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We choose a heater for a warm water floor: the advantages and disadvantages of thermal insulation materials. Thermal insulation for a warm floor system: a comparative review of insulation materials

Not every heater for underfloor heating available on the market is suitable; it must meet several requirements:

Sufficient strength and hardness so that it does not deform from incoming loads (people, furniture);
Low coefficient of thermal conductivity for efficient operation of the heating system;
Compatible with heating element - electric or water carrier.

Floor structures

The insulated floor is a puff "pie", which includes:

The base is thermally insulated
Reinforcing layer (water floor) / aluminum foil (electric heating);
Electrical system or water pipes;
Concrete screed;
Finish coating.

In terms of power, these systems do not actually differ; the degree of heating is regulated manually or automatically.

Accordingly, the thickness of the insulation under a water heated floor or an electric one is approximately the same, its value depends on the technical characteristics of the thermal insulation.

Styrofoam

Universal insulation for electric underfloor heating and water system. is not afraid of water, has sufficient rigidity and a low coefficient of thermal conductivity - 0.032 ... 0.044 W / m * K, depending on the density.

For the water floor, there are special polystyrene plates with bulges, along which the pipeline is laid and fixed.

Electric rods can be laid on ordinary flat plates.

Mounting of carriers is created directly on polystyrene foam without the use of waterproofing. To increase the effect of heat transfer, you can lay the foil with the shiny side up, it will reflect the incoming energy.

Penofol - roll insulator

A convenient type of insulation for organizing floor systems. created from foamed cellophane with the application of a foil reflective coating. There are 4 types of penofol:

"A": the foil is applied on one side of the roll coating;
"B": foil covers both surfaces;
"C": top - foil, bottom - adhesive film, self-adhesive insulation.
"ALP": top - foil, bottom - polyethylene thickened film.

The rolls are rolled out on the base with the foil side up to reflect heat towards the room.

The thickness of the insulation is small - 3 ... 10 mm, but it is enough to create the effect of a "thermos".

Laying thermal insulation

As you have already figured out, it is placed under a warm floor.

By all means shiny reflective surface upwards, to reflect heat to the surface of the tile.

It is necessary to lay exactly under the surface of the warm floor, it is not necessary to lay on a large area.

You need to keep in mind that the thermal insulation is located between the tile adhesive and the main screed, therefore it is not better to lay in a huge layer, the tile that will be installed on top may recede. For better bonding of tile adhesive and screed, it is necessary to make cuts or small holes in the thermal insulation where there is no heating element.

Also, a slot must be made for the thermostat sensor, as a rule, it is located under thermal insulation, and if you do not make a slot, then the warm floor can simply overheat and burn out, so this is a prerequisite.

The sensor of the underfloor heating thermostat also needs to be insulated with the same m, so that it does not give off heat faster than a warm floor.

After installing this thermal insulation, you can start laying tiles.

Insulation for underfloor heating, electric and water

Are you planning to insulate the floor?

The insulation system itself is not as important as the insulation laid under it. Specifically, he asks for a painstaking selection both for the type of insulation and for the room itself. Next, we will reveal the structure of the warm floor and carefully describe how to choose a heater for it and not be mistaken.

General information: energy losses and their avoidance

First of all, why do we need thermal insulation for underfloor heating? It is clear that 20% of the heat from floor heating goes down, in other words, we will simply waste energy and not get the desired result.

That's what thermal insulation will help us cope with

reduce natural heat loss.
Heat escapes to a cool surface directly outside or into the ground. As stated above, the loss is 20%.
will help to moderately distribute heat around the perimeter, that is, on the floor. Energy will not be spent on ceilings or elements below the heating area.
save energy for additional heating
reduce the cost of heating
create additional soundproofing
prevent water ingress through the floor covering
protect the heating system

In the diagram, we see the structure of a warm floor in a private house, regardless of its type. Whether it is an electric or water mechanism, the picture looks something like this:

The base may vary, depending on what is under the insulated surface.

To choose the insulation itself, it is worth finding what is under it: soil, basement, living quarters. This nuance is very important for the selection.

For example, if there is soil or a basement under the insulated floor, the recommended thickness of the insulation is 50-100 mm. In the event that there is a residential heated room under the floor, 20-50 mm is enough.

Types in for insulation

To choose, you need to be aware of which properties are more valuable in it. Here are the most important of them:

low thermal conductivity, which is logical
high compressive strength
elasticity
low deformation rate, ability to withstand loads
resistance to harsh environments
high density (minimum 25kgm3, experts advise 50kgm3)
moisture absorption - minimum

Regardless of whether the floor heating is electric or water, the general list of heaters recommended for use is unchanged, and the selection is made depending on the situation.

Consider the more popular heat insulators:

polystyrene foam
cork backing
polypropylene
mineral wool
profile heat-insulating mats

Expanded polystyrene is rightfully considered the best m-insulation. It applies to both electric and aqua warm floors. In terms of cost - inexpensive, in terms of quality - an impeccable option. Extruded polystyrene foam is especially excellent in combination with a metallized lavsan film, which protects the floor from alkali and destruction.

Cork backing is a good, environmentally friendly one that you can use.

But there are a number of limitations. The cost of the "cork" is quite high. This heater has limitations in the height of the premises. And the substrate asks for an additional ray-reflecting layer for the greatest efficiency. The option takes place only in electric underfloor heating, working as additional insulation.

Polypropylene - can both serve without the help of others, and in addition with expanded polystyrene. It perfectly withstands temperatures up to 130 * C, has a cellular structure, can be processed. The choice of polypropylene is a personal matter, depending on the characteristics of the insulation.

Mineral wool is also inexpensive and very useful.

Provides additional sound insulation.

It is better to use foil mineral wool, in order to avoid harm to health and provide additional reflection of heat rays. Important: it loses its characteristics when wet, has a relatively high rate of moisture absorption, which is why it is applicable only in electric heated floors.

The thickness of the insulation plate under the warm water floor

It must be announced that from which the insulation is made, it can be different. More famous polystyrene foam.

In some of its properties, it is identical to polystyrene, but its operational properties are even more practical. Mineral wool, ecowool, cork and others are also used for insulation.

But not only the characteristics of the insulation used for insulation affect the performance properties of thermal insulation and its ability to retain heat. An important role is played by such a parameter as the thickness of the heat-insulating layer.

Since we are talking about insulation under a warm floor, then paying attention to climatic conditions when determining the thickness does not make sense: the heating system of the warm floor itself levels out climatic contrasts.

But still there are certain rules. So, if expanded polystyrene is used, it is recommended to use a sheet with a width of at least 30 mm. In addition, for greater efficiency and highest density, the sheets are reinforced with a polymer sheet, which contains a reinforcing mesh.

By the way, polystyrene foam insulation for the floor with a water heating system can be purchased ready-made, with special markings. Such sheets are quite ready for use, it remains only to remove the excess.

According to the standard, they are square with a side length of 50 cm.

It must be kept in mind that underfloor heating is not just pipes “hiding” under the floor covering and heating rooms. In fact, this is a multilayer system, and the real work of the warm floor as a whole depends on the properties and correctness of the installation of each layer.

If such a floor is deprived of insulation, then during the winter it can completely lose approximately 25% of heat. Agree that this is extremely high. That is why high-quality thermal insulation is so necessary.

