Warm heated floor in Lately de facto becomes the standard for constructing heating systems and in apartment buildings and in private cottages. The use of heated floor systems allows you to create the most comfortable atmosphere in the room.

Underfloor heating - photo

Heating systems in warm floors may have different characteristics and operate on different principles. When constructing warm heated floors, you can use any type of finishing floor coverings, thus, a warm heated floor can be installed in a room for any purpose: in a bedroom or in a nursery, in a kitchen or in a bathroom.

A very important element when constructing a heated floor is its substrate. With its help, the efficiency of the heating circuit is greatly increased, be it an electric heating cable, infrared film or pipes with coolant liquid.

Main characteristics

1. In order to understand what type of underlay you need, you must know what the underlay is for in heated floor systems.
2. So, the underlayment must first of all have excellent thermal insulation and waterproofing properties. It should increase the efficiency of the heating system.
3. An important property of the substrate is its ability to reflect thermal rays.
4. The substrate must withstand temperature changes, working in close contact with the heating elements.
5. Also, the substrate should not allow water vapor formed during heating to pass through.
6. An excellent additional property of the substrate will be sound insulation.

A high-quality substrate is easy to install, has increased resistance to deformation and is environmentally friendly.

This photo shows a rolled underfloor heating substrate, which is equipped with an additional reflective layer with a characteristic metallic sheen.

Features of installing a substrate under a laminate board on a warm floor

One of the most sensitive finishing flooring materials is laminated board. It is made of wood, and, as a result, it has all the characteristics of a wooden board, which has both its advantages and disadvantages. When laying laminate flooring on a heated floor, the use of an underlay is a prerequisite.

In addition to preventing heat damage to the laminate flooring, the laminate underlay also serves as a sound insulator, preventing the finished flooring from being too loud. The minimum thickness of the laminate floor board substrate on a heated floor must be at least 3 millimeters. During operation, such a substrate becomes somewhat compacted without losing its insulating properties.

Step-by-step algorithm for laying a substrate under a laminate board on a heated floor

Let's consider the procedure for laying a foam polyethylene backing under a laminate board on a heated floor.

First of all, you need to clear out your workspace. To do this, you can use a regular broom or vacuum cleaner.

Then we lay the rolled backing on the cleaned surface.

The spread substrate can be secured with double-sided tape, after which you can proceed directly to laying the laminate boards.

Underlay for heated floors with liquid coolant

For any design of heated floors, the substrate must serve to increase the heat transfer of the heating elements. If you use a liquid coolant - that is, you are constructing warm water floors - your substrate can additionally perform the functions of waterproofing the surface.

When installing heated water floors, you can use a substrate that will additionally serve as the basis for installing the coolant piping system. Such a substrate has special protrusions, in the spaces between which the pipeline system is mounted.

As a rule, such a substrate is made of polystyrene foam. One type of substrate for a warm water floor is shown in the photograph.

It must be remembered that a good substrate will be based on foil. If your substrate does not have a foil layer, then it makes sense to place a separate thin foil material on the floor, and then a heat-insulating substrate.

In addition, when laying a warm water floor, you may need to additionally lay the mounting reinforcing mesh, which will serve as the basis for fixing the pipeline system.

In this case, the substrate under a warm water floor will look like a kind of “sandwich”, consisting of a foil layer, a layer of thermal insulation and a layer of reinforced mounting mesh.

A variant of such a substrate is shown in the figure.

Underlay for warm electric floor

The design of the underlay for a warm electric floor is similar to the underfloor heating with a liquid coolant. However, in this case, you may not need additional waterproofing of the surface.

In this case, a layer of substrate is placed on the leveled and pre-cleaned surface of the base, which may consist of a combined material including a foil layer. Next, a mounting tape is attached to the surface of the substrate, to which the heating cable is attached with clamps.

Laying a substrate under a heated infrared film floor

When installing a heated infrared film floor, it is also necessary to use a substrate with heat-insulating and reflective properties. In this case, the substrate is placed directly under the film of the heated infrared floor. In addition to the rolled substrate, you can use wood-fiber board and magnesite boards as a heat insulator.

