How to insulate the floor before screeding. How to insulate a concrete floor? Options for insulating concrete floors

To avoid troubles during operation, you need to carefully consider thermal protection 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 loss, 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. Recently, spray-on compounds have begun to gain popularity as an additional layer in a private home. When choosing an insulating material, more attention should be paid to the purpose of the room and the planned loads, since their thermal insulating properties are almost the same.

Features of using mineral wool

Manufacturers produce slabs designed specifically for floor insulation that are highly durable. 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 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 ( special case with lags)

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. He has high efficiency, resistant to moisture, but has its disadvantages:

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.

The advantages of this material include:

Increased strength characteristics.
Long service life.
Zero moisture absorption.
With the help of special additives, manufacturers obtain products belonging to the class fire safety 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 save high performance sometimes they use insulation of a concrete floor with polystyrene foam in two layers: the bottom one is made of foam plastic, the top one 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 type flooring in a 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.

Concrete pavement, especially cold in winter time years, so it must be insulated. You cannot do without a warm surface if there are small children in the family. It is advisable to carry out insulation of a concrete floor in a private house at the construction stage, then it will save heat and improve the microclimate in the rooms. Also, an insulated coating will allow you to save on heating and additional heating devices.

Types of insulation

To insulate a concrete floor in a private house, materials with heat-insulating properties are used. Today there are three methods of insulation:

spraying polymer insulation(penoizol, polyurethane foam);
fibrous materials (glass wool, mineral wool);
foamed molded insulation (polystyrene, polystyrene foam).

These materials have the same effect, but differ in installation technology.

Fibrous

When used, soundproofing and thermal insulation of rooms is ensured. The material is resistant to combustion, but does not like moisture. When in contact with liquid, it decreases in size and increases the heat transfer process. Fibrous insulation materials are not recommended for use in rooms with high moisture where there are leaks.

Technology

Installation of a concrete surface of a house consists of the following steps:

The concrete base is prepared: irregularities and cracks are covered, stains are removed. The floors are covered with film on top, and the joints are glued with tape.
Next, logs are installed, the thickness of which is equal to the thickness of the insulating layer.
A membrane film with waterproofing properties is laid on top of insulated floors, which is capable of removing steam from the insulating layer and preventing water from leaking out.
Next they lay plywood sheets one centimeter thick and fasten the insulation with self-tapping screws. Top, linoleum or other finishing coat.

Foam molded materials

Insulation of private houses is possible with polystyrene foam or polystyrene. These insulating layers are resistant to moisture and, thanks to this property, are used in insulating a bathroom, kitchen or other room with high humidity.

Technology

When insulating a concrete floor, it is important to ensure a clean surface, so before starting work, remove dust and debris from the coating. Cover possible cracks and remove bulges on the surface. To give the concrete floor an even coating, the floor is covered with a thin layer of sand. After preparing the surface, insulation boards are installed, installing elements in special grooves. This design of the slabs facilitates the laying of the product and prevents the formation of gaps.

The slabs are laid around the perimeter work surface. On concrete floors lay plastic film, which is attached on top of the insulation. The use of film prevents leakage of concrete mortar and the formation of voids and cracks. Next, install the reinforcement and begin pouring concrete. After laying the solution, the poured surface is leveled and left to dry, ensuring necessary conditions. The finishing coating is laid on the hardened concrete screed.

Polymer insulation

Use insulated polymer material in rooms with high humidity. Polymer material is a protective layer that is resistant to rotting and fungi. The disadvantages of polymer insulation include: fire hazard and toxicity in products manufactured without complying with sanitary standards.

Technology

Concrete floor insulation work polymer materials impossible without professionals. The insulating layer is applied in the form of foam, which then increases in size, which eliminates the need for seams during thermal insulation. Polymer insulation is applied using a designated device in which carbon dioxide and polymer liquid combine under pressure.

Before applying the insulating polymer layer, clean the surface from dust and debris, which can reduce adhesion to the material. Next, the logs are attached and secured with self-tapping screws. Moisten the surface, which will increase adhesion, and begin spraying the insulating composition.

Polymers are applied using special installations. The foam is sprayed between the joists, where it increases in size after application. Wait for the foam to harden, which occurs within 24 hours, and begin installing the joists and laying the finishing coating.

It is important to remember that polyurethane foam is susceptible to direct sun rays, therefore, if necessary, leave it for several days in the open sun, cover the material with film.

Other

Due to its characteristics, polystyrene foam is widely used for insulating surfaces.

There are other insulating materials, such as:

Styrofoam. It has low cost, thermal insulation and resistance to moisture penetration. The use of this insulation is popular in the world of construction, however, when using it, do not forget that foam plastic has a fragile structure.
Mineral wool. This insulation material is capable of excellent heat retention and sound insulation in rooms. The advantages of mineral wool include its fire resistance, chemical resistance to aggressive substances and fungi, as well as vapor permeability, durability and ease of installation. Mineral wool is an environmentally friendly product that does not harm human health. Disadvantages include high moisture absorption and lack of rigidity.
Extruded polystyrene foam. It has high thermal insulation and moisture resistance. Expanded polystyrene is an improved polystyrene foam, the cost of which is higher, but also greater strength, which allows you to work with this material without any problems and with your own hands.
Foam glass. The service life of this material reaches one hundred years; it is resistant to corrosion and temperature changes. It is not susceptible to deformation under mechanical stress and is not susceptible to mold, mildew and microorganisms. Foam glass is highly durable and does not require additional fastening during installation. The material is resistant to fire and moisture and has sound insulation. The disadvantages of foam glass include: high cost, fragility, inability to pass steam and heavy weight of the blocks.
Polyurethane foam. Has high adhesion with various building materials, is manufactured on site, which significantly reduces transportation costs and is responsive to changes temperature regime. Lightweight material and monolithic, which reduces the formation of joints and seams. However, the use of polyurethane foam is impossible without protection, as it can wear out under the influence of ultraviolet radiation. The protective layer is paint, plaster or panels.
Expanded clay. It has low thermal conductivity and is used in concrete mortar instead of gravel. Due to its high porosity, it requires insulation from moisture penetration. The advantages of insulated expanded clay include: low cost, ease of installation, which allows you to install it yourself, provides high sound insulation and resistance to sudden temperature changes. The material is highly environmentally friendly, does not emit harmful toxins and is safe for human health. The disadvantages include: the fragility of expanded clay, increased accuracy of installation and the greater thickness of the thermal insulation layer.

