What insulation to choose for a water heated floor. Choosing a heater for a warm water floor: the advantages and disadvantages of thermal insulation materials The thickness of the insulation for a warm water floor

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.

The choice of insulation thickness is primarily related to the technical parameters of the room. Where the ceiling height allows, it is best to use thick polystyrene plates with markings or a ready-made substrate with recesses for pipe installation. If the distance to the ceilings is critical, it is better to choose foil insulation.

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.

If you plan to install underfloor heating yourself, it is better to choose polystyrene boards with markings (with bosses). In this case, it will be much easier to lay the heating circuit.

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 you consider that plastic mats do not need additional components for fixing pipes, subsequent screed, then the difference in price becomes not so significant.

Features of laying insulation

When installing insulation, you should take into account the types of mats used, since the nuances of laying the material depend on this:

A foil substrate must be laid on top of the foam. A reinforcing mesh is laid, along which pipes are installed.
The thickness of the mats varies from 5 to 10 cm. It is allowed that the thickness of the cork sheet substrate be reduced to 2-3 mm.
The joints of the insulation are glued with adhesive tape. The plates are fixed with anchor dowels and adhesive.
The foil material is laid in such a way as to best reflect heat, i.e. metal side up.

Some installation details are indicated in the instruction manual. Strict adherence to the manufacturer's recommendations is the key to high heat transfer heating with underfloor heating.

We are all accustomed to insulating our homes lately. The main activities in this direction are related to the installation of heat-insulating materials on wall panels. The presence of a layer of insulation significantly reduces the intensity of heat transfer between the walls and the outside air. It is the preservation of heat inside residential premises that is the key to a comfortable stay, even with powerful heating equipment.

Warming is a task that concerns not only the structural elements of a residential building. When using a water floor, you also cannot do without thermal insulation. What is the need for thermal insulation in this case and what are its functions, we will understand in more detail.

The main task that thermal insulation performs in underfloor heating

The home heating systems we rely on are designed to provide us with efficient heating. In houses where radiators are installed, heat enters the heated room due to the contact of the surface of the heating devices with the air mass. As a result of heat exchange, up to 60% of the heat is used to heat the internal space as a result of air convection. Water heated floor in this regard is much more effective. By heating the floor surface, heat is evenly distributed inside the room, creating comfortable living conditions.

It is possible to achieve high efficiency of the underfloor heating system due to the correct installation and laying of all structural elements. Not the last place in this regard is played by thermal insulation for your warm floor, the water principle of operation. An improperly laid insulation layer, or lack of it, will cause your heating system to run at 50% empty. The heat from the heating circuit should go up, not down, heating the concrete screed or wooden structure.

On a note: experts say that a warm water floor without insulation leads to significant heat losses in the winter. Up to 50% of thermal energy is spent on heating the ceiling in the basement. The lack of insulation for underfloor heating on interfloor ceilings causes an insufficiently comfortable temperature in the heated room.

To avoid such troubles and get the maximum possible efficiency from the operation of the heating system, you will need a heater, on top of which the water circuit loops are then laid. Insulation can be made by various materials, each of which has its own characteristics and technological parameters. Styrofoam, which is familiar to all of us, extruded polystyrene foam and mineral wool, will allow, due to its low thermal conductivity, to create the necessary heat-insulating layer. Laying of thermal insulation is carried out depending on the type of flooring and the chosen installation scheme for the water floor pipeline. The method of laying water circuits and the further operation of the entire heating system depend on the choice of material, its technological characteristics.

For clarity, the following example can be given:

The previously used foam plastic has a density of 20-22 kg / m 3, however, in accordance with the technology for laying warm water floors, the density of the insulating material must be at least 35 kg / m 3 for interfloor ceilings and 50 kg / m 3 for floor equipment on the ground floor. The presence of such restrictions on thermal insulation materials is caused by technological factors that are determined by the very principle of operation of heating floors.

The water floor is a low temperature heating system. The floor in a heated room should not heat up above 30 0 C. Exceeding these parameters will create discomfort inside the room. A negatively high floor heating temperature will affect the design features of the floor covering, and the heating devices will work with increased load. The presence of a heat-insulating layer of the required thickness will eliminate heat losses during the operation of water circuits, and will create optimal conditions for heat to spread in the right direction. A smaller thickness of thermal insulation will lead to the fact that heat will go into the underground. The large thickness of the insulating material will be a serious obstacle to heating the floor and flooring. In this case, the operation of warm water floors will be fundamentally disrupted.