If your substrate does not have a foil layer, then you can also construct a “sandwich” from insulation and foil.

A good choice as a substrate for a warm film floor may be penofol insulator.

Backing: penofol

It has a reinforced structure with air cavities that have excellent heat-insulating properties and a foil layer that significantly reduces heat loss in the room.

The foil backing blocks up to 97 percent of heat rays, significantly increasing the efficiency of your heating system.

Important nuances

When laying the underlay on a warm floor under any type of finishing coating, you need to remember several important nuances.

1. First of all, note that the reflective foil side of the backing should be facing up.
2. The substrate should be laid end-to-end. In order to prevent heat loss at the joints, it is best to connect the substrate strips with metallized tape. This will also serve as an additional barrier to moisture and steam.
3. Heating elements, be it an electric cable, infrared film or a pipeline with a coolant liquid, must be mounted on top of a coating that reflects heat rays.

Warm floors are the most common way to improve temperature regime indoors, and their effectiveness is determined by the quality of installation and selection of accompanying materials. The article will discuss what the underlay for a heated floor should be and how to install it correctly.

Types of underfloor heating systems

There are two main types of underfloor heating systems: water and electric.

Water - consists of a heating circuit through which the coolant moves in the form of ordinary water or antifreeze (in some cases, when the system is not used year-round, but exclusively in winter period). It is used most often in private buildings, since in apartment buildings such a system can be installed only with the permission of regulatory authorities.

The main reasons for such difficulties:

• the impossibility of clear control over the consumption of energy consumed by individual payers, and as we understand, no one will allow the use of resources for free;
• increased energy consumption with the risk of overloading heating equipment (boiler).

Electric heating systems create thermal energy by filing electric current to heating elements.

Heating occurs due to the increased resistance of such elements, and the power is calculated using the formula Q = IR, where:

• Q – amount of energy released;
• I – current strength supplied to the heating element;
• R is the resistance of the heating element.

Such floors differ in the heating elements used: infrared film or regular cable with improved insulation. Their installation is simple, but the placement of each layer must be thought out. It is important to make preliminary calculations of the power of such a system so as not to end up with a real “beast” that no electrical network can withstand.

High-quality heating of the room can be achieved if there is approximately 250 kW of power per square meter, which in total gives a very great importance, almost too much for many owners.

Thus, the systems installed in many homes are significantly weaker than required. The difference in power (required and actual) will help to compensate for the lining under the heated floor, which has such parameters that the efficiency of the entire heating system increases. Let's consider the main parameters of such substrates in order to understand which substrate is better for a warm floor and how to install it.

Criteria for choosing underlays for heated floors

It’s worth immediately making a warning that we will consider the main parameters for choosing a substrate further, but you should not respond to advertising, even if it is high-quality, of such materials, since very often it is created to increase the sales volume of a product that is not of the highest quality. Beautiful photo does not yet indicate the effectiveness of the substrate.

The set of criteria for choosing a substrate is as follows:

