Do-it-yourself infrared underfloor heating under laminate or linoleum

Recommendation points

• What are the features of the use of infrared film
• Preparing the sub floor
• Heat shield rules
• Heating foil laying
• Electrical connection
• Floor covering device

It is always comfortable with a warm floor, but not every master decides to install a heating system with his own hands. If you have chosen laminate or linoleum as your flooring, study this article, where we will tell you about a simple way to heat the floor with infrared films..

What are the features of the use of infrared film

With a reasonable approach and understanding of the technical qualities of the film, it can even be used as the only heating method. And yet the most widely used IR film is to equip comfortable zones in the interior: floor heating in bathrooms, children’s rooms and places for games, on loggias. At the same time, the heating element absolutely does not steal height and does not require changes in the construction project, with the exception of its electrical part.

Like all innovative technologies, IR film is subject to harsh criticism, both constructive and completely meaningless. The film floor, like any other heating system, has a strictly defined scope. All kinds of myths about the inefficiency and insecurity of the film appear as a result of its improper operation or violations of the installation rules.

Preparing the sub floor

It is possible to use infrared film as the main heating system only if there are two layers of thermal insulation – the main one and the screening one. The optimal floor structures in such cases are dry screed and flooring on logs with filling of voids with stone wool. Concrete floors may be covered with an insulating polyurethane substrate: slabs or spraying.

If it is not possible to raise the floor height by 5–8 cm, IR films cannot be the main source of heat in the house and are used only for comfortable heating of floor coverings, including locally.

The junctions of the subfloor to the walls must be filled with polyurethane foam to eliminate convection, the gaps between the floor slabs must be sealed with cement mortar. Then the surface of the floor must be cleaned with a vacuum cleaner and to prevent further formation of dust – primed.

Heat shield rules

The shielding layer reflects heat rays and reduces heat transfer to the sub floor by 70–80%. The material for the device of this layer is a lavsan substrate, it is preferable to use products of the same brand as the film. That is, it is better to purchase not only heating elements, but also a system of thermal and electrical insulation.

It is allowed to use cheaper polyethylene foam with metallized film, but it is absolutely irrational. A cheap insulator has too high a thermal conductivity, which reduces the useful power. The payment for increased electricity consumption during the year is equivalent to the cost of high-quality insulation materials.

The device of the shielding substrate is necessary not only in those places where the heating circuit will be laid, but also over the entire area of ​​the room in order to exclude the height difference. The lavsan backing also replaces the conventional shock absorbing underlay under laminate flooring.

The substrate is produced in sheets or rolls and forms joints when laid. They must be glued with a special tape, which can be replaced with an aluminum tape with a polished surface. To increase electrical and fire safety, the metallized surfaces are connected with strips of aluminum foil and the surface is connected to a protective conductor to enable the circuit to be switched on through a differential machine.

Heating foil laying

The heating circuit must be calculated in advance, taking into account the bypassing of the installation sites of cabinet furniture, bathtubs and non-visited areas. In this case, laying the film under the kitchen set and furniture on remote legs is allowed.

Lay the foil on the substrate in rows, keeping the recommended distance from the walls of 30-200 mm. When laying the film, it is allowed to cut across, if the remaining roll is not enough in length, the film can be built up, keeping a gap of 20 mm at the joint.

The film is powered by two single-core stranded wires in non-combustible insulation. Connection is made with piercing clamps: first, the wire is crimped with pliers in the shank, then the jaws are applied to the metal of the contact pad and squeezed.

Wire connection points and open sections of contact rails are insulated with an adhesive bitumen film on both sides.

The temperature sensor is installed anywhere under the film. In the places where the sensor is installed, the insulation of the contacts and the ends of the film, small areas are cut out in the mylar substrate and the protruding elements are hidden in them. All wires are also placed in grooves cut with a knife, after which the surface is glued with transparent tape. They also connect the joints of the film to avoid shear.

The heating elements must be protected from abrasion with plastic wrap. It is even better to use a special grounding substrate for this, which scatters electromagnetic radiation from the floor and serves as the top contact base for more correct operation of the differential switch..

Electrical connection

It is not recommended to lay whole strips of film with a length of more than 10 m and connected stubs with a length of more than 7 m. Average electrical power of any film in an area of ​​1 m² is 200-240 W, which roughly corresponds to the current strength of 1 A. This greatly simplifies the calculation of the power of the entire system and its connection diagram, as well as the choice of the thermostat and protective devices. Conductive film strips are designed for a current of no more than 10 A, while the presence of contact connections reduces the loop throughput to 7 A.

It is not allowed to exceed the specified load norms. All units must be connected with separate wires going from the film on the floor to the thermostat, or, in extreme cases, to a junction box accessible for service.

Thus, it is allowed to use thinner wires PV-3 1×1.5 for connection, which at a load of up to 10 A will not heat up at all and will last a long time. A VVGng cable with a conductor cross-section corresponding to the total power of the controlled zone is used to power the thermostat. If the total power exceeds the permissible current of the contact group of the thermostat, the commutation is output to the magnetic starter without self-catch.

After the installation is completed, it is necessary to turn on the warm floor and check the operability of each section, and, if necessary, calibrate the sensor readings. After that, you can fasten the thermostat in place and proceed with the installation of the floor covering.

Floor covering device

Laminate can be applied directly onto the protective foil using standard methods.

Under linoleum, it is necessary to equip a leveling layer of 8 mm moisture-resistant plywood boards. To fasten plywood sheets without damaging the film, use technological gaps between the heating elements and the film fields. Plates are laid with an indent between them and from the walls of at least 10 mm, the joints are filled with silicone sealant. After it dries, the surface should be vacuum cleaned and primed, after which you can start laying the flooring.