Water floor heating

Warm floors, heated by water - quite an attractive solution. But if you want to install them yourself, without resorting to the help of professionals and without spending money on their services, you will have to thoroughly study the topic and find out all the subtleties. You should know both the connection principles and the methodology of the base device. Laying will also have to be done using special technology.

Design

There are many varieties of warm water floors on the market. It is produced by dozens of leading manufacturers. But regardless of the specific make and model mandatory components are:

• water heating boiler
• water pump
• ball valves (they are placed at the input to the boiler),
• pipes
• a collector device that allows you to configure and regulate floor heating at your discretion,
• fittings, through which the main route is mounted, starting from the heater, and pipes are also connected to the collectors.

Each of these constituent elements has its own characteristic features. So, the pipes should be made of polypropylene with a reinforcing fiberglass layer, otherwise there is a risk of their excessive expansion in the hot state. Polyethylene has a lower level of thermal expansion. At the same time, the optimal diameter of the pipes is from 1.6 to 2 cm. Find out when buying whether they can withstand the pressure of 10 bar when pumping water heated to 95 degrees.

The collector through which water enters the pipeline is sometimes called a splitter. One of these devices sorts hot water by heating circuits, and the other collects it after passing through the entire system. Both devices are placed inside the manifold cabinet. Qualitative performance of the collector group also includes:

• valves
• air outlets
• water flow control devices
• units for accelerated liquid outflow in a critical situation.

A collector with a shut-off valve is impractical, therefore it is better to choose options equipped with control systems that provide a smooth change in the flow of coolant into a particular circuit.

The exact length and installation step when installing the pipes is calculated individually for all rooms (rooms). There are no uniform standards here. If you do not feel prepared enough for self-calculation using specialized software, use the services of design organizations. Designers will need to know what the size of the room is, how powerful the boiler will be installed, what the walls in the house (apartment) are made of, what are the properties of ceilings, partitions. Be sure to take into account the type of flooring, the insulation layer and the diameter of the pipes.

The project should indicate not only how long the pipe is, but also the installation step and the rational installation path. Additionally, heat losses and hydraulic resistance are calculated (it should be exactly the same in each circuit). It is undesirable to use large contours (100 m and longer).

It is better to divide each such into several smaller ones. All circuits are strictly one pipe, so joints and couplings are not allowed when laying in the screed. Balconies, attics and loggias are heated by a separate option from adjoining rooms.

Remember that you need to lay pipes starting from the outer walls, and uniformity of reduction in heating is achieved due to the "snake" scheme.

In rooms where there are only internal walls, the design of the warm floor should be spiral, directed from the edges of the room to its middle. In this case, a double step is maintained between any pair of turns.

Note: to collect and buy a collector should only be after how the number of contours and their characteristic features will be calculated. The simplest solution, equipped with only one shut-off valve, is relatively cheap, but the lack of flexible adjustment capabilities will cause many inconveniences. The other extreme that should be avoided is an expensive collector equipped with servos and pre-mixers.

Such equipment in a private house or apartment is completely superfluous, with the exception of giant cottages. When deciding which boiler to install, focus primarily on its capacity, which, even when operating in peak design mode, should have a reserve of at least 15%.

To ensure the mixing of hot and cold coolant, use thermostatic mixers. They are two-way (paired structures are installed on the supply and return pipes) and three-way (with the addition of an electric drive, mounted on the boiler output). Take care of the presence of a servo drive, a thermostat: investments in these devices are justified in that it will be more convenient to use the system. Servos are placed on the combs of the water supply.

Mechanical thermostats are relatively simple and reliable to use, so it’s easy to use them even for people who are poorly versed in technology. Electronic controllers are a little more complicated, and if necessary, flexibly adjust the parameters of the warm floor will have to purchase a programmable device.

Having figured out in general terms the device and the configuration of the floor-heating equipment, we will now see how it works. From the boiler (in rare cases, from a heated towel rail), water enters the pipeline. Passing through a thermostatic valve, it transfers to it a known portion of heat. When a certain temperature is reached, the valve starts the process of mixing water taken from the return pipe. For this purpose, a two-way or three-way valve opens, installed before the circulation pump (inside a special jumper).

The mixed liquid, passing through the circulation pump, touches the thermostat, which ultimately gives commands for opening and closing the flow of coolant from the return circuit to the main one. Thanks to this scheme, the water temperature is maintained in a given range of values ​​and is instantly corrected when deviating from it. Then the water passes to the distribution comb (but only in a large room where there is a need to distribute the coolant in several circuits and then pump it in the opposite direction).

Mounting a warm floor in several rooms at once, put the collector that regulates the temperature. This is necessary not only because everyone needs their own degree of heating, but also because the completely identical length of the circuit cannot be maintained. Adjustment is especially useful if one of the rooms is internal and the other has external walls.

Thermostats can measure the heating of the air in the room, or the temperature of the flooring. Focus on what is important to you and do not confuse these two types.

Take care of the bypass in the heating system. It will allow you to keep the equipment in perfect order, if suddenly the water supply to all circuits is simultaneously stopped.

Advantages and disadvantages

Water floor heating economical. The low temperature of the coolant (not exceeding 50 degrees) will reduce the current consumption of the electric boiler by 20% (in comparison with heating with radiators). Homogeneous heating of the entire area of ​​the home with a physiologically comfortable temperature distribution (22 degrees on the floor itself, 18 degrees on the face level) can also be considered a positive side. The hidden location of the heating system completely eliminates burns and mechanical injuries in direct contact with it and the coolant, which is especially important if there are children in the house.

Safe water floor also serves for a long time. Properly completed installation and proper selection of components allows you to use the system for 30-40 years. Unfortunately, there are also disadvantages. For example, the increased complexity of installation (if you are not well versed in the problem or do not have the necessary experience, contact professionals, or choose the electric option). If the installation is carried out with errors, this not only reduces the heating efficiency, but also increases the risk of leakage.

If, due to installation failures, natural wear and tear or due to any other problem, water begins to leak, you will have to disassemble the floor, dismantle the heating structure, completely or partially replace it, and only then reconnect. Finally, in private residential buildings it will not be possible to use water floors as the only heat sources.

Long-term (tens of hours) heating cannot be considered a drawback: all the more so since significant thermal inertia will allow the floor to stably heat the air even during short-term interruptions. Be prepared that laying a water floor (even with your own hands) will be significantly more expensive than installing its electric version. Some materials in terms of 1 sq. M can cost at least 1,500 rubles. When a team is involved, she will need to pay no less.

A good result is achieved provided that the floor is raised by at least 10 cm. Costs are associated with the installation of control systems, manifold cabinets and exhaust air valves.

Device and principle of operation

Water underfloor heating is a room heating system in which the coolant circulates along a circuit under the floor covering. Please note that pipes are not always in the screed. There are "flooring systems" in which the circuit is not filled with concrete.

On closer inspection, a water floor heating cake consists of the following elements:

1. Prepared base
2. Screed (5 cm),
3. Heat insulator (5 cm),
4. Pipes (2 cm),
5. Screed (4 cm),
6. Floor covering (2 cm).

Depending on the pipes used, there may be several layers of waterproofing. The base is a draft floor in the basement or on the first floor of a private house. The first layer of screed is required precisely in the absence of a flat surface.

A 5 cm thick heat insulator is a standard solution. But if possible, it is better to increase the thickness to 10 cm. This increases the efficiency of the entire system by 10-15%. Especially if the underfloor heating is arranged on the ground floor. The best material for this layer is extruded polystyrene foam.

Pipes in the vast majority of water floor heating are used with a diameter of 16 mm.

The second layer of screed covers the entire system and serves as a giant heat accumulator.

The thickness of the cake is a warm water floor, varies from 18 to 23 cm. And the mass of 1 m 2 of this system reaches a quarter ton! Such harsh conditions significantly limit the spread of warm water floors.

The circuit is connected to the pump and boiler, through a control and monitoring system.