1. Thermal conductivity of the material. The efficiency of the substrate increases in proportion to how its thermal conductivity decreases. Affect given value two parameters: the material from which the underfloor heating is made and its thickness.
   Manufacturers have recently covered one of the surfaces of the substrate with a foil layer, which allows them to reflect radiated energy (used in combination with infrared heated floors) and retain up to 20-30% of heat.
   Standards of conduct construction work do not prohibit the use of any of the modern materials, presented as a substrate for a heated floor system. Therefore, the owner has only a choice among materials that differ in physical characteristics: strength, resistance to various types impact, etc. Naturally, the correct placement of the substrate and load distribution also plays an important role in determining efficiency. future system warm floor.
2. Manufacturability. The cost of installation is determined not only by the characteristics of the substrate material, but also by the complexity of its installation. There are various variations on this indicator. The easiest way to work is with expanded polystyrene foam, the layer of which is almost never more than 5 millimeters and is cut with ordinary scissors. The high elasticity of the material allows it to be simply laid without adjustment in case of small discrepancies between the dimensions of the cut piece and the area of ​​the surface being processed. Much more complex options are plywood sheets, OSB or chipboards, etc.
3. Additional properties. The manufacturer marks many substrates at the production stage for laying a heated floor system and adds special protrusions to their design, following which the heating circuit can be fixed. Such a substrate for a warm water floor greatly simplifies the installation process, and also increases the efficiency and long-term operation of the system. The markings prevent mistakes during installation in terms of maintaining equal intervals between heating elements or tubes, which ensures uniform heating of the surface.
4. Price. This factor, naturally, is very important, but the owner himself can reduce the cost of the substrate only if he has certain technical skills and an understanding of all the features of the types of material under consideration.
5. Environmental Safety. It is important to know that most plastic materials and resins produce various chemical emissions during use. Therefore, the intensity of such emissions should be determined in advance in order to understand whether the use of the substrate will be optimal in the conditions of a particular room. The high temperature of the heated floor requires the establishment of increased requirements for the substrate.

There are also a number of parameters that sellers like to operate with, but in fact they should not be taken into account:

• High-quality sound insulation. Any substrate that acts as a heat insulator protects floors well from the penetration of sound waves. The reason is that they block air flows, which in turn distribute sound.
• Good waterproofing. This parameter is useless, because in the case of electric floors, water does not form, and if the liquid was spilled accidentally, then it is better for it to pass through the ceiling faster, because otherwise there is a risk of short circuit. Liquid coolant accumulating in the ceiling on the substrate layer will create more problems for the apartment owner. It is better to detect such a leak earlier so that the costs of repair work are minimal.
• High resistance to ultraviolet rays. The question immediately arises: where is the source of ultraviolet rays under the floor covering, from which the reflective underfloor heating will actively protect itself, and how did the seller even come up with the idea of ​​advertising his product in this way.
• Price. Very often, the high cost of a material does not characterize its quality with the best side, but is only explained by the fact that the manufacturer is a global brand. Many owners, thinking about which underlay to choose for a warm floor, do not even realize the existence of cheap, high-quality materials and spend money on the name and logo. But it’s also not worth rushing for a low price, since very often materials with terrible quality are released onto the market and they set a minimum price for them in order to sell them faster.

So, when the main criteria for choosing a substrate have been determined, we will consider some of the features of its use for two types of underfloor heating systems.

Underlay for electric heated floor

The electric heating system involves the use of various substrates made of pressed cork, foil materials with reflective properties, and most of them foamed polymers (TMpro, Termodom). The latter are most advantageous because they can withstand high loads.

Types made from extruded polystyrene foam are thicker. These can be used under any type of electric floor. It does not recommend using aluminum-coated substrates, since this layer conducts electricity, and this can be critical if there is a leak in one of the sections of the power cable.

When choosing a substrate for a warm electric floor, it is recommended to base it on the following factors:

1. The material used for floor coverings. The strength of the substrate should increase in proportion to the increase in the mass of the layers laid on top of it (except for the heating system itself). For example, any foamed polymer can be laid under laminated parquet, and extruded varieties of materials with increased strength should be used under tiles or stone coverings.
2. Conditions of work: a new house under construction or renovation of an old premises. Based on the installation technology electrical system heating and floor features, the total thickness of the floor “pie” can vary from 3-4 to 10-15 centimeters. The importance of this parameter lies in the fact that due to the increased height, the door openings will have to be cut and, naturally, the door itself will have to be reduced. It is best when the installed floor does not interfere with the opening and closing of the door, but sometimes this does not work out and adjustments have to be made.

Remember that you should always follow the instructions given by the manufacturer or specialists regarding the installation procedure for purchased materials.

Substrates for water heated floors

The floor heating water circuit has a more complex design, therefore, when using it, more serious requirements must be placed on the structure of the floors.

