Installation Guide

HEATED FLOORS 11
Concrete Substrate
D-RHSS-17
Ceramic, porcelain or stone tile
Unmodified thin-set mortar
DITRA or DITRA-XL
uncoupling membrane
Unmodified thin-set mortar
Concrete
D-RHTS-17
Ceramic, porcelain or stone tile
Unmodified thin-set mortar
DITRA or DITRA-XL
uncoupling membrane
Unmodified
thin-set mortar
Lightweight or
gypsum concrete
Even and structurally
sound substrate
Wood Substrate
Thin slab (lightweight or gypsum concrete)
Areas of Application
over lightweight or gypsum concrete thin
slab placed over structurally sound wood or
concrete subfloor
interior dry or wet areas
Limitations
minimum 2" x 2" (50 mm x 50 mm) tile
Requirements
for wood substrates, subfloor/underlayment
configuration according to detail D-W16-T,
D-W19-T, D-W24-T, or D-W24-XL-T;
D-W24-XL-T for use with DITRA-XL only
where radiant heat tubes are laid over the
subfloor, gypsum or concrete fill poured to
a height that is 3/4" (19 mm) above the tops
of the tubes is required before installing
DITRA and DITRA-XL
residual moisture in gypsum concrete, 2.0%
(percentage by volume) or less before
installing DITRA and DITRA-XL
Substrate Preparation
gypsum or concrete – follow manufacturer’s
directions and/or design specifications
additional substrate preparation according to
heating system manufacturer’s directions
Movement Joints
DITRA and DITRA-XL do not eliminate the
need for movement joints, including perimeter
joints, within the tiled surface. Movement
joints must be installed in accordance with
industry standards and norms; see page 17
of this Handbook, TCNA EJ171, and TTMAC
301 MJ
Setting and Grouting Materials
unmodified thin-set mortar – ANSI A118.1
grout – ANSI A118.3, A118.6, A118.7,
A118.8
Setting and Grouting Specifications
tile – ANSI A108.5
grout – ANSI A108.6, A108.9, A108.10
heating system – follow manufacturer’s
directions
Other Considerations
if gypsum concrete is used, follow gypsum
manufacturer’s recommendations regarding
primers and/or special surface preparation
before installing DITRA and DITRA-XL
vapor barrier on crawl space floors according
to regional building codes
where a waterproof floor is required, all
DITRA and DITRA-XL seams and floor/wall
transitions must be sealed with Schluter
®
-
KERDI-BAND using unmodified thin-set
mortar; see page 12
certain moisture-sensitive stones, e.g., green
marble, or resin-backed tiles may require
special setting materials. Consult stone
supplier and Schluter
®
-Systems for more
information
Structural concrete slab
Areas of Application
over structurally sound and even radiant-
heated concrete floors
young concrete (concrete cured less than 28 days)
on or below grade concrete subject to
moisture migration
cracked concrete
Limitations
minimum 2" x 2" (50 mm x 50 mm) tile
concrete slabs subject to moisture migration
must have all seams in DITRA and DITRA-XL
sealed with Schluter
®
-KERDI-BAND using
unmodified thin-set mortar
any cracks in concrete subfloor must exhibit
in-plane movement only; thin-set tile
assemblies, including those incorporating
DITRA or DITRA-XL, cannot accommodate
differential vertical displacement
Requirements
slab to be structurally sound
slab to be free of waxy or oily films and curing
compounds (when present, mechanical
scarifying is necessary)
the installation of DITRA or DITRA-XL and
tile can begin as soon as the slab can be
walked upon
slab to be free of standing water
Substrate Preparation
any leveling or sloping of the slab or
assembly must be done prior to installing
DITRA and DITRA-XL
Movement Joints
DITRA and DITRA-XL do not eliminate the
need for movement joints, including perimeter
joints, within the tiled surface. Movement
joints must be installed in accordance with
industry standards and norms; see page 17
of this Handbook, TCNA EJ171, and TTMAC
301 MJ
concrete floors may incorporate various
movement joints; see page 18 of this
Handbook for guidelines on how to treat the
different types of joints (control/contraction
joints, expansion joints, etc.)
Setting and Grouting Materials
unmodified thin-set mortar – ANSI A118.1
grout – ANSI A118.3, A118.6, A118.7,
A118.8
Setting and Grouting Specifications
tile – ANSI A108.5
grout – ANSI A108.6, A108.9, A108.10
Other Considerations
where a waterproof floor is required, all
DITRA and DITRA-XL seams and floor/wall
transitions must be sealed with Schluter
®
-
KERDI-BAND using unmodified thin-set
mortar; see page 12
certain moisture-sensitive stones, e.g., green
marble, or resin-backed tiles may require special
setting materials. Consult stone supplier and
Schluter
®
-Systems for more information
★★★ ★ ★★★ ★
★★★ ★★★ ★★★ ★★