Varieties of underfloor heating and DIY installation + Video

Varieties of underfloor heating and DIY installation + Video Types of underfloor heating and DIY installation? The advantages of underfloor heating in a private house or apartment over standard radiators are well known to everyone. As you can see, such systems are popular - most owners of their own homes want to make a heating circuit, who heat it in a standard way - using batteries.

But here a number of difficulties appear, since the installation and connection of a water-heated floor from the existing heating system of the building should be correctly performed. The first task is to check and make sure that it is possible to lay the "pie" and connect the system to an existing line with minimal cost, and ideally also with your own hands.

How to fit the heating "pie" into a room with low thresholds

This problem is often faced by all homeowners who decide to make underfloor heating in a city apartment or an inhabited house .

.. The bottom line is that the height of the threshold of an interior or entrance door is often not enough to install a full-fledged "pie" of a warm floor with a screed, as shown in the drawing below.

Now we propose to consider the composition of the heating circuit of a monolithic type, which is located in the basement or interfloor ceiling:

  1. Varieties of underfloor heating and DIY installation + Video Waterproofing - coating, and most often it is a polyethylene film.
  2. Insulation - extruded polystyrene foam with a minimum allowable thickness of 3 cm, or foam with a thickness of 5 cm.

  3. Damping tape, which used for the entire perimeter of the room.
  4. Heating pipe (as a rule, it is cross-linked polyethylene 1. 6 * 0.2 cm, or metal-plastic), which is laid in the form of a snake / snail.
  5. Screed of sand and cement, thickness 8.

    5 cm.

  6. Floor covering ( in certain cases, a layer of vapor barrier is laid under it). The thickness will depend on the material you choose - linoleum and laminate will take up to 1 cm, and ceramic tiles with a mixture of about 2 cm.

Please note what if a monolithic floor will be arranged above the ground, then the thickness of the insulation should be increased to at least 10 cm of foam or 6 cm of extrusion-type foam. The density of the materials is 35 kg / m 3 .

As a result, it is easy to calculate that the total height of the "cake" with a laminate covering will be 12. 5 cm. Such high thresholds will not be provided by any owner of the living space. How to solve the problem with the height of the underfloor heating?

  1. First, remove the old screed to the very base - floor slab or soil.
  2. Instead of a layer of polystyrene, use multifoil with a thickness of 1 cm as thermal insulation.

  3. Reduce the screed thickness to 6 cm.This structure will have to be reinforced with a road / masonry mesh with a size of 15 * 15 * 0, 4 cm or 10 * 10 * 0. 5 cm respectively.
  4. Use flooring systems - a dry warm floor that can be installed in a wooden house without using a screed. The total thickness of such a "cake" will be from 6 to 10 cm.

  5. Heat the flooring with a carbon electric film instead of a water pipe system.

Interesting: the only place in the apartment where the threshold will be high is the loggia and the balcony. There is no need to trick, and the standard monolith will fit freely together with thermal insulation.

Some home craftsmen do not put a layer of insulation or even completely reduce the power of the screed to 4.5 cm.

In the first case, half of the heat generated will simply go to the basement, the ground or to the neighbors, and in the second it is a monolith, expanding from heating, will crack in the near future. A specialist will tell you how best to make floor heating with your own hands in the video:

Connection from centralized heating

According to the law of the Russian Federation, Belarus and Ukraine, as well as other countries the former USSR, intervention in the central heating system without permission from local authorities is strictly prohibited. Simply put, for connecting additional heating devices and floor heating you will face a large fine, as well as an order from the authorities to carry out dismantling work.

Please note, that similar measures are provided for connecting the warm floor to the central hot water supply network.

How to detect unauthorized connection from the central heating system:

  • Less heat is supplied to the neighbors in the apartment, tenants are constantly starting to write complaints to the management company or Housing office, a commission from the company finds your heating system.

  • Due to pressure and its surges or due to poorly executed installation, a breakthrough occurs, and you will flood the neighbors' apartment below.
  • Persons responsible for accounting and verification of data notice a big difference in the readings of apartment devices and general house ones for heat energy metering.
  • If you connect the underfloor heating circuit in series and together with the batteries, the hydraulic resistance of the entire branch will increase, the flow will become smaller, and in apartments along this riser it will be colder and colder.

Some "smart people" advise to connect the loops of the floor heating system through a heat exchanger with plates so that the circuits are isolated from the centralized heating. But there is a catch - the hydraulic resistance will not grow in the network and the breakthrough of pipes will not give much flooding, but the amount of heat taken away will still be large.