Thus, the substrate for underfloor heating pipes must have the following properties:

• High mechanical strength. To comply with this parameter, it is best to use extruded polystyrene foam substrates, plywood sheets, pressed wood boards, etc. In addition to high strength, these materials also have no residual deformation.
• Resistance to high humidity levels. Such materials can be laid repeatedly if they had to be dismantled for repair work on the heating circuit.
• Maximum stable fixation of the heating circuit. As mentioned earlier, special fastenings - bosses - are created on many ready-made substrates. This simplifies the process of laying pipes for the underfloor heating system. Since all measurements are made by the manufacturer himself, it will be very difficult for the owner to make mistakes during installation. Their advantage is that the pipes are placed at the same distance during installation, allowing the surface to heat up evenly. Also, maintaining the distance increases the service life of the equipment and minimizes the need for repair work with dismantling the system and substrate.

Other nuances of choosing a substrate

When choosing the thickness of the substrate, it is necessary to focus not only on those layers that are located above it, but also to consider the thermal insulation materials located below. For example, using mineral wool allows you to avoid a thick layer of lining under a warm floor. If the lining is positioned as the main heat insulator, then, on the contrary, the value of its thermal conductivity should be reduced to a minimum.

Bottom line

Only correctly selected elements for heated floor equipment will allow the system to function properly. maximum performance. But, it is always worth remembering the amount of money spent and increasing efficiency through reasonable allocation of capacity. A high-quality substrate with optimal parameters is the most important structural element. Using this article, anyone can easily choose a material that will make the house warm, comfortable and cozy for many years.

Even with heated floors, the house can be cold and damp. The fault lies with poorly selected material. To avoid problems, choose a substrate for infrared heated floors from professionals. This way you are guaranteed to get a warming result.

The substrate under the film heated floor is the main component of the heating design. Properly selected polystyrene foam or lavsan, technically precisely executed thermal insulation will invariably help avoid loss of precious heat. Choose a high-quality underlay for IR film heated floors. Be sure to consider its functions:

• thermal insulation;
• hydro and sound insulation;
• final alignment.

What kind of underfloor heating should there be: installation features

Depending on the type of flooring, different materials are selected. The main nuances are presented in the table:

Type of floor	Types of materials	How is the work carried out?	Meaning
Electric	Technical pressed cork	Performed in 2 levels	Uniform heat distribution from the cable, preventing its overheating, removing excess heat energy
	Foam materials	The first is at the stage of rough work
	Magnesite slabs	The second - during final installation
Infrared film	Foamed polystyrene	The substrate for infrared heated floors under the laminate is laid only on the screed, which is first covered with foil	Redirection of heat in the room, reflection of IR radiation, prevention of 30% heat loss
	Polymer	Installation of metallized lavsan is carried out on a film with resistors. The reflective side is directed upward
	Metallized lavsan	The insulation is applied completely, the joints are connected and glued
	Magnesite slabs	Heating elements are placed on top of the reflective coating layer
	HDL sheets	Then comes the heat-reflecting substrate for the infrared floor, IR film
Water	Roll stopper	Lay a layer of foil on a polymer base	Reduction of heat loss, auxiliary waterproofing
	Isoplat
	Extruded polystyrene foam	Fix the coating material
	Expanded polystyrene foam	Perform a reinforcing screed on a water floor
	Molded foam
Laminate flooring	Underlay for film heated floors under laminate	Installation is carried out on a cement screed between the insulated system and the laminate	Preventing deformation of laminate panels, eliminating creaking due to play
	Rolled polyethylene	They use the thinnest material up to 3mm, thickness varies from 2 to 5mm
	PPE laminated

When choosing polystyrene, pay attention to self-centering locks. With their help, you can lay foam boards easily and conveniently. You will not need additional fasteners; the pipe system is guaranteed to fit into special valves.

The underlay for laminate under infrared heated floors serves simultaneously:

• insulation;
• shock absorber;
• protection for laminate panels.

