Shower System Installation Handbook

Areas of Application
Interior showers with curbless access.
Over wood subfloors. See the Base information under Requirements
(below) for details.
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.
Requirements
Plywood or OSB subfloor must be clean, even, and load bearing.
Ensure a suitable structure and substrate for the shower floor. This may
require the services of a qualified design professional (e.g., architect,
engineer, etc.).
Maximum spacing of joists is 19" (488 mm) o.c.
Minimum subfloor thickness – 23/32", 3/4" nom. (19 mm) tongue-and-
groove OSB or plywood with 1/8" gap between sheets. Canada: 19/32",
5/8" nom. (16 mm) tongue-and-groove OSB or plywood in Canada with
16" (406 mm) o.c. maximum joist spacing, but 23/32", 3/4" nom. (19
mm) subfloor recommended.
Existing subfloor panels extended over recessed panels to be installed
according to Schluter Wood underlayment fastening schedule. See
Wood Underlayment content in the Schluter
®
-DITRA Installation
Handbook. Our recommendations currently support only dimensional
lumber for floor joists. See alternate joist manufacturer for attachment
specifications. Dimensional lumber shall not be ripped down from its
original dimension and size.
Recessing the floor of a bathroom must be done in a way that preserves
the structural integrity and safety of the construction. This may require
the services of a qualified design professional (e.g., architect, engineer,
etc.). Verify with the local inspector or authority having jurisdiction (AHJ).
Pre-drill holes in blocking and adjacent supports.
Base – KERDI-SHOWER-T/-TS/TT/-LT/-LTS.
Bench – KERDI-BOARD-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.
KERDI, DITRA or DITRA-HEAT shall be installed in all floor areas subject
to water exposure (i.e., wet area and drying area). Floor/wall connections
shall be sealed with KERDI-BAND.
When using the stainless steel KERDI-DRAIN bonding flange, use
KERDI-FIX to bond KERDI to the drain.
All horizontal surfaces (e.g. benches, window sills, shelves, etc.) must be
sloped toward the shower drain.
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-T/-TS/-TT/-LT/-LTS/-R and KERDI-BOARD-SB prefabricated
substrates.
Setting and Grouting Materials
Unmodified thin-set mortar – ANSI A118.1
Grout – ANSI A118.3, A118.6, A118.7
Installation Specifications
Tile – ANSI A108.5
Grout – ANSI A108.6, A108.10
Other Considerations
Curbless tiled showers rely on the slope of the floor to effectively contain
water in the immediate shower area and direct water to the drain. Given
the wide range of potential configurations, it isn’t possible to address
them all in this Handbook.
Waterproofing must be installed in all areas subject to water exposure.
Install KERDI over mortar beds and Schluter
®
prefabricated EPS foam
substrates. Use the DITRA or DITRA-HEAT uncoupling membrane over
plywood/OSB or concrete subfloors. All seams are sealed using KERDI-
BAND. Please refer to the Schluter
®
-DITRA or Schluter
®
-DITRA-HEAT
Installation Handbooks for complete details and warranty criteria.
If KERDI-LINE is placed at shower entrance, it is recommended that
grate assembly A, Pure, or the covering support (D) is chosen and that
the drainage openings span the maximum width of the entrance to limit
potential overflow; secondary drainage (e.g., KERDI-DRAIN) may be
required in the drying area.
Schluter
®
-SHOWERPROFILE-WS/-WSK system profiles can be used to
form a splashguard at the entrance of curbless showers. See Schluter
Illustrated Price List for more information.
Various building codes and other sources, such as the Americans with
Disabilities Act, include specific requirements for disabled access in
public buildings and must be consulted when applicable. Areas of
interest may include degree of slope, clearance, and supporting
structures such as grab bars.
When KERDI-SHOWER-T/-TS/TT/-LT/-LTS tray dimensions do not
match the dimensions of the shower compartment, the tray may be cut
or extended with dry pack mortar.
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. For curbless
showers a temporary dam must be provided at the threshold to perform
the water test.
Schluter
®
-Systems profiles may be used to finish and protect outside
corners and eliminate the use of sealant at inside corners; see Schluter
Illustrated Price List for more information.
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.
SHOWER ASSEMBLY — Recessed Curbless 15
Recessed Curbless Shower
K-SHCR-21
Curbless Showers – Ceramic or Porcelain Tile