How do you make floor heating legal so you don't have any problems in the future?

  1. Apply with your heating company and get special permission.
  2. Together with the document that authorizes the installation of a warm floor, obtain technical specifications for the installation and connection of the floor circuit.
  3. Develop and agree on project documentation.
  4. And now you can install the system with your own hands and put it into operation.

It should be noted that a large number of applicants are refused only when they apply.

Exceptions are allowed for apartments in new buildings with individual connection of apartment heating to the risers. But if you nevertheless decide at your own risk and fear to embed the heating circuit into the heat supply network, study the next section in detail.

Ways of connection

To ensure the normal operation of the circuits of floor heating radiators and get the desired feeling of comfort, the following two problems must be solved:

  1. Supply water (or any other heat carrier) with a temperature of no more than 55 degrees to the pipes of the heating circuits. Overheated floors will cause extremely discomfort, and the optimal temperature for the finish coat is +28 degrees.
  2. Provide the required type of water flow in the radiator and underfloor heating loops.

    If the diameter of the supply line is very small or the circulation pump cannot develop the required performance, underfloor heating and batteries will begin to heat equally poorly.

Let's look at a few diagrams that will help you connect a warm water floor to an existing heating system.

Consider how you can solve the temperature issue and determine the flow rate of the heat carrier for each option:

  • Direct connection with a two-pipe network from radiators.
  • Similar to the first, but using thermostatic control heads.
  • Connection to the main line of the system on one pipe with an additional pump.

  • Complete connection with a separate pipe from the boiler.

So, let's take a closer look at the first option.

Direct docking with the radiator network

Cutting the underfloor heating contour into the feed and return stroke with a two-work wiring will work normally when such conditions:

  • The total heating area is relatively small - up to 100 m 2 .
  • The heat source is a gas-fired boiler, which can maintain the temperature of the heat carrier at 40-50 degrees.
  • Circular pump, which is installed in the boiler room, and has a large capacity.

  • Underfloor heating is designed to heat rooms with a small area - a nursery, a bathroom, a kitchen.

The direct connection scheme has the right to be, but it has a number of imperfections. Judge for yourself - it will be much easier for water to move along a path with low resistance along the line than to flow into a long pipe of the heating circuit. The second point is that during large cold weather you will raise the temperature in the boiler, and the floor surface will heat up more and, as a result, the room will be stuffy. The bathroom, which is tiled, will turn into a steam room.

It is interesting that the overheated bathroom is completely useless, since people are the least of all in it.

Interesting: some home craftsmen do this sometimes - they turn on the floor gas heating circuit in the return line that goes from the battery to the heat source, and then they sincerely wonder why underfloor heating does not work together with radiators. The reason is an increase in the hydraulic resistance of the leg and a decrease in the consumption of the heat carrier.

Usage RT L valves

To solve the issue of adjusting the water temperature correctly when connecting the underfloor heating system, a special thermal head of the type RTL can help. Such an automatic valve is placed on the return pipe and can be easily adjusted to the temperature you need.

The algorithm of action looks like this:

  1. Until the temperature of the coolant reaches the value set on the thermal head, it will freely circulate through the pipes of the floor circuit.
  2. When the water temperature gets higher and rises to the set point, the head actuator will close the thermostatic valve. The circulation will be suspended, the coolant will have time to cool down.
  3. After the temperature has dropped, the thermostat will open the passage and water circulation will resume.

For information: a company of European origin О ve ntrop suggests block UniBox, which can be recessed into the wall.

Inside there will be a thermal head like an RTL, and the adjusting handle will be brought out. There are other versions, in which there are two valves - one performs the task of controlling the flow rate of the heat carrier by the return flow temperature, and the second by heating the ambient air.

Still, this solution has a certain drawback - the limitation of the pipeline length. If the length is more than 50 meters, then the warm floor will work unevenly due to high resistance. To heat rooms with a large and medium area, you will need to break underfloor heating into several contours and the same number of monoliths, which will be separated by expansion joints, as indicated in the drawing.

Now let's highlight the advantages:

  • Such heating in the form of a warm floor can be arranged in any room, no connection to the furnace and boiler is required.
  • The cost of the product cannot be compared with the price of a mixing unit and an additional canopy.
  • If the batteries have air thermal heads, then the system can work in the summer, and the radiators will turn off on their own.

This scheme is also suitable for connecting underfloor heating to a network of two central heat supply pipes. But a certain nuance should be taken into account - dirty water as a warm carrier will quickly clog the thermostatic valve, and this, in turn, can lead to its failure.

