Installation Guide

7
THERMOSTAT SELECTION
Only a thermostat equipped with a oor sensor maximizes the oor heating system’s efciency and, therefore, your comfort. All other control methods (e.g.
ambient air thermostat or switch) are not recommended since they cannot control the oor temperature. As a result, the oor temperature will always be either
too cold or too warm.
Also, the heating cable must be connected to a ground-fault GFCI circuit interrupter either integrated in the thermostat or electrical panel. For a bathroom,
the GFCI breaker must be class A (5 mA).
The maximum thermostat current must correspond to the sum of cable currents wired to it. Also, the voltage of the branch circuit must correspond to the
voltage prescribed for the thermostat. All thermostats wired to the heating cable must be certied by a recognized certication agency and wired in accordance
with electrical and building codes applicable in your region.
TYPES OF INSTALLATION
WITH CABLE SPACERS
The benet of using cable spacers is that the heating cable is embedded in the self-leveling mortar, which protects the heating cable and makes it
suitable for use with different types of ooring such as ceramic tiles, laminate, vinyl, engineered wood, etc. Although installation is more econom-
ical (since no membrane is needed), it takes more time (i.e. cost-effective for a DIY handyman, less so when contracting a professional installer).
CEMENT (OR CONCRETE SLAB) SUBFLOOR TIPS
Concrete suboor curing period
The curing period for concrete (typically 28 days) must be complete before the heating cable is installed. Consult a concrete manufacturer to
determine the precise curing period for the type of concrete you’ve chosen.
Surface preparation
The concrete surface must be solid, dry, clean and free of dust, oil, grease, paint, wax, sealant or any other substance that could interfere with
adhesion. Moreover, the concrete’s surface must be free from debris, protruding nails and screws, etc. that may damage the heating cable.
PLYWOOD SUBFLOOR TIPS
Surface preparation
Plywood surface must be clean, solid and dry. Remove any dust, oil, grease, paint, wax, sealant or any other substance that could impede
adequate adhesion. Also, the surface must be free of any debris, protruding nails and screw heads, etc. that may damage the heating cable.
Plywood suboor strength and strengthening (also valid for concrete slab suboor)
Each plywood sheet must be secured with screws spaced 8 inches (203 mm) apart on its center and 6 inches (150 mm) apart on its perimeter.
Plywood sheets must be spaced 1/4 inch (6.3 mm) from each other to allow room for material expansion.
In order to eliminate all risks of damage to the heating cable resulting from oor covering cracks, it is important to ensure sufcient suboor rigidity.
Floor joists spaced 16 inches apart or less require a plywood suboor thickness of at least 1 1/4 inch (2 x 5/8-inch sheets). Otherwise, if oor joist
spacing exceeds 16 inches, the plywood sheets must be strengthened to achieve a total thickness of 1 7/8 inches (3 X 5/8-inch sheets).
Besides plywood sheeting, there are other methods available for strengthening a suboor such as the use of metal screening, pre-stressed
concrete boards and other strengthening materials. Seek the advice of a oor covering specialist to make sure that the suboor is properly
strengthened.
WITH MEMBRANE
The benet of using a membrane to install the heating cables is that the cable is protected during installation and the process does not require
the use of hot glue. Although the membrane is more expensive, it makes cable insertion much easier and installation faster (i.e. less expensive
when done by professionals).
On the other hand, the use of a membrane restricts the choice of oor covering to ceramic tile.
The main advantage of using a membrane is that it absorbs the shear stresses since its embossed, hollow spaces allow for horizontal movement
which neutralizes the stresses between the thin-set and ceramic tile (uncoupling) that are the main cause tile cracking and lifting.
FIG. 2 FIG. 3 FIG. 4
U-LOOP WITH MEMBRANEU-LOOP WITH CABLE SPACERS
10 ft (3 m)