How to insulate a floor after screeding. Do-it-yourself insulation of the floor with penoplex under the screed. Preparatory work before insulating a concrete floor

In earlier times, it was considered normal practice to lay finished flooring directly onto concrete base private or panel house, resulting in cold floors. This is very uncomfortable for the people living there due to the unpleasant feeling of cold in the legs. In digital terms, heat loss through such a coating amounts to 20% of the total heat loss of the building. This is why it is important to insulate a concrete floor, and we will tell you how to do it correctly with your own hands in this article.

What is the best way to insulate a floor?

The range of materials that can be used to insulate concrete floors in a private home is so wide that it is sometimes very difficult for an ignorant person to choose the appropriate insulation.

To determine what can be used to insulate a concrete floor and which material is the best, you should find out the following points:

• Where is it planned to carry out thermal insulation - in a house, apartment or country house?
• How is the insulated concrete base located relative to other structures: above the basement of a panel house, on the ground on the ground floor of a private cottage, or is it the interfloor ceiling of an apartment?
• Is the purpose of the event to carry out simple insulation or the installation of a warm water floor (as an option - electric)?
• What is the chosen method of thermal insulation?
• the amount of budget allocated for the event.

Generally speaking, you can take any of the currently existing insulation for a concrete floor. The main thing is that it fits the listed conditions. There is only one limitation: materials containing glass wool cannot be used inside residential premises. This is the answer to a frequently asked question - is it possible to insulate the floor with foam plastic.

What does clarification of the first point give us? If we're talking about about an apartment in a brick or panel house, then we may be limited by the height of the ceilings, and therefore we need to choose the most effective and thin insulation– penoplex or extruded polystyrene foam. Otherwise, the floors will rise by no less than 150 mm; this must be taken into account when insulating the floors on the loggia. Moreover, penofol or isolon will not work, it has insufficient thermal resistance.

For reference. To imagine the required thickness of different materials for floor insulation, it is suggested to study the diagram with thermal conductivity coefficients. How less value coefficient, the better the properties of the insulator, and the thinner the layer will be.

You can inexpensively insulate a concrete floor in your dacha by using expanded clay for this purpose, you just need to choose the right layer thickness. It should be noted that expanded clay transmits 3-5 times more heat than foam plastic. If the dacha is heated constantly and the requirements for thermal insulation are high, then the thickness of the layer on the ground must be at least 300 mm. When periodically heating a dacha, it is enough to make the thickness of the expanded clay insulation 100-150 mm so that the event will cost you quite cheaply.

The greatest heat loss through floors is observed when a concrete screed is placed on the ground. Then there are 2 options: use the best and most effective insulation like penoplex, or something cheaper, but with a thicker layer. As a rule, in these cases, all types of foamed polymers are used, as well as high-density mineral wool. You can also take rolled materials, but there is only one way to install them in insulation – on joists.

It makes sense to insulate interfloor floors in a panel house only in one case - when installing electric or water heated floors. If this is not done, then your heated floor will heat the ceiling of the neighbor below, and there will not be enough heat for your own home. Since the temperature difference on both sides of the ceiling will be small, polystyrene foam up to 50 mm thick or polystyrene foam 25-30 mm thick will be suitable for insulation. Layer mineral wool you will have to do more or lay it together with foil penofol, which will also serve as waterproofing.

Advice. The ceiling on the ground floor of an apartment or private building should always be insulated if the basement is not heated.

Thermal insulation methods

On this moment There are only 2 methods for insulating concrete floors in any residential buildings; the choice of suitable material largely depends on them:

• the so-called dry method - insulation on joists;
• “wet” method - laying insulation under a cement-sand screed.

Note. There is a practice of thermal insulation of rooms on the first floor from below, from the basement. This is convenient and cheap, but not very effective, since it must be combined with insulation of the foundation and basement of the building. When there is none, the cold will penetrate from the street through the edge zones of the concrete foundation.

The method of insulation on joists is quite accessible and, with the proper approach, can be easily done with your own hands. It involves the use of both roll and slab insulation for a concrete floor and is designed for the subsequent laying of a final covering of linoleum or laminate over a flooring made of boards or OSB boards(chipboard). The list of insulation materials used is very wide:

• mineral or ecowool in rolls and slabs: has high fire resistance, but easily absorbs moisture and at the same time ceases to be an insulator;
• foamed polymers in slabs (foam plastic, extruded polystyrene foam, penoplex), on the contrary, are not afraid of water, but are susceptible to combustion and have better thermal insulation characteristics than cotton wool;
• foamed foil polyethylene (penofol, isolon): the material repels moisture well and has zero vapor permeability, but is flammable. Works great together with other insulation materials;
• sprayed polyurethane foam: the best insulation of all, but also the most expensive, resists moisture, flame (for a certain period of time) and has the highest thermal insulation rates;

For reference. There is also cork insulation on sale, but it is usually not chosen for insulating concrete floors; it is intended for heat and sound insulation of walls.

The essence of the second method of insulation is to monolith the heat-insulating layer under a cement-sand screed, and on top of it almost any flooring. This means that floors insulated in this way are made not only for laminate or linoleum, but are also suitable for installation tiles. This is true in the kitchen or bathroom, where there is high humidity, the screed will last much longer there.

When installing electric or water heated floors this technique insulation is also the most effective. Of course, it is possible to lay heating circuit pipes between the joists, but this will not achieve large area heat transfer. And the screed monolith becomes like a solid heating device, heating the room with its entire surface. Therefore, warm floors are usually made of the same type (under screed) throughout the entire house, and not just in the bathroom or kitchen.

