Use and Care Guide

UNCOUPLING MEMBRANES
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the substrate and the tile, thus eliminating the
major cause of cracking and delaminating of
the tiled surface.
Waterproofing
DITRA and DITRA-XL provide reliable
waterproofing in interior and exterior
applications. Its polyethylene composition
protects the substrate from moisture
penetration, which is particularly important
in today’s building environment where most
substrates are moisture-sensitive.
Vapor management
The distinguishing feature of DITRA and DITRA-
XL is the existence of free space created by the
configured channels on the underside of the
matting. The free space provides a route for
excess moisture and vapor to escape from the
substrate that could otherwise cause damage
to the tile layer above. Thus, DITRA and DITRA-
XL effectively manages moisture beneath the
tile covering.
Support/load distribution
When placed on a solid foundation,
columns or pillars can support tremendous
loads. The same physical principle applies
to DITRA and DITRA-XL installations.
Column-like mortar structures are formed
in the cutback cavities of the matting.
Loads are transferred from the tile covering
through these column-like mortar structures
to the substrate. Since the matting is
virtually incompressible within the tile
assembly, the advantages of uncoupling
are achieved without sacrificing point load
distribution capabilities. The ability of DITRA
and DITRA-XL installations to support and
distribute heavy loads while preserving the
integrity of the tiled surface has been verified
through extensive laboratory and field testing,
including applications exposed to vehicular
traffic.
Material Properties and
Areas of Application
DITRA and DITRA-XL are manufactured using
high-density polyethylene (HDPE), which
does not rot and is inert, non-toxic, and
physiologically safe. The material is highly
resistant to solutions containing salts, acids,
and alkalis, as well as many organic solvents,
alcohols, and oils. Resistance to specific
stresses can be provided if concentration,
temperature, and exposure time are known.
DITRA and DITRA-XL are waterproof and
minimize the transmission of vapor (water
vapor permeance of DITRA is 0.006 perms
per ASTM E96).
DITRA and DITRA-XL meet the American
National Standard for Load Bearing,
Bonded, Waterproof Membranes for Thin-
Set Ceramic Tile and Dimension Stone
Installations (ANSI A118.10), are listed by
cUPC®, and are evaluated by ICC-ES (see
Report Nos. ESR-2467 and PMG-1204).
For copies of the above listing or report,
please contact Schluter
®
-Systems at
800-472-4588 (USA) or 800-667-8746
(Canada) or by e-mail at [e-mail].
Links to the listing and report can also be
accessed at www.schluter.com.
DITRA and DITRA-XL were evaluated
according to the "Standard Method for the
Testing and Evaluation of Volatile Organic
Chemical Emissions from Indoor Sources
Using Environmental Chambers, Version
1.1" for California Specification 01350 and
found to comply with the VOC requirements.
California Specification 01350 is referenced
by various green building standards and
rating systems.
Note: Due to air space within the assembly,
tile coverings installed over DITRA or DITRA-
XL may have a hollow sound when they are
walked upon with hard shoes or tapped with
a hard object.
Suitable Substrates
For complete installation guidelines and
warranty criteria, please contact Schluter
®
-
Systems at 800-472-4588 (USA) or
800-667-8746 (Canada) or by e-mail at
[e-mail] to receive a copy
of the Schluter
®
-DITRA Installation
Handbook and a step-by-step installation
video. To download a PDF version of the
Handbook or to view the installation video
online, please visit www.schluter.com.
All
substrates must be clean, even, and load
bearing. Bond-inhibiting surfaces must be
removed prior to the application of DITRA
and DITRA-XL.
Note: Type, thickness, and format of the tile
or stone surface covering must be suitable
for the intended application. Minimum tile
format is 2" x 2" (5 x 5 cm).
Wood
All wood materials, including OSB, plywood,
and framing members, are subject to
expansion, contraction, bending, and deflection
as a result of changes in moisture content
and loading. Further, these deformations
fluctuate over the life of the building structure.
DITRA and DITRA-XL’s uncoupling
function protects the ceramic or stone
tile covering from the aforementioned
deformations by neutralizing the differential
movement stresses between the wood
structure and the tile, thus eliminating the
major cause of cracking and delaminating
of the tiled surface. Therefore, DITRA
and DITRA-XL can replace a second layer
of plywood in most applications. Since
the uncoupling function of the matting is
based on its geometric configuration, the
increased thickness of DITRA-XL results in
increased uncoupling capacity. Thus, DITRA-
XL is optimized for tile installation over
bending and deflecting substrates such as
plywood and OSB, including applications
over single-layer plywood/OSB subfloors on
joists spaced at 24" (610 mm) o.c.
Wood continually absorbs and releases
moisture. The free space beneath
DITRA and DITRA-XL allows the wood
to breathe and provides a route for any
residual moisture in the wood substrate
to escape.
Since DITRA and DITRA-XL is virtually
incompressible within the tile assembly,
the advantages of uncoupling are
achieved without sacrificing point load
distribution capabilities.
Industry standard guidelines referencing
uncoupling membranes over wood
substrates include methods F147 and F148
in the TCNA Handbook for Ceramic, Glass
and Stone Tile Installation and method 313F
(Detail D) in the Terrazzo, Tile and Marble
Association of Canada (TTMAC) Specification
Guide 09 30 00 Tile Installation Manual.
Note: DITRA and DITRA-XL may be installed
over existing vinyl floors (no cushioned or
perimeter bonded vinyl). However, various
steps must be taken to ensure a successful
installation. Please refer to the Schluter
®
-DITRA
Installation Handbook for details.
Concrete
There are various challenges associated with
the installation of hard surface coverings on
concrete substrates. To begin, the coefficient
of thermal expansion of concrete is close
to twice that of ceramic tile. Additionally,
tile contractors are often expected to install
tile over young concrete (concrete cured
less than 28 days). However, rigid surface
coverings installed over young concrete
are susceptible to damage as a result of
shrinkage during curing. Pre-stressed/
post-tensioned concrete slabs are also
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