Substrate under a water heated floor: types, features of choice, laying rules. Substrate for underfloor heating: how to choose? Substrate under the warm floor foil Underlay under the IR film

Warm floors, depending on the method of heating, are of two types.

Water

Heating is carried out by a system of pipelines, the heat carrier is hot water.

They are used in most cases in private homes, during the connection of hot water in multi-apartment buildings there are big problems due to the disagreement of the management companies to give permission to connect to the common house heating networks for two reasons. Firstly, in this case it is difficult for them to control the specific consumption of thermal energy by each consumer individually. Secondly, boilers may not be able to withstand a significant increase in energy consumption.

Installing a separate heating boiler in city apartments is not always possible, and such installation, along with the price of equipment, is quite expensive.

Electrical

The temperature rises due to the resistance of current conductors. From the school bench we know the formula Q (energy released) = I (current) × R (conductor resistance).

Depending on the physical characteristics of the conductors, warm floors can be film (infrared) or cable (ordinary flexible cables and improved insulation serve as conductive elements). Electric floors have their own difficulties, during their installation it is necessary to take into account the parameters of the existing wiring and special protective fittings.

For efficient floor heating, the power per square meter must be at least 250 kW, in total terms, large values are learned.

Currently, manufacturers produce a wide range of substrates that differ in linear characteristics, materials of manufacture, and the ability to perform additional functions.

A very important point, we consider it necessary to consider this issue before proceeding to a direct description of the various types of substrates for underfloor heating. It should be borne in mind that absolutely all manufacturers are trying to increase sales of their products, for this they quite often advertise it in every possible way, including using not entirely benign methods.

What in reality should be paid attention to when choosing the optimal substrate option?

Thermal conductivity indicators. The lower they are, the more efficient the substrate works. These parameters depend on the thickness and materials of the products. To enhance the effect, modern substrates have a foil top layer - due to the reflection of infrared rays, heat saving indicators increase by about 20–30%. With regard to heat conservation, all materials used meet today's stringent requirements of housing construction standards.

Physical characteristics of strength, resistance to dynamic and static loads. There are materials (foamed and extruded polystyrene foam) that “stick together” under the influence of long-term static loads. The thickness decreases, the thermal conductivity increases. This phenomenon must be avoided due to the correct calculation of the load, the forces must be distributed as evenly as possible over the entire surface.

Manufacturability. The easier it is to work with materials, the cheaper installation is. According to this indicator, various materials have a wide range of characteristics. Foamed polystyrene foam is considered the most technologically advanced, the substrates from it are thin, the thickness rarely exceeds 5 mm, it is perfectly cut with ordinary scissors.

Expanded polystyrene substrates are flexible, there is no need to equip the joints of the base of the warm floor with the walls for a long time, measure, cut and adjust, the material in these places is simply folded. It is somewhat more difficult to work with sheet plywood and OSB or chipboard.

Additional properties. To facilitate installation work, some substrates have a drawn grid or special protruding bosses on the front surface.

Such devices simplify the process of laying pipeline systems, allow them to be fixed simultaneously with laying. As a result, not only installation is accelerated, but also the efficiency and long-term functioning of the heating system increase. Heat carriers can be placed at the same distance, the possibility of overheating of individual sections is excluded, the floor is heated evenly over the entire surface.

Price. An important factor is that if you have special technical knowledge, you can achieve an excellent heat saving effect at a much lower financial cost.

Environmental Safety. Keep in mind that all plastics and resins release chemical compounds into the air, safety is determined by their quantity. Since the substrates are operated at elevated temperatures, the requirements for material safety must be more stringent.

Now it’s worth saying what you don’t need to pay attention to when reading manufacturer’s brochures.

High noise absorption rates. Absolutely all materials used for thermal insulation do not transmit sound waves well, this is known from school physics lessons. Thermal insulation materials prevent the movement of air, namely, it conducts sound waves.