What is the basis for the choice of insulating material

The basis for a warm floor is the so-called "layer cake" - a stacked structure in which each layer performs its specific functions and tasks. Insulation in this pie occupies one of the leading places, so a lot depends on the quality of the insulating material, its composition and structure. Thermal insulation must meet any changes in the operating conditions of the heating communication. The safety of an insulating material is one of the main factors in determining its choice.

The second most important technological parameter of thermal insulation materials is thermal conductivity. There is a close relationship between the thickness of the material and the coefficient of thermal conductivity. The proposed figure shows the parameters of various building materials used in a domestic environment.

The advantage of synthetic insulating materials and mineral wool is that with a small thickness, they have good thermal conductivity. When it comes to the installation of underfloor heating on interfloor floors or in wooden buildings, the small width of heat-insulating materials and their low weight play a decisive role.

Therefore, based on the data presented, it is easy to draw the following conclusion. Thermal insulation for warm water floors is created from materials with the following characteristics:

low coefficient of thermal conductivity;
fire resistance;
moisture resistance;
soundproofing;
technological compatibility with other materials.

The thickness of the insulation is determined by the texture and structure of the material. When buying insulation materials, be guided by the given parameters. The price in this case does not play a special role. Today, all materials offered in the trading network have approximately the same cost. In the general context of costs for underfloor heating equipment, the price of thermal insulation is not critical.

How thick should the insulation be?

The distribution network offers materials of a certain standard thickness. What thickness of thermal insulation is required in your case is determined by the conditions of the heating system project. The laid layer of thermal insulation in the case of using extruded polystyrene foam on the ground floor must be at least 100-115 mm. In the absence of expanded polystyrene of the required thickness, the thermal insulation is laid in two layers (50 + 50 mm).

For laying water floors on the concrete floor of the second floor, you will need a much thinner thermal insulation layer, 25-35 mm. We have already talked about the density of foam plastic earlier. The optimal density for thermal insulation foam should be 38-45 kg/m 3 .

Features of the practical use of various insulating materials

Styrofoam

Let's start with the fact that the thermal insulation is placed at the very bottom of the puff cake, directly on the rough coating. Before laying the thermal insulation layer, waterproofing is laid on the subfloor and only after that the laying of the thermal insulation layer begins. Let us consider separately how work is performed with the most common and popular materials.

Let's start with styrofoam. The material is available in the form of sheets or plates. This form is very convenient for installation work. The thickness of expanded polystyrene may vary. The thickness of the sheets varies from 30 to 120 mm. For installation work of all categories, especially in the case of underfloor heating, a type of expanded polystyrene is used - penoplex (extruded polystyrene foam).

Expanded polystyrene has an extremely low thermal conductivity, it is very convenient and practical in the laying process. However, this material has a significant drawback, insufficient hardness.

Important! Do not forget that penoplex is a fragile and fragile material, however, to give strength and rigidity to the entire subsequent structure of the water floor, you will need a concrete screed or a stable flooring system.

In order to get rid of this drawback, when forming the cake, reinforcement is used for a concrete screed, or additional flooring is made from plywood slabs or GVL sheets.

A simpler way out of this situation is to use a cheap analogue - ordinary foam.

For foam plastic, the optimal thickness of the heat-insulating layer is at least 100 mm. When equipping underfloor heating on floors, the thickness of the foam will be sufficient by 25-30% less.

We use mineral mats

To get the necessary rigidity for a puff cake, most often they pay attention to mineral mats. They are based on well-known mineral wool, however, thanks to the production technology, the material has received a rigid structure. With the help of mineral mats, you can easily fill the existing voids in the subfield, fill all the cells of the puff cake with a slatted set. Despite the obvious advantages in comparison with expanded polystyrene, the material is not resistant to moisture.

On a note: a broken layer of vapor and waterproofing can cause the mats to absorb the available moisture and lose their insulating properties. The water floor can be laid on mineral mats made on a basalt base or made of fiberglass.

Other, less used thermal insulation materials include cork. Cork thermal insulation has low thermal conductivity, but weakly resists moisture. Often, fungal formations occur in floors with such thermal insulation. For best performance, waxed cork material should be used. The price in this case rises, and in terms of its technological characteristics, cork is inferior to polystyrene foam and expanded polystyrene.

A new material, which today is increasingly used in domestic construction for the installation of water floors, are profiled mats. Unlike other materials, mats are versatile. Their design immediately has a vapor barrier layer and bosses, special protrusions that facilitate the installation and installation of the heating circuit.

