Ceramic, slate, and tile floors
are elegant and durable, although they often feel cold even at comfortable
room temperatures. Radiant-floor heating systems are an effective and
economical method of removing the chill from ceramic, marble, or stone-type
floors. Installed between the sub floor and the finish flooring material,
these cables will heat the floor to a comfortable warm temperature with a
minimal use of electricity.
Heating Systems. There are a number of these products on the market,
but in general they consist of an insulated, flexible resistance-type
heating element with attached no heating leads. The product shown here has
the conductors contained in a fabric material. The fabric keeps the
conductors spaced properly.
Where the final flooring is tile or stone, the system should have a heat
density of 10 or 15 watts per square foot. The National Electrical Code
requires that these systems be provided with ground-fault
Floor Preparation. Heating cable may be installed over wood flooring.
Drive protruding nails flush or below the flooring, and sand uneven edges
where floorboards come together. Nail down any loose flooring. For concrete
floor installation, remove all debris, and grind down sharp edges of small
cracks. Some manufacturers recommend installing a thermal barrier or layer
of insulation under the heating cables. Secure the thermal barrier to the
floor with a high-temperature adhesive.
Testing Cables. Unpack the heating cable, and check the ohms, or
resistance between the two conductor wires, to ensure that there is no break
in the non heating and resistance conductors. Each set of heating cables is
marked with the proper ohms. Follow the manufacturerís testing procedures
carefully. They are designed to keep you from tiling over a heating system
that does not work.
Placing Cables. Plan the heating-cable layout. Remember that the non
heating conductors must be able to reach the control unit, which wilt be
mounted on the wall. Donít overlap the heating cables, and do not allow the
non heating leads to overlap the heating area of the mat. The National
Electrical Code requires non heating conductors to be protected where they
leave the floor by rigid metal conduit, rigid nonmetallic conduit, or by
other approved means.
Radiant heat can be used in any room, especially if it is specified when
the house is being built. But in the remodeling world, the most popular room
for installing radiant heat is unquestionably the bathroom. There is nothing
quite like stepping out of the shower onto a warm floor when itís about 10
degrees out side. In most cases, these systems are used under ceramic tile.