It is logical to assume that for the second method of insulating concrete floors it is impossible to use soft or rolled materials. Foamed polymers or basalt wool in slabs, and the density of the latter must be no lower than 115 kg/m3, and thickness - 100 mm. Expanded polystyrene can be taken thinner - 50 mm, polystyrene - 80 mm with a density of 35 kg/m3.

Floor insulation with polystyrene foam

If you chose the first method, then on a leveled and cleaned concrete screed You should lay wooden blocks - logs, maintaining an interval between them equal to the width of the selected insulation. The lags are fastened with anchors or self-tapping screws on steel corners; their leveling is done using wooden spacers. Calculation of the height of the upper plane of the block above the floor looks like this: insulation thickness + 50 mm clearance for ventilation.

Advice. When concrete floors are insulated with mineral or basalt materials, it is better to make the distance between the joists less than the width of the insulation by 1 cm so that the insulation fits there as tightly as possible. For expanded polystyrene boards, the interval should be made smaller by a couple of millimeters for the same purpose.

Now let’s talk about how to properly install the insulation. First, waterproofing is laid from a dense polyethylene film with an overlap of 100 mm between the sheets and the joints are taped. Then the thermal insulation slabs are laid. On top they are again covered with a vapor barrier film so that moisture from the premises does not penetrate into the insulation.

Advice. Contrary to popular belief, expanded polystyrene absorbs moisture, although in very small proportions. That's why protective films on both sides of the insulation are always needed when using any materials, especially cotton wool and polystyrene foam. This will significantly extend their service life.

Penofol is often used instead of film; it allows you to reduce the layer of the main insulator and protect it from moisture. The joints are also taped, only with foil tape. This completes the insulation of the concrete floor; you can lay the coating and laminate or linoleum.

Floors under cement screed are also insulated using waterproofing laid on a concrete base. If the process begins with the soil itself, then it must be compacted and then concrete preparation 5 cm thick. After it has completely hardened, the film of the waterproofing layer is laid out, and then the polystyrene foam slabs are laid out. Usually the cement screed is poured directly on top of the insulation, but we recommend laying a second layer of film first. This is inexpensive, but it will help preserve the insulating material of the floors longer.

For reference. The thickness of the cement screed should be in the range from 50 to 80 mm. The best option, taking into account different loads on the floors of a living space - 70 mm.

When it comes to wooden house, then it should be taken into account that such structures may be slightly deformed because the wood “breathes”. This is almost unnoticeable in an old house, but in a newly built one, concrete floor coverings can crack if damping is not provided. To do this, along the entire perimeter along the walls, even before the start of work, thin layer polystyrene (up to 15 mm), as shown in the photo:

Similar measures should be taken before installing heated floors, where a special damper tape is laid around the perimeter of the premises, and only then waterproofing is laid, which is reflected in the diagram:

Owners of old houses often wonder whether it is possible to insulate the floor without opening it. There is no definite answer, since it all depends on the condition concrete covering. If the screed has retained its strength and does not crumble or crack, then laying insulation on top of it is possible. Only then will you have to raise the thresholds of all the doors and trim their leaves, which will immediately affect the interior. So the best solution would still be to open up the old floors, insulate them and pour a new coating.

Floor insulation with expanded clay

This insulation can be used for thermal insulation of floors in any way, even by filling it between joists or laying it under a screed. It simply replaces polystyrene foam or cotton wool, and the entire technology remains unchanged. It will cost less, but there is a question about the effectiveness of such insulation. In simple words, most the best expanded clay The thermal insulation properties are three times worse than the worst polystyrene foam.

Hence the conclusion: the expanded clay layer must be at least three times larger, otherwise such insulation will be of little use, the concrete floors will remain cold. It turns out that you need to fill in 300 mm of material, but in what rooms is this possible? In an apartment and on a loggia - definitely not, it won’t work above the ceilings either. Floors remain on the ground in buildings with a high base or on joists supported by brick columns.

But in the first case, most often there is ground floor and there is also nowhere to place such a thick layer of insulation, and there is no need to, it is necessary to insulate the foundation there. Floors with joists remain brick pillars, these are found in old houses and on verandas. By the way, similar open veranda You can glaze it and insulate the floors with expanded clay underneath, there will be enough space for it.

Conclusion

Each method of insulating concrete floors has its own advantages and disadvantages. It is impossible to say that one of them is better and the other worse. They just need to be applied according to the circumstances and in accordance with financial capabilities. Of course, wood floors are always better than screeds, but it requires repair and does not last that long. But anyway good thermal insulation will not cost you cheap, you need to understand this.

Thermal insulation of concrete floors with polystyrene foam, mineral wool, expanded clay, insulation installation technology.

Choosing insulation for a concrete floor

Market modern thermal insulation great These are both natural and artificial insulation, produced by the latest technologies. Among the thermal insulation materials suitable for concrete floors, it is worth noting polystyrene foam, expanded clay, mineral (basalt) wool, ecowool, and polyurethane foam (PPU).

Expanded polystyrene for thermal insulation of concrete floors

Two types of this material are used in construction - foam plastic and penoplex. Without going into too much detail, we can equate them. But this is not true, since the insulation materials, despite their external similarity (ease of installation, light weight, feel), are different.

Penoplex (extruded polystyrene foam) has closed pores. The insulation itself has a dense, uniform structure, does not crumble, and has good bending density (foam cannot be bent at all, it will burst and crumble into small pieces). It is more convenient to work with penoplex because it is cut with a hacksaw and does not fall apart.

