It is better to insulate the concrete floor. How to insulate a concrete floor in a private house

Concrete floors are the most practical option for a private home, due to their strength, durability and low manufacturing costs. But concrete is a cold material, and without high-quality thermal insulation In winter the house is not very comfortable. In addition to high heat loss, problems are also caused by condensation, which is formed due to the large temperature difference between the internal and outside concrete base. There are several ways to insulate a concrete floor in a private house, and even a novice master can do all of them.

Concrete floors can be insulated in three different ways:

simplest - lay insulation on concrete surface continuous layer. To do this, the base is cleaned of dust, unevenness is eliminated, and, if necessary, filled with leveling mixtures. The insulation can be attached with glue, dowels, or a combined method, after which the finishing coating is installed. Individual insulation materials themselves act as finished flooring, which allows you to reduce installation time and save a little money;
frame method - logs are first installed on a concrete base, then the space between them is filled with insulation, and a finished floor is laid. The method is more labor-intensive, but allows the use of materials with a lower density that cannot withstand high loads;
laying insulation under the screed - mounted on concrete floor a layer of thermal insulation and poured cement-sand mortar on top, resulting in the formation of a monolithic solid foundation. The method is the most labor-intensive and time-consuming, but this base is perfect for any floor covering - from linoleum to tiles. Besides, this option used in the installation of electric and water heated floors, which ensures uniform heat transfer over the entire area of the room.

When choosing, the determining criterion is the type of flooring and the method of its installation. For example, soft and roll materials, since they are not designed for high loads. The same applies to insulation materials laid directly under the finishing coating: they must have good density and rigidity so as not to be pressed through during operation. It is also worth considering that logs and insulated screed take up to 15 cm in height, so for rooms with low ceilings The first installation method is preferable.

Selection of insulation materials for concrete

The insulation market now provides a wide selection of materials, both domestic and foreign. Most often used for thermal insulation of concrete floors. particle boards, fibrous materials, foamed polymer boards. Sprayed insulation, which is applied using special equipment, is also gaining popularity. Among inexpensive options for a private home, it is worth noting expanded clay - natural, environmentally friendly pure material with excellent thermal insulation properties.

The key characteristics of insulation are:

density– the higher this indicator, the greater the amount of heat will be retained;
strength– determined by bending and compression. The higher the expected loads, the stronger the insulation should be;
thermal conductivity– the efficiency of heat conservation in the room depends on this indicator. Preference should be given to materials with the lowest thermal conductivity coefficient;
moisture permeability– the higher the indicator, the faster the thermal insulation properties of the material deteriorate. Insulation saturated with water is not able to retain heat, so it will have to be replaced;
durability– in order to save money, it is worth choosing a material with the longest service life, because frequent replacement of insulation and accompanying repairs are expensive;
environmental friendliness– in residential premises it is necessary to use only environmentally friendly insulation, since the floor covering is not a good protection against toxic fumes.

The weight of the material does not play a big role, because, unlike a city apartment, there is no need to worry about increased loads on the floors between floors.

So, let's look at popular insulation materials, their properties, pros and cons.

Material	Main characteristics
	It has low thermal conductivity and perfectly muffles sounds. Available in rolls and slabs, differing in density. It does not burn, but has high moisture permeability, and therefore requires high-quality waterproofing during installation. The service life, subject to installation technology, is 25-30 years. Insulation mineral wool performed only on joists, since the material does not withstand high loads
	They have good strength and heat capacity, have soundproofing characteristics, and can be laid directly on concrete or on logs. For floor insulation, slabs with a thickness of at least 20 mm are suitable. Moisture resistance is average, so waterproofing is required on damp substrates. In dry rooms, the material can be laid directly on concrete, pre-treated with a primer
	This group includes polystyrene foam and EPS. They are lightweight, easy to install, and have very low thermal conductivity. They can be laid under a screed or between joists, and EPS can also be laid on the concrete floor itself. Polystyrene foam is cheaper, but less durable, so if there are increased requirements for floor construction, it is better to use extruded polystyrene foam. Foam insulation is resistant to moisture and lasts on average from 20 to 30 years
	Form a seamless durable coating with low thermal conductivity and moisture resistance. They are used for insulating concrete along joists. Such thermal insulation is one of the most reliable and durable, but it is also much more expensive than other materials. This is due to the need to use a special installation, with the help of which spraying is carried out
	The most environmentally friendly insulation affordable price. Used for insulation along joists and under screeds. To provide maximum thermal insulation the material should be covered in a thick layer - from 10 to 20 cm. Expanded clay does not burn, has a long service life, but is very fragile and loses its thermal insulation properties due to damage to the structure
	Lightweight, environmentally friendly insulation with water-repellent properties. Cork has a very low thermal conductivity, it is always warm to the touch, so it is ideal not only as a substrate, but also as an independent floor covering. It can be laid directly on a concrete floor, painted or varnished. The only disadvantage of insulation is the high price

