Installation of cable underfloor heating (under the screed)
Preparing the wall and floor for installing the thermostat
Installation of a warm floor begins with the preparation of a place for installing a thermostat and a floor temperature sensor.
The thermostat is installed on the wall in any convenient place so as not to interfere with the arrangement of furniture, at any convenient height, but not less than 30 cm from the floor.
Thermostats controlling the floor heating in rooms with high humidity (bathroom, sauna, pool) should be installed outside such rooms.
A hole for installing the thermostat and a groove for laying the mounting ends of the heating cable and the floor temperature sensor in the corrugated tube are gated in the intended place in the wall and in the floor.
It is necessary to bring power to the installation site of the thermostat, while the cross-section of the conductor of the power line must correspond to the current strength of the warm floor.
Preparation of the base for underfloor heating.
To remove construction debris, it is necessary to clean the room before installing a warm floor.
The base on which the heating cable will be laid should be flat without cracks and potholes. The rough surface must be leveled with a leveling mixture.
After the floor is treated with a primer to improve contact of the surface of the base with a solution monolithic heating cable. If thermal insulation is used, priming is not necessary. The main thing is to prepare the surface for laying and attaching heat-insulating material to it.
Then, places where a floor heating device is not required, for example, under stationary furniture, plumbing, etc., are marked. In addition, you should take into account the indents from the walls of at least 5 cm.
Laying thermal insulation and attaching mounting tape.
If heat loss through the base of the floor is minimal, for example, there is a heated room under the room, then heat insulation of small thickness 3-4 mm can be laid only on the heated floor area.
If the base of the floor is cold, you should choose the thermal insulation of the appropriate thickness and strength and lay it over the entire area of the room.
Thermal insulation can be fixed with any adhesive material that does not violate the integrity of the thermal insulation structure. Along the perimeter of the lower part of the wall of the entire room, lay a damping tape (porous material) to the entire thickness of the proposed construction of the warm floor, you can use the thermal insulation used.
To lay out the heating cable, fix the segments of the mounting tape in increments of 0.5 - 1 m. You can fix the tape in various ways, for example, using dowels and screws with the condition of maintaining the integrity of the waterproofing carpet.
Installation of cable underfloor heating.
Before installing the underfloor heating, it is necessary to calculate the step of laying the heating cable, taking into account the final adjustment of the heated area.
The permissible deviation of the pitch from the calculated one is not more than 10 mm.
Laying the underfloor heating begins with the connection of the mounting end of the heating cable to the location of the thermostat. Fix the coupling and the initial section of the cable on the floor and from this point begin the layout of the section.
Lay the cable evenly, without intersections. Strictly observe a constant laying pitch throughout the entire heated area. The rapprochement of the laid turns of the cable to a distance of less than 80 mm (preferably not more than 150 mm) is unacceptable.
Lock the ends of the cable by bending the protruding tabs of the mounting tape around it. The bends of the loops should be smooth, without kinks or cable tension.
The distance from the heating cable to the wall should be about 5 cm around the entire perimeter of the heated floor area, if it is adjacent to the wall. Cable connectors and terminations must be on the floor. Lead the cable ends to the thermostat.
When laying a single-core cable underfloor heating, the same rules are observed as for a two-core, but when planning the layout, it should be noted that both cable ends are connected to the thermostat.
The heating cable must be laid so that it is at least 100 mm from other heating appliances, for example, from risers and central heating pipes. In order to avoid mechanical damage to the heating section, it should be installed in shoes with a soft springy sole, or cover the unfolded cable with plywood or any other materials that impede mechanical impact on the heating section of the warm floor when walking on it.
The step of laying the heating cable is calculated by the formula:
laying pitch (in cm) = (100S) / L
where S is the actual area onto which the section is laid, sq m;
L- section length, m, is indicated in the section passport or in the cable marking,
for example, the length of the heating cable 14 TLBE 2-13 is 13 m
the length of the heating cable 20 TLOE2-48 is 48 m.
Installing the floor temperature sensor and thermostat
When installing an electric heated floor, two options for connecting a floor temperature sensor are possible:
directly (thermostat - heating cable);
through the junction box (thermostat - junction box - heating cable).
Here we look at the option of directly connecting the floor temperature sensor.
Place the temperature sensor in a plastic corrugated tube with a diameter of 16 - 20 mm (included in the Thermolux kit).
The sensor should be located inside the tube near its end, and its connecting wire should go out from the other end of the tube. Close the end of the tube with the sensor that will lie in the floor tightly to prevent cement mortar from getting inside, for example, using a heat shrink tube and a hair dryer.
Remove the handset from the thermostat to the floor. The bending radius of the tube must be at least 5 cm. The distance from the wall to the end of the tube in the floor (sensor installation location) is 50-60 cm.
Fasten the tube between the threads of the heating cable at an equal distance from them using the tabs of the mounting tape.
The end of the corrugated tube should extend to the thermostat mounting box or intermediate junction box. This method of mounting the sensor is used so that, if necessary, the sensor can be replaced without opening the floor.
After installing the floor temperature sensor, the groove for the mounting ends of the heating cable and the sensor is greased with a solution.
The ends of the mounting wires of the cable and floor sensor must be irradiated and connected to the thermostat.
Check electrical connections. Then briefly (for about 1 minute) apply the mains voltage and check the operability of the warm floor. The LED on the front panel of the thermostat will light up and the cable should start to warm up. Turn off the power again until the system is fully turned on.
In accordance with the manufacturer's warranty requirements, draw a diagram of the installation of a warm floor cable in the appendix “Instructions for the installation and operation of a warm floor Thermolux” with the designation of connectors and terminations, a floor temperature sensor with a binding to the room.
The device of a cement-sand screed over a warm floor.
The installation of a cement-sand screed begins with cutouts in the thermal insulation of the technological holes designed to set the screed with the base. The holes are cut through 30 - 40 cm in size 10 x 15 cm.
In accordance with the instructions for the preparation and use of dry mixes, prepare the solution in the required quantity. Level the beacons. Fill the screed. The thickness of the screed over the cable underfloor heating should be 3-5 cm.
If the floor structure is “hanging”, i.e. not on a concrete base, but on a layer of heat or sound insulation, the thickness of the screed should be at least 3.5 cm.
In accordance with the requirements of the Building Standards and Rules (SNiP), ensure the optimal temperature and humidity conditions in the room to increase the strength of the screed, protect the room from drafts.
In the case of the installation of warm floors of large areas, the device of temperature joints is necessary. The maximum surface of the floor slab on which floor heating will be performed is 30 sq m and the ratio of its sides is 2/1.
Due to the fact that the screed in the construction of the warm floor is “hanging”, it must be protected from mechanical stress for at least 4 to 5 days.
Lay the floor covering.
Operation of underfloor heating is possible 28 days after pouring screed.
The preparedness of the hardened solution:
7 days - for fixing tiles
28 days - exploitation of underfloor heating.
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