Waterproofing characteristics. Indeed, aluminum foil does not let steam or water through. And why do these properties need underfloor heating? In the case of water, the sooner leaks are detected, the less damage the owner will suffer, the less building structures will be exposed to prolonged exposure to moisture. Underfloor heating with electric heating is even more difficult. The presence of water, among other things, is the cause of short circuits - the risk of electric shock increases.

Resistant to the negative effects of ultraviolet rays. This property is very useful only in two cases: under the warm floors there is a small sun that emits such rays or an x-ray machine. If your apartment does not have these factors, then you can safely buy substrates without "effective protection of the material from harmful UV radiation."

Price. You need to know that in many cases, consumers pay a high price not so much for the actual quality, but for the brand awareness of the manufacturer. There are quite a few obscure companies that produce very high quality substrates, but at a much lower price. In this way, they try to attract real and potential buyers, increase the number of sales, and compete with more well-known manufacturers.

We hope that this information will help developers to choose the right types of underlays. Warm floors will serve for a long time and efficiently, and installation of structures will be much cheaper.

Substrates for underfloor heating with electric heating

Under these types of warm floors, thin substrates made of technical pressed cork, Foiloplast, Polyfom, Thermodom, TMpro and others made of foamed polymers are used.

Cross-linked polyethylene foam "Polyfom"

"Polyf", characteristics

The latter, by the way, are far superior to their competitors in terms of their ability to withstand loads, due to this feature, the scope of their use is expanding. Substrates with increased thickness parameters are made of extruded polystyrene foam. The material has high characteristics of physical strength, can be used as a base for a concrete screed. The substrate is used under all types of floors with electric heating, including ordinary ones with flexible conductors.

If the base is not very even and its leveling is required, then substrates made of plywood, OSB and chipboard can be used.

Important. For electric floors, it is not recommended to use substrates having an aluminum reflective layer. In the event of an insulation failure, an unforeseen current leakage appears with possible negative consequences. The reflective layer should be on a vacuum-coated polyethylene film.

When choosing a particular brand, two initial factors must be taken into account.

Finish flooring. The lighter it is, the less durable the substrate can be. Under the laminate it is allowed to use ordinary substrates made of foamed polymers, and under ceramic tiles or artificial stone, a substrate made of extruded materials of increased strength is used.
The heat-insulated floor keeps within in new rooms or during repair old. Depending on the chosen technology of underfloor heating with electric heating and the characteristics of the supporting floor, the total thickness of the cake can vary from 10-15 to 3-4 centimeters.
These parameters should be taken into account when designing the height of door and window openings. During the repair, it is necessary to take all construction measures to reduce the thickness of the warm floor - you don’t have to solve problems with reducing the height of the doors, etc. The ideal option is that the mounted warm floor does not interfere with the opening / closing of the doors, acceptable - the door leaf and vertical trim are needed for several centimeters from the bottom cut. The most unpleasant option - it becomes necessary to raise the lintel of the doorway, the heating system requires alteration.

Under linoleum, only rigid substrates are used and or a screed of small thickness is made. The technology of laying the substrates depends on the materials of manufacture, during the production of work it is necessary to follow the instructions of the manufacturers.

Underfloor heating underfloor heating

Due to the fact that water floors in most cases have an upper cement-sand screed, more stringent requirements are imposed on the substrates than for warm floors with electric heating.

High mechanical strength. It is recommended to use underlays made of extruded polystyrene foam, sheet plywood, chipboard and OSB boards. These materials are able to withstand high loads and do not have the effect of permanent deformation.
Humidity resistance. After liquidation of emergency leaks, the materials must be suitable for reuse. All lumber for substrates must be moisture resistant. Of course, leaks during the operation of a water floor are an extremely undesirable phenomenon; during the installation of the system, all measures should be taken to prevent them throughout the entire period of operation of the floor.
Ensuring reliable fixation of the pipeline system in a given position. Currently, manufacturers offer special pads with bosses for water floors, which not only simplifies and speeds up the installation process, but also ensures the same distance between pipelines over the entire floor surface and guarantees long-term operation of the equipment.