Therefore, choose specialized material with enhanced thermal conductivity.

How to choose a substrate for a heated floor?

Choose a substrate for an infrared floor with good characteristics; only in this case will you properly arrange the heating system. Signs of a high-quality and safe substrate for infrared heated floors:

• high level of reflection;
• service life more than 100 years;
• efficiency;
• excellent thermal and waterproofing properties;
• resistance to temperature fluctuations;
• ease of execution;
• sound and vapor barrier;
• fire safety;
• resistance to deformation.

There is a huge variety of insulation on the market for heating electric and water structures. The most effective and safe ones include:

Groups	Materials	Examples
Natural	Jute	"Jute inter-crown insulation"
	Suberic	"Izospan" D, DM, FB
		"Sedacor" thickness 10/4/2 mm
Artificial	Lavsan underlay for heated floors	PPE laminated “Termoizol” foil, thickness 2-10 mm
		"Merilon" foamed polyethylene
		"Euro-insulation" foil insulation
	Polystyrene	"Izolon" foil foam, 2/4/5/8/10 mm
		"Stenofon" foam insulation
		"Folgoplast"
	Expanded polystyrene	"Polifom"
		"Izobond"
	Polyethylene foam	"Multifoil" from Valtec
		"Energoflex" polyethylene foam, thickness 3-5 mm
	Polyvinyl chloride foam	"Arbiton Izo-Floor" extruded polystyrene foam

The cost of a heat-reflecting substrate for a heated floor varies between 300-900 rubles, it all depends on the thickness and manufacturer.

Laying technology: secrets of specialists

Follow the following list of work stages when laying the infrared film underfloor heating:

• Prepare a hole for the thermostat.
• Provide power to your system by choosing a convenient outlet.
• Carry out thermal insulation work. Use reflective insulation. Correctly calculate the thickness of the lavsan substrate layer under the infrared heated floor, it should be within 3-5 mm.
• When laying insulation, fasten it with mounting tape and direct the film towards the wall with a thermostat, this way you will significantly reduce the size of the wire.
• Maintain a distance of 10-20 cm near the walls. If there are installed heaters, such as a fireplace, stand back at least 1 meter.
• Lay the substrate evenly under the infrared heated floor under the laminate, watch the density of the material. If you do everything correctly, the approximate value will be 150g/m2.
• Lay the film carefully along the joints.
• Use IR film systems to heat floors with underlays.
• Cut the coating only in bright areas.
• Tape the joint edges and outer sides with tape.
• Insulate the ends of the film, stick on bitumen insulation.
• Place the wires in the thermal insulation of the covering.

Carry out professional work taking into account the type of heating system and the selected material of the heat-reflecting substrate.

Order a specialist consultation for the right choice and installation of the substrate for film heated floors: infrared, electric, water. Call or leave a request on the website.

Heating a home using underfloor heating is becoming increasingly popular. These systems vary in the type of heating elements, allowing you to choose for any home. To be like this heating system worked efficiently and reliably, it is necessary to properly insulate it. To ensure that the heat does not escape in vain, the underfloor heating is intended. It is made of heat-reflecting materials that will retain heat.

Material selection

Usually the material for lining under the heating elements is polyethylene foam or

Foam backing.

polypropylene, which, moreover, are covered with a lavsan film with a layer of metal coating. The metalized coating helps heat to be evenly distributed under the floor covering, and the insulation itself prevents heat from being absorbed by the screed.

The foam underfloor heating has a low degree of thermal conductivity, which prevents heat from escaping into the ceiling and screed. The temperature limit of the material (up to 90 degrees) allows you to lay pipes or heating cables directly on the film. Along with excellent thermal and waterproofing properties, a layer of such material also has excellent sound insulation. It is also worth considering that the markings applied to the substrate will allow you to lay the cable according to the calculated step, this will increase the accuracy of the work and a reliable result.