Insulation under a warm water floor on a draft concrete floor

A good insulation for underfloor heating on a water base is, in particular, penoplex. Its sheets are laid out on a primed concrete base, covered with polyethylene, which acts as a waterproofing, and after that the heating elements are mounted.

It must be said that the use of underfloor heating (water heating system) when installing thermal insulation will make your floor resistant to water and extend its life.

What does an effective water floor with the greatest result ultimately consist of? Here are the ingredients:

Draft concrete floor or screed to retain heat from lowering it and going outside.

The thermal insulation is foil, so that the heat, reflected, returns back to the room. The use of foil thermal insulation significantly reduces heat loss, which leads, accordingly, to an increase in temperature in the heated room.

Thus, the same “pie” mentioned above comes out, but with the correct “filling”, therefore it is necessary and durable.

Insulation for a warm water floor in the photo

How exactly it is necessary to install a heater under a warm water floor, how it looks and how it happens, you can see in the photos we have proposed. Specifically, on top of the heaters below and fit into the upcoming underfloor heating system.

In conclusion, I would like to add that any useful knowledge greatly simplifies life, and if this knowledge also has an applied nature, then its cost is especially high.

Insulate your floors for pleasure and live with warmth in your heart. Good luck! If the article turned out to be useful to you, you and your friends can click on the buttons:

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Do I need insulation in the "pie" of a warm floor?

For almost all professionals involved in the design of heating systems, this question will seem unnecessary. Why? Therefore, the answer to it is obvious - a heater is needed. For them, the question of warming sounds like this: “Does a person need clothes in winter?”

Nevertheless, besides designers, there are many people who are far from designing and calculating heating systems, and, in connection with this, do not have sufficient knowledge and certain numbers to answer the question: “Do I need a heater for a warm floor?

And if needed, then what thickness? First of all, customers who plan to build a house fall into the category of such people, but they want to save on something and do not see the need to lay a layer of insulation. In the middle of the category given to us, there are “experienced” who carry out not the first construction and, using only their feelings, say: “I have already built one house, and there I have warm floors. I put my hand, and the floor is warm. I didn't use a heater. What is he needed for? I saved."

There are also specialists who specialize in the installation of underfloor heating systems, who continue to be interested in the question of the need to use insulation, its thickness and the criteria in which it can change.

Here, in essence, for these 2 categories, as well as for everyone who wants to study this question, this article was written.

So, we answer the question: “Do I need a heater for a warm floor?”

First, let's agree on something:

We will observe the solution of 8 tasks.
The conditions for each will be similar. The difference will be only in the presence of insulation or in its absence, as well as in its thickness.
For all other characteristics, the "pie" of the warm floor will be similar. The area of \u200b\u200bthe warm floor, the length of the circuit pipe, the pipe laying step, the temperature of the coolant and the finish coating will be similar - ordinary clay tiles.
Since we are solving a problem for a small room, the floor of which is mounted on the ground (4 * 2.5 \u003d 10 m 2), we will use the design temperature for outside air -26 0 С (design air temperature for Voronezh and the Voronezh region).

General conditions for solving the problem:

Given:

The solution of the problem:
(click to enlarge)

no insulation	insulation 1 cm	insulation 2 cm	insulation 3 cm

As you can see, in a system without insulation, it can be completely possible to get a good heat flow per square meter of 90 W / m 2. But the heat loss in this case is huge 118 W/m 2 . Most 1 kW loss from 10 m 2 That would be such a "warm floor" turn upside down. It would be warmer. And what about our gas costs? If for the heating season with a normally designed heating system the owner would pay (conditionally) 10,000 rubles, then without a heater it would be useful for him to pay 23,100 rubles (roughly). The temperature of the surface of such a floor, when you touch it with your hand, completely gives a tangible true result, complemented by a bursting sense of pride from understanding your technical savvy and fidelity to the chosen strategy for “saving” money on insulation.	This solution is already on the technically right track. Such a solution allows you to save not only heat, but, as we have already seen, the means of the owner of the house. However, if you pay attention to the value of the heat flow down 59.1 W / m 2 through the insulation, it becomes clear that the thickness of the expanded polystyrene is still not enough. One of the fundamental features that directly affects the amount of heat loss is the resistance to heat transfer, which is measured in m 2 * W / K and when installing underfloor heating on the ground must be equal to 2.25 m 2 K / W. And at the moment, what is our resistance to heat transfer? 0.409 m 2 K / W. This is 5 times less! Let's add another 1 cm of insulation.	What do we have with the heat flow going to heat the room? 98.5 W / m 2? Did it increase insignificantly in comparison with the previous width of the insulation? Is it worth it to spend more on insulation? What about heat loss? 37.8 W/m2!!! This is an even savings for the owner of the house in terms of operating costs! If things go on like this, then very soon we will shake your hand and say: “You are one of the best Professionals in choosing the right thickness of insulation for underfloor heating systems and we can safely advise you to your Customers.” While we do not say it yet, but we cheer you up with cheers. Why? Therefore, the losses are still very significant and the resistance to heat transfer of the layers of the warm floor cake located under the pipes is insignificant. Look, it is currently equal to 0.659 m 2 * W/K. We follow further. plus 1cm	I would like to congratulate you. With what? Have we really reached that luminous value of the thickness of the insulation, which corresponds to the norms and is more optimal? I'll tell you: "Not yet." But pay attention to the amount of useful heat flux. You have reached 100 watts with 1 m2. This is a harsh indicator. From an area of 10 m 2 you get 1000 W of heat flow. 1 kW! Do you remember how it started? Without insulation, such a stream was oriented downwards for all the money! Thanks to the insulation thickness of only 3 cm, you managed to increase the required heat flux from 90 to 100 W per 1 m 2. Reduce heat loss to the ground from 118 to 27 W per 1 m 2 and reduce the cost of the owner of the house from 23,100 rubles to 13,000. However, it is too early to relax. What do we have with heat transfer resistance? 0.909 m2 * W/K. Already good. Add another 1 cm.
insulation 4 cm	insulation 5 cm	insulation 7 cm	insulation 8 cm

Don't pull the cat's tail. This is the name of adding 1 cm to the previous 3. Characteristics have changed in the top direction slightly. And the heating bills have been paid. Where is the profit? Where is the savings? I assure you it is even in this case, although not as significant as in the past. Compare the readings at least with the option when there is no insulation. Feel the difference? Well, then go ahead plus another 1 cm. We will draw conclusions later.	Now that's something. 5 cm is not one for you. That's four more! And what about our indicators? The required heat flow is 103 W / m 2. Heat loss - 16.8 W / m 2. In essence, 168 W from our 10 m 2 floor heating area according to the conditions of the task. What about heat transfer resistance? What about him? 1.409 m2 * W/K. Okay. Absolutely good. We are close to the target. I propose to change the strategy and add 2 cm at once.	This option almost reached the goal (or maybe the previous one?). The required heat flow practically does not increase, heat losses are no longer significantly reduced. Only 4.9W (49W over the entire surface). The thermal power of our 10 m 2 has increased from 1030 to 1045 watts. Just 15 watts. The resistance to heat transfer increased significantly from 1.409 m 2 * W / K to 1.909 m 2 * W / K. But it must be 2.25 m 2 K / W.	Finally, we have reached the finish line! Here it is an option when, with a heater thickness of 8-8.5 cm, we achieve a suitable resistance to heat transfer. What are our main indicators? Useful heat flow - 105 W from 1 square meter; heat loss - 10 W from the same meter; heat transfer resistance 2.159 m 2 * W / K.