Where can i use

In view of the sufficient thickness and mass of the entire system, its use is limited to private housing construction. In apartments, a water heated floor is extremely irrational to install.

The main reason is the difficulty with connecting the power. The central heating system can only be connected after permission from the regulatory authorities. And getting it is almost impossible. Even if it does, the main leitmotif - autonomy - will disappear. We know the options for installing electric and even gas boilers in an apartment, but these are isolated cases that only confirm the rule: water floor heating is used only in private homes.

Advantages and disadvantages

The advantages of water floor heating in its entirety are revealed only when using cheap energy sources, such as gas, coal, firewood.Heating the heat carrier with an electric boiler is approximately 7 times more expensive than using gas equipment.

The giant heat capacity of the underfloor heating system is another plus. The room in which ≈ 100 kg / m 2 of heated concrete is located cannot quickly cool down (only the top layer of the screed is taken into account).

But there are also cons. First of all, this is a monstrous inertia. To warm such a layer of screed, time and energy are needed.

Inertia leads to the fact that adjusting the temperature of the warm water floor is very arbitrary. Monitoring equipment takes temperature readings from the heat carrier, the surface of the floor and air (in some temperature controllers). But the changes introduced through the thermostat manifest themselves very slowly.

Installation of underfloor heating

The task is quite difficult, but doable. Only first you need to level the base. This is a very important requirement, considering that you still need to level it, and the first layer of screed is more effective. Why?

For example, the height difference in the room is 3 cm. If you immediately lay the pipe and only then level it with a screed, it turns out that in one corner the height of the cement mixture will be minimal - 4 cm, and in the other 7. Therefore, during the use of underfloor heating, on the one hand they will warm 4, and on the other 7 cm of concrete. Such an uneven load, very detrimental to the entire system as a whole and leads to quick damage to the floor covering.

Therefore, the first and most important step is to level the sexes on the horizon. To prepare concrete floors you will need:

• Beacon profile,
• Laser level,
• The square is construction,
• 5-10 kg of gypsum,
• Primer,
• Mobile concrete mixer,
• Cement,
• ASG
• Polypropylene fiber.

Progress:

The floors are swept and primed. While the soil is drying, put up beacons. To do this, in the middle of the room set the laser level so that the projection of the horizontal beam is at a height of 15-20 cm from the floor. Then, using a square, measure the height from the floor to the beam in different corners of the room and determine the highest point according to the results. In this place, the height of the screed will be the minimum allowable - 4 cm. In other places - according to need.

To install lighthouses, gypsum is bred to a state of thick sour cream. Then, small piles are made of the resulting mass along one wall, in increments of 60-80 cm, and a beacon profile is laid on them. Putting a square to it, align it with the horizon, placing it at the desired height. From the wall to the first lighthouse should be 50 cm. Between adjacent lighthouses the distance varies depending on the length of the rule (focus on 1-1.3 m). Remember, gypsum sets quickly, work is carried out "without a smoke break".

After about 30-40 m, you can fill in the screed. Cement is bred with ASG in a ratio of 1: 5. Polypropylene fiber is added at the rate of 80 g. per 100 l of the mixture. Fiber is an element of dispersed reinforcement, qualitatively increasing the strength of the coating. In addition, after hardening, the new surface will be perfectly smooth.

Pour the mixture in such a way that each next portion, 10-15 cm went to the previous one. By level, the screed is aligned with the rule, with orientation along the beacons.

After pouring the entire surface, it takes time for the technical maturation of the cement-sand screed. Calculation of approximately the next 1 cm of thickness - 1 week.

Insulation installation

Extruded polystyrene foam and cross-linked polyethylene foam, only these two materials can be used for thermal insulation in a system of underfloor heating.

Before laying the sheets of the heat insulator, a damper tape 10-12 mm thick is glued around the perimeter of the room. It serves not only to compensate for the thermal expansion of the screed, but also to prevent heat from escaping into the walls. In height, it should protrude beyond the boundaries of the upper layer of the screed.

The sheets of the insulator are laid out in a flip-flop and necessarily on a layer of waterproofing. For waterproofing, it is best to use a 0.2 mm thick plastic film.

If you decide to make the insulation thickness of 10 cm, it will be better if you lay two layers of plates with a thickness of 5 cm. Be sure to spacing between the layers.

There is an option to use special plates as a heat insulator, designed for the organization of water heat-insulated floors. Their difference is in the bosses on one of the surfaces. Between these bosses lay a pipe. But their cost is unreasonably high. In addition, not all pipes will be held in such plates. For example, polypropylene and polyethylene pipes are too elastic, they will require additional fixation.

Fastening pipes to the heat insulator is not carried out. Fasteners must pass through the foam layer and lock into the screed. This is a very time-consuming process, given the amount of work.

Mounting tapes are a more acceptable solution, but it is very difficult to lay the pipe on them with a spiral (snail).

The best option is to fix the pipes on the grid. In this case, the grid will serve precisely for pipe fastening, and not for reinforcing the screed.

There are special mesh made of biaxially oriented polypropylene, and you can use a simple masonry mesh.

Choice of pipes and their laying

The following types of pipes are suitable for water floor heating:

• Copper
• Polypropylene
• Polyethylene PERT and PEX,
• Metal-plastic
• Corrugated stainless steel.

They have their own strengths and weaknesses.

* pipe characteristics are considered during operation in warm water floors.

** Prices are taken from Yandex.market.

The choice is very difficult if you try to save on yourself. Of course, copper can not be taken into consideration - very expensive. But corrugated stainless steel, at a higher price, has exceptionally good heat dissipation. The temperature difference in the return and supply, they have the largest. This means that they give out heat better than competitors. Given the small bending radius, ease of operation and high performance, this is the most worthy choice.

Pipe laying is possible with a spiral and a snake. Each option has pros and cons:

• Snake - easy installation, almost always observed "zebra effect."
• Snail - uniform heating, material consumption increases by 20%, styling is more time-consuming and painstaking.

But these methods can be combined within one circuit. For example, along the walls of the "looking" to the street, the pipe is laid by a snake, and on the rest of the area by a snail. You can also change the frequency of turns.

There are generally accepted standards that professionals are guided by:

• Pitch - 20 cm
• The length of the pipe in one circuit is not more than 120 m,
• If there are several contours, then their length should be the same.

For stationary and bulky interior items, pipes are best not to start. For example, under a gas stove.

IMPORTANT: be sure to draw the layout scheme in accordance with the scale.

Stacking starts from the collector. Unwinding the bay, fix the pipe according to the scheme. It is convenient to use plastic clamps for fastening.

Corrugated stainless steel is available in bays of 50 m each. Branded couplings are used to connect it.

The last element laid between the turns of pipes is a temperature sensor.It is pushed into a corrugated pipe, the end of which is muffled and tied to a grid. The distance from the wall is at least 0.5 m. Do not forget: 1 circuit - 1 thermal sensor. The other end of the corrugated pipe is led to the wall and then, along the shortest path, is led to the temperature regulator.

Control system and pressure testing of the circuit

The control system for underfloor heating includes:

The layout of all elements in compliance with technical parameters is a very difficult heat engineering task. A lot of parameters are taken into account, starting from the number of fittings and the length of the pipes, and ending with the wall thickness and the region of the country. In general, you can focus on the following data:

1. The pump can only be used as a circulation pump. “Wet” type of pump, more reliable than “Dry” and less demanding in maintenance.

To calculate performance, use the following formula:

Where W is the power of the heating system.

For example, with a system power of 20 kW, the pump capacity should be 20 x 0.172 = 3.44 m 3 / h. Round the result up.

Pressure is calculated by a more complex method. After all, the pipes are located horizontally, and the characteristic of the pump shows a vertical head. Use the following formula: H = (L * K) + Z / 10. Where L is the total length of the circuits, K is the coefficient of pressure loss from friction (indicated in the pipe passport, translated into MPa), Z is the pressure attenuation coefficient in the additional elements

Z₁ - 1.7 thermostat valve,

Z₃ - 1.3 valves and fittings.