When choosing the thickness of the substrate, one must take into account the effectiveness of the thermal insulation of the base. If the house is wooden and the floors are thermally insulated with mineral wool, then the thickness of the substrate may be insignificant. Conversely, if the substrate serves as the main heat-insulating material, then its thermal conductivity should be minimal. The aluminum heat-reflecting film on the front part gives a great positive effect; its presence is welcomed by all professionals.

The correct selection of all elements of a warm floor, taking into account the widest possible list of individual characteristics, increases the efficiency of its functioning, reduces the estimated cost of construction and installation work and increases the duration of operation. The optimal choice can only be made if it is made consciously on the basis of knowledge about the varieties and technical indicators of various types of substrates.

Video - Installation of pipes on a substrate with bosses

Under the substrate for a warm floor, isoline is often meant, it is also foil isol and it is also foamed polyethylene. Often, plumbers or salespeople in a store offer it to you as the main insulation, arguing that it is not worth overpaying for polystyrene foam, and you will save the height of the warm floor cake. In this article you will receive a detailed answer to the question: why the substrate is the enemy of your warm floors.

The warm floor consists of the following elements:

Floor slab (reinforced concrete)
Waterproofing, since the slightest moisture from below seriously impairs the thermal insulation properties of any insulation material
Insulation (its task is to minimize heat losses downwards and create maximum heat flow upwards, i.e. into the room that we are trying to heat with our water heated floor system)
Underfloor heating pipe, from which heat flows in all directions

The minimum is 65 mm and the minimum distance from the top edge of the pipe to the edge of the screed is 45 mm. Be sure to fit around the perimeter of the room to minimize heat loss through the walls and compensate for the expansion of the concrete screed. Since there is no rigid connection between the concrete screed and the wall, the screed breathes. Accordingly, it must be separated from the wall with a damper tape.

Our task is to direct the heat up into the heated room and not let it go down into the basement, into the street. For this, we are offered to install a substrate for a warm floor.

Varieties of insulation materials

To prevent heat loss, the following types of heaters are used:

Styrofoam boards with bosses

Available with and without coating. Uncoated board easily loses bosses during installation and installation of a warm pipe. Coated slabs allow you to move on it with care, without losing the bosses. But the floor heating pipe is not fixed between them, i.e. for its additional fastening it is necessary to use anchor brackets. The average cost of a coated slab is about 600 rubles per 1 square meter.

Styrofoam boards with plastic coated bosses

The thickness of such a plate is 2 cm, the coating is made of plastic, which allows you to calmly walk on the plate, the bosses do not get off. The pipe is firmly fixed between the bosses, does not pop out, whether it is metal-plastic or cross-linked polyethylene. Additional elements for fixing are not required. The average cost of such a plate is 680 rubles per 1 square meter.

Styrofoam smooth boards

Lower density, thickness from 2 to 10 cm, cost per slab 2 cm thick - 100 rubles per 1 square meter.

Substrate for underfloor heating with markings

Folgoizol, isoline and substrates for underfloor heating are not insulation! Their thickness is 3-4 mm, polyethylene foam. The only function is to increase convenience when laying out smooth plates.

What does saving on insulation lead to?

For example, take a room of 50 square meters.

Usually they use expanded polystyrene with bosses, the cost of 1 sq. meters on average 600 rubles, thickness - 2 cm. In most cases, this thickness is not enough for insulation, with the exception of the southern regions. Additional insulation up to 4 cm will cost another 150 rubles per square meter. The total amount will be 7,500 rubles. Savings on this amount are discussed when choosing a heater. The owner of the house seeks to reduce costs and often chooses the cheapest option - underfloor heating, instead of the insulation itself. In the end, the economical owner of the house heats the street and spends even more money to maintain a comfortable indoor temperature.

Calculation of the cost of water heated floors

We have two rooms:

the first with a normal, high-quality insulation of the required thickness;
the second - with a substrate for a warm floor under a heater and an "economical" owner.