In work, profile mats are more practical and more convenient. Using them in the process of laying a warm floor, you can lay a water circuit according to any scheme, quickly and without additional fasteners.

Conclusion

The condition of the rough surface of the floor, the method of equipping the warm water floor determines the type and type of thermal insulation. When working with a concrete screed, polystyrene foam, mireral mats or profile mats are usually used. Concrete coating provides a sufficiently reliable fixation of the insulating material. In the case of flooring systems, mineral mats and foam can be used during work.

The method of fixing the material is carried out using glue or construction tape. For strength, foam sheets are treated with a sealant. It is important not to forget to lay a reinforced mesh or sheets after a layer of insulating materials to give the entire structure the necessary strength.

If you wondered about the installation procedure for a warm floor, then you paid attention to a kind of pie that you have to lay. One of its layers is a heater under a warm water floor. But if the floor is warm, then why is there a heater? And if it is needed, then which of the abundance to choose? This article will help you not to get confused in the variety of heaters and choose the one that will best show itself in specific conditions.

Insulation as an important component

The task of a warm floor is not only to heat a certain area. In this case, it is important to achieve minimal heat loss. One contour of a laid pipe with a diameter of 16 mm without much difficulty can warm up a screed with a thickness of 15 cm. It should be borne in mind that heat does not only spread upwards. It also goes down. If there are neighbors below who heat their premises well, then this will not be so noticeable. But if there is a basement, then the heat loss will be noticeable. This will be noticeable not only by the air temperature, but also by the bill for the media.

Another very important reason why insulation is important in the overall pie is the uniformity of the distribution of the waves. Due to the presence of a heater, the temperature is not concentrated only at the place where the pipe passes, but is transmitted to the entire surface. Some types of insulation make it possible to facilitate the process of creating a pattern along which a pipe of a warm water floor is laid. The main types of insulation are polystyrene derivatives, products made from mineral components and polyethylene. Each of them deserves separate consideration.

mineral plate

It is known to almost everyone and has been used in production and construction for a long time. Their predecessors are glass wool, which had to be rubbed off for a long time so that the hands would not itch. But mineral wool, which comes in rolls, is not suitable for underfloor heating. This is due to the fact that its rigidity is insufficient, and because of such a heater, a flooded screed subsides. Only basalt or another, which is sold in slabs, is used. Such insulation has an excellent indicator of compressive strength. Other positives include;

resistance to moisture;
good thermal insulation;
sufficient sound insulation;
resistance to fire;
resistance to chemical solvents.

Mineral insulation is also called stone wool, because it is made from molten rocks. Such a heater does not have harmful impurities and emissions. For a warm floor, insulation boards with a density of 175 kg per m 3 are suitable. Of the disadvantages of such a heater, the presence of pores that allow water and steam to pass through is obvious. Therefore, during installation, additional waterproofing will be required.

Polystyrene boards

Insulation, which consists of expanded polystyrene, is also not new. Initially, such material is known to builders and users as foam. But pure foam has its drawbacks. Although it has excellent thermal insulation properties, such insulation is very brittle in compression. This is due to the large air bubbles that form during the manufacturing process. To eliminate this shortcoming in the insulation, it was necessary to change the technology. Thanks to this, the technology of extrusion was born. Its essence lies in the fact that the formation of the canvas occurs under high pressure. Due to this, the balls with air in the insulation take the correct shape and become smaller. This makes it possible to reduce thermal conductivity at the same thickness compared to conventional foam. The choice of many falls on insulation in the form of extruded polystyrene foam for the following reasons:

light weight;
ease of installation;
resistance to compression;
no toxic emissions;
excellent waterproofing properties.

Such a heater is rarely called by its composition, more often you can find such a name as "Penoplex". In fact, this is the name of the plant that produces it. Insulation under a warm water floor is better to take one that has lock ends. They are cut in half, which eliminates cold bridges. There are also options for insulation boards with bosses. These are small guides. Thanks to them, the pipe is fixed without any additional clips and is easier to bend. For a water-heated floor, a heater with a thickness of 5 cm and a density of 35 kg per m 3 is suitable, it is usually labeled as “comfort”.