Both penoplex and foam plastic originated from polystyrenes. And if the first one passes through a special form (extruder), acquiring its final form by pressing through it, then foam plastic is just inflated balloons polystyrene, sintered together at high temperatures. During the production of penoplex, polystyrene undergoes significant changes, turning into a single viscous mass (hence the properties inherent in a solid substance), while the foam remains as separate balls.

In terms of technical characteristics, extruded polystyrene foam is better:

• Strength - 0.18 (MPa);
• Thermal conductivity - 0.032 (W/m*K);
• Water absorption - 0.4%;
• Flammability class - G3, G4;
• Operating temperatures - -50+75°C.

However, for insulating a concrete floor with polystyrene foam the right decision will choose its usual variety - polystyrene foam. It is much cheaper, and under a finished floor or under a leveling concrete screed, its characteristics such as weak strength, fairly high water absorption and flammability will not have any significance. DIY installation is not difficult.

Expanded clay for insulating concrete floors

Natural insulation made from baked clay. There are different fractions - gravel, crushed stone, sand. Insulation of a concrete floor with expanded clay is carried out with gravel various sizes. To achieve the required level of thermal insulation, a layer at least 15 centimeters thick will be required.

Technical characteristics of expanded clay:

• Density - 250, 30, 350, 400, 450, 500, 600 (kg/m3);
• Strength - 1.2 – 2.5 (MPa);
• Thermal conductivity - 0.1-0.18 (W/m*K);
• Water absorption - 8-20%;
• Flammability class - NG;
• Operating temperatures - up to +1300°C;
• Frost resistance - at least 25 cycles.

Expanded clay requires mandatory double-sided protection from moisture!

Mineral wool and ecowool for thermal insulation of concrete floors

That's two different insulation, both in composition and properties. Mineral wool is produced from rock waste (rock, basalt), slag (slag wool), quartz (glass wool). Ecowool is the smallest fraction of paper waste, supplemented with fire retardants and water-repellent agents (brown and boric acid).

Basalt wool is a non-flammable insulation material, but is expensive. Therefore, insulation of concrete floors is usually carried out with the cheapest type of mineral wool - slag wool or glass wool. Not used under concrete screed. Do-it-yourself installation is not difficult. Wooden floors are laid on top of the insulation.

Ecowool has excellent specifications, is inexpensive. Flammability class - G2, G3. It has fairly high water absorption and is not used in concrete screed. It can be used to insulate the floor on a concrete slab by backfilling or spraying (an adhesive or plain water is used for wetting) under a finished wooden floor. Possible DIY installation dry method.

Tools and materials for insulating concrete floors

For thermal insulation works You will need a variety of materials and tools:

1. Insulation.
2. Waterproofing film.
3. Construction stapler for fixing waterproofing film.
4. Metal tape for connecting waterproofing or polystyrene foam boards together.
5. Dry self-leveling concrete mixture. It will be required if insulation with expanded polystyrene or basalt wool slabs is chosen.
6. Dry adhesive mixture for rigid installation of polystyrene foam.
7. A hacksaw with a fine tooth for cutting polystyrene foam or basalt wool slabs.
8. Trowel for leveling rough and finishing concrete screeds.
9. Needle roller for rolling a sheet of polystyrene foam and removing it from self-leveling concrete mixture air bubbles.
10. A drill with a “mixer” attachment for fluffing ecowool and mixing self-leveling concrete mixture.
11. Bucket.
12. Level.
13. Chisel, hammer, spatula - for leveling work.

Preparatory work before insulating a concrete floor

Remove the finished floors; if tiles are laid, they also need to be dismantled, reaching the main concrete slab. Inspect it and check it with a level. If there are no humps or depressions, and the height difference is about 2 cm per meter, you are in luck. All that remains is to remove the debris and dust.

If the concrete slab is poured poorly, follow these recommendations:

• Remove debris and dust.
• Remove the bumps and fill the holes with cement mortar.
• Let the solution dry (a couple of days).
• Level using self-leveling mixture.
• Allow the floor to dry thoroughly.

Leveling work is necessary for insulating a concrete floor with any type of polystyrene foam and mineral (basalt) wool in slabs. For expanded clay, ecowool and mineral wool in rolls, you only need to remove debris, dust, knock down obvious bulges and cover up holes.

Concrete floor thermal insulation technology

Work with expanded polystyrene, expanded clay, mineral wool and ecowool is available for independent execution. detailed instructions for laying each insulation will help to avoid mistakes and complete everything in the shortest possible time.

Insulation of concrete floors with foam plastic

This is the most economical option. Polystyrene foam is suitable for insulation both under concrete screed and over joists. In the second case, it is worth considering that the thermal conductivity of wood is much higher. Therefore, the logs will become bridges of cold.

The procedure for insulation under a concrete screed (floating installation):

1. Cover concrete slab plastic film. Secure the joints with metallized tape. Place the film on the walls by 15 centimeters. Then cut it off when installing the baseboards.
2. Lay the first layer of polystyrene foam, following the dressing technique - the vertical seams in adjacent rows should not coincide.
3. Lay down a second layer of foam. Above each seam of the first level there should be a whole slab of insulation in the second.
4. Cover the seams in the second layer of foam with metallic tape.
5. Lay a second layer of waterproofing if you plan to pour a thin concrete screed on top. If installation is to be done wood covering, a second layer of waterproofing is not needed.
6. Prepare a self-leveling mixture: pour water into a bucket and pour the dry mixture into it in accordance with the instructions.
7. Divide the floor into equal squares. Pour the concrete screed over them, carefully leveling the surface with a trowel.
8. Allow the surface to reach working strength.
9. Apply any topcoat.