Underlay for laminate

Currently, laminate is almost the most popular floor covering: it has a reasonable price, looks very similar to parquet, and its installation is very simple. If you plan to install heating under the laminate, you must make sure that a lining is installed under the heated floor system, which will help protect the wood from overheating. Otherwise, gaps will form in areas of the floor with a gap between the laminate and the base, and the coating itself will knock heavily.

To avoid such problems, a special thin (2-5 mm) part is placed under the laminate, which has increased thermal conductivity.

This move will not only avoid damage to the boards, but will also act as insulation, equalize possible height differences and prevent the laminate from squeaking. This backing is usually foil and is placed under a heated floor, where, in addition to its function of leveling the laminate, it also helps to retain heat.

Foil backing for laminate.

This component is mounted between the heating elements and the laminate. Manufacturers of wood flooring themselves advise using roll-type polyethylene for lining. A substrate made of this material combines well with concrete and cement and is poorly exposed to chemical compounds and living organisms. But in addition to compatibility with the finishing floor covering, the underlay must combine well with the selected type of heated floor, which will be discussed further.

Under a warm water floor

Water-based heated floors are quite popular due to their cost-effectiveness and ease of installation. When using a water heated floor system, you must take care in advance of the presence of a special layer. It is made of polystyrene foam; a little less often you can find linings made of cork or isoplat.

The correct underfloor heating will ensure that warm air rises upward, thereby making the structure work optimally. Thanks to the high technologies used in production, polystyrene foam substrates have many advantages:

• Provide additional heat and sound insulation;
• Practically do not absorb moisture, are fireproof;
• They help retain heat, which means they are economical and environmentally friendly;
• Maintain structure and integrity even with sudden temperature changes;
• Very durable - minimum term work life is 100 years.

Under film (infrared) heated floor

The best choice for a film floor is a heated floor substrate made of lavsan - foamed polyethylene, which has a metal-like reflective top layer. Lavsan is known for its amazing resistance to aggressive chemicals and microorganisms, as well as resistance to microorganisms.
The substrate is placed directly under, which ensures greater efficiency due to reduced energy loss. A lavsan substrate, which is placed under a heated floor, will not only help to heat the room, but will also save money, thanks to the same low thermal transmittance.

Installation steps

First you need to thoroughly clean the surface that you plan to cover with interlayer material. After this, we put a vapor barrier, which can be used as a construction film made of polyethylene; it should be used to cover the floor with a slight “climbing” of the material onto the walls (2-3 cm). The joints of the film can be sealed with ordinary construction tape. We glue a damper tape to the wall around the perimeter of the entire room, which will prevent the wood from expanding excessively. Next, you need to carefully cut out even strips of lining from the roll, which we place on the floor, trying to ensure that the lining fits snugly between each other and near the walls.

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We also use construction tape at the joints. Sometimes we may come across a corrugated underlay for an infrared heated floor; it needs to be laid with the smooth side up.

Secrets of installing underlays under infrared floors

In order for the film system to function correctly, it is necessary to install the components as efficiently as possible.

Proper installation of the heated floor underlay is also very important, and when working with it you should know some features:

• If the underfloor heating substrate is made of fiberboard or magnesite tiles, it is laid on a screed covered with aluminum foil;
• If it is made of a polymer metallized film, then it is placed under the film with infrared resistors, the reflective side up;
• The insulating material is laid in a continuous mass over the entire surface.

If individual elements of the substrate require connection, this can be done with tape or regular adhesive tape, which will provide additional vapor and waterproofing properties.

The underlay for a modern heated floor is very important when installing the system. This detail will allow you to fully experience the capabilities of heating systems and help the house retain heat inside.

Warm floors are not new to the construction market. Depending on the type of heater, they are divided into water and electric. The entire design of the system is a multi-layer cake, which contains a base, a substrate, a heating element and a finishing coating. Each “layer” performs its own task, and in order to avoid heat loss, you need to select the right materials. So, the underfloor heating depends on the top floor covering and the type of heater. Let's look at how it is chosen for different systems.