Conclusions:

Underfloor heating needed. As we saw at the very beginning, this is as natural as the need for warm clothes in winter.
Should the thickness of the insulation tend to be normalized? In design, yes. But, in agreement with the Customer, this value can be changed. There is always a reasonable optimization based, among other things, on the criteria in which the system will be operated.
Not so much a conclusion as an addition to all of the above.
Sometimes there are owners of houses, and sometimes installers, who say that during construction, insulation has already been laid in the floor. For example, sand was brought in as soil, then it was thrombosed, then, after waterproofing, styrofoam or polystyrene foam 10 cm was laid on top of it. Later, a screed 8 or 10 cm wide was poured on top of it. Now it is necessary to do floor heating. And here the question arises: “Is it necessary to lay a heater in the“ pie ”of the warm floor?” Read no further. How would you answer this question?
Do a thought experiment.
November. For you to want to sit down. You sat on the curb. What are your feelings? Are you comfortable? The answer is obvious. At this time, your friend was walking by. He was carrying home some sheets of Styrofoam. Seeing your situation, he gave you one sheet, and you sat on it. There is already a layer of insulation between you and the curb. Has it gotten better for you? Again, the answer is obvious. And for now, imagine that you put polystyrene foam under the curb, and you yourself sat on top of it. What are the feelings now?
And now attention to the question: do you need a heater for the "pie" of a warm floor, if a heater is already laid under the reinforced concrete slab?
decide for you.
And this is another question: why did the designer or the foreman, or someone else, put insulation in the ground in this place.

Insulation for a warm water floor - types, tips for choosing and installing

Installation of underfloor heating is not a particularly difficult task and is carried out according to strictly regulated technology, using one or the other that performs certain functions.

Insulation for a warm water floor plays the role of a heat-insulating barrier that directly affects the efficiency of the system.

Do I need to install insulation under underfloor heating?

Qualified specialists say that heated floors installed using the technology are a guarantee of preserving thermal energy inside the room, since without a heater the installed floor can suffer up to 25% of heat loss in winter.

Do you need underfloor heating?

Underfloor heating insulation, the cost of which depends on, will allow you to save electricity by making it difficult for heat to penetrate down under the insulated wood floor in the house. Insulation for underfloor heating can be different, but the most popular is extruded polystyrene foam, which is a plate similar to polystyrene, but with the most practical characteristics.

For an insulating layer on the floor, a sheet of extruded polystyrene foam (penoplex) is used at least 3 cm wide.

So that the joints between the sheets do not allow heat to pass through and are very tight, the joints are additionally foamed and reinforced with a polymer sheet with a reinforcing network. In this case, your water heated floor will be resistant to moisture and have a long service life.

The following points are essential for the installation of an effective underfloor heating:

1. Concrete screed will retain and retain heat on the way down;
2. Foil insulation will reflect heat back into the room;
3. Insulation under the warm floor will retain maximum heat, reducing electricity consumption.

Which ones should be used?

In modern suburban construction and repair, several types of thermal insulation are used.

Each type has its own advantages and disadvantages. Before proceeding with the thermal insulation device, it is necessary to comprehensively study the capabilities of heaters, compare the properties of mineral wool and other favorites - glass wool, foam plastic, expanded polystyrene, etc.

The best insulation for a warm water floor should have a fundamental function - to reduce the radiation of thermal energy under the floor. In this way, the heat and the flow of warm air remain in the room, thereby reducing energy costs, while the efficiency and efficiency of a water heated floor remains constant. What kind of insulation is best to put under a warm floor in a house or apartment?

Today, the choice is not small.

In stores, you can now purchase a heater for a warm water floor with labels and purchase everything you need right away. Such plates of polystyrene foam are ready to work. Thermal insulation boards for underfloor heating have superior thermal and acoustic insulation, good water repellency and fire resistance.

Choosing a substrate for a warm water floor

Styrofoam for underfloor heating

Expanded polystyrene is available in sheets, it is easy to mount it on the floor base.

The thickness of the plates varies from 30 to 120 mm. The largest thickness of foam boards should be taken when there is an unheated basement under the floor. A plate thickness of 30 mm is mounted if a heated room is located under the ceiling. Expanded polystyrene must be protected from water penetration with a waterproofing film.

The disadvantages of polystyrene include low strength. Due to the fragility and low strength of expanded polystyrene, when constructing a concrete screed, it is necessary to reinforce the heat-insulating layer.

The advantages include low cost, due to which foam boards have become the most popular insulation, as well as Knauf warm floors in our country.

Mineral mats for underfloor heating

Insulation under floor heating

The advantages of mineral wool include the ability to fill the entire place, ensuring the solidity of the heat-insulating layer. The disadvantages of mineral wool include higher hygroscopicity. Mineral mats tend to absorb water and lose their characteristics in the process. The mineral wool layer needs a high-quality vapor barrier, which cannot always be at the highest level without the help of others.

For a substrate under a warm water floor, mineral heaters from different manufacturers can be used.

The line of favorite brands includes types of basalt and fiberglass insulation that can withstand severe overloads, which are intended for floor insulation in a house on screw piles, floor insulation on the first and basement floors.

Cork insulation for underfloor heating

Cork insulation impregnated with wax

To insulate the base under the "warm floor" you can use cork insulation soaked in wax. Mounted on adhesives. The disadvantages of cork insulation include sensitivity to moisture and biodegradation.

Before laying, you should take care of reliable sealing and vapor barrier.

Insulation of the floor with a cork, laying agglomerate panels under the floor covering is a good way to reduce heat loss at home. Although cork panels are inferior in terms of heat saving to synthetic m, they are completely appropriate.

Choosing the best insulation for underfloor heating.

Profile heat-insulating mats

Insulation for underfloor heating. Profile mats

Profile mats are provided for water-type underfloor heating systems.

They provide reliable thermal insulation of the ceiling and are covered with a vapor barrier membrane. This removes some of the problems in the form of the need for additional laying of the vapor barrier. On the surface of the heat-insulating mats there are protrusions designed for laying and fixing flexible pipes of the water-heated floor system.

The main task of the heat-insulating layer is to direct the thermal energy strictly upward, that is, into the room for which heating is needed. The thermal insulation layer prevents the penetration of heat through the lower floor slab.

Features of laying insulation

Scheme of the device of a warm water floor

To correctly make a warm floor, you need to take care of a sufficient layer of insulation, which will firmly protect the coolant from a concrete base or compacted soil.

To avoid these troubles, logs from a bar are first installed. Then, an insulating, heat-reflecting film or foil is laid out between the timber, followed by a system of coolant pipes.

After the pipe is poured with a gypsum or cement substance, and after drying, a finishing floor covering is made. The floor will steal about 10 cm of room height, but will be warm and comfortable in any frost. Heating and cooling of the floor will occur smoothly, because after turning it off it will be warm for some time, you can walk at home in socks or slippers in the most severe frosts.