The insulation of the concrete floor is completed. The complexity of the process can only be caused by pouring a concrete screed. Its thickness when laid on top ceramic tiles or porcelain stoneware must be at least 5 centimeters. The insulation of concrete floors on the ground is carried out in the same way, only the polystyrene foam is not laid on a rough slab, but on a sand-crushed stone cushion covered with a waterproofing film.

Important! By insulating the concrete base with polystyrene foam, you can additionally lay a warm floor (water or electric). To do this, instead of the second layer of polyethylene, use foil insulation - foil insulation or foil penofol. A “warm floor” system is installed on top of it.

Thermal insulation of concrete floors with penoplex

Insulation of a concrete floor with penoplex is carried out in a similar way. This material does not require double-sided waterproofing and can be “planted” with glue directly onto a concrete base (hard method):

• Treat the rough concrete floor with a penetrating antiseptic and wait until it dries.
• Mix the adhesive mixture with water according to the instructions, mix with a drill and a mixer attachment. Let sit for 5-7 minutes and stir again.
• Roll the insulation board with a needle roller to increase adhesion to the glue.
• Apply a continuous layer of adhesive to the foam using a wide spatula.
• Remove excess with a notched spatula.
• Place the insulation in a corner and press it to the surface.
• Continue with the remaining slabs. When laying, follow the dressing technique.
• Once installation is complete, seal the joints with silicone sealant.
• Install a reinforcing mesh on the penoplex.
• Divide the floor area into equal sections.
• Carry out finishing concreting, carefully smoothing the mortar in each compartment with a trowel.
• Wait until the surface reaches working strength.
• Apply finishing touches.

Insulation of concrete floors with expanded clay backfill

Concrete floors are insulated with this material in private or multi-storey building on the first floor. This type of thermal insulation is not acceptable for small apartments with standard height ceilings, as it “eats” up to 25 cm of space (ask a specialist to calculate the thickness of the insulation for your region).

Procedure for working with expanded clay:

1. Fill in the expanded clay and level it with a rake.
2. Install the reinforcing mesh.
3. Prepare cement mixture for rough screed. Use ready-made dry compounds in bags, sealing them with water according to the instructions. The finished solution should not flow!
4. Divide the floor into squares of approximately equal area.
5. Fill in squares, leveling each with a trowel. Then move on to the next one.
6. Give finished floor gain working strength.
7. Fill with a thin finishing screed (up to 5 cm thick).
8. Lay the finishing surface - tiles, parquet, laminate, classic wood flooring or linoleum, carpet.

Insulation of a concrete floor with basalt wool

Mineral wool is not the best cheap material for thermal insulation. However, his choice is justified if it is necessary to insulate concrete interfloor ceilings. An electric heated floor can be laid on top of the basalt wool.

To insulate a concrete floor you can use basalt slabs and cotton wool in rolls. The slabs are laid identically to expanded polystyrene (floating installation), and for rolls it is necessary to lay logs. Upon completion of the insulation work, a finished wooden floor will be laid on them. An electric heated floor is laid on top of the matt insulation. With a lot of help from the room: the base is divided in half if the room is narrow and long, or into equal 4 parts.

Laying basalt slabs:

• Carry out waterproofing, covering the walls to the height of the insulation being laid. Use thick polyethylene or special mastic for this.
• When laying, follow the sequence - the vertical seams between the slabs should not coincide.
• Insulate the joints with metal tape.
• Instead of a second layer of waterproofing film, lay thin foil insulation with the foil facing up. It will push heat back, and cotton wool will keep the cold out.
• Install a “warm floor” system. Proceed strictly according to the instructions, do not bend in the wrong places and do not overlap the heated floor elements on top of each other. Place the switch just above the level of the future baseboard. If the floor area has been divided into parts due to big size, in each of them a “warm system” is installed and a switch is installed for each.

To lay mineral wool rolls, a log system is installed - along the perimeter of the room and across, along the width of each roll. The insulation must fit into the cavities intended for it with some effort. The procedure for laying rolled basalt wool:

1. Pave plastic film. Insulate the joints with construction tape.
2. Secure the waterproofing with a stapler to the joists.
3. Place insulation between the joists.
4. Cover it with a vapor barrier membrane.
5. Lay the rough and then the finished wood floor.

Insulating a concrete floor with your own hands using basalt wool is a labor-intensive, but quite feasible process. This type of thermal insulation is suitable not only for interfloor ceilings in a high-rise building, but also for insulating the floor in a private house on any floor.

The distance between the “warm floor” laid on foil insulation and finishing should be at least 3 cm. Only in this way will the foil be able to perform its functions - to push heat back into the room.

Thermal insulation of concrete floor with ecowool

Waste paper is an excellent heat insulator. Therefore, use ecowool to insulate interfloor ceilings in a private and multi-storey building. It is always recommended to call a professional to work with this insulation. However, to save money, try filling the material yourself.

No special preparation is required for ecowool insulation. The material “doesn’t care” whether the base is flat or crooked, it crumbles and fills even the smallest cracks. Ecowool concrete floor insulation technology:

• Remove the finished floor. If the boards are normal, sand them, open them with drying oil or any other antiseptic.
• Inspect the joists. If they are quite strong, go over them with drying oil.
• Clean the concrete slab.
• Lay thick plastic film over the joists.
• Unpack the bag of ecowool, pour the contents into a deep tank and fluff it using a drill with a mixer attachment. The insulation will approximately triple in volume.
• Place ecowool into one of the cavities. Start tamping with your hands or using the widest trowel. Perform the action until you feel significant reverse force.
• Fill the remaining cavities and compact the insulation thoroughly.
• Lay plywood along the joists.
• Install a finishing floor on top.