Note! Insulation made of extruded polystyrene foam is afraid of exposure to various solvents and burns well, releasing toxic smoke. When working with insulation, it is important to avoid the presence of these factors.

roll material

There are situations when it is necessary to fill the screed, but the height of the ceilings does not allow this to be done too much. In order to reduce the overall height of the cake, roll insulation is suitable. Most often, its representative is foamed polyethylene. By itself, this material does not have sufficient density to guarantee high thermal insulation properties, so foil is applied to one or two of its sides. It allows you to reduce the thermal conductivity to 0.037 W/m×°C. Such insulation is commercially available with a thickness of 3 to 10 mm. Many choose this particular material, because:

has a small weight;
easy to install;
has a low cost;
often marked for styling.

The foil is a metal, so it can react with water or other ingredients that are included in the screed mix. To prevent damage to the insulation, you will need a layer of waterproofing or take such insulation, which is initially covered with an additional layer of polymer. The disadvantages of the material include a small resistance to compression. Over time, polyethylene foam tends to shrink, which will affect its effectiveness.

Cork insulation

If you are an adherent of everything natural and want the insulation to be free of chemical impurities, then you should look towards cork slabs. It is a natural material best known for corks used to stopper wine. The thermal conductivity of such a heater is on the same level as high-quality foam foam, in the region of 0.037 W / m × ° C. There are no problems with its installation either. There are insulation options that come in rolls. Sufficient rigidity of the material will not affect the strength of the future screed. The disadvantages are the rather high price and the availability of the material is not in all regions. Cork also absorbs moisture well, so it will need several layers of waterproofing membrane.

Insulation for various bases

The heat-insulated floor is mounted not only in apartments, but also in private houses. Some heaters for a warm water floor are universal, others are more suitable for specific situations. For example, in some dwellings, thermal insulation has to be laid on the ground, in others on wooden logs. For the first case, one that absorbs moisture well is not suitable. It is worth considering the general cases in more detail.

floor slabs

Concrete floor slabs are most often used in apartment or private houses with basements. In new buildings, they may be without a screed, so they will require additional maintenance. Due to the presence of a metal base in the floor slabs, they conduct heat very well. And this means that if they install a warm floor on them, then its efficiency will be low. That is why a rough screed is applied before starting work. Some masters use expanded clay as a filler for concrete. It creates an additional air gap, which provides blocking of heat escape. If there is a basement or other room below where there may be dampness, then it is advisable to lay waterproofing under the screed.

As an insulator for a warm floor, which will be laid on top, any of the listed heaters is suitable. For those sensitive to moisture, the rough screed and the insulator itself are waterproofed from above before pouring the finishing screed. Concrete slabs withstand the load well, so problems with the thickness of the screed should not arise.

Ground insulation

There are times when insulation has to be carried out directly on the ground. The reason for this may be the special design of the house. Before starting work, it is necessary to prepare the base well. To do this, you need to go deep to such a level that there is 50 cm from the bottom point to the top point of the future floor. The bottom layer of soil is well rammed. If there is excess moisture in it, then it is necessary to dry it. This can be done by constant ventilation or the use of heat guns.

A gravel pillow is laid on top of the compacted soil. Its thickness should be at least 20 cm. It is leveled and brought out approximately below the level. Next, medium-grained sand is poured at 20. It is compacted as much as possible and brought under the level. The next step is waterproofing, which will prevent the development of the fungus and excessive heat transfer. A heater is laid on the membrane. In this case, it is better to use penoplex. It has excellent compressive strength and does not absorb moisture. It is better if its thickness is 10 cm. Another layer of waterproofing is laid on it, then a reinforcing mesh and a floor heating pipe is laid, followed by a concrete screed.

Note! If in your area the groundwater is at a shallow depth, then it makes sense to think about building a house on a strip or pile foundation. In this case, there will be less likelihood of moisture rising into the living space and the insulation will last longer.

Floor in a wooden house

Warming the floor under the water in a wooden house has several options. If the house has a rough concrete floor, then you can act as in the case of floor slabs. If there is a dry bulk insulation under the beams, then you can use the underfloor heating system with a dry screed. As a heater, you can use extruded polystyrene foam with bosses. But first you need to level the surface of the wooden floor and lay waterproofing on it. If the ceilings allow, then it is good to use a heater with a thickness of 10 cm.