For example, it looks like this, for example, there are 3 circuits, 120 m each. In total there are 18 fittings, 3 thermostat valves, 1 mixer. Pipe - corrugated stainless steel ø16 mm, loss factor 0.025 MPa.

H = (120 * 3 * 0.025) + ((1.7 * 3) + (1.3 * 1) + (1.2 * 18)) / 10 = 9 + (5.1 + 1.3 + 21 , 6) / 10 = 11.8 m. The result is rounded upwards - the pump head is 12 m.

1. The boiler power is calculated by the formula W = S * 0.1. Where S is the area of ​​the house. There are also a lot of correction factors, depending on the thickness and material of the walls of the house, the climate of the region, the number of storeys, the availability of adjacent rooms.

Please note that the outlet water temperature must be more than 30 - 35 ° C. To withstand this temperature, a mixer is installed in front of the collector. In it, water is mixed to the desired temperature before being fed into the circuit.

1. The collector controls the water supply in each circuit. Without it, water will follow the path of least resistance to flow, that is, along the shortest path. The adjustment is carried out by servos, according to the data from the thermostat.
2. Thermostats monitor the temperature in controlled rooms, taking readings from temperature sensors.

Before crimping the circuit, it is washed and only then connected to the collector. Water is supplied under normal pressure, but the temperature is increased by 4 ° C per hour, up to 50 ° C. In this mode, the system should function 60-72 hours. IMPORTANT: constant pressure monitoring is required during crimping!

At home, without the use of special equipment, it is impossible to pressure test.

If the check did not reveal installation flaws, then you can proceed with further operations.

Screed

IMPORTANT: fill the top layer of the screed only when the circuit is full. But before that, the metal pipes are grounded, and closed with a thick plastic film. This is an important condition to prevent corrosion due to electrochemical interactions of materials.

The issue of reinforcement can be solved in two ways. The first is to put a masonry net on top of the pipe. But with this option, cracks may occur as a result of shrinkage.

Another method is dispersed fiber reinforcement. When pouring water-heat-insulated floors, steel fiber is best suited. Added in an amount of 1 kg / m 3 of the solution, it will be evenly distributed throughout the volume and will qualitatively increase the strength of the hardened concrete. Polypropylene fiber, for the upper layer of the screed is much less suitable, because the strength characteristics of steel and polypropylene do not even compete with each other.

Beacons are installed and the solution is kneaded according to the above recipe. The thickness of the screed should be at least 4 cm above the surface of the pipe. Given that the ø of the pipe is 16 mm, the total thickness will reach 6 cm. The ripening time of such a layer of cement screed is 1.5 months. IMPORTANT: It is unacceptable to speed up the process including underfloor heating! This is a complex chemical reaction of the formation of "cement stone", which occurs in the presence of water. And heating will cause its evaporation.

It is possible to accelerate the maturation of the screed when special additives are included in the recipe. Some of them cause complete hydration of the cement after 7 days. And besides this significantly reduce shrinkage.

You can determine the readiness of the screed if you put a roll of toilet paper on the surface, and cover it with a pan. If the ripening process is over, then in the morning the paper will be dry.

First inclusion

A very important stage in the operation of a water floor heating. So that the screed does not crack from uneven heating, and the pipes are not damaged, the inclusion is carried out according to the following scheme:

1 day - temperature 20 ˚C.

2 days - increase the temperature by 3 ˚C.

3 and the next day, they raise the temperature by 4 ˚C, until reaching the operating mode.

Only after that, you can proceed to the installation of flooring.

Warm floor and topcoat

Best of all, a warm water floor system is combined with laying under porcelain tiles and tiles.

• Firstly, both materials are strong and durable.
• Secondly, they do not emit harmful substances when heated.
• And thirdly, heating perfectly complements the tile (the material itself is cold), and you can walk on it even barefoot due to its high heat capacity.

Of course, underfloor heating can be done under the laminate, under linoleum, PVC tile and even carpet, if there is a special mark.

But, for example, there is no point in heating the carpet, and you can not exceed the surface temperature above 31 ° C, according to SNiP 41-01-2003. Otherwise, it will provoke the release of harmful substances.

Installation in the apartment

Probably, many tenants had the idea of ​​independently connecting “for free” water heated floors to a central heating system or hot water supply. And some even do it, but in most cases it is prohibited by local law.

For example, in Moscow, government decree No. 73-PP of February 8, 2005 is in force, Appendix 2 clearly states the prohibition of re-equipping public water supply systems for floor heating devices.

Violating the rules, at best, you can get a fine at the first visit to plumbers. And at worst - the risk of leaving neighbors without heating.

In some regions, the ban is not valid, but the connection requires an examination in order not to disrupt the system.

In general, from a technical point of view, such options are possible, but only when connecting a separate pump and mixing unit and maintaining the pressure in the outlet system.

Note! If there is a jet pump (elevator) in an apartment building, then metal-plastic and polypropylene pipes cannot be used.

Floor Mounting Methods

There are several ways to arrange a warm water floor.

• The most popular and reliable of them is a concrete screed. Unlike electrical types, 16 mm pipes cannot be hidden in tile glue, and it won’t work out. Therefore, the screed is poured at least 3 cm above the pipes.
• The second way - laying pipes in the cut grooves of expanded polystyrene. The grooves are done manually, pipes are laid inside, then the screed is poured.
• The next option is often used in houses with wooden floors, although it requires a lot of labor - this is laying in wooden grooves. To do this, boards are filled on the floor, which create a gutter of the desired shape for laying.

Types of pipes used

For a warm water floor, three types of pipes are suitable.

• Pipes made of cross-linked polyethylene (PEX-EVOH-PEX) are inconvenient to work because it is difficult to give them the desired shape (when heated, they straighten).But they are not afraid of liquid freezing and are repairable.
• Plastic pipes - the best option: low price, ease of installation, stably hold shape.
• Copper pipes are expensive, when used in a screed they must be covered with a protective layer to prevent alkaline exposure.

Calculation of a warm water floor

Before installation and procurement of materials, it is mandatory to calculate the warm floor. To do this, draw a diagram with contours, which will then come in handy during repairs to know the position of the pipes.

• If you are sure that furniture or plumbing will always be in a certain place, do not lay pipes in this place.
• The length of the circuit with a diameter of 16 mm should not exceed 100 m (for a maximum of 20 mm it will be 120 m), otherwise the pressure in the system will be poor. Thus, each circuit approximately occupies no more than 15 square meters. m
• The difference between the length of several circuits should be small (less than 15 m), that is, they should all be of uniform length. Large rooms, respectively, are divided into several circuits.
• The optimum pipe laying pitch is 15 cm with good thermal insulation. If in winter there are often frosts below -20, then the step is reduced to 10 cm (only possible at the outer walls). And in the north can not do without additional radiators.
• With a laying step of 15 cm, the flow rate of pipes is approximately 6.7 m per square meter of the room, and when laying every 10 cm - 10 m.

In general, the question of how to calculate a warm water floor requires a separate consideration, because when designing, many nuances are taken into account: heat loss, power, etc.

The graph shows the dependence of flux density on the average temperature of the coolant. Dotted lines indicate pipes with a diameter of 20 mm, and solid lines - 16 mm.

The graph shows data that are valid only when using cement-sand screed with a thickness of 7 cm, coated with tiles. If the thickness of the screed is increased, for example, by 1 cm, then the heat flux density decreases by 5-8%.

• To find the flux density, the amount of heat loss in the room in Watts is divided by the pipe laying area (the indents from the walls are subtracted).
• The average temperature is calculated as the average value at the circuit inlet and outlet.

The optimum temperature at the inlet and outlet should not differ by more than 5-10 degrees. The maximum temperature of the heat carrier should not exceed 55 ° C.

To calculate the length of the circuit, the active heating area in square meters is divided by the laying pitch in meters. To this value is added the size of the bends and the distance to the collector.

According to the above scheme, you can only make a rough calculation and make the final adjustment due to the mixing unit and thermostats. For accurate design, be sure to contact a professional heating engineer.