Ecowool does not require double-sided waterproofing. If exposed to moisture upper layer The insulation is taken with a fairly strong crust. Inside such a “shell” the insulation remains in the same state, its thermal insulation characteristics do not change.

Watch a video about thermal insulation of concrete floors:

Can't decide how to insulate a concrete floor? Analyze the technical characteristics of thermal insulation materials. Calculate how many of them will be needed to insulate the floor in an apartment or house. Check with construction stores price. And make a decision. Remember, warm floors mean comfort in the room and good savings on heating costs.

In a home's heat exchange system, floors are one of the places where heat is lost most. This is especially true for concrete floors, which, despite all their excellent performance qualities, have one serious drawback - concrete is a very cold material. And for comfortable stay in the house with concrete floors high-quality, multi-layer thermal insulation is required. Insulation of a concrete floor in a house, especially if it is the floor of the first floor, is a strict necessity, but performing all the work is not particularly difficult. The main thing is compliance with insulation technology and the availability of skills in handling the tool.

Insulation for concrete floors

Reliable and high-quality thermal insulation of a concrete floor directly depends on the thermal insulation materials used, which differ in performance characteristics, as well as location and operating conditions. By choice the right material should be addressed first when looking for an answer to the question of how to properly insulate a concrete floor.

When choosing thermal insulation, you need to pay attention to the following characteristics:

• density is responsible for total weight material. The lower this indicator, the more porous the material and the more heat it can retain indoors;
• strength material, can be both in bending and compression. To insulate a concrete floor, materials with a high strength index will be required due to large loads on the floor surface;
• coefficient of thermal conductivity shows the ability of a material to transmit heat through itself. The lower this indicator, the better;
• moisture resistance the material must be very high, otherwise the material located between the concrete screed and the soil will quickly lose its properties;
• moisture permeability, unlike moisture resistance, should be minimal. Otherwise, the material will quickly gain excess moisture and will lose its thermal insulation qualities;
• durability. With this indicator, everything is simple: the higher it is, the better;
• environmental friendliness. This characteristic will be useful to those who strive to build environmentally clean house, using natural materials.

The following materials are often used to insulate a concrete floor:

• mineral and basalt wool. These thermal insulation materials are always popular. They have low thermal conductivity and density (although there are slab positions with high density), as well as excellent sound insulation. Unfortunately, cotton wool is not environmentally friendly, absorbs moisture well, and does not tolerate a humid environment. The use of cotton wool as insulation for a concrete floor is justified only when the raised floor is insulated;
• Styrofoam. The second name is expanded polystyrene. Today, insulating concrete floors with polystyrene foam is common practice. This material has excellent thermal conductivity, moisture resistance and moisture permeability. It has the following disadvantages: it is not environmentally friendly and quite fragile;
• extruded polystyrene foam. This material is a derivative of conventional foam and has a number of significant differences. Firstly, extruded polystyrene foam is much stronger. Secondly, the durability of EPS is greater than that of conventional foam. Thirdly, thermal conductivity, water absorption and water resistance are an order of magnitude higher in XPS.

• polyurethane foam. This material has excellent thermal conductivity and is resistant to moisture and temperature changes. Perfectly tolerates mechanical loads without loss of thermal insulation properties, durable. The only drawback is that it is not environmentally friendly;

• expanded clay This material is often used as a substitute for crushed stone in concrete and for insulating the latter. The thermal insulation properties of expanded clay make it possible to reduce the thermal conductivity of concrete several times. Despite the low thermal conductivity coefficient and environmental friendliness, expanded clay has a number of significant disadvantages. Firstly, the total weight of the expanded clay insulating layer is quite large. Secondly, expanded clay perfectly absorbs and retains moisture;
• foam glass. As a heat insulator, foam glass has a number of undeniable advantages. These include low thermal conductivity and specific gravity, the ability not to absorb moisture, environmentally friendly material, not susceptible to moisture, very high durability. The only serious drawback is the certain fragility of the material, which does not withstand mechanical loads well;
• cork. Absolutely natural insulation with excellent thermal insulation characteristics. The only thing that should be noted is that cork is best used for insulating raised floors and as a thermal insulation layer under the finishing floor covering;
• perlite This thermal insulation material is similar in the way it is used with expanded clay. The difference lies in the characteristics of perlite, which are an order of magnitude better than those of expanded clay.

The table below shows the main characteristics of thermal insulation materials that you will have to focus on when choosing them. Of particular note is thermal conductivity various types concrete with different fillers. This little secret will help answer the question of what is the best way to insulate a concrete floor.

Table 1.

Features of concrete floor insulation

Before you begin directly to work on insulating a concrete floor, you need to understand the insulation technology, as well as choose the most suitable one. suitable option insulation from existing ones.

The technology for insulating a concrete floor consists of creating multi-layer thermal insulation and consists of several stages of work. The first stage of concrete floor insulation is performed before pouring the rough screed. The second stage of insulation occurs during the creation and pouring of the concrete mixture. At the third stage, insulation of the concrete floor is performed during the creation of the floor covering. It should immediately be noted that it is best to insulate a concrete floor when creating it from scratch. This is the only way to ensure a high-quality level of insulation.

There are only a few ways to insulate a concrete floor. Each of them is performed at its own time as the floor is created. Each of these methods is discussed in more detail below.