There is another type of insulation that appeared not so long ago and has not yet gained widespread popularity. This is liquid thermal insulation - a new generation material with unique properties. Looks like a thick white paint, and is applied in the same way, forming an elastic, durable coating. A layer of 1 mm can replace roll thermal insulation 50 mm thick, in addition, this coating is impervious to moisture, chemical attack, does not burn and does not emit toxic substances. This paint is used not only for insulating concrete floors, but also for walls, slopes, pipelines, facades, and various containers. The coating lasts for about 15 years if applied correctly.

Liquid thermal insulation coating "Astratek"

We insulate a concrete floor with our own hands

Before insulation, the concrete surface must be inspected and all defects eliminated. This applies to potholes, cracks, and crumbled areas. Small differences in height are leveled with leveling mixtures. This preparation is a mandatory step and ensures the reliability and durability of the floor. Now let’s look separately at the most popular methods of insulating a concrete floor in a private house.

Insulation with polystyrene foam

To work you should prepare:

Eps boards;
waterproofing film;
damper tape;
vapor barrier membrane;
construction tape;
gypsum fiber sheets;
GVL glue;
tools and fasteners.

The surface of the concrete floor must be clean, absolutely dry and not have differences in height of more than 5 mm.

Step 1. The floor is covered with a waterproofing film, the sheets of which are overlapped by 10-15 cm, and the joints are secured with tape. To increase sound insulation, you can lay a second layer of geotextile fabric with a density of 300 g/m2.

Advice. Waterproofing is mandatory for bathrooms, kitchens and other areas with high humidity, in other rooms the insulation can be laid directly on the concrete base.

Step 2. A damper tape is laid around the perimeter of the room so that its bend falls exactly at the junction between the wall and the floor.

Step 3. The first row of polystyrene foam is laid. The slabs fit tightly together using grooves and ridges on the side edges. The last slab in the row is trimmed if necessary.

Step 4. The insulation must be laid with offset seams, staggered, so the second row begins with a cut slab. Everything else is exactly the same: EPPS is laid joint-to-joint, leveled, making sure that all the slabs are located in the same plane.

Step 5. A vapor barrier membrane is laid on top of the polystyrene foam. Its canvases are also overlapped, the edges are placed on the wall to a height of 10 cm, all joints are sealed with tape.

Step 6. A prefabricated screed is installed. Gypsum sheets are laid on the floor joint to joint in a checkerboard pattern. Next, glue is applied along the seams between the rows in continuous wavy strips and a second layer of gypsum fiber board is laid so that the seams are completely covered by the sheets.

Step 7 When the glue hardens, both layers are mechanically fixed to each other. Self-tapping screws are screwed into each sheet in the corners and in the center, slightly recessing the fastener heads into the material.

After this, you can lay any finishing coating and even install a warm floor under the tiles. Heating elements can be located both in the screed layer and in the tile adhesive layer.

Insulation with mineral wool on joists

To work you will need:

mineral wool in slabs or rolls;
waterproofing film;
wooden beam for logs;
plywood or chipboard for flooring with a thickness of 18 mm;
dowels and screws;
tape measure, level and mounting knife;
drill and hammer drill.

Step 1. The concrete base is covered with a layer of waterproofing film. Adjacent canvases should be overlapped by 15-200 cm, the joints taped.

Step 2. Logs with a cross-section of at least 110x60 mm are installed on top of the film. The distance between the logs depends on the thickness of the floor covering; in this case, it is recommended to take a step of about 300 cm. The timber is placed on the edge, be sure to control the plane level, and also make sure that the logs are positioned strictly parallel to each other.