What kind of insulation to put under the floor heating system? Let's find out what are the popular types of thermal insulation materials, their strengths and weaknesses. I will talk about 5 options for insulation, which I personally used during the repair process.

Types of materials and their description

Popular thermal insulation for underfloor heating:

Styrofoam;
extruded polystyrene foam;
Mineral wool;
Penofol;
Mats heat-insulating assembly for a heat-insulated floor.

Option 1 - foam

The most popular option due to the following advantages:

Availability. The material can be purchased at almost any hardware store;
Cheapness. The price per square meter is from 100 rubles per square meter;

Large range of products. You can purchase material with a density of 15 to 35 kg / m 3 and a thickness of 20 to 200 mm. For use on the floor, I advise choosing options with a density of 20 kg and a thickness of 30 mm;

Versatility. The material is suitable for water, infrared and electric underfloor heating.

The option also has disadvantages:

Low material strength. Under high loads on the floor covering, the surface may be pressed through. To avoid this, it is necessary to make a screed of at least 6 cm;
Installation inconvenience. It is difficult to tightly connect the sheets with your own hands, so the joints must be filled with mounting foam or the sheets must be fixed on the surface.

The process of floor insulation looks like this:

Illustration	Stage description
	Styrofoam is laid on the floor. The material can be laid without preparation on concrete screed, slabs or rough wood decking. The most important thing is to place the sheets tightly so that there are no gaps between them.
	Elements are fixed with dowels. Special fungi are used for fixing thermal insulation. All cracks are filled with cement mortar or mounting foam.
	The film is laid. The process is simple: the material is covered with 10 cm overlaps on the walls; joints are glued with ordinary tape.
	Foil is covered for infrared systems. Reflective material can be used for other types of floors, but it is not required. Penofol is often used instead of foil, it creates a reflective surface and makes the surface even warmer.
	A warm floor is laid on top of the insulated surface. It all depends on the type of construction. The surface is prepared with high quality and is suitable for any systems.

Option 2 - extruded polystyrene boards

Extruded polystyrene foam or, as it is also called, Penoplex, is an improved version of polystyrene. Its main advantages are:

High thermal insulation performance. Penoplex is 40% warmer than conventional foam plastic, which allows the use of thinner elements for insulation;

High strength. Of all the thermal insulation materials that I talk about in the review, this one is the hardest and most durable. Therefore, Penoplex is ideal for rooms with a high load on the floor;
Convenient connection system. The presence of grooves on the ends allows you to join the sheets very tightly. This increases the effectiveness of insulation and simplifies the work, you just need to combine the elements until they stop;

durability b. The service life of the material is 50 years or more. Extruded polystyrene foam is not afraid of moisture, mold, chemical attack.

Of the significant disadvantages, one can be distinguished: high cost. A square meter of insulation 5 cm thick will cost you 250-300 rubles.

Installation instructions are simple:

Illustration	Stage description
	Penoplex is laid on the floor. The sheets are just tightly joined to each other. The elements are trimmed along the edges, narrow sections can be laid in pieces, after which it is recommended to carefully fill all the cracks with mounting foam.

	Reinforcing mesh is laid but. If you are laying insulation under a warm water floor, then you can use this work option. It is simple, because you need to put a grid, and you can immediately attach underfloor heating pipes to it. It is convenient and reliable.
	It is possible to lay reflective material under the reinforcing mesh. This option allows you to reflect heat into the room, so I recommend not saving and putting a layer of foil or Penofol on the surface.

If you are laying an infrared floor, then the foil is not covered over the Penoplex, but over the screed, after pouring the surface under the heating mats, so the system will be much more efficient.

Option 3 - mineral wool boards

This version of insulation for underfloor heating system has the following features:

High quality insulation. Mineral wool has good thermal insulation characteristics and is excellent for constructions in which complete insulation of the cold surface is of the greatest importance;

Compatibility with all materials. If styrofoam and extruded polystyrene foam are not well suited to wood, then mineral wool is an excellent solution in all cases. For wooden floors, it is recommended to use mineral wool;
Environmental friendliness. The material does not emit any harmful substances into the air, is not damaged by rodents and does not support combustion.

The disadvantages are:

High price. For a square meter of high-quality mineral wool 5 cm thick, you will have to pay around 250 rubles;
Low moisture resistance. The material must be carefully protected from water, otherwise a fungus may occur over time.

The workflow looks like this:

Illustration	Stage description
	The surface is waterproofed. A polyethylene film can be laid on the surface. If you have a wooden base, then it is better to put a vapor-permeable membrane. The material should go on the walls by 10-15 cm, the joints must be glued with adhesive tape.
	Mineral wool is laid. The material is tightly packed on the surface. When cutting pieces, make them a little larger than necessary, this will allow the elements to fit tightly. Lay a damper tape along the walls immediately to create a deformation gap.
	If you have a wooden structure, mineral wool is laid between the beams. The material may be below the crate or be flush with it. Subsequently, the surface is covered with moisture-resistant slabs and the underfloor heating system is already laid on them.
	Foil is laid on top of the mineral wool. The material is placed with laps of 10 cm at the joints and the obligatory gluing of the joints with foil tape. This results in a continuous reflective surface that is suitable for both water and electric underfloor heating.

Option 4 - Penofol

This material is different from all the previous ones. Its main advantages are:

Cheapness. For a square meter of material with a thickness of 5 mm, you will pay about 50 rubles;
Ease. 40 square meters of Penofol weigh only 8 kg. It can be laid on any structures without weighting them;
Efficiency. Foamed polyethylene has high thermal insulation characteristics. The reflector on the front side ensures the preservation of heat inside the room. That is, it turns out that the foil on the warm floor is combined with a heater;

Penofol - material based on polyethylene foam with a reflector on the front side

Choice of options. The material may have a thickness of 3 to 10 mm.

The cons are:

It is not worth using this option as a full-fledged heat insulator in the private sector;
It is better to combine two materials, for example, extruded polystyrene foam 3 cm thick and Penofol 5 mm thick. This is quite enough to create a very high-quality insulation;
Before laying this material, it is necessary to prepare the surface.

The workflow looks like this:

Illustration	Stage description
	Waterproofing material is laid on the floor. The film is glued at the seams and put on the walls to a height of about 10 cm, the excess is easily cut off later.
	Penofol is laid on top of the film. It is positioned in the same way as the film. It is important to carefully straighten the material so that it lies without folds, and adjacent panels do not overlap each other. If you already have insulation installed and you need foil under a warm floor to create a reflective effect, then I recommend using Penofol instead. Due to the polyethylene layer, it is stronger and more durable.
	Joints are glued with special tape. This is a metallized adhesive tape with foil, which allows you not only to fasten Penofol, but also to create a continuous reflective surface throughout the room.
	An underfloor heating system is laid on top of the insulation. It all depends on the option you choose. Next, the screed device is made.

Beacons are placed on top of the structure and a screed is poured. The minimum thickness of the solution layer above the insulation elements is 30 mm, the maximum is 60 mm. This allows you to make the floor reliable and efficiently transfer heat from the system to the room.