• Laying insulation under a concrete screed. Such insulation is performed during the creation of a concrete floor from scratch. Therefore, if you want to insulate the floor in an already built house, you will first have to completely destroy the old concrete screed to the base. With this method of insulation, materials with high strength, resistance to mechanical loads, moisture-resistant and durable are used.
• Today it is especially popular "warm floor" system, which allows you to create active heating of the concrete floor over its entire area. Such a system is placed on top of a layer of insulation and filled with concrete screed. Warm floors can be water or electric. In any case, heating the floor using such a system will require the use of a third-party energy source. Concrete heated water floors or electric heated floors are more related to the active heating system. But in general, they are perfect for insulation.
• Another option for insulating a concrete field is adding such fillers to the mixture, like expanded clay or perlite instead of the usual crushed stone. Thanks to your thermal insulation characteristics These materials make it possible to reduce the thermal conductivity of concrete several times. Concrete with expanded clay or perlite can be used both to create a base on the ground and for screed.
• One of the most common options for insulating concrete floors is upper floors is creation of a “raised floor”. This method of insulation involves the arrangement wooden logs and filling the space between them with insulation. This approach is useful in that it reduces the overall load on the foundation of the house, and is useful for those who do not want to bother with pouring a concrete screed.

• You can also insulate a finished concrete floor using a floor covering. To do this it is enough to use insulated flooring materials . For example, warm linoleum or carpet. In addition, when creating a finishing floor covering, you can lay a layer of cork, foamed polyethylene or other thin-layer insulation underneath it.

All of the above insulation methods, depending on the situation, can be used both in combination and separately. So, for example, if it is impossible to lay insulation under the screed, you can limit yourself to using expanded clay and creating a multi-layer finishing coating. Or, when creating a “warm floor” system, do not install a multi-layer warm finishing coating.

How to insulate a concrete floor

There is nothing complicated about how to make a warm concrete floor. The first thing you have to do is perform a series of preparatory work. And depending on whether the floor insulation will be on the ground or on the interfloor ceiling, choose insulation methods and materials.

As previously noted, there are several ways to insulate a concrete floor over the ground. Below we will look in more detail at the two most commonly used ones. This is the creation of multi-layer thermal insulation and a “warm floor” system.

Insulation of a concrete floor - multi-layer cake

Regardless of the insulation method, you must first do the following:

• if you have to repair and insulate a concrete floor in an already built house, you will have to remove old screed to the ground. Re-make the bedding from the sand-gravel mixture, and then compact it thoroughly;
• a layer of “skinny” concrete is poured on top of the resulting cushion, which serves as the basis for waterproofing and insulation;
• After the concrete base hardens and gains strength, we lay a layer of waterproofing on top. At the same time, we strive to make it as reliable as possible. Errors or shortcomings at this stage can lead to the penetration of moisture into the insulation, which will reduce its performance characteristics, and over time the moisture will reach finishing screed. As a result, high humidity indoors and constantly cold floors. To prevent this from happening, we overlap the waterproofing and seal the joints with tape;
• Now that the waterproofing is ready, we lay a layer of thermal insulation. For these purposes, you can use polystyrene foam, extruded polystyrene foam, foam glass, and polyurethane foam. Materials in the form of mats or slabs are laid on an adhesive composition. We place the materials themselves staggered, thereby reducing the likelihood of cold bridges appearing and increasing the strength of the thermal insulation layer. We lay a damper tape along the perimeter of the heat-insulating layer between the wall and the edge of the material;

Important! A layer of thermal insulation made of polyurethane foam can be constructed from slabs, or by spraying. In the second case, you will get a seamless coating. Another important point is the optional arrangement of vapor and waterproofing when using polyurethane foam.

• Having arranged the main layer of thermal insulation, we lay another layer of waterproofing on top of it, after which we install the reinforcing mesh and fill in the rough concrete screed. At this stage, you can also further insulate the concrete floor. To do this, we use expanded clay or perlite as a concrete filler instead of crushed stone.

Important! Due to their specific performance characteristics, expanded clay and perlite are best used in a semi-dry mortar screed. Another feature is the use of filler of different fractions, which will ensure more dense filling of the screed and its strength.

• After allowing the screed to dry completely and gain strength, you can begin arranging the final floor covering. At this stage you can also insulate the concrete floor. For this purpose, a special insulating substrate and floor materials with good thermal conductivity are used. You can use cork or polyethylene foam as a backing. It is worth noting that for a certain type of flooring it is necessary to use a different type of underlay. So, foamed polyethylene is not suitable for linoleum; instead, you need to use cork. Therefore, before laying the insulating underlay, you need to make sure that it is compatible with the floor covering.

Installation of a "warm floor" system

To make a concrete floor on the ground really warm, so much so that it will be pleasant to walk on it barefoot, you will have to install a water or electric heated floor system. It should be noted that a concrete water heated floor is somewhat more difficult to install, since in addition to water pipes placed under the screed, you will have to install equipment for heating and forced circulation, which will affect the volume and complexity of the work.

Such a system is laid directly on the thermal insulation layer. But there is one important feature- the thermal insulation material must have a foil coating to reflect most of the heat into the room. Of course, you can use any suitable thermal insulation material, but be sure to lay a reflective foil barrier on top of it.

After laying and checking the functionality of the system, we lay the reinforcing mesh and pour the concrete screed. To install a heated floor system concrete mortar can be done without crushed stone or expanded clay.

Insulation of a concrete floor in a house with several floors is carried out using one of the methods described above, as well as by creating a false floor. Such a floor can be quite easily installed in any room on the upper floors.

Important! It should be noted that if the ground floor can still be deepened relatively painlessly in order to maintain the height of the room, then when insulating the upper floors it is necessary to very carefully monitor the thickness of the floor with insulation.