Surface preparation

Installation begins with the leveling of the screed. If the height difference in one circuit will exceed half the pipe section (

6 mm), then the probability of formation of air jams in the pipes sharply increases, which in turn will interfere with the normal movement of the coolant and reduce the efficiency of the system.

Next, it is necessary to provide hydro-, steam- and thermal insulation of the ceilings. This can be done using a combination of special waterproofing mastics, plastic film, insulation based on foamed polyethylene and polystyrene foam.

To begin with, with the help of mastic or plastic film, it is necessary to provide vapor and waterproofing. Foamed polyethylene has high insulating properties with a relatively small layer thickness (3-5 mm). However, do not lay the concrete screed directly on top of it. It is very soft and easy to push, so there is a risk of cracking during shrinkage. Perform styling in small increments (2 it is better to use a "snake".

In the case when it is necessary to provide heating for a large room (> 18-20 m 2), and it becomes necessary to lay two or more circuits, it is still advisable to use several “spirals”, but use it as additional insulation. To ensure the necessary rigidity and proper shrinkage of the screed, as well as the minimum level of heat loss through the plane of the floor ceilings, it is recommended to use expanded polystyrene with a thickness of at least 20 mm. When installing thermal insulation on slabs laid on top of the ground or over unheated rooms, it is necessary to bring the thickness of the insulating layer to 80 mm.

If you plan to arrange a water heated floor in a wooden or other structure without reinforced concrete floors, the formation of the screed must be done in a prepared box of waterproof plywood, which will prevent the spreading of the mortar over the structure and under the floors. In this case, it is necessary to take into account the bearing capacity of the beams based on the mass of the screed formed for the device of a water heated floor. In order to minimize the weight of the structure, it is advisable to reduce the thickness of the screed to the minimum possible, but not less than 20 mm above the pipe. The pipe pitch should be uniform and not exceed 15 cm for the most uniform heating. The calculated temperature of the coolant should not exceed 40 ° C. At the same time, lightweight particles (shavings, expanded clay) can be introduced into the screed, but the dosage of such additives should be carefully calculated so as not to reduce the heat transfer properties of the formed surface. For additional protection of the structure from the flow of mortar, it is recommended to sheathe the box inside and out with plastic wrap.

Helpful advice
Polyethylene - a fairly strong chemically stable material - is suitable for laying in a screed, both in the form of a film, and in foamed thermal insulation.

Layout of the heating circuit pipe.

After you have decided on the step and layout of the pipe layout in each room and prepared the surface for laying the pipes, it is recommended to transfer the sketch of the scheme to the top layer of thermal insulation, on top of which the direct layout of the pipe is planned. This can be done with a conventional marker, if the surface allows. In the future, such a drawing will greatly facilitate and speed up the installation process, and also identify errors made at the design stage, if any.

There are several ways to fix the pipe over the surface of the insulation in the desired position. The most common way is the layout using a reinforcing mesh. A reinforcing mesh with a step of 5-15 cm is laid out on the surface of the insulation, the pipe is fastened every 50-80 cm and at the bend points by means of plastic clamps or a thin wire. In this case, you will immediately get a double effect: you will fix the pipe and prepare a reinforcing layer for the screed, which will positively affect its resistance to shrinkage and operation. In this embodiment, it is recommended that after the final layout of the pipe, before filling the mortar, “raise” the mesh with the pipe 5-10 mm above the surface using wooden or plastic elements.
The second, no less common option for fastening a pipe for a contour of a water heated floor is special polystyrene plates. A feature of such plates are special regular elevations on the upper surface, staggered ("bosses"). Around the "bosses" and the layout of the pipe.

In this embodiment, in addition to the pipe fixing element, a 20 mm heat-insulating layer is provided, but in the future, reinforcement of the screed in one form or another will be required.

In addition to the traditional ready-made layout methods, you can also prepare the mounting base for asclading yourself. To do this, you will need long boards with a thickness of 15-25 mm and a width of 50-80 mm.Using a jigsaw, you can form a frame for laying out the pipe with any step and type of layout. To do this, you will need to cut the grooves on the outside diameter of the pipe with the required interval, then fix the boards so that the contours of the future layout of the layout are formed, while the insulation should be laid out so that the lower edge of the grooves is flush with the upper plane of the insulation layer . Further, a pipe is laid in the recesses in order to repeat the previously designed scheme and the layout step.

Helpful advice
"Seven times measure cut once". This is exactly what you need to do when laying out the pipes. Before starting the layout, the beginning of the circuit is connected to the supply manifold and only after the installation is complete the pipe is cut and connected to the return manifold

After the frame is finally ready, it is recommended to lay vertical planes with a damper tape in order to avoid compression fracture of the structure during the thermal expansion of the screed.

To decompose a contour pipe with a “snake”, it is necessary to form a rectangular frame.

Depending on the size of the room, 2-3 blanks will be required along the length corresponding to the length of the room, as well as 2-3 boards for fixing the frame in width. In the case of laying out the pipe with a “spiral”, it will be necessary to fix the boards diagonally or with two triangles. At the same time, it is rather difficult to calculate the places of the notches “on paper”. It is advisable to first assemble the frame and decompose the insulation, transfer the sketch of the design scheme to the surface and outline the places for cuts. After that, carefully remove the frame, cut out the recesses and return the frame to its place. In this case, you can guarantee full coincidence of the picture and the frame. In addition, when laying out the pipe with a “spiral”, it will not be possible to achieve the correct geometry of the circuit. It is worth noting that this layout option is the least expensive in terms of acquiring materials, but from the point of view of additional work, this, of course, is longer and more complicated.

After all the pipes of the floor heating circuits are laid out and connected to the distribution nodes, it is necessary to check the system for leaks. First of all, you should be interested in the tightness of the joints and pipe sections, which will be in the screed. In addition, you must ensure that all connections are made correctly and withstand the planned pressure.

All these steps must be completed before filling the screed. First you need to fill the system with water or a special solution - antifreeze. It is recommended that you fill out the contours one at a time. To do this, leave one circuit open and start dispensing water. Once the circuit is completely full and the air is removed, turn off the taps and open the next circuit. In the same way, you need to fill in all the circuits connected to this distribution node. When the entire system on the floor is completely full, open all the circuits and raise the pressure to 4-5 bar, which will correspond to 1.5 times the maximum working pressure. The pressure will gradually drop, but subject to the tightness of the system after a while stabilizes, which will mean the functionality of the system. In order to additionally check the connections for leaks, it is necessary to once again bring the pressure to 4-5 bar and leave for 2 hours, then relieve pressure and leave for 2 hours. The cycle is recommended to be repeated 3-4 times.

Helpful advice
For hydraulic testing of heating and water supply systems, special pressure pumps are used, which, if necessary, allow testing systems at pressures up to 50-60 bar

After the test is completed, it is advisable to set the working pressure to 1.5-3 bar and leave the system for a day - the pressure should no longer drop. In case of pressure drop, check all connections and circuits.As a rule, taking into account a certain degree of dust in the repaired building, it is not difficult to detect fresh streaks. If antifreeze is poured into the system, then a specific smell will also let you know about the leak. At the end of the filling and testing of the underfloor heating circuits, it is possible to fill and pressure test the supply circuits and the boiler. Open the manifold of the distribution nodes and fill the main riser, supply piping and boiler. Carry out hydraulic tests in accordance with the regulations prescribed in the operating instructions for your boiler. After hydraulic testing, we can proceed to thermal testing of the system. Block all the contours of the "warm floor" on the distribution nodes. Set the working pressure, turn on the circulation pumps to the design stage and bring the temperature in the main riser to the calculated one. Open the floor heating circuit farthest from the boiler and wait until it is fully warmed up.

Helpful advice
Be careful! If ethylene glycol-based antifreeze is poured into the system, then in the event of a leak, it is necessary to increase the ventilation of the room and eliminate the leak as soon as possible, in order to avoid poisoning the mixture with fumes.