Step 3. Screw the logs to the base. To do this, drill them through and go deep into the base by 50-60 mm. Next, insert the dowels and screw in the screws. The fastening pitch is 40-50 cm.

Advice. To fix the joists to the floor experienced craftsmen It is recommended to use screws whose threads do not reach the head. Such fasteners allow you to tighten the beam more tightly to the base.

Step 4. Install insulation. A roll of mineral wool is rolled out over the joists, after which the insulation is cut into strips so that each of them tightly fills the space between the beams. If slab insulation is used, the slabs are inserted one at a time between the joists and, if necessary, cut to width. The joists should protrude above the insulation by approximately 20 mm.

Step 5. Next stage– laying the subfloor. The plywood is cut out and the sheets are laid end to end in a continuous layer. You can use tongue and groove slabs with protective moisture-resistant coating. The material is laid with its long side perpendicular to the joists and attached to the frame with self-tapping screws at 20 cm intervals. The rows of slabs are laid with offset seams, and the joining of the seams in the row is carried out along the longitudinal axis of the joists.

Before laying the slabs, the adhesive is applied to the ends with a brush, which ensures high degree moisture resistance

To provide greater protection to the insulation from moisture, before installing the flooring, it is recommended to lay a vapor barrier membrane with an overlap of strips of at least 10 cm. You can also glue the joints of the slabs during installation, ensuring complete tightness of the subfloor. After this, all that remains is to lay the finishing coating and secure the baseboards.

Prices for Rockwool mineral wool

rockwool mineral wool

Prepare everything you need in advance:

polystyrene foam boards;
reinforcing mesh;
profile for beacons;
rule;
glue;
damper tape;
cement and sand for mortar.

Step 1. The concrete floor is thoroughly cleaned of dust and debris. Damper tape is glued around the perimeter of the room.

Step 2. Take the first insulation board, apply glue with a spatula in the center and in the corners, lay it on the floor and press it with your hands over the entire surface. The next plate is fastened end-to-end with the first, pressing tightly along the seam. In the same way, lay the whole thing to the end, if necessary, trimming the outer slab.

Step 3. The first slab of the second row is cut to create an offset joint installation. Further installation is carried out in the manner described above. If a second layer of insulation is required, the top slabs are placed so that they completely overlap the seams in the bottom layer.

Step 4. A reinforcing mesh of metal rods is laid on top of the insulation. There should be a distance of 20-30 mm between the edges of the mesh and the walls.

Advice. Before laying the mesh, it is recommended to cover the insulation with thick polyethylene film, gluing the joints of the strips with tape. This is necessary not to protect the insulation from moisture (expanded polystyrene is a moisture-resistant material), but to avoid the solution from seeping into the joints between the plates and the formation of air voids in the screed.

Step 5. Profile beacons are laid on the reinforcing mesh and fixed with a small amount of solution. Here it is very important to set the beacons at the level, because the evenness of the floor depends on this. All beacons must be strictly horizontal and in the same plane.

Step 6. Mix the solution and pour it between the beacons. Next, using the rule, the mixture is stretched along the beacons and leveled. If grooves form, more mortar must be added. The thickness of the screed is made within 4-6 cm.

After leveling the surface, the screed is left to dry. When the solution has set well, you should carefully remove the beacons and seal the grooves with fresh cement mixture.

While the floor is drying, it must be protected from direct sun rays and drafts, and periodically moisten the first 10 days so that the screed does not crack.

In former times, it was considered normal practice to lay finished flooring directly on the concrete base of a 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, along the ground on the ground floor of a private cottage, or is it interfloor covering apartments?
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 are talking 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 give you an idea of the thickness required different materials for floor insulation, it is proposed to study the diagram with thermal conductivity coefficients. The lower the coefficient value, the better the properties of the insulator, and the thinner the layer.

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 one and effective insulation like penoplex or something cheaper, but in 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 put them into 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. You will have to add a larger layer of mineral wool or lay it together with foil foam, 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 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 base.