You can insulate a concrete floor using a raised floor as follows:

• clean the surface of the ceiling from dirt and, if necessary, level it;
• using wooden beam 50x100 mm, we install logs throughout the entire area of ​​the room. The step between the lags is 50 - 60 cm;
• Lay a layer of waterproofing on top. Let the edges overlap and seal with tape;
• We put insulation inside. This can be cotton wool, polystyrene foam, EPS, expanded clay, perlite or other insulation;
• lay moisture-resistant plywood on top of the joists or chipboards, after which you can install the finishing floor covering.

Important! A raised floor can significantly reduce the height of a room. Therefore, before insulating a concrete floor using a raised floor, you need to make sure that this method of insulation is appropriate.

When insulating concrete floors, the main thing is to choose the right method and materials to use for the work. And following the technology will allow you to create truly reliable insulation that prevents heat loss. It should also be remembered that insulation of concrete floors is just part of the overall thermal insulation of the house. Of course, quite a lot of heat is lost through the floors, but by insulating only them, you may not get the desired effect. That’s why it’s so important to insulate the entire house as a whole.

One of the weakest places for retaining heat in a house is the floors. This is especially true for apartments on the ground floors and private houses. Therefore, it is imperative to insulate the concrete floor. For this, various thermal insulation materials are used. The insulation technology depends on the selected material.

Concrete floor insulation scheme.

Basic properties of insulation

Various thermal insulation materials can be used to insulate a concrete floor. Each has certain properties and operating conditions. When choosing, you must take into account the following indicators material:

Scheme of floor insulation with polystyrene foam.

1. Density. The lower this indicator, the lower the weight and the more pores in the material. Accordingly, it has better thermal insulation properties.
2. Strength. When insulating a concrete floor, the strength of the insulation plays an important role, since significant loads are placed on it.
3. Moisture resistance. The higher this indicator, the better. Otherwise, the insulation will quickly absorb moisture and lose its properties.
4. Coefficient of thermal conductivity. The indicator characterizes the ability of insulation to transmit heat through itself. Low values ​​of this value indicate good thermal insulation properties material.
5. Moisture permeability. This parameter must have minimum indicators, otherwise the material will absorb moisture from the air and concrete and lose its properties.
6. Durability. Everything is clear here: the greater the durability, the longer the material will last.
7. Environmental friendliness. This indicator is very important, because insulation is carried out indoors, and, accordingly, the material must be safe for humans.

Materials for thermal insulation

Among the most common home insulation materials, the following materials should be highlighted:

Scheme of thermal insulation of the floor with polystyrene foam.

1. Mineral wool. This material is one of the most common insulation materials. It has low density and thermal conductivity, good sound insulation, and is relatively inexpensive. However, mineral wool absorbs moisture well, which is why it loses its thermal insulation properties. Therefore, when using such a material, it is necessary to provide a vapor and waterproofing layer. In addition, mineral wool is not environmentally friendly; it must be used with extreme caution.
2. Polystyrene foam or polystyrene foam. This material is also very often used for thermal insulation of concrete floors. Polystyrene foam retains heat perfectly, does not absorb moisture and is completely indifferent to it, and is the cheapest insulation material. Negative properties material is not environmentally friendly and increased fragility.
3. Extruded polystyrene foam. This material is a derivative of conventional polystyrene foam, but has better performance characteristics. It is much stronger, more durable, and has better thermal insulation properties. At the same time, it is also resistant to water.
4. Polyurethane foam. This material is waterproof, has high thermal insulation properties, resistance to temperature changes and mechanical loads, and a long service life. The disadvantage is, again, not environmentally friendly.
5. Expanded clay. The material is most often used as a substitute for crushed stone in concrete mortar. Thanks to this, the thermal conductivity of concrete floors is significantly reduced, and the material itself is environmentally friendly. However, expanded clay has such disadvantages as greater overall weight and high moisture permeability.
6. Cork. This material is natural and, accordingly, environmentally friendly. It has durability and excellent thermal insulation. However, it is better to use cork as insulation material raised floor or as a substrate for finishing floor finishing. The cost of cork is an order of magnitude higher than that of other insulation materials.
7. Perlite. According to the method of application, the material is similar to expanded clay, but many of the performance characteristics of perlite are better.

Related article: Choosing fabric for roller blinds

Thus, we examined the main materials used for insulating concrete floors and their properties.

Features of insulation

Before you start insulating a concrete floor, you should select not only a thermal insulation material, but also decide on the method of insulation.

Scheme of thermal insulation of the floor with expanded clay.

Let's look at the main methods:

1. Installation of thermal insulation under a concrete screed. This method is used only at the stage of building a house. Otherwise ready-made screed will have to be completely destroyed, to the very foundation. With this method of insulation, it is necessary to use materials that can withstand significant mechanical loads, are durable and moisture-resistant.
2. Installation of a "warm floor" system. This method allows you to heat the entire floor surface. The system is mounted on top of the insulation and filled with concrete screed. For heating you will have to use a third-party energy source ( hot water or electricity). The most commonly used are water or electric heated floors. However, recently, infrared heated floors, which are laid on top of the screed, have become increasingly used.
3. Adding to concrete solution special fillers. If you add materials such as expanded clay or perlite to the concrete solution, the floor will conduct much less heat. As a result, heat loss will be significantly reduced.
4. Raised floor installation. IN in this case Logs are placed on top of the concrete floor, between which insulation is laid. The log is attached on top wood flooring from boards. With this method, it is worth considering that the height of the room will decrease significantly.
5. Laying flooring. IN finished house The easiest way to insulate a concrete floor is by installing a special insulated floor covering. For example, by laying carpet or linoleum with a thick base. You can additionally insulate the base by laying a substrate, which also increases the thermal insulation properties of the concrete floor.