After the temperature difference between the supply and return manifold reaches 5-10 о С, open the following circuit. Thus, run the entire system sequentially. After the entire system warms up and reaches its design capacity, increase the temperature in the circuits to the maximum provided in the design. If the floor heating system is the only source of heating for the building, then check the boiler settings.
If the system is combined, set the required values ​​on the mixing units or thermostats. The maximum temperature of the coolant in the floor heating system should not exceed 55 ° C. The system should work in peak mode for at least 6 hours. Record pressure and temperature at peak heat load at different points in the system. In the future, in the event of an emergency protection of the boiler or detection of incorrect operation of the system, you can use this data to diagnose and identify malfunctions. After thermal testing, check the system again for air and leaks.

After you verify the tightness and operability of the heating system, you can proceed with the installation of concrete screed. To do this, check the insulation again and prepare the solution. Do not forget to add plasticizer and fiber. To prevent the destruction of the screed due to linear thermal expansion, it is necessary to lay a damper tape around the perimeter of the room. Through the damper tape, only the supply and return pipes are allowed to pass - it is advisable to lay them in the corrugation for additional protection against accidental damage during operation. Start the system. Set the average design pressure to 1.5-2 bar. Do not heat the coolant. The maximum temperature in the circuit for pouring the screed should not exceed 25 ° C until the final hardening of concrete (17-28 days). After this period, the system can be launched at design capacity. The thickness of the screed directly above the pipe should be 30-50 mm. The smaller the thickness of the screed, the faster it will warm up, and the “thermal zebra” effect may appear when the passage of the pipe with the coolant is clearly felt. Accordingly, the larger the step between the pipes, the proportionally greater thickness the screed should have for uniform heating of the floor surface. After pouring the screed, it is recommended to vibrate the surface to remove air bubbles and more tightly adhere concrete to the pipe. This will significantly increase the efficiency of your heating system. After the screed has completely hardened, you can lay the flooring.

Helpful advice
For screeding, use cement-sand mortar or M-300 sand concrete

Where is it used?

Such a heating system in the apartment room can only be used theoretically. Technical obstacles are very serious. The fact is that it is extremely dangerous and simply forbidden to feed the pipeline with finished hot water, and the special heating of road cold water is complicated. In addition, any efficient systems are voluminous and heavy, that is, they take up a considerable part of the height of the room, exerting a significant load on the surface of the floor and floors.

In a private wooden house, thermal loads on individual circuits, if they differ, are not significant. Therefore, carefully think about whether to install expensive, complex automatic control systems in a small home. A large cottage or a house with unheated rooms is another matter.

It is quite possible to put a water floor in a frame house, but its installation has an important difference - because of the foundation lightened to the limit, you will have to abandon the use of heavyweight concrete screeds or cement-sand mixtures. It is more correct to apply dry polystyrene laying. It was specially invented for frame houses. Keep in mind that to maximize the thermal effect, you will have to think about good insulation of the external walls, which are usually made thin.

The water heating system for floors has its own specifics in the bathroom. If it is installed in an apartment, we recommend that you consult with a design organization, as well as form and register an official project and obtain consent from your neighbors. It is advisable to supply the circuit with coolant from the heated towel rail, and two-way valves at the inlet will not reduce the temperature of the water lower and higher in the riser. Regardless of whether you want to heat the bathroom in an apartment or in a private house, pay maximum attention to waterproofing. It is worth investing in a special kind of film or euroroofing material.

The foundation is poured using expanded clay or fine gravel. To exclude the appearance of irregularities, beacons must be put up. Please note that it is forbidden to walk on the floor coverings of the bathroom for 5-6 days. In this case, you will have to moisten the surface regularly, otherwise it may crack. Since a rare builder will be able to independently produce a cement mixture (which will not be covered with an intricate pattern of cracks in the next few years), it is better to purchase a fully finished composition in the store. And to engage in experiments another time, when thinking over the design of a heated bathroom, for example.

Work Tools

During the installation of water heated floors, you need to use 18 different tools. Necessarily needed:

• Angle grinder
• electric drill,
• screwdriver
• building hair dryer.

Of the manual devices required:

• scissors,
• ordinary saw,
• saw for metal
• work knife
• hammer,
• bit,
• vise
• pliers,
• file.

Work with coatings is carried out using a spatula and a paint brush. You need to measure the required dimensions with a tape measure and a meter ruler, but in addition to them, you will also need a sanding mesh or sandpaper.

In addition to the tools, you will need materials:

• for thermal insulation, foil mats made of expanded polystyrene or plates made of the same material processed by extrusion are most often used,
• self-adhesive damping tape should have a thickness of 0.5 to 1 cm. Pipes are attached using brackets, mounting rails, rotary arcs and some other parts.

Warm floor cake

The technology for laying a warm water floor consists of several layers, which are laid in a certain sequence. The total thickness of the cake is 8-14 cm, the load on the floor is up to 300 kg / sq. m

In case the base is a concrete slab:

• waterproofing
• perimeter damping tape,
• insulation
• reinforcing mesh
• water floor heating pipe,
• screed.

For waterproofing, it is permissible to use ordinary plastic film or special materials. The damper tape is made from chopped insulation strips 1-2 cm thick, or buy a finished version with a self-adhesive base.
The choice of insulation depends on several factors: region, base material. For example, extruded polystyrene foam with a thickness of at least 5 cm (optimally 10) is also used for floors on the ground, and if there is a warm base under the floor of the first floor, then thinner options from 3 cm can be used.

The main purpose of the insulation is to direct heat from heating upward and prevent large heat losses.

In the event that the base is ground floors:

• bulk soil 15 cm,
• crushed stone 10 cm,
• sand 5 cm
• rough screed
• waterproofing
• perimeter damping tape,
• extruded polystyrene foam at least 5 cm,
• reinforced screed with coolants.

The preparatory layers for the rough screed it is important to carefully tamp in layers. With a tightly compacted base and the use of extruded polystyrene foam, it is not necessary to make a rough screed.

Waterproofing

Someone puts waterproofing under the bottom of the insulation, someone, on the contrary, up, and some use both there and there.
If extruded polystyrene foam is used, it practically does not need waterproofing, so its position is not so critical. But it will not allow cement milk to penetrate between the joints of the insulation and go into the slab and will additionally restrain moisture from below.
If you fix it to the bottom of the insulation, then you can fix the pipes on the warm floor directly to the insulation. If the waterproofing is laid up, then fixing the pipes will require installation grid installation.

We put waterproofing with an overlap on the walls by 20 cm, and on top of each other. We glue the joints with tape for sealing.

Damper tape

If you bought a finished tape - just glue it around the perimeter. It usually has a thickness of 5-8 mm and a height of 10-15 cm. The height should be above the fill level, the excess cut off with a knife. If the tape is made by yourself, then be sure to glue or screw it with screws to the wall.

The linear expansion of concrete is 0.5 mm per meter when heated to 40 ° C.

Reinforcement

The first layer of reinforcing mesh is usually laid on the insulation and is used as a base for fastening the contours and uniform distribution of heat over the surface. Between themselves nets are connected by wire. Pipes are attached to the grid on nylon clamps.

The diameter of the wire rods is 4-5 mm, and the cell size, depending on the step of laying the pipes, for convenient fastening.

In addition, it is necessary to lay the reinforcement on top of the pipes, because even when using the net from below, it will have almost no effect if it lies at the bottom. Or, during pouring, put the grid on the supports, creating a gap.

Pipe Fixing Methods

Water floor heating can be laid in several ways, we list them.

• Polyamide tightening collar. Used for quick fastening of pipes to the mounting grid. Consumption - about 2 pieces per 1 m.
• Steel fixing wire. Also used for mounting to the grid, the flow rate is exactly the same.
• Stapler and clamps. Suitable for fast fixing pipes to thermal insulation. The consumption of clamps is 2 pieces per 1 m.
• Locking track. It is a U-shaped strap made of PVC, which serves as the basis for laying 16 or 20 mm pipes in it. Rigidly attached to the floor.
• Mats for polystyrene underfloor heating. In the middle of the grooves between the columns a pipe is laid.
• Distribution aluminum plate. It is used for installation in wooden floors, reflects and evenly distributes heat over the surface.