Option 5 - special heat-insulating mats for underfloor heating

This option has the following advantages:

Convenience. The product is a sheet of extruded polystyrene foam, in the upper part of which there is a profile with grooves or bosses for laying underfloor heating pipes. The size of the recesses is made for a standard metal-plastic pipe with a diameter of 16 mm, so the laying work is carried out very quickly;

Choice of options. The thickness of the insulating layer can be from 20 to 70 mm. The configuration of the upper part may also differ, although this is not a fundamental point;
Fast installation process. The work takes a little time due to the fact that you quickly and efficiently lay pipes, and then you can lay tiles or lay flooring without additional preparation. If desired, you can pour the screed, this also happens quickly and easily.

The disadvantage is the high cost, you will have to pay 300 rubles per square meter. But when you consider how much easier the process is, the costs are worth it.

The working process:

Illustration	Stage description
	The floor surface is leveled. For this, cement mortar is most often used. The fewer flaws there are, the easier it is to lay a flat floor with minimal time. If plywood or OSB boards (oriented strand board) will be laid over the mats, then pay special attention to leveling.
	Preparing damper tape. The roll is unwound, the protective layer on the adhesive strip is removed from the back, you don’t need to remove a lot, separate about a meter, then the film is removed as it is laid.
	The tape is glued to the walls around the perimeter. The material is gently pressed to the surface, pay special attention to the corners. The tape is cut with an ordinary construction knife.
	The first row is laid along the wall. The photo clearly shows that there is a special protrusion at the junction that tightly connects the elements and prevents them from moving, providing a reliable and even base for the underfloor heating system. Docking is carried out carefully so as not to damage the connection.
	Laying is done over the entire surface. If a strip needs to be cut somewhere, it can be used on the other side, thanks to the connections, when using these mats, there is almost no waste left.
	The pipe is laid. It is simply guided along the line, it is most convenient to push it with a light step of the foot.
	The pipe is laid over the entire area. Thanks to the bosses, you can easily place the warm floor correctly and do not bend the pipe. Next, the floor covering is laid or the screed is poured.

If it is not necessary to insulate the floor under the heating system, you can use mats without a layer of insulation. With their help, installation will be much faster than on an unprepared surface.

Output

Using the review as an instruction, you can easily select the insulation under the warm floor and lay it correctly. The video in this article will help you better understand the important points of the workflow. If something still remains unclear, ask in the comments.

Currently, many install engineering systems in the form of underfloor heating at home. They replace the classical (radiator) method of heating, as well as the use of convectors, heating panels, fan heaters, etc. as heat sources for space heating.

One of the varieties of such a system is a warm floor of the electric type. It is installed instead of the main heating system during the construction of private mansions, repair work in existing residential premises. Electric floors can also serve as an additional source of heat throughout the room or heat the desired spaces (kitchen, bathrooms, nursery, etc.).

The use of warm electric floors in apartments and houses is currently not a tribute to a fashion trend, but a necessity that is caused by such factors:

creation of comfortable conditions;
health care;
economy.

The essence of creating a floor of an electrical structure is laying a special cable, electric heating mats or sections under the main floor covering. A huge plus of such heating is that it can be carried out at will, as well as programmed to turn on and off at a certain time.

A warm electric floor is a complex structure, its performance depends on the correctly selected materials, components and devices, as well as the installation of all components in their place. Insulation is an important component of such a system. Properly selected for specific needs, it will direct and retain heat in the room, help save electricity consumption and household money.

A well-known fact from the basics of physics: warm air in a room tends to rise to the top, while at the same time it remains cold below. Such fluctuations negatively affect the well-being of a person. You can get a cold, there is a feeling of discomfort. The body will be healthy only when the feet are warm.

The installation of an electric underfloor heating contributes to the uniform distribution of heat, proper heat exchange and the creation of the necessary microclimate in the room. The creation technology is simple, well-established by companies specializing in the installation of underfloor heating. It applies to all types of premises. Such a floor is safe in operation and does not require maintenance during the operation of the system.

When creating an electric underfloor heating, you must adhere to 5 prerequisites:

it must occupy at least 70% of the area of the room in which it is installed;
it is necessary to use a resistive one when arranging - preferably a two-core heating cable, always shielded, infrared film or special electrical mats;
high-quality insulation must be selected and correctly laid;
the screed must be made necessarily sand-cement in compliance with the required proportion, it must be no more than 50 mm thick;
as a floor finish after installation of the electrical system, you can use ceramic tiles, natural and artificial stones, laminate, carpet, parquet and other materials that will match the installed electrical system.

Electric floor systems

Currently, there are electric floor heating systems cable, rod, liquid and film. Cable floors appeared in the 90s. A special shielded cable heats the floor surface to the set temperature. It is set on a thermostat that responds to the signals of a temperature sensor or a special external device that records the air temperature in the room. The heating cable can be mounted in special mats with a certain pitch, which speeds up the process of installing underfloor heating.

A warm electric floor of a rod type is a coal heating element. They are connected by conductors and represent a grid. Each carbon element is a separately functioning device. This is very important - if one of them fails, the rest will work.

The electric fluid system is polyethylene pipes of a certain diameter filled with a heat-conducting liquid, inside of which there is a heating core. The pipes at their ends have a coupling on one side and a damper device on the other. The latter compensates for the expansion of the antifreeze liquid. Such a system is connected to the mains using a special regulator.

A polymer film is a product with heating elements deposited on it, which emits heat in the long-wave range. Film thickness - no more than 3 mm, width - 0.5 ÷ 1 m; it has, depending on the production technology, different heat transfer.

The polymer film is not used for laying under tiles.

thermal insulation requirements

Why do we need thermal insulation (it is also called a heater) when arranging warm electric floors? During the operation of such a floor, heat losses occur, which are associated with the heating of the cable / mat / film and the floor. Laying a special material called heat-insulating will help to avoid heat loss. It will be the basis on which the components of the warm floor are mounted.

In the distribution network, materials with thermal insulation properties are presented in a large assortment, it is not difficult to buy them. They are made from various components in the form of rolls, panels, films and membranes. Not all materials are suitable for creating an electric floor heating. The requirements for thermal insulation material for electric underfloor heating are as follows:

must have a low coefficient of thermal conductivity;
be resistant to high temperatures;
easy to fit and not deform in the process;
must even out small irregularities in the base;
must withstand heavy loads;
have soundproof properties;
withstand the action of aggressive environments;
have a high degree of strength;
do not absorb moisture;
be electrically safe;
be made of environmentally friendly materials (should not release toxic substances into the environment);
have a long service life.

The main types of thermal insulation

Heat-insulating materials for arranging electric floor heating are made from natural and synthetic raw materials. From a large assortment, the following heat-insulating materials can be distinguished.

Natural thermal insulation is made using a special technology from cork oak bark, which is why it is called cork. Such insulation is supplied to the distribution network in the form of rolls 10 m long and 1 m wide. The thickness ranges from 1 to 10 mm. During installation, there is no need to glue it, it is easy to install, has excellent sound and heat insulation properties, can have a rubberized base, which eliminates the need for additional waterproofing.

Installation must be carried out using heat-reflecting material, as in the design there is no obligatory component of the electric floor, which allows reflecting heat to the floor surface.

Modern heat-insulating materials of artificial origin for the electric floor include the following products:

Penotherm. It is made of porous polypropylene, has a cellular structure, without marking and with it. The latter facilitates the installation process. A foil made of aluminum serves as a heat-reflecting layer. Depending on the quality of the installation, it can increase the thermal efficiency by up to 70%. Insulation is supplied to the distribution network with a width of 1200 mm and a length of 10 and 30 m, of various thicknesses.

