Use and Care Manual

2
Schluter
®
-DITRA-HEAT
HEAT and DITRA-HEAT-DUO installations.
Column-like mortar structures are formed
in and between the studs on the surface of
the matting. Loads are transferred from the
tile covering through these column-like
mortar structures to the substrate. Since
DITRA-HEAT and DITRA-HEAT-DUO are virtually
incompressible within the tile assembly, the
advantages of uncoupling are achieved without
sacrificing point load distribution capabilities.
Material Properties and
Areas of Application
DITRA-HEAT is a polypropylene membrane
with a cut-back stud structure and an anchoring
fleece laminated to the underside. The thickness
of the mat, including the stud structure is
1/4" (5.5 mm). DITRA-HEAT-DUO is a
polypropylene membrane with a cut-back stud
structure and a thermal break anchoring fleece
laminated to the underside. The thickness of the
mat, including the stud structure and thermal
break fleece is 5/16" (8 mm). Polypropylene is not
UV-stable in the long term; the product must not
be stored in places with prolonged exposure to
direct sunlight.
DITRA-HEAT-PS and DITRA-HEAT-DUO-PS
feature a UV sensitive pressure-sensitive adhesive
that should be not be stored in places with
prolonged exposure to direct sunlight. The PSA is
also temperature sensitive and should be stored
in a frost-free environment 41 - 86 °F (5 - 30 °C).
If product is exposed to conditions outside of
recommended temperature range, product shall
be re-acclimated to range for a minimum of 24
hours. The PSA is not water soluble and is free
of solvents.
The DITRA-HEAT and DITRA-HEAT-DUO
mattings do not rot and are 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-HEAT and DITRA-HEAT-DUO are
waterproof and minimize the transmission of
vapor.
Although peel and stick versions of DITRA-
HEAT do not comply with requirements of ANSI
A118.10, they may be used in bathrooms or wet
areas not requiring this specification if seams
are properly treated with KERDI-BAND and
KERDI accessories. If meeting ANSI A118.10
specifications is required and peel and stick
membranes are to be used, the entire area must
be covered with KERDI membrane in conjunction
with appropriate KERDI components.
DITRA-HEAT-DUO offers the same functions as
the DITRA-HEAT membrane, but also features an
integrated thermal break in the form of a thicker
bonding fleece. The thermal break reduces
impact sound transmission through floor-ceiling
assemblies, reduces heat loss to the substrate,
and improves the floor warming response time at
the standard three stud cable spacing.
When tested according to ASTM E2179, an
assembly of DITRA-HEAT-DUO and 12" x 12"
porcelain tile installed and grouted with cement-
based setting materials produced an increase
in impact insulation class (ΔIIC) of 20 to a
concrete slab floor-ceiling assembly (Test Report
NGC 7016078). The same basic assembly
tested according to ASTM C627 reached a
classification of “Light” in accordance with the
“TCNA Handbook for Ceramic, Glass, and Stone
Tile Installation,” defined as suitable for “light
commercial use in office space, reception areas,
kitchens, and bathrooms” (Test Report TCNA-
455-15 Test #1).
In laboratory testing, DITRA-HEAT-DUO reduced
floor warming response time from 68°F (20°C)
to 78°F (25.5°C) by approximately 80% (90
minutes) compared to DITRA-HEAT over a
concrete substrate. Wood substrates act as
insulators and typically do not pose the same
challenges as concrete substrates. In the same
laboratory testing, DITRA-HEAT-DUO only
reduced floor warming response time from 68°F
(20°C) to 78°F (25.5°C) by approximately 20%
(5 minutes) compared to DITRA-HEAT over a
plywood substrate. Schluter
®
-DITRA-HEAT-E-
HK heating cables were spaced at three studs
in all of the above tests. Results above are
based upon laboratory testing. Actual results
may vary depending on various factors, including
concrete substrate thickness, concrete substrate
temperature, room temperature, heat losses, etc.
DITRA-HEAT and DITRA-HEAT-DUO have been
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.
DITRA-HEAT-E-HK are twisted pair heating
cables designed for integration with the DITRA-
HEAT and DITRA-HEAT-DUO uncoupling
membranes in interior floor warming applications.
The cables can be installed without returning
to the thermostat and produce virtually zero
electromagnetic fields.
DITRA-HEAT-E-RS1/-WiFi/-RT/-R are digital
thermostats to control the DITRA-HEAT-E-HK
heating cables (either 120 V or 240 V). The
thermostats feature a built-in Class A ground
fault circuit interrupter (GFCI) with indicator light.
The DITRA-HEAT-E-RS1 is a smart thermostat
designed to be mainly operated via the Schluter
Smart Thermostat app. It features a sleek design
with a mirror-finish and third-party integration
with popular voice and home assistants to easily
include floor warming into your smart home
capabilities. The DITRA-HEAT-E-RRS power
module may be used in conjunction with the
thermostat when the heating load exceeds
15 amps (e.g., in large floor applications) to
maintain a single point of control. This power
module can only be used with the DITRA-HEAT-
E-RS1 thermostat. The DITRA-HEAT-E-WiFi
programmable WiFi thermostat features LCD
touchscreen controls and comes with a pre-set
schedule, but may be adjusted to fit any schedule.
When connected to WiFi, the thermostat provides
convenient monitoring and adjustment of the floor
warming system via the web or mobile app. The
DITRA-HEAT-E-RT programmable thermostat
features LCD touchscreen controls and comes
with a pre-set schedule, but may be adjusted
to fit any schedule. The DITRA-HEAT-E-R non-
programmable version features a simple on/
off function. Multiple heating cables may be
connected to the thermostats, up to the total
heating load limit of 15 amps. The DITRA-HEAT-
E-RR power module may be used in conjunction
with the DITRA-HEAT-E-RT/-R thermostats when
the heating load exceeds 15 amps (e.g., in large
floor applications). A floor temperature sensor is
included.
Two floor temperature sensors are provided with
each DITRA-HEAT-E-HK heating cable box. Both
floor temperature sensors are installed within the
tile assembly. One sensor is connected to the
thermostat, while the other sensor is stored in the
thermostat electrical box, but not connected to
the thermostat. The second sensor can easily be
connected to the thermostat to replace the first
sensor in case of damage.
Suitable Substrates
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.
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
commonplace in today’s construction environment.
Although pre-stressing is used to help control
deflections in concrete structures, these slabs are
still subject to deformations caused by changes
in moisture, temperature, and loading. Many
concrete slabs on or below grade are subject to
moisture migration, which can be problematic.
Furthermore, these structures experience the
same deformations as stated above.
Gypsum
Bonding ceramic or stone tiles directly to
gypsum concrete substrates is generally
considered questionable or not recommended.
The challenges associated with gypsum-based