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, it is necessary to take into account the following material indicators:

Scheme of floor insulation with polystyrene foam.

Density. The lower this indicator, the lower the weight and the more pores in the material. Accordingly, the better thermal insulation properties it has.
Strength. When insulating a concrete floor, the strength of the insulation plays an important role, since significant loads are placed on it.
Moisture resistance. The higher this indicator, the better. Otherwise, the insulation will quickly absorb moisture and lose its properties.
Coefficient of thermal conductivity. The indicator characterizes the ability of insulation to transmit heat through itself. Low performance given value indicate good thermal insulation properties of the material.
Moisture permeability. This parameter must have minimum values, otherwise the material will absorb moisture from the air and concrete and lose its properties.
Durability. Everything is clear here, the greater the durability, the longer the material will last.
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.

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.
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.
Extruded polystyrene foam. This material is derived from conventional foam, but has better performance indicators. It is much stronger, more durable, and has better thermal insulation properties. At the same time, it is also resistant to water.
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.
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.
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 backing for finishing floor finishing. The cost of cork is an order of magnitude higher than that of other insulation materials.
Perlite. According to the method of application, the material is similar to expanded clay, but many performance characteristics Perlite is 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:

Installation of thermal insulation under a concrete screed. This method is used only at the stage of building a house. Otherwise, the finished 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.
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.
Adding to concrete mortar 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.
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.
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.

Insulating a concrete floor in a private house allows you to save heat, improve the microclimate in the house, and also save on heating. It is known that a concrete slab with a large temperature difference from the outside and inside condensation forms on a “cold” surface, which increases humidity in basement and on the first floor. Insulation allows you to solve this problem.

To insulate a concrete floor, you can use almost any modern heat insulating materials, but there are currently three main methods of insulation:

using fibrous insulation - mineral, basalt or fiberglass wool;
using foamed molded materials - foam boards, polystyrene;
by spraying polymer insulation - polyurethane foam, penoizol.

All of these insulation materials are quite effective, and depending on the type of insulation, the technology for installing them varies.

When choosing insulation, it is necessary to take into account the characteristics of the materials. Fiber insulation has good heat and sound insulation, does not support combustion, but is afraid of water. When wet, it sharply decreases in volume and loses its thermal insulation properties. Therefore, it is not recommended for use in damp rooms where leaks are possible, and in other rooms it must be waterproofed on both sides.

Polystyrene foam is flammable and not mechanically strong, although it has low price. If it is necessary to insulate floors when minimum costs, you can choose foam plastic slabs as insulation, but it must be covered on top with a material that redistributes point loads - plywood, chipboard or plasterboard. An analogue of polystyrene foam - extruded polystyrene foam - does not support combustion, since its bubbles are filled not with air, but with carbon dioxide. It has increased strength, so it can be used to insulate a concrete floor directly under concrete screed.

Modern and very effective method sprayed thermal insulation is distinguished by the fact that it does not require leveling or surface preparation, forms a seamless coating, and its heat-insulating properties are very high. At the same time, the application of sprayed insulation requires calling specialists with a spraying installation.

Insulation of concrete floors with fibrous materials

When insulating a concrete floor with mineral wool, you should remember its features and follow the sequence of layers. The thickness of the insulation layer is determined by the characteristics of the material. This information is usually provided by the manufacturer. Usually a 5-10 centimeter layer of mineral insulation is sufficient.

Insulation of a concrete floor with polystyrene

Insulation with foam plastic or polystyrene is usually used under a concrete screed. These materials are waterproof, so they can be used in the bathroom, kitchen and other wet areas.

The technology of floor insulation with polystyrene is used when making warm water floors. In this case, the heating circuit is placed on reinforcing mesh, after which they are filled with concrete.

A highly effective method that requires the participation of professionals. The insulation is applied to the floor in the form of foam with a closed cellular structure, and after application it expands in size, forming a seamless layer of thermal insulation. Foam is applied using a special installation in which polymer liquid and carbon dioxide under pressure.

There are other methods of floor insulation that are less effective. For example, making a dry expanded clay screed also allows you to create an insulating layer. The concrete screed itself, when polymer or cellulose fillers are added to the solution, acquires heat-insulating properties. When choosing a method for insulating a concrete floor in a private house, it is necessary to take into account all factors, including the method.

There are several ways to insulate a home. 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 debris 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 selected thermal insulation material for the floor under the screed 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 of the same price category, then its 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 affordable and practical way to insulate a floor is to use conventional 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, can withstand various loads, which 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 the fire safety of 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 it on top of the insulation waterproofing material. 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 should be equal in height 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 under the 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.