Electric underfloor heating: layout and sequence of laying, design advantages

There are several types of underfloor heating on the building products market today, the main difference between which lies in the principle of operation of the heating element and the rules for laying. The leading positions are occupied by electric models, so if you want to install a heated structure in your apartment, you should familiarize yourself with its main advantages in advance. You need to know what schemes for laying a warm floor exist, and what errors there are when installing it.

Underfloor heating benefits

Electric floors are now being installed in apartments and private houses. In the recent past, heated structures have been used mainly in bathrooms or toilets. With the growth of their popularity and the development of new technologies, the possibilities of use have expanded. Today they are laid in living rooms, garages and public spaces, which is largely due to the advantages of the structures.

Among the advantages of this type of floor includes:

• versatility of use, the ability to install in small rooms and buildings for specific purposes;
• optimal price / result ratio;
• ease of installation and commissioning;
• uniform heating of the floor surface;
• ease of management and the possibility of self-regulation.

Electric models include a low temperature heater capable of maintaining a constant level from 30 to 35 ⁰ C. The even distribution of heat ensures a comfortable indoor environment. Some people consider the disadvantage of warm floors to be a short service life, which is 15 years.

Main varieties

All existing designs of warm floors are divided into three main groups: cable, warm mats, infrared. Electric floor heating cables are divided into resistive and self-regulating. Their advantage is their versatility, they are able to repeat the bends and take into account the structural features of the room, they are suitable for laying under almost any type of floor covering.

The disadvantage of cable models is the need to take into account the height to which the floor rises after installation, therefore, they are used with caution in rooms with low ceilings.

Other types of warm structures are devoid of such a drawback, for example, when installing a mat, the level rise can be only 3 cm.

Resistive floors

In the design of the first, a heating core acts as the main element, on top of which an insulating layer is laid. A metal braid is placed on top of it, which performs the function of grounding and a protective shield.

Resistive cables are available in single-core and double-core types. In the first version, the connection diagram is carried out using the closed circuit principle. The disadvantage is the resulting magnetic field, which appears regardless of the presence of the braid. Single-core systems are equipped with couplings on both sides.

A two-core cable has a heating and conductive core, which leads to a decrease in the possibility of generating radiation, on the one hand it is equipped with couplings.

When using a resistive cable, it should be borne in mind that excessive pressure on the floor surface can lead to overheating. A similar problem arises with poor contact with the screed, so such nuances must be taken into account when installing an electric underfloor heating.

Self-leveling floors

Self-regulating cables have 2 cores, but they are conductive. A special polymer matrix is ​​responsible for heating. When the temperature of the cable rises in a certain area, an instant increase in its resistance occurs, the strength of which depends on the degree of heating of the structure. As the temperature rises, the value increases, the current strength and heat generation decrease.

Thermal mats

On the building materials market today, you can find thermal mats intended for the installation of an electric floor. Their design is also based on a heating cable, but it is laid on a special fiberglass mesh. The cable has a cold wire connection with a length of 1 to 2 m, which is responsible for connecting the entire structure to the network.

Heat mats are immediately applied to the concrete screed. Their advantage is ease of installation, and due to their small thickness, the system can be mounted directly under the floor covering.

Infrared floors

The design is based on a thin film capable of providing uniform radiation of infrared rays, which are absolutely safe for humans. The main difference during installation is that when laying, it is necessary to ensure the presence of thermal insulation material. Such structures are not used in rooms with a high level of humidity and are used to heat an area with a floor covering with ceramic tiles.

Floor laying sequence

Regardless of the type of heating element and its design features, the installation of an electric floor has no fundamental differences. Installation consists in the sequential formation of a "layered cake" consisting of a rough concrete coating, heating element, glue and coating. The latter is often tile or laminate.