Pipe laying

Pipes are laid indented from the walls 15-20 cm. Each circuit is highly desirable to make a single pipe without welding, and their length should not be more than 100 m.The step between the pipes near the walls is 10 cm, closer to the center - 15 cm.

The layout of the underfloor heating is different, for example, with a spiral or a snake. At the outer walls, they try to make the laying step more often or draw a contour from the feed next to the cold walls. An example of a scheme for enhanced heating of external walls is shown in the photo, this option is best used in cold regions:

In other cases, the contours are usually laid with a spiral (snail), this is a universal option.

In places with a large congestion of pipes, in order to avoid overheating of the surface, some of them are closed with a heat-insulating tube.

Metal reinforced plastic 16 mm and 20 mm is easy to bend manually, without the use of special tools. In order to bend the pipes evenly with a small radius and at the same time prevent it from cracking, the corners are bent in several passes (hand interceptions).
At an angle of 90 °, approximately 5-6 interceptions are required. This means that at first, resting against the thumbs, they make a small bend, then they slightly shift their hands towards the bend and repeat the actions.

The presence of kinks on the pipes in places of sharp turns is unacceptable.

Polypropylene pipes are much more difficult to bend because they spring. Therefore, for bending, they are heated or welded using special fittings, but in the case of a warm floor, they simply attach to the grid, making the bends less sharp.

Installation of a water heated floor begins with connecting the first end of the pipe to the distribution manifold, and after laying the room, the return line (second end) is immediately connected.

Connection of circuits

In most cases, the circuits are connected through a distribution node. It has several functions: increasing the pressure in the system, adjusting the temperature, uniform flow in several circuits, combining with radiators.

There are many schemes for connecting to the boiler, which we wrote about in the article about pump and mixing units: with manual adjustment, with weather automation and automatic adjustment with the help of servos and sensors.

Eurocone fitting

Pipes are connected to the manifold using Euroconus clamp fittings.

Crimping

When you have completed the installation of all circuits, it is imperative to carry out pneumatic tests of the system for leaks. To do this, using a compressor, pressure testing is done. For testing, a small household compressor with a pressure of more than 6 bar is suitable. The pressure in the system is brought to 4 bar and left for the whole time, until the system starts.

Since air molecules are much smaller than water molecules, even a slight depressurization can be detected. In addition, water can freeze if you do not have time to connect the heating, and nothing will become of the air.

Expansion joints

The absence or incorrect position of the temperature gaps is the most common cause of screed failure.

Shrink seams are made in the following cases:

• The room has an area of ​​more than 30 square meters. m.,
• walls have a length of more than 8 m,
• the length and width of the room differ by more than 2 times,
• over expansion joints of structures,
• the room is too curved.

For this, a damper tape is laid around the perimeter of the seams. At the seam site, the reinforcing mesh should be divided. The deformation gap should be at the base with a thickness of 10 mm. The upper part is treated with sealant. If the room has a non-standard shape, it must be divided into simpler elements of a rectangular or square shape.


If the pipes pass through expansion joints in the screed, in these places they are laid in a corrugated pipe, 30 cm of corrugation in each direction (according to SP 41-102-98 - 50 cm on each side). It is recommended not to separate one circuit with expansion joints; feed and return pipes should pass through it.

Correct passage of contours through technological seams

When laying tiles on expansion joints, the likelihood of peeling off due to the different expansion of adjacent plates increases.To avoid this, the first part is laid on tile adhesive, and the second part is attached to an elastic sealant.

For additional separation, expansion joints of an incomplete profile can be used. They are made with a trowel, 1/3 of the thickness. After concrete hardens, they are also sealed with sealant. If pipes pass through them, they are also protected by corrugation.

Screed Cracks

A fairly common phenomenon is the appearance on the screed cracks after drying. This can trigger a number of reasons:

• low density insulation
• poor compaction of the solution,
• lack of plasticizers,
• too thick screed,
• lack of shrink joints,
• concrete drying too fast
• wrong proportions of the solution.

Avoiding them is very simple:

• insulation must be used with a density above 35-40 kg / m3,
• screed mortar must be plastic when laying and with the addition of fiber and plasticizer,
• in large rooms you need to make shrink seams (see below),
• it is also impossible to let the concrete set quickly, for this it is covered with plastic wrap the next day (for a week).

Screed mortar

It is imperative to use a plasticizer for a warm floor to increase the elasticity and strength of concrete. But you need to use special types of non-air-borne plasticizers for underfloor heating.

Without experience, making a cement-sand screed for a warm floor without crushed stone / gravel will not work, and the correct branded DSP will cost more than factory concrete. Therefore, in order to avoid cracks due to a violation of the composition of the solution, concrete with crushed stone is poured.

M-300 mortar of cement of the M-400 brand, washed sand and gravel is made in the following proportions.

• The mass composition of C: P: Sh (kg) = 1: 1.9: 3.7.
• Volumetric composition per 10 liters of cement P: Щ (l) = 17:32.
• Out of 10 liters of cement you get 41 liters of mortar.
• The volumetric weight of such concrete M300 will be 2300-2500 kg / m3 (heavy concrete)

There is also another option using granite screenings instead of sand, the following elements were used to prepare it:

• 2 buckets of crushed stone with a fraction of 5-20 mm,
• water 7-8 liters,
• superplasticizer SP1 400 ml of solution (1.8 l of powder is diluted in 5 liters of hot water),
• 1 bucket of cement
• 3-4 buckets of granite screenings with a fraction of 0-5 mm,
• bucket volume - 12 liters.

High-quality concrete should not emit water during installation (delaminate). If everything is done correctly and the air temperature is 20 ° C, it should begin to set in 4 hours, and after 12 hours it will not leave traces of heels.

After 3 days after pouring, the screed will gain half its strength, and will harden completely only after 28 days. It is not recommended to turn on the heating system up to this point.

Mounting on a wooden floor

Wood does not conduct heat so efficiently, unlike concrete, but installation on it is also feasible. For this, aluminum distribution plates are used. Pipes are laid in wooden grooves made by attaching pre-prepared boards.

For the installation of linoleum, carpet and other materials that require a flat surface, an equalizing layer of chipboard, plywood or GVL is laid over the pipes. If parquet or laminate is used as the finishing coating, the construction of the warm floor can be slightly simplified without the use of a leveling layer.

When choosing plywood and particleboard, make sure that they have sanitary-hygienic and thermomechanical indicators that allow them to be used together with a warm floor.

Prices for water floor heating

The price of a warm water floor is formed from several components:

• the cost of materials (pipes, insulation, fasteners, etc.),
• cost of pump and mixing unit and collector,
• work on leveling the base and pouring the top layer of the screed,
• the cost of installing a warm floor.

On average, the price of a water heated floor during turnkey installation, together with all materials and work, will cost about 1,500-3,000 rubles. Per 1 sq. M.m

Below is an approximate estimate for a house of 100 square meters. m., but the prices of water underfloor heating strongly depend on the region, so it is best to drive your data there and make an independent calculation. It does not include the costs of installation and purchase of radiators, a boiler, topcoat and screed.

Installation of warm water floors is shown in the video:

Foundation preparation

The old screed according to the technology must be completely eliminated so that the base overlap is exposed. Level the floor immediately if the deviation from the horizontal exceeds 1 cm. If cracks, chips and crevices remain after removing the old flooring, use a cement or gypsum leveling mixture. Further, making sure that there is no dust, dirt and construction debris on the surface, a layer of waterproofing is placed on top of it.

The damper tape occupies the perimeter of the base, which will help compensate for the thermal expansion of the main floor covering during heating. It is important to consider when there are several contours at once, the tape should be placed in the intervals of contours close to each other.