"Penofol". Made from polyethylene foam. It has a foil layer 100 microns thick. Available in four types with different surfaces. Penofol type A has a foil surface on one side, type B has a foil surface on both sides, type C has one side foiled, and the other has an adhesive layer, type ALP also has a foil side, and on the other it is located polyethylene film. The rolls have a thickness of 3÷10 mm and a length of 10÷30.

"Folgoizolon". It is made of polyethylene foam and has air bubbles in its design, as well as a foil layer. It is produced in two modifications: from cross-linked (PPE) and non-cross-linked (NPE) polyethylene foam, differing in service life. For products made of cross-linked polyethylene, it is much higher. Thanks to the material with high technical characteristics, it retains heat well. Supplied with and without underfloor heating markings in rolled sheets of various thicknesses and lengths. It is an ideal heat-insulating material for arranging underfloor heating on balconies, loggias and other cold rooms.

The foil layer must have a lamination.

An additional insulation can be a polyethylene laminated film with markings for underfloor heating. Use products with a thickness of 3 or 5 mm, a width of 1 m and a length of 10 to 30 m.

Mounting Features

Properly selected material for thermal insulation not only makes the stay in the room comfortable, but also reduces the consumption of electrical energy. It depends on the technology for performing electric underfloor heating.

All work on the arrangement of an electric underfloor heating is reduced to the following operations:

ground preparation;
installation of thermal insulation;
installation of heating cable/mats/film;
screed execution;
floor finish installation.

At the stage of preparing the base, it is necessary to dismantle the old screed, level the surface as much as possible (differences should not exceed 10 mm) and clean it from dirt and dust. If necessary, the base surface must be waterproofed.

Before proceeding with the laying of thermal insulation for electric underfloor heating, it is necessary to determine its thickness. It has been experimentally established that over unheated premises it should be 50 ÷ 100 mm, and for interfloor ceilings - 20 ÷ 30 mm. Seams and joints of thermal insulation must be glued with special tape (foiled), between the wall and the screed - damper tape. When laying several thermal circuits with different temperatures, a T-shaped damper profile is used to separate them.

Thermal insulation material is laid not only on the base of the floor, it must be laid along the perimeter of the wall to a height of up to 20 mm.

Installation of electric heating elements must be carried out taking into account the characteristics of the system being laid (cables one or two cores, mats, UV films).

It is better to screed the floor with a sand-cement mortar with the addition of special plasticizers that will prevent cracking. Its thickness should be at least 3 cm. After drying, they begin laying the floor finish. They can be tiles, parquet, linoleum or other types. They are installed according to the manufacturer's recommendations.

Video

A heat-insulating layer under a warm electric floor is not a luxury, but a necessity. It will help to evenly distribute heat from the heating elements, save it and direct it in the right direction. Poorly executed installation at any stage of creating electric underfloor heating will entail negative consequences. This will affect comfort, increased energy consumption and, as a result, waste of money.

Due to the rapid development of modern technologies for home improvement, various devices are increasingly being used to increase the comfort level of residents. One of these devices is underfloor heating. And for its productive operation and functioning, a number of materials are required, among which thermal insulation occupies a special place.

The task of underfloor heating, regardless of type and configuration, is to ensure uniform distribution of warm air in the room. Since everyone knows that cold air accumulates at the bottom, and heated air rises, the difference in temperatures for a person is very noticeable. The system of warm electric or water floors minimizes these temperature fluctuations in the dwelling, creating an acceptable and comfortable heat exchange.

The main feature of the device can be considered a heat-insulating substrate, which, along with the entire heating system, is responsible for maintaining heat. Among the proposed range of similar products on the modern market there are a number of materials that are used to equip the system.

In order not to be mistaken with the choice of raw materials, one should proceed from the tasks that the products will solve in the complex of the entire installation of underfloor heating.

Among the main functions of the heater, it is worth highlighting the following points:

The presence of thermal insulation reduces the natural loss of heat that escapes through the coldest parts of an apartment or house to the outside or into the ground. In the absence of any materials for insulation, the level of exit of warm masses from the room through the floor surface is 20%.
Due to the laying of insulation, thermal energy circulates proportionally over the entire heating area, eliminating unnecessary heating of floors and other components of the building structure, which are located under the floor.
Due to thermal insulation, you can save money spent on heating your home.
In addition to the main functions, the material provides additional sound insulation, which is important in multi-storey residential buildings.
The properties of thermal insulation products make it possible to create a protective barrier that prevents moisture from entering basements or soil through the floor covering into the dwelling.

Insulation for underfloor heating

Device "warm floor"

Heated floors today are one of the most attractive systems for additional space heating, both in individual housing construction and in apartment buildings. All manufacturers of "water-heated floor" systems, when installing this system, recommend that the floor be thermally insulated in order to prevent the radiation of thermal energy in undesirable directions. In other words, by installing a "warm floor" on a concrete screed, you will not heat the neighbors from below, the basement or the foundation of the house. By laying insulation on concrete under the PENOPLEX ® water-heated floor, you can avoid unnecessary heat losses and energy costs. In most cases, additional waterproofing of PENOPLEX ® thermal insulation under a warm floor is not required, since this material has almost zero water absorption.

This is especially true of the bathroom, since this room is a place with a high level of humidity. Thermal insulation of the bathroom will prevent the formation of condensate, which adversely affects the finish of the room.

Installation instructions:

The thermal insulation layer of PENOPLEX ® boards is laid on the floor panel. Directly on them, a “warm floor” construct is carried out (according to the recommendations of suppliers). If the hydromembrane is located under a layer of PENOPLEX ® boards, flexible heating pipes can be attached directly to the boards. To prevent cement “milk” from getting into the seams between the insulation boards, the seams must be closed before pouring the screed (glued with adhesive tape);
If a hydro- or vapor barrier membrane is placed on top of the PENOPLEX ® boards for fixing flexible heating pipes, an additional layer must be used to ensure complete waterproofing. Particular attention should be paid to the execution of expansion joints. In addition, measures should be taken to prevent the formation of heat-conducting bridges at the joints between the plates;
It is not recommended to lay laminate flooring on PENOPLEX ® without a load-distributing screed device. As a screed, you can use both a reinforced screed made of DSP with a minimum thickness of 40 mm, and two layers of plate materials (GVL, DSP, etc.) in the overlap of the joints.

Well-organized warm floor insulation at the construction or insulation stage will bring you a visible bonus in the form of significant savings on home heating, a long period of maintenance-free operation and, most importantly, comfort and coziness for the whole family. Plates PENOPLEX ® are the most optimal insulation for the floor.

How to insulate the floor between heated rooms. The design of the "warm floor"

The role of PENOPLEX ® in the case of operation of underfloor heating between heated rooms is to reduce the degree of radiation of thermal energy in undesirable directions. It is in this case, due to the lack of heat flow dissipation, energy costs are significantly reduced (otherwise, not only your floor is heated, but also the ceiling of a neighbor or basement, respectively).

When insulating floors between heated rooms, including in the construction of a "warm floor" (required), the required thickness of PENOPLEX ® is 40 mm.

