108.6, A108.10
Other Considerations
When KERDI-SHOWER-ST/-L/-LS tray dimensions do not match the
dimensions of the shower compartment, the tray may be cut or extended
with dry pack mortar.
When KERDI and tile are installed on the ceiling, the solid backing and
fasteners must be able to support the load of the tile and setting and
grouting materials.
A water test is recommended before setting tile to verify a successful
installation. Wait 24 hours minimum after the membrane installation is
complete to allow for final set of thin-set mortar and ensure waterproof
performance at seams and connections.
Schluter
®
-Systems profiles may be used to finish and protect outside
corners and eliminate the use of sealant at inside corners; see page 38.
Schluter
®
-SHOWERPROFILE-S/-R profiles eliminate the need for cutting
wedges of tile by covering the exposed wall area where the floor slopes
to KERDI-LINE.
Intermittent Use Steam Showers – Ceramic or stone tile
Schluter
®
-KERDI waterproofing membrane
K-SSH-K-17