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 thermal insulation characteristics better 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;
spray polyurethane foam: the most best insulation of all, but also the most expensive, it resists moisture, flame (for a certain period of time) and has the highest thermal insulation rates;

For reference. There is also on sale cork insulation, 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 lay almost any floor covering on top of it. This means that floors insulated in this way are made not only under 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 insulation method 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 monolith of the screed becomes, as it were, 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 should not be lower than 115 kg/m3, and the thickness should be 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 should be laid 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 dense polyethylene film with an overlap between the sheets of 100 mm and gluing the joints with tape. 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, polystyrene foam 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. Thickness cement screed should be between 50 and 80 mm. The best option, taking into account different loads on living room floors – 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 Still, it will be necessary 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, the best expanded clay thermal insulation properties 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 is worse. They just need to be applied according to the circumstances and in accordance with financial capabilities. Certainly, wooden floor 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.

There are several ways to insulate a house. You can use one of them: lay insulation under the concrete screed. It is possible to carry out all the work on floor insulation and you just need to have some simple skills and thoroughly study all the available information on this issue.

Preparing the base for thermal insulation

Before insulating the floor under the screed, the following preparatory work should be carried out:

Gaps between walls and floors should be insulated. To do this, you can use a special sealant or prepare cement mortar. Both methods are good. They differ from each other only in how much time it takes to complete the sealing: the sealant is already ready-made composition, but the solution will still need to be prepared.
The surface must be cleaned of existing construction waste and dust in order to protect the insulation from damage. If it is damaged, the thermal insulation of the room will be compromised.
If pockets of fungus or mold appear, they should be removed. In the case where the floor is wooden, it is necessary to remove all rotten or damp boards and joists and put new ones in their place. Of course, mold is not dangerous for thermal insulation material, but inhaling the air in a room where it is present is very harmful, and over time the air will become more and more dangerous (read also: " "). All new wood material should be coated with antiseptic and fireproofing agents.

Insulation characteristics

In order for the thermal insulation to be good, the insulation under the floor screed must have certain qualities:

The insulation must have high moisture resistance and not be exposed to various microorganisms.
The thermal conductivity coefficient should be as low as possible. However, other indicators, on the contrary, should be as high as possible. And this should not be confused.
The insulation must be durable and resistant to mechanical stress; these qualities are very important for rooms with high traffic. Huge loads can be applied to the foundation.
When choosing how to insulate the floor under the screed, you need to consider what it will be made of.

Correctly chosen thermal insulation material for a floor under a screed, this is a guarantee of a cozy and comfortable room. In this case, the cost of the material should not be the main selection criterion.

Types of insulation

Now let's look at the most popular thermal insulation materials, which are most in demand in the domestic market.

Such insulation materials include:

expanded polystyrene;
mineral wool;
Styrofoam.

Expanded polystyrene has a number of positive qualities:

This insulation is very lightweight and easy to install; you can easily install it yourself without any help. Light weight allows it to be transported passenger car, and also raise to high floors. Also with his small sizes expanded polystyrene can also be transported in an elevator. Read also: "".
It has significant strength and long service life. After a long period of time, the material will not collapse or crumble. It is quite often used in industrial premises, that is, where large and heavy machines are located.
To seal joints, it is not necessary to use a special sealant. They can simply be insulated with tape.
If we compare polystyrene foam with other insulation materials, it is the same price category, then the degree of sound and heat insulation is higher.

Mineral wool is also used as thermal insulation under the screed, which has the following features:

The cost of this material is low, so it is quite popular. It can be classified as publicly available materials.
It does an excellent job of protecting the room from heat loss and cold penetration.
Mineral wool has low noise insulation, but is quite suitable for use in a country house.
Installation is as easy as polystyrene foam, the only difference being that you need to work not with sheets, but with rolls.

Whatever type of cotton wool it is necessary to follow the rules when working with it personal protection: Protective gloves and a mask should be worn. This is necessary because the insulation pile contains microscopic dust particles that can be harmful to health if inhaled in large quantities.

The most accessible and in a practical way floor insulation is the use of ordinary polystyrene foam.

This is all thanks to the advantages it has:

the material is very light;
easy to handle and install;
safe for humans;
reliable and has a long service life, it can withstand various loads that affect the floor in residential and administrative premises.