Estimated consumption of materials

Oriented consumption of materials when insulating an open balcony with a concrete fence (loggia) with an area of 4 m2, with a ceiling height of 3 m.

What insulation to choose for a water heated floor

Why do you need insulation under water floors
- Plates
- Roll thermal insulation
- Features of laying insulation

Almost every instruction for self-laying a water floor indicates the need to use insulation. The insulating layer helps to evenly distribute heat in the room. Insulation for a water-heated floor reduces heat losses and provides uniform heating of the room.

Why do you need insulation under water floors

According to the installation instructions, it is necessary to include a layer of thermal insulation in the cake under a warm water floor. Although some installation teams miss laying the insulating layer, this is a gross violation of the rules for laying the heating system.

Why do you need a heater at all?

A special heat-reflecting substrate under the water-heated floor serves as a kind of screen that prevents thermal radiation from escaping in an unnecessary direction. Simply put, with the help of insulation, the heating system does not heat the apartment of the neighbors living below, but its own housing.
The use of a substrate serves another purpose related to the peculiarity of underfloor heating. The substrate evenly distributes thermal energy throughout the room, allowing you to stabilize the convection heat flow in one direction and at the same speed of movement.
Heat-insulating mats for a water-heated floor with bosses make it easier to install a water circuit. The device of such a system includes special latches, due to which the laying and fixing of the pipe is carried out quickly and reliably.

Types of heaters for underfloor heating

Although there are a large number of very different thermal insulation, in fact, it can be roughly divided into just two categories.

Plates

This category includes polystyrene foam and polystyrene foam under a warm water floor. The advantage of polystyrene systems is high strength and ability to withstand mechanical stress.

This group should also include a profile mat for installing a warm water floor. The use of a profile system (lugs or guide grooves) is very convenient for pipe laying.

Profile guide mounting mats for a water-heated floor, after laying the pipeline, are poured from above with a small layer of adhesive solution. After drying for 1-2 days, you can start operating the heating system.

Styrofoam for underfloor heating is an unprofitable option. Plates after laying are easily deformed, after which the thermal insulation ability of the material decreases.

Roll thermal insulation

Enjoys well-deserved popularity. Foil reflective thermal insulation for a water-heated floor allows you to reduce the thickness of the "pie". The foil effectively reflects heat radiation.

Foil insulation for a water-heated floor often has a special marking that facilitates the installation of a heating circuit. The thickness of the roll-type substrate does not exceed 1-1.5 cm.

Mineral heaters are rarely laid, since a protective layer will need to be laid on top. It is not advisable to use mineral material for the substrate.

According to customer reviews, one of the best solutions is to purchase a heater such as Teploizol.

You can also use cork insulation. Cork insulation has good performance in terms of: compressive strength, sound insulation and lack of adhesion to cement mortar.

When deciding which thermal insulation material to choose, one should be guided by the technical characteristics of the heated room. Possible disadvantages of the substrate should be taken into account: cost, thickness, maximum allowable compressive load, etc.

How should a water floor cake look like in layers

Preparation of the pie under the floors should be carried out in strict accordance with the manufacturer's recommendation. Installation work is carried out as follows:

Laying a warm water floor on mats, as shown by a comparison of heat-insulating materials (their technical characteristics and difficulties associated with installation), is more appropriate. Permissible load on the polystyrene foam system is 50 kN/m². The weight of the structure allows installation even in high-rise buildings on the last floors, where the use of a concrete cake is prohibited.

In addition, the laminated extruded polystyrene foam with bosses is resistant to moisture, easy to install and facilitates the laying of the water circuit. The only disadvantage of polystyrene material is its cost. But if we take into account that plastic mats do not need additional components for fixing pipes, subsequent screeding, then the difference in price becomes not so significant.

Thermal insulation for a warm electric floor, which one to choose?

The use of warm electric floors in apartments and houses is currently not a tribute to a fashion trend, but a necessity that is caused by such factors:

creation of comfortable conditions;
health care;
economy.

The structure of the electric floor heating

Features of electric floor heating

When creating an electric underfloor heating, you must adhere to 5 prerequisites:

it must occupy at least 70% of the area of the room in which it is installed;
it is necessary to use a resistive one when arranging - preferably a two-core heating cable, always shielded, infrared film or special electrical mats;
high-quality insulation must be selected and correctly laid;
the screed must be made necessarily sand-cement in compliance with the required proportion, it must be no more than 50 mm thick;
as a floor finish after installation of the electrical system, you can use ceramic tiles, natural and artificial stones, laminate, carpet, parquet and other materials that will match the installed electrical system.

Electric floor systems

The polymer film is not used for laying under tiles.

thermal insulation requirements

must have a low coefficient of thermal conductivity;
be resistant to high temperatures;
easy to fit and not deform in the process;
must even out small irregularities in the base;
must withstand heavy loads;
have soundproof properties;
withstand the action of aggressive environments;
have a high degree of strength;
do not absorb moisture;
be electrically safe;
be made of environmentally friendly materials (should not release toxic substances into the environment);
have a long service life.

Types of thermal insulation

The main types of thermal insulation

Installation must be carried out using heat-reflecting material, as in the design there is no obligatory component of the electric floor, which allows reflecting heat to the floor surface.

Thermal insulation cork

Modern heat-insulating materials of artificial origin for the electric floor include the following products:

Penotherm. It is made of porous polypropylene, has a cellular structure, without marking and with it. The latter facilitates the installation process. A foil made of aluminum serves as a heat-reflecting layer. Depending on the quality of the installation, it can increase the thermal efficiency by up to 70%. Insulation is supplied to the distribution network with a width of 1200 mm and a length of 10 and 30 m, of various thicknesses.

Heater "Penoterm"

"Penofol". Made from polyethylene foam. It has a foil layer 100 microns thick. Available in four types with different surfaces. Penofol type A has a foil surface on one side, type B has a foil surface on both sides, type C has one side foiled, and the other has an adhesive layer, type ALP also has a foil side, and on the other it is located polyethylene film. The rolls have a thickness of 3÷10 mm and a length of 10÷30.

Material for thermal insulation "Penofol"

"Folgoizolon". It is made of polyethylene foam and has air bubbles in its design, as well as a foil layer. It is produced in two modifications: from cross-linked (PPE) and non-cross-linked (NPE) polyethylene foam, differing in service life. For products made of cross-linked polyethylene, it is much higher. Thanks to the material with high technical characteristics, it retains heat well. Supplied with and without underfloor heating markings in rolled sheets of various thicknesses and lengths. It is an ideal heat-insulating material for arranging underfloor heating on balconies, loggias and other cold rooms.

Material "Folgoizolon"

The foil layer must have a lamination.

An additional insulation can be a polyethylene laminated film with markings for underfloor heating. Use products with a thickness of 3 or 5 mm, a width of 1 m and a length of 10 to 30 m.

Insulating film

Mounting Features

All work on the arrangement of an electric underfloor heating is reduced to the following operations:

ground preparation;
installation of thermal insulation;
installation of heating cable/mats/film;
screed execution;
floor finish installation.

Thermal insulation material is laid not only on the base of the floor, it must be laid along the perimeter of the wall to a height of up to 20 mm.

Installation of electric heating elements must be carried out taking into account the characteristics of the system being laid (cables one or two cores, mats, UV films).