In the first house, with a heater of 4 cm, the heat flow into the room is three times higher than the heat flow down. All the heat that the owner of the house pays for is used to heat the room, not the street!
In the house of an “economical” owner, the heat flow upwards (to the room that needs to be heated) is almost equal to the heat flow down (to the street, to nowhere). Forty watts per square meter flies "down the pipe."

On 1 square meter with underfloor heating we lose 40 watts, on 50 square meters - 2000 watts.
1 cubic meter of natural gas provides 10 kW of thermal power and costs 4.5 rubles (the price depends on the region, from 4 to 8 rubles).
10 00 W / 2000 W = 5 hours - 1 cubic meter of natural gas is enough for heat loss.
The boiler operates on average 12 hours a day. 12/5=2.4 cubic meters of gas is spent per day on street heating.
2.4 (cubic meters) x4.5 (ruble) x30 (days) x7 (months of the heating period) = 2,268 rubles per year.

They paid 7500 rubles for the insulation / 2268 rubles = 3.3 years - the payback period of the insulation. When using a substrate for a warm floor, heat losses will increase! These materials are not insulation!

DO NOT USE UNDER HEATED FLOOR INSTEAD OF INSULATION!

When using insulation materials with insufficient thickness for full thermal insulation or when using foil isol, isolin (they are also a substrate for underfloor heating), the owner of the house loses a lot of heat in the lower direction. This is either unreasonable savings, or a serious delusion of the homeowner. The heat loss in this case is comparable to the heat flux entering the room. The use of high-quality insulation of the required thickness pays off on average in 3-3.5 years of operation of a heated floor, when natural gas is used as an energy source. Natural gas is the cheapest source of energy. If we talk about other sources, then the insulation can pay off in 1 heating period (i.e., in 7 months).

Underfloor heating video

A warm heated floor has recently become de facto the standard for building heating systems in apartment buildings and private cottages. The use of heated floor systems allows you to create the most comfortable atmosphere in the room.

Substrate under the warm floor - photo

Underfloor heating systems can have different characteristics and operate on different principles. When constructing underfloor heating, you can use any type of finishing flooring, so a warm underfloor heating can be installed in any room: in the bedroom or in the nursery, in the kitchen or in the bathroom.

A very important element in the design of a warm floor is its substrate. With its help, the efficiency of the heating circuit is extremely increased, whether it is an electric heating cable, infrared film or pipes with a liquid heat carrier.

Main characteristics

In order to understand what type of underlay you need, you need to know what underlay is for in underfloor heating systems.
So, podolzhka first of all should have excellent properties of thermal insulation and waterproofing. It should increase the efficiency of the heating system.
An important property of the substrate is its ability to reflect heat rays.
The substrate must withstand temperature fluctuations while working in close contact with the heating elements.
Also, the substrate should not pass water vapor formed during heating.
An excellent additional property of the substrate will be sound isolation.

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

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

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

One of the most sensitive 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 on a warm floor, the use of a substrate is a prerequisite.

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

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

Consider the procedure for laying a polyethylene foam underlayment under a laminate board on a heated floor.

First of all, you need to clean up the workspace. To do this, you can use a regular broom or vacuum cleaner.

Then we lay the spread out rolled substrate on the cleaned surface.

The spread substrate can be fixed with double-sided tape, and then proceed directly to laying the laminate boards.

Substrate for heated floors with liquid heat carrier

For any design of heated floors, the substrate must perform the functions of increasing the heat transfer of heating elements. In the event that you use a liquid heat carrier - that is, you design warm water floors - your substrate can additionally perform the functions of waterproofing the surface.

When installing heated water floors, you can use such a substrate, which will additionally be the basis for installing the heat carrier pipeline system. Such a substrate has special protrusions, between which a pipeline system is mounted.

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

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

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

In this case, the substrate under the 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.

Substrate under a warm electric floor

The underlay for a warm electric floor in its design resembles a substrate for a warm floor with a liquid heat carrier. However, in this case, you may not need additional surface waterproofing.