However, such insulation for concrete floors under screeds, when ignited, emits toxic smoke, which can cause serious harm to human health. Therefore it is necessary to take care of fire safety the room in which it is installed.

Installation features

If you plan to make a screed from cement-sand mortar, then it is necessary to lay a waterproofing material on top of the insulation. This is done to protect the material from exposure to moisture from the solution. The waterproofing must be laid overlapping, the joints must be secured with tape.

If a “floating floor” is being made, then even before screeding, it is recommended to lay strips of wooden slabs, which in height should be equal to the thickness of the future screed.

A small gap of approximately 1-3 mm should be left between the screed and the wall. This will help avoid the formation of “sound bridges”.

Conclusion

After studying all the information about thermal insulation materials for screed, you can choose the most suitable one for yourself. You should also remember about consistency and compliance with the rules when performing floor insulation, otherwise you may get a completely different result than you would like.

Insulating the floor by laying insulation on a concrete floor slab, followed by pouring a cement composition is enough difficult process. In order to carry it out with guaranteed quality of the final result, you must first decide on choosing the thermal insulation material itself. There are a considerable number of types of floor insulation for concrete under screed, and each has its own pros and cons. Let's look into them thoroughly.

What do manufacturers offer today? It is necessary to indicate that all heat insulators are divided into several groups depending on their structural composition:

roll and slab,
bulk,
sprayed

The first include mineral wool in rolls and mats, glass wool, polystyrene foam boards, foil penofol(foamed polyethylene). To the second group - expanded clay, perlite, polystyrene chips. To the third - polyurethane foam.

Let’s immediately make a reservation that although the latter is the best, it is very expensive, and the method of applying it requires special equipment.

The rest are often used for thermal insulation of concrete floors, so let's look at them.

Expanded clay

If we talk about insulation under the screed specifically for a concrete base, then This is what expanded clay was originally created for. These are granules of foamed clay, which are simply scattered on the floor, leveled in thickness (usually within 7-20 cm) and covered with a semi-liquid concrete composition.

It is not necessary to cover the material with waterproofing. Concrete penetrates upper layer, forming expanded clay concrete, which in its thermal properties is not inferior to any insulation.

The thermal conductivity of expanded clay is 0.16 W/m K.

Foamed polyethylene

It is also called penofol. This is a thin layer of polyethylene foam, which is covered on one or both sides. aluminum foil. The latter performs two functions:

waterproofing,
reflector of thermal energy.

Thermal conductivity – 0.037-0.051 W/m K depending on the thickness.

If you are laying it on a concrete floor, then it is better to use a model covered with foil on both sides.

Polyethylene foam itself does not absorb moisture very much. But after its penetration it sharply loses its qualities. Therefore, it must be protected on both sides.

Moisture from the screed mortar will begin to penetrate into all the cracks, which can negatively affect technical condition penofol.

Penofol should be laid on the floor in strips, joint to joint. The connection boundaries are covered with self-adhesive foil tape.

Using Penoplex

The name Penoplex itself is a brand. And the material itself is a high-density polystyrene board. For screed floors this is the best option.

It has low thermal conductivity - 0.031 W/m K.
It has a high density - 45 kg/m³, which affects the compressive strength. And for genders this is one of the important indicators.
Does not absorb moisture.
Does not allow steam to pass through.
Chemically inert.
Absolutely environmentally friendly.
Easy to process.

Today, manufacturers produce foam boards with a tongue-and-groove connecting lock, which makes it possible to floor base collect seamless coating.

The process of insulation with penoplex is simple. It is necessary to lay the slabs over the entire surface of the concrete floor, connecting them together with a lock, then stretch the reinforcing synthetic mesh over the top, and only then you can pour the solution.

Mineral wool

It should be noted that of all the insulation offered under the screed, this is the most inconvenient. The thing is that mineral wool is a hygroscopic material. It quickly absorbs moisture, becoming practically unnecessary. Therefore, it must be closed on both sides: on the side of the concrete floor vapor barrier film, from the screed side waterproofing membrane. Therefore, the pouring process itself begins with the installation and laying of the lower protection.

Typically, the film is laid in strips with edges overlapping within 10-15 cm, which must be secured with construction tape along the joint. Be sure to lay it over the walls, taking into account the thickness of the entire insulated pie plus the screed.
Next, the thermal insulation material itself is laid out. It is better to use mats for the floor. They should be laid tightly to each other so that there are no gaps left, which can later become cold bridges.
The top film is laid, like the bottom one, in strips with overlap and installation of tape.
A reinforcing frame in the form of a metal or synthetic mesh must be applied to such a heat-insulating cake.

note, if mineral wool is laid in two layers, then the mats should be offset by half the panel. The seams between the thermal insulation elements must not coincide vertically.

The process of laying insulation under the screed

Insulating the floor under the screed with your own hands is not difficult, if you take into account the nuances of installing each heat-insulating material. For example, polystyrene boards do not need to be covered with waterproofing. And without this, mineral wool, after a while, will become just a layer that has nothing to do with the category of heat insulators.

In this regard, expanded clay is a dual material. That is, it can be used in its pure form without covering it with a waterproofing layer . But often craftsmen also use membranes, covering them with insulating flooring.

In principle, the technology itself is the same, regardless of the chosen thermal insulation material.

Correctly lay the thermal insulation taking into account a complete and dense covering for the concrete floor.
Do not leave gaps and cracks that can become cold bridges.
Fill concrete mortar carried out using standard technology, taking into account thickness.

More and more often, craftsmen are talking about the fact that any screed, even when poured over an insulated floor, it must be carried out with a reinforcing element. The costs are small, labor intensity does not increase, but the strength characteristics of the layer increase. And this increases the service life.

Estimation of the cost of screed with insulation

The only thing that will affect the cost of a poured floor screed with insulation is the price of the latter. Here are the prices for insulation materials that are used for thermal insulation of floor bases.

Mistakes when insulating under a screed

The insulation of the screed must be approached from the position correct implementation laying out all the layers used. As mentioned above, if waterproofing is used, then the film must be placed on the wall. If this is not done, the liquid solution will find a way to penetrate under protective layer and into the insulation itself.

If foam boards are used for insulation without lock connection, then they must be laid, pressing tightly against each other. Many people recommend filling the gaps between the slabs, as well as between them and the walls. polyurethane foam. You can't do this. Foam easily absorbs moisture, decomposing under its influence. If you have already used it, then cover the insulation completely with waterproofing film.

The reinforcing frame must be laid in the body of the screed, and not on the insulation. Therefore, the mesh is laid with a slight rise from the surface of the heat-insulating layer. This can be done using special plastic stands, which are sold in hardware stores today.

Before insulating the floors with screed, the last must be cleared of debris. Pebbles, small debris may damage the waterproofing film or the insulation itself.

To avoid troubles during operation, it is necessary to carefully consider the thermal protection of the building. Very often when designing, a decision is made to use prefabricated or monolithic reinforced concrete floors. If the building does not have a heated basement or basement, it will be necessary to insulate the concrete floor on the ground floor in a private house.

Why is insulation performed?

Before insulating a concrete floor, it is necessary to understand the feasibility of this measure. Concrete has high thermal conductivity. This means that it transmits heat well through itself and removes it from the room. To prevent heat losses materials with better thermal conductivity are used.

Laying insulation as an additional layer in a private house on the ground floor floor prevents the following problems:

condensation on the cold surface from the side warm air;
the appearance of mold, mildew and other microorganisms dangerous to humans;
violation of the temperature and humidity conditions of the room;
high heating costs.

If you leave a concrete floor in a private house without insulation, then in addition to the fact that it will be uncomfortable to use, the structure will soon require serious repairs.

Methods for insulating a concrete floor

Insulation of a concrete floor on the ground floor can be carried out both from above and from below the ceiling. The most commonly used method is from above. You can understand why this is so by considering the disadvantages and advantages of each of them.

Insulation concrete floor from below (from the basement or underground)

Advantages insulation from below:

high efficiency;
protection concrete structure floors from freezing;
Condensation is expected to occur from the basement side;
does not reduce the height of the room on the ground floor when clean;
the base for the floor covering becomes durable concrete slab, and not porous insulation.

Insulation of a concrete floor from the cold air side is more effective, but in case horizontal design it becomes more complicated. It is quite difficult to carry out work in a low technical underground, constantly raising your head up. Because of this drawback, in the vast majority of cases, the floors in the house are insulated from the warm air side.