Video

The choice of insulation for a water heated floor

The device of a water heated floor requires competent design and strict adherence to technological standards. The choice of insulation is one of the important points. Consider the main types of heat-insulating materials, their properties and characteristics.

Which heater is better

The heater is an obligatory element of a heat-insulated floor. Without it, the system will not be economical, and most of the energy will be wasted on heating the underlying floor or ground floors. This issue is especially acute when arranging the system on the ground.

So, what heat-insulating materials should be used when installing water-heated floor systems? In general, any material that meets certain characteristics is acceptable. First of all, it must be distinguished by a sufficient level of thermal insulation, also be resistant to moisture and chemicals from the concrete screed, and have sufficient rigidity.

In one way or another, all these requirements are met by such materials:

expanded polystyrene (polystyrene);
extruded polystyrene foam;
mineral wool boards;
foamed polyethylene (penofol);
natural cork.

Let's consider each of them in more detail.

Styrofoam

Expanded polystyrene (EPS) is popularly called Styrofoam. This material is obtained from polystyrene by foaming. In addition to polystyrene itself, the composition of the insulation includes a large number of additives and modifiers that improve its properties. Thanks to foaming materials, up to 98% of the volume of PPS consists of air bubbles.

Consider the characteristics and properties of expanded polystyrene. The heat transfer coefficient, which is the main characteristic of thermal insulation materials, in expanded polystyrene varies from 0.030 to 0.047 W / m ° C. It depends on the manufacturer and on the density of the material. PPS is produced in different densities, on which the rigidity and weight of the material depend. In this case, the thermal conductivity depends little on the density.

Expanded polystyrene refers to combustible materials. Also, when heated to a relatively low temperature (about 80 degrees), harmful substances can be released from it. Other features of this material include:

resistance to fungi and microorganisms, but the material can be destroyed by rodents;
PPS poorly absorbs water (not hygroscopic), which is convenient when it is installed in a wet screed.

Expanded polystyrene is convenient to use and is often used in underfloor heating systems.

Extruded polystyrene foam

Extruded polystyrene foam (EPS) is a type of expanded polystyrene. It is produced in the same way as PPP, the only difference is in the method of obtaining granules. Its characteristics include low thermal conductivity of 0.029 - 0.034 W / m ° C, not high hygroscopicity.

Various types of XPS are produced, with a density of 25 to 45 kg / m³. In terms of thermal performance and lightness, it surpasses expanded polystyrene up to the PSB-35 grade and is similar to the characteristics of high-density PPS.

This material is tougher, better resists mechanical stress than expanded polystyrene, so it is more convenient to use and it is less destroyed. The main disadvantage is its higher price.

Please note: Both XPS and ordinary polystyrene foam are produced in a special modification for underfloor heating, in which a system of special grooves and channels is made on the upper edge of the plate for laying a floor heating pipe. This simplifies the job.

Mineral wool boards

Rigid rock wool slabs are sometimes used for underfloor heating systems. Its characteristics are similar to ordinary mineral wool. The difference is in rigidity and ease of installation. The main positive characteristics of mineral wool include:

zero flammability - the material is not exposed to high temperatures;
high soundproofing characteristics;
good thermal insulation properties;
chemical resistance.

Rigid mineral wool boards with a density of 175 to 200 kg/m³ are used for screeding, the thermal conductivity coefficient of which is about 0.039 W/m °C. The main negative property of mineral wool is hygroscopicity and vapor permeability. Because of this, when installed in a wet screed, they require careful hydro and vapor barrier.

Foamed polyethylene

Recently, polyethylene foam has been used for thermal insulation of underfloor heating. It is a rolled material with a thickness of 3 to 10 mm. Foamed polyethylene can also be foil-coated on one or both sides. Foiling allows you to create a reflective layer for infrared rays. The use of foiling allows you to reduce the thickness of the required heat insulator.

However, there is a nuance: the reflection of infrared rays by such a layer is difficult in a solid body, such as a cement screed. But still, the use of such material can significantly save on the height of the screed. This will not reduce the height of the room.

According to its thermal characteristics, foamed polyethylene is similar to expanded polystyrene and other materials. The thermal conductivity coefficient of this material in a dry state is in the range of 0.037 - 0.049 W / m ° C, while it must be borne in mind that the foamed polyethylene absorbs water, while its thermal insulation properties decrease.

It is also important to know that foil can be corroded by chemicals in the concrete mix. To eliminate this problem, many manufacturers produce sheet material that is coated on top of the foil with special polymer films.

Natural cork

For water-heated floor systems, a natural heat-insulating material is also used - cork. The heat transfer coefficient of cork is 0.034 and is similar to the best artificial materials. The main positive characteristic of cork is naturalness. It does not include foreign chemical additives and harmful substances.

The main disadvantage is the high cost. The use of natural cork in a cement screed of a warm floor is justified mainly by its naturalness. But the question arises: is it worth pouring expensive and natural material into cement.

Cork is a relatively hygroscopic material. It can absorb up to 12%. In order to protect against getting wet, the cork insulation must be closed with a dense layer of polyethylene or polyvinyl chloride film with or without foil.

"Pie" underfloor heating

After analyzing the possible types of heaters for a water-heated floor, we will analyze the composition directly, the so-called pie. After all, the quality of the system depends not only on the correct choice of insulation, but also on proper installation. In what order are all layers of a water-heated floor mounted?

The order depends on what the system is mounted on. If the underfloor heating device goes to the ground base, then first of all it is advisable to arrange a rough concrete screed, on which the cake will be laid further.

insulation of the required thickness, and when installed on the ground, the thickness of the insulation can reach 150 mm, and for ordinary floors, the thickness of the insulation is selected up to 50 mm;
if the insulating material is not covered with a protection on top or a pipe laying system is not arranged on it, then it must be covered with a vapor barrier film to protect it from moisture from the cement mortar (except for foam plastic and XPS);
further, a special panel for laying pipes or a reinforced frame is installed to create rigidity;
the pipeline is attached to the frame or to the panel.

The whole system is ready for pouring the screed and installing a decorative floor covering.

Underfloor heating scheme.

When choosing a heat-insulating material for a water-heated floor, you need to focus on financial capabilities and availability. For most applications, extruded styrofoam or conventional styrofoam boards will do. If it is not possible to arrange a thick screed, polyethylene foam is used. Mineral wool boards are more often used when installing a system in a wooden floor. But it is also possible to use it in a cement screed. Cork - for connoisseurs of natural materials.

In one way or another, all these requirements are met by such materials:

expanded polystyrene (polystyrene);
extruded polystyrene foam;
mineral wool boards;
foamed polyethylene (penofol);
natural cork.

Let's consider each of them in more detail.

resistance to fungi and microorganisms, but the material can be destroyed by rodents;
PPS poorly absorbs water (not hygroscopic), which is convenient when it is installed in a wet screed.

Expanded polystyrene is convenient to use and is often used in underfloor heating systems.

This material is tougher, better resists mechanical stress than polystyrene foam, so it is more convenient to use and it is less destroyed. The main disadvantage is its higher price.

Please note: Both XPS and ordinary polystyrene foam are produced in a special modification for underfloor heating, in which a system of special grooves and channels is made on the upper edge of the plate for laying a floor heating pipe. This simplifies the job.