In this case, a substrate layer is laid 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 a heating cable is attached with clamps.

Laying the substrate under the 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 laid directly under the film of the heated infrared floor. In addition to the roll 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 a thermal insulator and foil.

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

Substrate - penofol

It has a reinforced structure with air pockets with excellent thermal insulation properties and a foil layer, which significantly reduces heat loss in the room.

The foil layer underlay retains up to 97 percent of heat rays, which significantly increases the efficiency of your heating system.

Important nuances

When laying the substrate on a warm floor under any type of topcoat, you need to remember a few important nuances.

First of all, note that the reflective foil side of the substrate should be facing up.
The underlay 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 adhesive tape. This will also serve as an additional barrier to moisture and steam.
Heating elements, be it an electrical cable, infrared film or a pipeline with a liquid heat carrier, must be mounted on top of a coating that reflects heat rays.

When installing underfloor heating and most types of floor coverings, a special substrate is used that performs a lot of functions. One of the most popular types of it is foil for underfloor heating. Some, trying to save on repair work, believe that it is possible to refuse it. However, this step would be a blunder. A substrate for the installation of underfloor heating must be used.

Before we get acquainted with the foil substrate for floor installation, we will find out what types of underfloor heating exist and can be used in rooms for various purposes. Depending on the type of system, various types of foil material are used, differing in certain properties.

Why is an underlay needed?

The material that plays the role of a substrate for a heated floor system is necessary, first of all, so that heat flows do not go down, do not spread below the concrete screed, but, on the contrary, go up, warming the floor and the room.

On a note! Inside an ordinary floor, the heat coming from the heating element will evenly heat the material from which this floor is made. However, it will no longer penetrate below the screed due to the heat-insulating layer.

At the same time, not just an insulating material, but a substrate with foil allows you to save heat much better and more efficiently. For example, it can be noted that the coefficient of thermal insulation for an 8 cm thick foam will be exactly the same as that of polyethylene foam with a foil layer.

A quality underfloor underlayment should have:

high reflectivity;
resistance to temperature fluctuations;
soundproofing;
waterproofing;
high rates of thermal insulation;
ease of installation;
environmental and health safety.

Most of these properties are also possessed by materials with a layer of foil. In particular, they have the maximum properties reflecting thermal energy.

Such material is used when installing underfloor heating quite often. It allows you to reduce heat loss during the use of the heating system, which makes it possible to save money spent on paying bills for heating or electricity. Materials with a foil surface are considered the most efficient in terms of energy saving.

However, all of the above properties are possessed not only by the foil itself, but also by the materials on the surface of which it is glued during production. There are several main groups of thermal insulation materials that can have a foil layer.

The structure of the foil heat-insulating material

Most types of foil thermal insulation materials are produced in rolls, which ensures ease of use during installation work. In general, most heaters have a two-layer structure - a base and a foil.

The basis May be:

basalt;
mineral;
polystyrene foam;
polyethylene.

Each of these materials is environmentally friendly, safe for health due to its inertness, and excellent fire safety indicators. Also, most types of bases have a bubble structure, and air, as you know, is one of the worst conductors of heat.

Foil polyethylene foam - structure

foil layer- This is a foil made of aluminum, the role of which is the direct reflection of thermal energy. It allows you to evenly distribute the returned heat, but the base does not allow it to go into the screed.

On a note! Foil insulation for the most part is elastic and soft materials, so the process of laying them is quite simple.

Due to the fact that most heat-insulating materials with a foil layer are able to withstand heating up to +90 degrees, such substrates can be used for any type of underfloor heating systems. By the way, on the surface of the foil insulation there is often a marking that facilitates the process of laying the cable - you don’t have to constantly mess around with a tape measure. Even with such material it is easier to lay the floor water system. Another feature of some foil materials is the sticky layer. It allows you to fix the insulation in one place during installation and will not allow it to move.