Concrete has excellent strength properties and durability, which makes it very popular building material. But as a floor structure, it is in itself uncomfortable due to its high thermal conductivity. In this article we will look at how to insulate a concrete floor in a private house in order to eliminate this drawback.

Photo of a floor that is warm to sleep on

Insulation materials

Insulation of a concrete floor in a private house involves the use special materials, increasing its thermal insulation qualities. What requirements are put forward for them?

Tip: if there is enough quantity financial resources it is recommended to install a water or electrical system underfloor heating. Its price is quite high, but the effect is corresponding: you will get perfectly warm floors and an economical heating system for the whole house.

Underfloor heating system in concrete

Required qualities

• Density. The lower this indicator is for the insulation, the large quantity there are pores in it, and, therefore, it is able to retain more heat.
• Strength. The floor experiences the greatest load of all elements of the house, and the material used to insulate it must also withstand it.
• Thermal conductivity. Her high level means rapid transfer of thermal energy, that is, cooling, which is unacceptable.
• Moisture resistance. It is especially important if the insulation is placed between the soil and concrete.
• Durability. Remember that only cutting reinforced concrete with diamond wheels will allow you to get to the insulating material in the future. Therefore, it is desirable that it be able to survive the top coating.

Diamond drilling of holes in concrete in the event of a major breakdown of the water heated floor system

Suitable materials

Taking into account the above requirements, let's now figure out how to insulate a concrete floor in a private house:

• Mineral wool. It retains heat perfectly, has a low density and, in addition, creates high-quality sound insulation. But the high rate of moisture absorption and lack of rigidity limits its use to installation in a raised floor structure.

Roll of basalt wool

• Styrofoam. Low price, high moisture resistance and low thermal conductivity make this material very popular, but when using it, you must also remember about its fragility.

Insulating a concrete floor with polystyrene foam requires extreme care.

• Extruded polystyrene foam. This is essentially an improved foam. Its cost is a little higher, but its higher strength characteristics make working with it with your own hands much easier. Its thermal insulation and water resistance are also higher.

Extruded polystyrene foam boards

• Polyurethane foam. Another remarkable synthetic insulation, endowed with increased resistance to temperature changes and capable of withstanding extreme mechanical loads without losing its technical characteristics.

White polyurethane foam mattresses

• Expanded clay. Possessing low thermal conductivity, such material is usually added to concrete mortar instead of gravel or covered under it with a kind of cushion, but you should remember about its high porosity and consider reliable moisture insulation for it. Also inconvenient are its large volumes, due to which the floor level rises significantly.

Insulation of a concrete floor using expanded clay in a garage

• Foam glass. Here, high thermal insulation and moisture-resistant properties are observed, combined with absolute environmental friendliness. But the weak resistance to mechanical stress makes it more rational to insulate walls with such material rather than the floor.

Foam glass does an excellent job of reducing the thermal insulation of vertical surfaces

Insulation technology

Insulation of the concrete floor of the first floor represents a certain multilayer cake. In this case, the insulation can be located in any of the layers or even several.

Locations thermal insulation material

• Under the concrete. Perfect option, but only possible if work is carried out from scratch. Here we lay all the materials on the ground, after which we perform the pouring.

Pouring the solution onto the insulation laid in the baths

• Added to concrete. This is the case with expanded clay replacing gravel.
• Above concrete by installing a raised floor. Logs are laid on the frozen surface, and between them there is already an insulating substance. Everything is closed from above finishing coat. Requires additional costs, but makes it possible to use any insulating material.

On top of cement logs, mineral wool and tongue-and-groove boards

• On top of the finishing layer. Carpet covering, cork or soft floors can also improve the comfort of your home.

A carpet not only makes a room warmer, but also decorates it.

Tip: It is recommended, if possible, not to limit yourself to just one layer of insulation. Combination different ways leads to a stronger effect, which has a positive effect on the creation of favorable living conditions.

Carrying out the necessary work

To better understand the method of installing heat-insulating material, let’s consider an option in which all of the listed layers of the floor structure are insulated.

Instructions:

We fill the “bare” base with a gravel cushion, and then tamp it down thoroughly.

Pour a thin layer of liquid cement mortar on top.

Next, lay down a plastic film to create waterproofing. We lay each canvas overlapping each other and overlapping the walls. We glue the joining seams with mounting tape.

Creating waterproofing using plastic film

We glue damper tape around the perimeter of the room.

We lay sheets of extruded polystyrene foam or other material of your choice in a checkerboard pattern for greater reliability.

Installation of improved polystyrene foam boards

Now we cover it again with a layer of waterproofing. At the same time, with construction tape we glue the edges of the upper film with the protruding ends of the lower one, creating a kind of bag for the insulation.

We install a reinforcing grid, which will increase the strength of the heat-insulating layer, and beacons.

Steel grate with guide beacons

Mix the concrete solution using expanded clay instead of crushed stone.

Fill the floor with the resulting concrete, leveling it according to the guides.

Concreting a prepared and insulated base

After the screed has completely hardened, you can also install logs by laying sheets of mineral wool between them, or you can limit yourself to installing carpet or cork.

Concrete itself is cold due to its high thermal conductivity, so it needs additional insulation. It can be done both before and after pouring the solution, or even combine several methods. Using the recommendations outlined above, you can easily cope with this task yourself (find out here what types of crowns there are for drilling concrete).

A high-quality insulated concrete base can be covered with any finishing finish

The video in this article will provide Additional information. Now you know how to insulate a concrete floor on the first floor.