To reduce unproductive heat loss, it is necessary to additionally insulate the floor. Only in rare cases is it initially ready in this sense. The choice of thermal insulation material is determined by such considerations:

• if the underfloor heating serves only as an assistant to the main heating system, you can limit yourself to foamed polyethylene with a reflective layer of foil,
• when the apartment is located above the heated parts of the building, it is required to use extruded polystyrene foam with a thickness of 2-5 cm, or at least durable substitutes,
• in apartments located above a cold basement, more serious protection is required - expanded clay is poured and expanded polystyrene is laid with a total layer of 5 cm or more.

Modern manufacturers offer special insulation materials for underfloor heating. One side of such heaters has channels for the installation of pipelines. It is recommended to use mineral wool, polystyrene foam and special mats. To strengthen the screed layer, a reinforcing mesh structure is used to which pipes can be attached. Their connection is provided with plastic ties, so there is no need for fixing strips and special clips. When the foundation is ready, it makes no sense to wait for something else - it's time to start installing the floor heating equipment itself.

Wiring diagram

Installation of a water heated floor always starts with the installation of a manifold cabinet. They put it in such a way that the distance to the pipelines going to and from all rooms is approximately equal. You can hide an unsightly-looking cabinet by embedding it in a wall (load-bearing walls are not suitable for this). Note that the box is located above the warm floor, otherwise the air outlet will be blocked.

In a modern system (with rare exceptions), circulation is provided by pumping equipment.The pump installed inside the boiler is enough to pump water over an area of ​​150 sq m, even if the building is two-story. If the total area of ​​the building is larger, you will definitely need to install additional pumps with advanced features.

In order to be able to maintain the heating system without draining the water, the boiler inlet and outlet are equipped with shut-off valves. Using them, you can disconnect the heater for repair and maintenance at any convenient time. If there are two or more manifold cabinets, the main supply line is equipped with a splitter, immediately behind which the narrowing adapters are installed.

Connecting pipes to the manifold involves the use of compression fittings, or Euro cone devices. If necessary, it is possible to conduct such pipes through the walls, cover them on all sides with an insulating layer of foamed polyethylene. When all parts are stacked and each unit is connected to its proper place, the system must be tested. Having supplied water to the pipes, they are kept under pressure of 5 or 6 bar for 24 hours (depending on the design working value). If such a check did not lead to the appearance of visually noticeable extensions, you can safely proceed to pouring the concrete layer.

It is allowed to fill in a coupler only when fluid is supplied under the planned pressure. Drying time to readiness is at least 4 weeks (under ideal conditions). If the tile will be laid on top, the screed should have a thickness of 30-50 mm, and the pipes are distributed at a distance of 100-150 mm from each other. Non-observance of these rules, even if the connection of all elements is in accordance with the norm, will lead to uneven heating of different parts of the surface.

Under the laminate or linoleum, the screed can be thinner. Then the reinforcing mesh helps to compensate for the decrease in its strength. If the warm floor is placed under the laminate, it is not necessary to equip the insulation, otherwise the energy efficiency of heating will be reduced.

Shrink seams are equipped with a screed necessarily if:

• the room area exceeds 30 sq m,
• there is at least one wall longer than 8 m,
• the length is less than 50 or more than 200% of the width of the room,
• The configuration is complex and bizarre.

For the design of screeds, it is allowed to use a cement-sand mixture based on Portland cement (minimum M-400, and even better to use M-500). When ready-made concrete is used, its grade should be M-350 and higher. In addition to laying the damper tape, the reinforcing mesh where the seam passes is separated. The thickness of each seam is 1 cm, and the upper lobe is treated with sealant. When passing pipes in these places they should only be placed in the outer corrugated pipe.

The launch of water floors in work should occur at the onset of the first cold weather. Keep in mind that the thermal inertia of the flooring is great, and only a few days later, when it is overcome, the optimal conditions will be created.

The battery (as well as the existing central heating system and hot water supply) must not be connected to the underfloor heating! This will not only cause the sanctions of controlling state bodies, but also lead to disruption of the normal functioning of communal systems. Be sure to install an autonomous heating boiler, which will become a source of hot water in the system. In addition to manual adjustment, it is possible to control a warm floor by means of a servo drive and a sensor, or weather automation.

Since the system must have control and regulation components, it must be connected to electricity. Underfloor heating in different rooms can be controlled by one thermostat only under the condition that the thermal conductivity of the floor covering completely coincides. Such a circuit requires the same or slightly different contour lengths. Thermostats can be connected to power networks directly or through an RCD, which is much safer.

To lay power cables, either a strob in the wall or an additional corrugation overlay is used.

Please note that at the time of the initial connection machines must be in the “off” position. Carefully see which wire, which phase should be connected. An alternative installation scheme (without concrete screed) will be disassembled a bit further. For now, let's just say that its main options are placing pipes in polystyrene grooves, or in grooves made of wood. The time has come to see how the pipes of a water heat-insulated floor will be laid.

Styling technology

Modern technology for installing underfloor heating involves laying pipes with their special retaining profiles. The profiles themselves are attached to the base with dowels or screws. The advantage of this solution is that the profile in the production is equipped with clamps. You do not need to carefully measure the step from one turn to another and carry out its careful calculation. A simpler option is fastenings on plastic ties, pressed to the reinforcing structure.

However, the simplicity of such a scheme requires the elimination of unnecessary force when tightening. Make sure that the loop is free. Pipe coils are carefully unwound, and not immediately, but directly in the process. The manufacturer's instructions always require that the bend runs neatly b along the smallest possible radius. When using structures made of polyethylene, it is usually 5 pipe diameters. Do not pinch the product if a whitish strip appears on it., since this means the appearance of a crease, which subsequently easily breaks and leads to flooding.

Installation according to the “snail” or “spiral” scheme is recommended for large rooms, and makes heating even more uniform. The classic "snake" works best in small rooms, and if you want to apply heat to the flooring in a medium-sized room, it is advisable to prefer a "double snake" in which the hot and return pipes are directed in parallel.

Whatever methods are chosen, try to reduce the number of joints between the pipes, as well as the number of turns. Such areas, despite all the perfection of modern technology and careful execution by professionals, dramatically increase the risk of leaks. Ideally, the connections should be made only at the entrance to the boiler and at the output from it.

Docking on bends and turns is strictly unacceptable. When fastening the laid pipes to the screed, place retaining elements on each meter.

For connecting pipes, in addition to the options listed above, there are also such devices:

• attracting clamp made of polyamide (2 pcs per meter),
• steel wire (similar flow rate),
• stapler and 2 clips per meter,
• fixing tracks, or strips based on PVC,
• polystyrene mats,
• aluminum spreader plates.

The operating rules indicate that regardless of the method of holding the pipes, their fixation is ensured by nets with a square mesh of 15x15 mm and a wire diameter of maximum 0.5 cm. By introducing modern automatic devices into the system, it is possible to control the flow of water flowing through the pipes, not only independent of human factor, but also remote.

The final choice of installation option should occur taking into account the private properties of the premises and the functionality of their individual parts. The “snake” system is designed to supply water initially to a cold area, and only then throughout the rest of the floor, for example.

When the screed under the laminate or linoleum becomes thinner than usual indicators, an additional reinforcing mesh is placed directly below it over the contour of the heating pipes.

How to do it without concrete screed?

A long wait (about a month or even more if the weather conditions are unfavorable) does not suit everyone. Instead of concrete screed, you can use a flooring.When you lay the pipes, you will need to form a substrate for the finish floor. If there is a laminate at the top, use cardboard and foamed polyethylene. Pouring under the tile is also optional. Under it, as under linoleum, a special design is prepared on the basis of cement-bonded particleboards.

A warm water floor is mounted on a wooden floor using aluminum distribution plates. Pre-cooked boards in which the necessary grooves are formed. It is possible to make the most even surface in the bathroom with your own hands if you lay chipboards, plywood or gypsum-fiber sheets over the pipes. Always carefully check that these materials are in compliance with sanitary standards.