Types of thermal insulation with foil

	Name	Rating
#1	Styrofoam	⭐ 96 / 100
#2	Foamed polyethylene	⭐ 98 / 100
#3	Basalt insulation	⭐ 85 / 100
#4	mineral wool	⭐ 78 / 100
#5		⭐ 96 / 100
#6		⭐ 93 / 100

Styrofoam

The most popular thermal insulation material used for underfloor heating is foil polystyrene foam. In general, he is able to cope with changes in air temperature from -180 to +180 degrees without prejudice to himself, but, of course, in domestic conditions, the floors do not exactly heat up to such an extent.

A fairly durable material that is not afraid of sharp temperature fluctuations.
Also, expanded polystyrene is not afraid of exposure to various chemicals.
He is not afraid of rot, various pathogens do not settle on it, which also demonstrates the material as safe for human health.

Low resistance to UV radiation.

Expanded polystyrene with a foil layer

Mineral wool

Mineral wool is purchased and used much less often, even with a layer of foil. Such insulation is often used only in industrial facilities.

affordable cost;
low class of fire hazard.

Not suitable for laying a water heating system. The fact is that in the event of a liquid leakage, the material is easily saturated with it and loses all its qualities - it will not be able to retain heat. Yes, and for electric underfloor heating, mineral wool is not recommended. The main reason for the negative reviews is that this material, when heated, begins to release substances that negatively affect the body.

mineral wool foil

Polyethylene foam

Polyethylene foam is another commonly used type of substrate for underfloor heating.

lasting;
plastic;
not afraid of moisture;
various chemicals are not terrible;
pathogenic microorganisms do not settle on it.
can be used both under a water heated floor and under an electric one;
usage can be very long.

fear of ultraviolet, but under the flooring, sunlight will not reach the material.

Polyethylene foam foil

Basalt insulation

Basalt insulation has a base consisting of thin fibers of molten rocks of gabbro-basalt. It is very similar to fiberglass, made up of basalt rather than quartz.

Fire resistance.
Vapor permeability.
It is not afraid of sudden temperature changes and will calmly withstand from -200 to +700 degrees, and therefore does not burn.

Seams not sealed.

basalt wool with a foil layer

Folgoizolone is often used in the construction / repair of saunas and baths.

Not afraid of moisture or sudden changes in temperature.
The service life of the material is quite large.
Doesn't rot.
Possesses the increased sound-proof properties.
Safe from an environmental point of view.

Folgoizolon is very expensive, therefore it is practically not used in residential areas.

There is another type of thermal insulation with a foil layer. It is known as multifoil and consists of several layers. The foil layer is covered with a bubble layer filled with air, then polyethylene and polypropylene film are laid. Under the foil layer is a special protective coating.

If you use this type of thermal insulation, then heat loss will be reduced to a minimum.
In addition, the multifoil is not afraid of high humidity.

Not detected.

Attention! Do not use for the installation of underfloor heating systems materials intended for insulation of walls and other parts of the building. On the floor, they will experience a strong mechanical impact, and therefore can quickly lose their properties. Use only those materials that are specifically designed for laying on the floor.

Video - Penofol and its analogues

Do you need reflective foil for underfloor heating?

The most commonly used types of foil substrate are polypropylene and polyethylene. But is such a layer needed when arranging a warm floor, or is its necessity an invention of marketers? So, the following fact speaks in favor of a heat-insulating substrate with a layer of foil - its use allows you to save about 90% of the heat emitted by the underfloor heating system. Thus, the amount of energy spent is significantly reduced. Already this is enough to recognize the need to use the material.

The foil backing has other advantages:

it practically does not increase the thickness of the floor, since for the most part it is very thin (2-10 mm);
affordable for everyone;
easy to install;
strong, durable.

Use of material with foil

Installation of foil under a warm floor is quite simple. Difficulties and difficulties here with a 99% probability will not arise even for a novice builder. In order to lay this material on the subfloor, you will need scissors or a clerical knife, a tape measure, aluminum tape, and the heat-insulating material itself (for example, foamed polyethylene).