Insulation over the ceiling has the following features:

the dew point (condensation) is located inside the floor structure;
the supporting structure is not protected from freezing;
in addition to the vapor barrier of the insulation on the warm air side, waterproofing will be required on the cold air side;
it is necessary to install a reinforced cement-sand screed on top of the insulation;
The clean height of the first floor premises is significantly reduced.

Currently, screed reinforcement can be avoided by using insulation materials with increased strength, specifically designed for use in floor construction.

Materials for insulating concrete floors

The most common thermal insulation materials include mineral wool And expanded polystyrene. IN Lately Sprayed compounds have begun to gain popularity as an additional layer in a private home. When choosing insulation material more attention It is worth paying attention to the purpose of the room and the planned loads, since their thermal insulation properties are almost the same.

Features of using mineral wool

Manufacturers produce slabs designed specifically for floor insulation, which have high strength. Mineral wool has the following advantages:

Resistant to high temperatures and fire.
Vapor permeability.
Resistance to fungus, mold and other microorganisms.

It is important that mineral wool is not highly resistant to water, so its use in wet areas is not recommended. When wet, the insulation sags and loses its useful properties.

Mineral wool is a soft material, so it is best to lay it between joists so that the insulation does not take on the load.

Insulation of the ceiling from above (a special case with logs)

Depending on the source raw material, mineral wool is divided into:

glass;
stone;
slag

It is important to take precautions when working: small particles of material can enter the lungs and skin and cause health problems. When working with mineral wool, builders must be provided with protective clothing, gloves and masks.

Types of expanded polystyrene and its application

The cheapest option for insulation in a private house on the ground floor, not counting the simplest materials such as expanded clay, is Styrofoam. It is highly efficient and resistant to moisture, but has its drawbacks:

If the foam is exposed to wet conditions low temperatures, it will crumble into small balls and cease to perform its function.
The material has a fairly low strength, so when insulating the floor, a reinforced cement-sand screed is used over it.
Polystyrene foam is a moderately and slightly flammable material and, when burned, releases substances harmful to humans.
Use with caution in damp areas.

The use of polystyrene foam insulation eliminates many of the disadvantages extruded polystyrene foam. By appearance it is similar to polystyrene foam, but differs in manufacturing technology.

To the advantages of this material can be attributed:

Increased strength characteristics.
Long service life.
Zero moisture absorption.
With the help of special additives, manufacturers obtain products belonging to the fire safety class NG (non-flammable).

The main obstacle to insulation with extruded polystyrene foam in a private home can be its fairly high cost. But despite this, the material is the best solution.

To reduce cost and maintain high performance, concrete floors are sometimes insulated with polystyrene foam in two layers: the bottom layer is made of polystyrene foam, the top layer is made of extruded material. Such a solution in private construction will be the best compromise between price and quality. A layer of dense extruded polystyrene foam is taken 30-50 mm thick. It is advisable to select the required foam layer using thermal engineering calculations. If this is not possible, approximately take a thickness of 70-100 mm depending on the climate of the construction area.

Laying insulation

Before starting work with expanded polystyrene you will need to prepare everything necessary tools. For installation you will need:

knife for cutting material;
glue;
polyurethane foam;
foil polyethylene as a vapor barrier;
metal tape for gluing polyethylene sheets together.

How to insulate a concrete floor on the first floor correctly? It is important to carefully prepare the base for the insulation and clean it of dust and dirt. Depending on the type of flooring in the house, sometimes thermal insulation material is laid between the ribs of wooden or metal frame. After installation is completed, the insulation material is cement-sand screed.

And this video shows the process of installing polystyrene foam screeds:

Tools and materials needed to work with mineral wool:

waterproofing (for example, durable polyethylene film);
vapor barrier (for example, vapor barrier membrane);
tape for gluing joints of film and membrane materials;
tool for cutting insulation boards.

Insulation of a concrete floor in a house requires a careful approach, the right choice insulation and compliance with its installation technology. Working with expanded polystyrene is much easier than with mineral wool, and it protects no worse. Costs at the construction stage will easily pay off during operation (savings on repairs and heating).

In this video, experts talk in detail about all the nuances that you need to keep in mind when installing a floor.