You can connect a warm water floor without a screed by laying pipes, both between the lags and on the surface of the subfloor. The modular variation (wooden blocks with milled grooves) can be replaced by a rack, in which the plywood sheet is covered with slats. The intervals between them serve for the installation of pipes. Laying between the logs necessarily requires the use of waterproofing, insulation, reflective plates with holes for the passage of pipes, the pipes themselves, a sheet of plywood and a final coating.

Laying on the flooring also implies placing the insulation in the gaps of the lags on top of the waterproofing, and plywood or rough boards are placed above. Nuance: grind the boards so that channels for laying pipes appear. The reflective layer is made of foil, attached to the boards using brackets. Pipes in the channels are held by narrow metal plates placed on top, and the plates themselves are also attached to the boards.

Instead of boards, you can use polystyrene mats of standard dimensions 1x0.5 m, attached to each other by a “lock” format mount.

Always (regardless of the method of laying the underfloor heating) keep the interval to the wall of 0.1 m, since it will allow you to largely offset the effect of thermal expansion of floor materials. A hydrophobic coating is placed over the floor or logs. Only after this comes the turn of the formation of the finishing floor.

In addition to the two described options for the formation of a heated floor without screed, it is allowed to use a foam or wood substrate, chipboard. Light, relatively thin floors are more expensive and not too durable, but they are recommended to be used:

• if necessary, lay a new coating over the old one without dismantling,
• if the height of the home is limited,
• if installation speed is critical to you,
• if it is not possible to arrange the delivery of concrete properly,
• if the floor is wooden,
• if the structure is high and the load cannot be exceeded.

In addition to facilitating the design, a system of underfloor heating without screed has another indisputable advantage - it is easier to repair. Even the best pipes, laid correctly and operated carefully, can suddenly burst. If you still want to use a full screed, but do not wait for 28 days to dry completely, you should apply semi-dry mixes. Special additives in them allow you to reduce the required amount of water, but the cost of such building materials is higher than in a simpler version.

Please note that the installation of underfloor heating without screed is permissible only provided that the floor level drops are 0.2 cm for every 2 sq m of surface. If it is less even, the contracting layer, even the thinnest, is still necessary to create.

Possible mistakes

Even experienced home craftsmen, who first take up the installation of a warm floor, can make serious mistakes. Often, dried concrete screed is covered with a mesh of cracks. The reasons for this defect are diverse. You can avoid its appearance if:

• take care of the optimal density of the insulation,
• to make qualitatively shrink seams,
• do not overestimate the recommended screed thickness,
• Do not try to dry it excessively fast, accelerate the normal solidification process,
• thoroughly condense the solution and strictly observe the proportions during its formation,
• add plasticizers according to the recipe.

The minimum density of the insulation is 35 kg per cubic meter. To prevent excessively quick drying of concrete, covering it with a film of polyethylene will help.

Eliminate installation errors by 95% (except those caused by carelessness, rush, and production defects) will help drawing up outline designs. Thinking over the implementation of the system, “seeing” it on a piece of paper, you can detect defects in advance and avoid their manifestation. It is better to mark on the sketch the furniture placement areas and other places where for some reason the circuit with the coolant should not go through.

The entire area that must be warmed is divided into sections of 15 sq m each. In any section, the installation step of the pipeline is 10 cm. A common mistake is that people don’t think in time which wall it is better to install a collector or excessively bring it closer to one heating circuit, moving away from others. Correctly choose a heat source that connects to a warm floor.

Comfortable life is provided at a temperature of the heat carrier from 40 to 45 degrees, which allows you to warm the floor to 26-30 degrees. Such heating is provided by condensation boilers, while other heating devices are not able to heat water to less than 60 degrees.

Never put a heat-insulating layer over a warm floor and do not use carpets indoors, because these solutions will only worsen the quality of heating. Remember that polystyrene thermal insulation is dense, and it is not able to correct roughness of rough screed, so from the first steps you need to do everything as accurately as possible. As for the thickness of polystyrene, contrary to the recommendations of most manufacturers, it is not necessary to withstand 10 cm (as a rule, 8 cm is enough even on the first floors).

On top of the insulation layer, you should not just lay a reflective film (this is a mistake), but it should be laid out evenly and wound around the edges of the polystyrene. The bottom material itself should be pressed closer to the walls through the damper tape. Do not connect parts with tape, as they are designed for completely different purposes. It can be harmful.

Grease the edges of the blocks with glue. Another mistake that is often found in the work of lay people and “shabashniks” is a different indentation of pipes from the walls. Real craftsmen make it at least 100 mm and uniform in all rooms.

If it is necessary not only to lay pipes, but also to organize the rotation of the pipeline, it is necessary to bend the metal-plastic structure manually (and not with the help of springs and other auxiliary tools). Please note that the reinforcing mesh should not touch the surface of the pipes, as this is considered a gross error. Subjected to thermal contraction and expansion, the circuits will constantly push the network, and it will soon become deformed and fail.

Professional Tips

According to experts, in the coldest parts of the room it is necessary to tighten the step of laying the "snake" to 0.1 m. First of all, they do this by laying a warm floor near the outer walls. Do not try to heat more than 40 sq m of floor with one circuit. It is also worth organizing separate contours for neighboring rooms with different temperature conditions. Installation of plastic pipes under the screed is preferable than installing a pipeline of other materials. The temperature of the coolant should increase systematically with reaching the level you require 70-72 hours after connecting.

The best installation point for the pump is the return pipe immediately in front of the boiler. Most often, expansion tanks are mounted in the highest section of the circuit, however, closed membrane systems can be performed in any other way. If you are supplying a gas boiler from a main pipeline, and not from cylinders, you should obtain the approval of local authorities.Only specially trained personnel working in licensed organizations should be involved in the work.

Hinges from a single pipe with a cross section of 1.6, 1.7 or 2 cm have a minimal risk of leakage at the joints.

The average temperature of the floors of residential premises is 26 degrees, according to current standards, and in those places where people visit from time to time, and a special thermal regime is required, it is 31 degrees. The highest allowable difference in heating of individual parts of the floor and coatings in different rooms is 10 degrees.

In order for the thermal return to be optimal and not to force the system to work excessively, it is necessary to carefully level the floor.

Deviations of more than 5 mm from the plane are not allowed. Their presence leads to overflow of circuits with air and unstable, inefficient heating. The functions of vapor and waterproofing are often performed by a polyethylene film, and its minimum thickness is 0.02 cm, otherwise it will not be possible to guarantee full protection of the insulation from dampness.

Laying of the film should be overlapped up to 100 mm, and its borders are held by adhesive tape, which covers the intersection of the floor and walls. When all the lower layers are laid and even the pipes themselves are installed, they need to be crimped in different ways depending on the material. Thus, metal-plastic structures must be subjected to an internal pressure of 6 bar for 24 hours. Before this, the circuits are filled 100% with water, air is completely exhausted through the drain taps.

There is another option: fill the coolant, bring its temperature to 80 degrees, maintain it for 30 minutes, after which, while maintaining the pressure, they put a concrete screed.

If the pipeline is made of cross-linked polyethylene, reducing the pressure, you will need to add water, and then after 30 minutes repeat the test. Then they wait 90 minutes, restore the previous pressure and leave the heating circuits alone for 24 hours. By the end of this pause, the pressure drop should be a maximum of 1.5 bar.

After mounting and checking all the details of the pipeline and additional components, photograph their location and make a description with reference to landmarks. Subsequently, if it is necessary to repair a warm floor, such information will greatly simplify and speed up the work.

When you need to heat a very small area (the area around the sofa, armchairs, tables and other furniture, for example), flexible rolls with built-in plastic tubes are preferred. The technology allows cutting the desired part of the roll, bending it at any angle - the main thing is that the channels for the passage of fluid remain intact.

Observance of these points will make it possible to achieve complete success in the installation of a warm floor and enjoy its stable operation for several decades.

See how to make a water heated floor with your own hands in the next video.