In the case when the house stands on a pile foundation, then it will be necessary to insulate the underground well. To do this, the final floor is dismantled and the state of the log is assessed. If a fungus has already appeared on them, then you will need to scrape everything off and treat it with an antiseptic. Next, boards are stuffed onto the lower end of the log to form a small cavity. Waterproofing is laid in it, and a heater is placed on top. You can use stone wool or polystyrene foam. In the second case, with the same thickness with mineral wool, the effect will be better. The next step is to install another layer of waterproofing, and then a warm floor system with a dry screed. Some information about the process of insulation can be gleaned from the video:

Conclusion

As you can see, there is a large selection of heaters for underfloor heating. Some of them are inapplicable in certain situations due to their peculiarities. Others are universal. If you are faced with the task of installing a warm floor, the first thing to do is to evaluate the existing base well and analyze what condition it is in and whether repairs are needed before laying the insulation.

Are you equipping a water-heated floor system in a country house and it's time to lay an insulating substrate? Agree that among the variety of offers of heat-insulating materials offered by manufacturers, it is sometimes not easy to make the right choice.

We will help you determine which insulation for a warm water floor is better. Together with you we will deal with all the intricacies of assembling heat-insulating systems. We explore the characteristics of popular materials, evaluate the key advantages and disadvantages.

Independent home masters will find installation instructions with us. To make it easier to navigate the assortment offered by the building materials market, we have selected videos with recommendations for choosing insulation and installation.

Any instructions for installing a water-heated floor for independent craftsmen indicate that it is necessary to use a heater.

The layer of insulation in the arrangement of the water floor performs several significant functions. It helps not only to ensure uniform heating of the room, but also, acting as a heat shield, can significantly reduce the energy losses of the system.

The screed laid over the insulating layer acquires the properties of a one-piece heat transfer element having a large surface area.

The main purpose of the insulating layer is to evenly distribute heat in the heated room, preventing it from leaking through the floor slabs.

Due to the uniform distribution of energy, an ordered convection heat flow begins to move at the same speed and in the same direction. As a result, evenly distributed heat waves will not form cold and hot spots on the floor, creating the most comfortable conditions for households.

In addition, due to the direction of warm air flows in one direction, it is possible to reduce the energy costs for operating the system, while maintaining its capacity unchanged.

When installing a warm water floor, the main task is to direct all the thermal energy into the room, so it is important to properly distribute it over the entire area, and also not to let it go to the neighbors.

For this, special materials are used - heaters. There are a number of other reasons to use floor insulation:

Types of materials used for floor insulation

There are many options for pipe insulation, but all materials can be divided into:

The choice of insulation depends on:

Bulk materials and their laying technology

The main advantage of bulk materials is their low cost and ease of use. In many respects, they are not inferior to more expensive counterparts. The only enemy of bulk compositions is moisture - they are hygroscopic and lose their characteristics when wet.

Before laying the insulation for pipes in the form of bulk materials, the subfloor should be prepared:

make wooden logs, the distance between them should not exceed 800 mm;
under each lag you need a sheet of roofing material;
instead of lags, you can use a reinforcing mesh;
the material is poured (the layer thickness should be at least 5 cm), and it is well rammed - this is a very important point, since bulk compositions shrink over time;
then you can proceed to the layout of the pipes. It is not very convenient to do this on a bulk basis, since there is nothing to fix them with. That is why such heaters are not in great demand.

Spray insulation

The most common type of spray composition is polyurethane foam. Its advantages:

it is quickly applied;
fills all the cracks;
quickly adheres to any coating;
creates an airtight seal.

The disadvantage of this method of insulation is that it will be difficult to do it yourself, with your own hands, since special equipment is needed, which is not practical to buy for a single use. If there is a great desire to do all the work without involving specialists, you can rent the necessary equipment.

Before applying to the concrete base of the floor, wooden forms with a width of not more than 50 cm are mounted on it. The composition is distributed using a special pneumatic gun.

At the same time, it is important to take care of the skin and respiratory protection system - you need a special suit, since polyurethane foam is quite toxic.

The thickness of the layer should not be more than 3 cm - it increases very quickly in volume. If necessary, you can apply a second layer. The next step is cutting off the protruding reliefs. After that, the floor is ready for pipe laying. To facilitate their fastening, you can lay a reinforcing mesh with small squares on top.

Installation of a warm floor, insulation of the base before laying pipes

How to use roll heaters

The most common roll insulation for a warm water floor is foil material. It has two layers:

the basis, which can be a variety of heat insulators:
- expanded polystyrene;
- cork;
- foamed polyethylene;
- mineral wool;
reflective coating - foam-propylene metallized film or thin aluminum foil.

The thickness of rolled polyethylene foam is from 2 to 10 mm, it can have a self-adhesive surface, which greatly facilitates the installation process.

The most popular brands in Russia: