15 mistakes when laying underfloor heating

The underfloor heating system is quite popular today. Using a heating cable, thermomats, infrared film or pipes, you can make the floor heating. Actually, it is not too difficult to do the installation of heating elements with your own hands, however, many inexperienced masters make the simplest oversights, because of which the entire system can fail even after some time after installation. Below we will consider the main errors when installing a warm floor of water and electric type.

Errors in laying heating cable

  1. Incorrect material calculation. When calculating the length of the heating cable or the size of the mats, you need to use the usable area of ​​the room, and not the total. Useful area refers to the space that will not be blocked by furniture, appliances and other objects. If you install heating elements under large-sized objects, overheating of the system will occur in these places, because of which it will fail. To prevent this error, we recommend that you familiarize yourself with the technology calculating underfloor heating.
  2. It is forbidden to cut resistive cable into suitable pieces. If the conductor is more than necessary, try to lay it a little closer to each other, while not violating the requirements of the manufacturer. We draw your attention to the fact that self-regulating cable devoid of such a drawback, so when you install it, you are unlikely to make this mistake.
  3. Keep track of the laying step, as well as the indentation from walls and other objects. Remember that the loops of the conductor should not intersect each other, otherwise overheating may occur.
  4. Observe the minimum bending radius, which is indicated in the technical specifications. Typically, it is 5 to 10 cable diameters.
  5. Heating elements should only be laid on a clean surface. During installation, make sure that the underfloor heating does not lie on construction debris, otherwise it will quickly fail after pouring the screed under mechanical stress. It is even recommended to remove all dust before installation.
  6. An elementary mistake, which is also made by inexperienced specialists, is the ignoring of recommendations on how to ring the system after installation. Before filling the screed or laying parquet (on infrared film), be sure to measure the resistance of the system and compare this value with the nominal value indicated in the passport. Perhaps you made a mistake in the connection and the system is no longer working. Then it will be much more difficult to repair the warm floor. About, how to check the warm floor after laying, we described in detail in a separate article.
  7. You can turn on the warm floor only after the screed has hardened. If you decide to check if the floor is warming up before the mortar dries, it can damage the system. It is strictly forbidden to turn on the cable in the bay.
  8. The temperature sensor must be laid in the corrugation, so that at any moment it can be easily removed (for repair or replacement). The end of the corrugation must be tight so that the solution does not get on the sensor.
  9. The sensor itself needs to be located in the middle between two turns of the cable so that it shows the temperature as accurately as possible. Too far a distance from the cable will provoke continuous operation of the system and vice versa. It is recommended that the temperature sensor be placed closer to the surface of the new floor covering.
  10. Each room should have its own floor heating circuit and its own temperature controller. A gross mistake is to save materials during installation and create a single system with one temperature controller.
  11. Do not step on the cable during installation work, especially in shoes with hard soles. This can damage the conductors and insulation. Try to go around the turns of the heating element.
  12. Before filling the screed, take a photo of the layout of all the elements so that you can know where what is during the repair.
  13. In no case do you need to contribute to the quickest solidification of the solution by turning on the system. Those who advise turning on the heating immediately after installation, sooner or later will encounter a situation when the system quickly fails.
  14. Before starting work, be sure to read the instructions in which the manufacturer can recommend important points. Our main mistake - we first make, and then read the instructions. So it's better the other way around.
  15. Remember, infrared floor heating needs to be laid for parquet, laminate and linoleum, and thermomats and a heating cable for tiles. If you spread the film floor in the bathroom and pour tile adhesive on it, the system will not work. It seems to be obvious facts, but sometimes they manage to do it.

We also recommend watching a video that discusses some of the points in more detail:

So we provided 15 errors when installing a warm floor of water and electric type. Be sure to keep them in mind and share with your friends on social networks so that they don’t have to reinstall the system, which, due to improper installation, will quickly fail!

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(5 votes)


  • Andrew

    Is it possible to lay the cable through the wall (brick floor) between the toilet and the bathroom? One floor in two rooms. Thank you.

    To answer
  • Alexei

    Read Learn Bug # 10

    To answer

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