Install Instructions

Mortar Applications: There are two types of thin-
set and two types of thick-set mortar applications
illustrated on these pages.
a. If backer board or plywood sheeting is used
to strengthen the floor, or if the mat will be placed
directly onto the slab, install SunTouch in the thin-set
mortar bond coat above these materials. See illustra-
tions #1 or #2.
b. If a thicker mortar bed is used to strengthen the
floor, SunTouch can be installed in either the mor-
tar bed (dry-set) or in the mortar bond coat directly
below the tile or stone. See illustrations #3 or #4.
In this application, SunTouch is generally installed
above the self-leveling mortar in a thin-set bond coat.
If you use plastic lath instead of the typical metal
lath, the SunTouch can be installed in the
self-leveling mortar bed.
CAUTION: If metal lath is used in the mortar
bed, do not allow the SunTouch to come in
direct contact with the lath because this could
damage the wire.
Self-leveling Mortar Applications: There are only
two approved methods of installing cement-based,
self-leveling mortar beds over SunTouch. One for
framed floor construction and one for slab construc-
tion (see illustrations #5 and #6). These are appro-
priate applications if installing engineered wood,
vinyl, laminate, or carpet floor coverings. Attach the
SunTouch to the subfloor or slab, then pour self-lev-
eling mortar 1/4” to 1/2” thick according to manufac-
turer’s specifications. Install floor covering after the
mortar has cured.
Special Precautions
Isolation Membrane: Install the SunTouch above
the membrane, whenever possible, unless recom-
mended otherwise by the membrane manufacturer.
Insulation: Do not install rigid insulation
directly above or below backer board or mortar.
If possible, install insulation as shown in diagrams.
Insulation dramatically enhances the performance
and efficiency of floor-warming systems.
Mosaic Tile: When installing mosaic tile, we
recommend a two-step process. First embed the
SunTouch in a thin mortar bed (1/4”–3/8”), then
thin-set the mosaic tile according to typical practice.
Expansion Joints: Do not install heating mats
through an expansion joint. Install mats right up to
the joint, if necessary, but not through the joint.
Illustrations #5 and #6 show the best method if
you are installing non-masonry floor coverings.
Insulation (per International
Residential Code, Chapter 11)
4. THICK-SET MORTAR BED OVER SLAB
(Cement mortar bonded; TCA #F112-03)
Tile/stone or
laminate flooring
SunTouch
Mortar bed
Slab
Mortar bond coat, crack
isolation membrane, or cork
underlayment, as needed
Latex-Portland cement
mortar bond coat
Insulation (per International
Residential Code, Chapter 11)
Concrete slab with
rewire or rebar
Crack isolation membrane or
cork underlayment, as needed
SunTouch
Self-leveling mortar bed
Insulation (per International
Residential Code, Chapter 11)
Plywood
SunTouch
Self-leveling mortar bed
6. SELF-LEVELING MORTAR OVER SLAB ON GRADE
5. SELF-LEVELING MORTAR
OVER FRAME FLOOR
SunTouch Space Warming Manual 7
Phase 2. SunTouch Installation
SELF-LEVELING APPLICATIONS