Cabling

At the initial stage, design work is carried out, drawing up a detailed plan and choosing an installation scheme. Calculations are made according to the required cable length and the step of its laying. The area where furniture or dimensional equipment is located is not taken into account. Exceptions are items with high legs. The calculation of the step is calculated by the formula:

installation spacing (cm) = (100 x heating area) / cable length (cm)

First, the thermostat is mounted on the wall, the recommended height is considered to be at a level of 50-100 cm. To install a warm floor:

• the phase, zero and ground are supplied to the installation site from the junction box;
• 2 plastic tubes are placed in the prepared groove, one is intended for the power wires of the heating cable, the second is for wiring the sensor;
• the floor surface is leveled;
• a damper tape is glued along the wall;
• an insulating layer of at least 2 cm is formed, a mounting tape 50 cm thick is placed on top of it to fix the cable;
• power wires are pulled to the box, controlling the location of the connecting sleeve in the concrete screed;
• install a temperature sensor;
• check the quality of the installation and control the permissible deviations.

When checking the resulting deviation, they are guided by the passport data, for example, the take-off run is not more than 10%.

After carrying out the control procedures, they proceed to pouring the cement-sand screed. For a hard subfloor, its thickness should be at least 3 cm while providing a layer of thermal insulation of 5 cm. At the last stage, the heating cable is connected by connecting the temperature sensor and power wires to the thermostat clamps. The chain is closed using electrical wiring, which is responsible for powering the entire structure of the warm floor.

Installation of a heat mat

Before starting, work is carried out to determine the installation scheme for warm mats. It is necessary to take into account the future location of furniture, stationary items and household furniture. When installing the structure, a number of features should be taken into account. The main ones are:

• the strobe for the temperature sensor is cut out on the surfaces of the wall and floor, since the thickness of the latter will vary from 1 to 1.5 cm;
• after carrying out the preparatory work, they immediately proceed to laying the construction of the heat mat, excluding the laying of the heat-insulating material, since it provokes overheating of the cable.

At the first stage, the mat is rolled out over the entire area of ​​the room. The direction is changed with scissors, cutting the reinforced mesh without touching the cable. A distance of 5 cm is left between the two strips. Next, tear off the protective tape on the underside and roll out the roll. A layer of tile adhesive is placed on top of the mat, controlling the moment of protrusion of the heating cable on the floor surface. After it is completely dry, after 3-5 days you can start finishing work.

How to install infrared film

After carrying out preparatory work, thermal insulation is laid on the primed surface. Sequence of further actions:

• an infrared structure is placed on top of the film, preventing the sheets from overlapping;
• install a thermostat;
• fix the mounting mesh, controlling the absence of damage to the contacts with self-tapping screws;
• a cement-sand screed is poured.

After complete drying of the base of the floor, proceed to laying the tiled covering.

Important points

The end result largely depends on how correctly the calculations were made in terms of the characteristics of the warm floor, and the rules for its installation were followed. They start laying only after leveling, carrying out groundwork and thoroughly cleaning the floor from debris. It is recommended that the connection points of the heating cable and electrical wiring be noted in the plan document, which may be required in the future when carrying out repair work.

When choosing a resistive cable, you should focus on the power density calculated by the manufacturer for 1 m². The layout of the structure may involve installation in the form of a snake or shell; when using electric warm floors, they often resort to the first option.

The following points are important:

• damage to the heating cable must not be allowed, therefore all work must be carried out as carefully as possible;
• cutting and piercing objects are not used during installation;
• work is carried out in shoes with soft soles;
• step on the cable only in extreme situations;
• clearing the seams is done with jewelry precision.

Failure to follow these simple rules can damage the cable, as a result of which all efforts will be in vain.

When laying tile adhesive, it is important to ensure that no bubbles form. The error can lead to excessive heating of the cable, which can fail as a result.

From the time of finishing work and floor covering, at least 30 days must pass in order for the chemical processes to be completed in full. After that, the structure can be put into operation.

Installing an electric floor in a room has a number of advantages, the main of which is the comfort of living. It is necessary to start laying a warm floor by determining the type of heating model, then perform calculations for sufficient heating of the room and carry out the installation, observing the basic rules and recommendations.