The following table will help you navigate the entire laying technique.

Table. The technology of laying foil under a warm floor.

Steps, photo	Description of actions
	The material is laid close to the wall. The process starts from the corner of the room. The edge of the roll of foil material is placed in the corner of the room with the reflective side up - it will always be directed towards the heat source. The roll is untwisted to the end of the wall, the tape of material of the required length is cut off.
	Similarly, the material is rolled out on the floor of the entire room. The strips are laid end to end.
	All mounting seams are glued with adhesive tape to achieve maximum heat and moisture insulation.
	Next, the floor heating system can be installed, then the flooring is laid.

However, it is worth remembering that the foil substrate should be laid on a thoroughly dried subfloor, if it was leveled and filled with building mixture. Already then, work is carried out on the installation of thermal insulation, and then the selected floor heating system is laid according to the scheme and certain requirements. After that, again, depending on the requirements, it is either filled with a cement mixture, or simply covered with a finishing coating.

Video - Laying a rolled foil substrate

It is necessary to lay a heater when installing a warm floor, especially if the floors are installed in a private house or are laid in an apartment on the ground floor. And when using foil materials, the heating efficiency will be significantly increased. Therefore, do not save on this subtle, but such an important addition.

A foil substrate under a warm floor is a common heat-insulating material that can be used in the arrangement of various types of heating circuits. They can be of two types: water and electric. The heat-reflective lining has unique physical properties that can save the energy required for heating.

Description

Foil substrate is a material that is a combination of polyethylene foam with foil. It is the foil layer that acts as a reflector of thermal radiation. Very often, such a substrate is used when arranging a warm floor for a laminate. Often used as.

In the photo - a foil substrate under a warm floor

The main difference between the lining under the warm floor and other materials is that the foil has a heat-reflecting function. A foil or metal coating is laid on top of the substrate. It is it that reflects the thermal energy released by the heating system and directs it upwards to the floor covering. Foil substrate is a unique material with which you can save 30-97% of heat. Thus, it becomes clear that when arranging a warm floor, this material is mandatory.

In order to facilitate installation and ensure safe use for a certain type of underfloor heating system, there are various types of substrates.

On the video foil substrate under the warm floor:

For underfloor heating

For a warm floor, which consists of pipes, the lining based on a dense and rigid material will be the best solution. Its surface should be corrugated, and it is released in the form of plates. Most often, for the production of such material, molded foam is used, which has high density indicators. On the surface of the heat insulator there are protrusions that are staggered. These are the so-called bosses, which provide convenient fixation of pipes and guarantee their bends.

If the arrangement of a warm floor is carried out in a private house, and there will be an unheated cellar or foundation below, then the layer of heat-insulating material should be as thick as possible.

This version of the foil substrate cannot boast of high waterproofing characteristics, so before laying it, it is necessary to provide for the installation of a film with a moisture-proof coating. Thus, it is possible to secure the system in the event of a pipe leak or burst.

On the video foil substrate under the warm water floor:

For electric

If it is necessary to equip a cable or infrared floor, then it is necessary to use elastic rolled foil substrates based on foamed polymers. This may include polyethylene, polypropylene or cork.

If infrared film underfloor heating is being laid, then due to the high risk of a short circuit, it is not always advisable to use a foil substrate. In this case, it can be replaced by a material with a metallized coating. The substrate can be presented not only in the form of rolls, but also in the form of boards obtained on the basis of wood-fiber material. Under the plates it is worth mounting aluminum foil.

On the video foil substrate under the warm electric floor:

There is only one type of underfloor heating, during the arrangement of which the laying of a foil lining is not needed. This includes mats that consist of a heating cable. They are fixed on a flexible base. But such actions can be taken provided that the base has a substrate with a heat-reflecting layer.

Advantages and disadvantages

Before you buy a foil substrate, you need to understand its pros and cons.