Video presentation of the substrate for water heated floors

Why do you need underlayment in heated floors?

The substrate is the material placed between the concrete base and the heating system. Its main task is to prevent the heat emanating from the heating elements from going down, where it is wasted. In your own house, it will simply go into the basement or foundation, and in an apartment, it will warm up the ceiling of the neighbors below. If there is a correctly selected substrate, the floor warms up evenly over the entire area and at 2 r. faster.

In addition, the substrate serves as a barrier to the penetration of cold, moisture and steam rising from below, and corrects unevenness of the base. In multi-storey buildings, it provides high sound insulation, so the hectic life of the neighbors below will no longer interfere with your relaxation.

Main selection rules

When laying heated floors, the following materials are used for the substrate:

• foamed polymers;
• extruded polystyrene foam;
• foil materials;
• cork;
• penofol, etc.

Their choice is determined by the quality of the base (smooth or not) and the floor covering that the owners plan to lay.

Water heated floor: choice of substrate and features of its installation

If the underfloor heating system will operate from hot water pipes, then the substrate must perform at least 2 functions: reflect heat into the room and become a barrier to water leakage in the event of an accident. Most often, during installation, high-density foam (25-35) is used, on top of which foil or foil-coated polystyrene foam is laid. It is recommended to lay thick foam in cases where there are unheated rooms under the floor, such as a basement or foundation. A special foam plastic with “bobs” on the surface is very convenient. This makes it easy to lay out the pipeline.

If the substrate has a surface with “bobs”, then it is easier to fix all the bends of the pipeline

Such a substrate for a water-heated floor perfectly reflects heat, but its waterproofing qualities cannot be called ideal. To be on the safe side, an additional waterproofing layer is always created from a film that is laid overlapping and overlapped onto the walls.

When laying, the foil should extend onto the walls so that the top screed can freely “play” under the influence of heat. The insulation is not fixed in any way, because the entire system is poured from above concrete screed. It will press down the layer of heat insulation, preventing it from moving.

If you are installing a heated floor system that will run on electricity, it is not recommended to use materials that contain aluminum (i.e., foil) as a substrate. This metal conducts electricity perfectly, and if contacts are broken somewhere in the system, the situation will end in a short circuit.

Therefore, the substrate for a film heated floor can be made of penofol (metalized film), polypropylene, foamed polymer materials, or cork. It is also allowed to use magnesite slabs and fiberboard, especially in cases where increased sound insulation and base leveling are required.

The easiest to install and cheapest is polyethylene foam, which is why it is most popular among the population. But it should be taken into account: with frequent use, the heat insulator will begin to deform, so it is better to lay this option in dachas, country houses where they live temporarily.

Penofol provides the highest percentage of heat retention. It is based on the same polyethylene foam, which is laminated on top with a polymer film with metal threads. The film serves as a barrier to heat leakage and prevents the polyethylene foam from heating up and deforming.

Penofol rolls are fastened together with metallized tape

Select a substrate based on the finish coating

• Underlay for laminate flooring

Laminate flooring requires an extremely flat surface. Therefore, to correct the shortcomings of the screed, it is better to lay a soft backing. This can be foamed materials, but cork is considered the most suitable for the structure of the laminate. It comes in rolls or slabs and is created from pressed cork oak chips. The rolled version is preferable, as there will be less waste during installation. The cork is not subject to deformation and does not shrink.

• Under linoleum

If linoleum is chosen as the finishing coating, then the substrate for the infrared heated floor must be hard. This will avoid dents on the floor from heavy furniture or heels, because the fiberboard will make the flooring harder.

• Under ceramic tiles

Durable and moisture-resistant tiles have a big disadvantage: they are cold. Therefore, the warm floor should warm it up as much as possible. It is best to place foil-coated polystyrene foam under a water floor, and a metallized lavsan coating under an electric floor. They have the least heat loss.

When installing the substrate, join the slabs or rolls with tape or glue them together. You cannot use materials of different thicknesses!