Installation Guide

STEAM ROOM ASSEMBLY — Schluter
®
-KERDI-DS waterproofing membrane 19
Areas of Application
Interior continuous use steam rooms (e.g., applications in spas, fitness
centers, etc.).
Over wood or concrete subfloors. See the Base information under
Requirements (below) for details.
Areas requiring disabled access/curbless applications; see detail K-SHBF
on page 12.
Limitations
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.
When KERDI-BOARD is used, steam room must be operated in a
manner such that the maximum service temperature of KERDI-BOARD
158°F (70 °C) is not exceeded.
Gypsum-based solid backing panels shall be limited in use to intermittent
use steam showers (e.g., residential applications)
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 – KERDI-BOARD, cementitious backer unit, fiber-cement
underlayment, Portland cement mortar bed, concrete, or masonry.
Base – Portland cement mortar bed.
Curb – KERDI-BOARD-SC, KERDI-BOARD, concrete, masonry block, or
sawn lumber sheathed with solid backing (see above).
Bench – KERDI-BOARD, KERDI-BOARD-SB, 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).
Minimum KERDI-BOARD thickness – 1/2" (12.5 mm) for studs spaced at
16" (40.6 cm) o.c. and 3/4" (19 mm) for studs spaced at 24" (61.0 cm) o.c.
KERDI-BOARD shall be fastened to wood or metal framing with appropriate
screws (i.e., coarse thread wood screw for wood studs and self-tapping for
metal studs) and corresponding KERDI-BOARD-ZT washers. Screws must
reach a depth of at least 3/4" (20 mm) in wood studs and 3/8" (10 mm) in
metal studs. Maximum allowable on-center fastener spacing is 12" (30 cm)
for walls and 6" (15 cm) for ceilings.
Install KERDI-DS waterproofing membrane on all surfaces, including
the ceiling. For enclosed areas, also install on door jambs, door header
and past the door frame gasket, as applicable.
It is the specifier's responsibility to treat and address all penetrations
through the KERDI-DS membrane (e.g., steam inlet, lights, etc.) in the
installation. All penetrations must be treated with KERDI-SEAL-PS seals,
room temperature vulcanizing sealant or other suitable sealant.
When using the stainless steel KERDI-DRAIN bonding flange, use
KERDI-FIX to bond KERDI-DS 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 40.
All horizontal surfaces (e.g., benches, curbs, window sills, shelves, etc.)
must be sloped toward the shower drain. This can be done by sloping
the substrate or the tile.
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-SR and KERDI-BOARD-SC/-SB.
Solid Backing Materials
KERDI-BOARD
Cementitious backer unit – ANSI A118.9 or ASTM C1325
Fiber-cement underlayment – ASTM C1288
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
Shower grab bars must be anchored in the structure or solid blocking
behind KERDI-BOARD.
When KERDI-DS 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 strongly 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. Refer to local
plumbing codes for any specific requirements in your area.
Schluter
®
-Systems profiles may be used to finish and protect outside
corners and eliminate the use of sealant at inside corners; see page 40.
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.
Schluter
®
-SHELF-E/-W/-N are alternatives to tiled shelves that can be
easily installed on walls and in corners and niches; see page 40.
Where a waterproof floor adjacent to the shower is desired, DITRA or
DITRA-HEAT uncoupling membranes shall be installed. Floor/wall
connections shall be sealed with KERDI-BAND.
Continuous Use Steam Rooms – Ceramic or stone tile
Schluter
®
-KERDI-DS waterproofing membrane
K-SR-20