The positive qualities of the material include:

additional thermal insulation and protection against leakage of thermal energy down;
protection of the heating system from moisture ingress from below;
the material perfectly eliminates minor flaws on the surface;
has soundproof properties;
foil material evenly distributes thermal energy, because the heating parts are concentrated at a certain distance from each other, and the presence of a substrate will allow the coating to warm up not only directly above them;
the substrate accelerates the heating of the surface by 2 times;
the material removes heat energy from the heating parts, protecting them from overheating;
reflects heat energy.

As for the disadvantages, the foil substrate has only one, and this is a high price. Today, not everyone can afford such pleasure, despite the high technical qualities of the material.

Installation

The process of laying the substrate under the warm floor is carried out overlapping or butt-to-butt. The choice of a suitable mounting option is determined by the thickness of the material. It is clear that it is unrealistic to overlap a heat insulator with a large thickness, then the butt-to-butt method comes to the rescue.

The thickness of the foil substrate can be 2-20 mm. Taking into account these parameters, the installation method is selected.

For material with a thickness of not more than 6 mm, you can use the overlap method, that is, run on top of each other. Fix the formed joints with adhesive tape so that the completed flooring is durable. It is unacceptable to shift it when installing pipes or brackets. If a laminate acts as a floor covering, then a non-thick reflector can be used. If you use a thick material, then a soft pillow will appear. It will negatively affect the upper screed, which will be subject to deformations and cracks. How it looks and how the substrate under the linoleum is laid on the concrete floor, you can see in this article

On the video installation of a foil substrate under a warm floor:

If auxiliary insulation is required, then sheets of extruded polystyrene foam should be laid under thin insulating material. It also differs in thickness. And it depends on how much thermal insulation is needed.

Install a hydraulic barrier under the reflector if you are not sure that the screed is equipped with waterproofing. Thanks to the laid dense cellophane, a reliable barrier is created.

When installing a foil lining under a warm floor, you must adhere to the following simple recommendations:

The use of a lining with a foil layer is a must. This is the only way to keep up to 98% of heat and eliminate its losses in the room.
For laminate flooring, the lining must have a soft base. This will correct the uneven laying of the board.
For the base of linoleum, you need to choose a solid heat-insulating material. Then the floor will not be pressed under the influence of furniture.
If there are significant irregularities in height on the floor, then a soft lining will be able to eliminate them, because it is plastic. When installing a foil lining on a surface with significant defects, a material of a rigid configuration must be used.

How it looks and how the substrate under the arbiton underfloor heating laminate is used can be seen in this article.

Manufacturers and prices

You can buy a foil lining for the underfloor heating system at any hardware store.

At the same time, pay attention to the following trusted manufacturers:

DH-Hilon. Foil material is produced in South Korea. The substrate is made of polypropylene, and it can be used for arranging a thermal water floor. The cost of the product is 1200 rubles.
Free-foil underfloor heating DH-Hilon
Ecofol. This is a Russian brand that produces foamed polyethylene with foil film. The material can be mounted when arranging a warm water or electric floor. Also, the product is used on the balcony and loggia. The cost of the material is 718 rubles.
In the photo - a foil substrate under the heated floor Ecofol
SEDACOR. The material is delivered from Portugal. It is presented in the form of a cork substrate, when laid, excellent heat and sound insulation is achieved. It can be used for rooms with a normal level of humidity; when arranging a warm floor, you will need to lay an additional heat-reflecting layer. You can buy the product at a price of 2200 rubles.
In the photo - foil substrate under the warm floor SEDACOR
Poliform. The substrate is made of closed-cell cross-linked polyethylene. The material is characterized by high thermal insulation qualities. The cost of production is 650 rubles.
Thermohouse. This is a Russian brand that produces material at an affordable price. Universal lining is suitable for arranging any warm floor. You can buy the product at a price of 812 rubles.

Foil substrate for underfloor heating is a versatile material with which excellent sound and heat insulation is achieved. When laying such a substrate, heat will not escape through the bottom of the room, remaining in the room for a long time. The installation process of the foil product is simple and easy, so even an inexperienced builder can cope with this task.