Is it possible to connect to one-pipe wiring

To power the warm floor from the heating system - the one-pipe system loved by most masters, you will have to assemble the mixer assembly with your own hands and install the second pump, as indicated in the diagram.

For normal operation, the following conditions must be met:

  • The inner diameter of the dispensing type line must be at least DN25, and a maximum of 5 radiators are allowed on one ring.
  • The underfloor heating loop is connected to the return pipe after the batteries.
  • The minimum allowable distance between the return of the underfloor heating and the infeed must be 0.3 meters.

  • To maintain the temperature in the circuit, a three-code mixing valve must be installed.

Interesting: such a system is used by apartment owners to illegally connect a warm floor to centralized heating of old types - vertical single-pipe risers.

The three-code valve is a simplified type of design that is capable of pumping water at a fixed temperature of 45 to 50 degrees. The pump will "drive" the water along the loop, and the valve will mix in some hot water from the main line. In practice, this scheme is rarely used, since the system is caused by unstable operation and imbalance of radiators, which are connected to a single pipe in the form of a vertical riser.

When the valve begins to open and feed the heating circuit, the pumping pressure begins to be transmitted to the main line and the water flow rate in the battery changes.

Good advice! If you want to create a reliable underfloor heating system, it is better to lay a separate supply and return pipe from the gas boiler. Believe me, the consequences of perversions with a single-pipe radiator network are difficult to imagine.

Traditional layout with mixing unit

When you want to create underfloor heating in every room of a two-storey house , in no case should you connect to an existing radiator heating, and you should lay a separate pipe and install a distribution comb.

There are such options:

  • In the case when the total length of the circuits is not more than 50 meters, together with the piping to the collector, thermal heads should be inserted on the comb, which will to respond to the return flow temperature.

  • Mixing unit with dual-code manifold and valve.
  • Mixing unit and manifold with thermostatic valve.

In the first version, the principle of operation will be similar to plunging one loop through the RTL head, but the regulators will stand on the comb and control all the circuits separately, as shown in the photo. The pump will provide circulation, which is located in the furnace or inside the wall-mounted gas boiler.In the second option, hot water will be mixed with a two-code valve, which is installed on the supply and a thermal head with control and a remote temperature sensor.

The latter will be hidden in the collector pipe or screwed on the outside.

When the temperature of the supplied water becomes higher, the liquid from the sensor cone will begin to press on the valve stem, and it will simply close. The scheme provides for the installation of an additional pump that pumps water through each loop of the underfloor heating of a private house. The system using a three-code valve, the principle of operation of which is described above, is more advanced and is designed for a large flow of heat carrier in a warm floor. The disadvantages of these two options are the high cost of the required equipment and the complexity of installation work.

Tips for installing underfloor heating

When all issues are resolved - at the expense of the "pie", connection diagrams, you can start pouring heating plates. First you need to find out what the thermal power of the circuit is, as well as the diameter and distance between the pipeline. Before installation work, level the surface and remove all debris. When creating a screed on top of the ground, prepare a sand cushion, compact it well or make a foundation with a thickness of 4 cm.

The process of pouring a warm monolithic floor is as follows:

  1. Make a layer of waterproofing from a film, which should be spread over the entire area of ​​the room and have an overlap of 10-15 cm.

    The joints should be well glued with tape, and along the edges make gaps on the walls with a height up to the level of the clean floor.

  2. The lower surface of the walls, which is in contact with the screed, should be pasted over with a damper tape around the entire perimeter, as seen in the photo. The overlap of the waterproofing film must remain on top of the strip.
  3. The thermal insulation boards must be tightly placed against each other. When opening the coil and straightening the pipe, the loops of the heating circuit should be expanded with the required pitch.

    Fixation of the pipeline to the insulation layer is performed using plastic staples and at intervals of 0.4 meters.

  4. We bring the ends of the loops to the point of connection - to the mains or to the radiator heating manifold. Before the final assembly of the circuit, the circuit should be filled with coolant, expelled air, and also check the system for leaks (there should be a pressure of 3-4 bar).

Please note, that if you plan to pour a thin screed of 6 cm, then a reinforcing mesh should be laid on top of the polystyrene boards.

Do not connect pipes inside the monolith, but lay only solid ones, so that there are no joints.


Listening to the opinion of specialists - experts and ordinary plumbers, we want to give the last recommendation - avoid connection of underfloor water heating to the working branches of the system. It is better to tie the heating circuits of the underfloor heating directly on the boiler, and then the floor heating will work independently of the batteries, including in summer.