Insulation inside the wall which is better. Insulation from the inside: myths and reality

Many people suffer from the cold in their apartments and are thinking about how to insulate the walls. This matter can be done at any time, and if there is a major overhaul, then, as they say, God himself commanded. By insulating houses from the inside, we can protect them from frost in winter, as well as from excessive humidity when it starts to rain. The main criterion for such work is still considered thermal protection. Today there are materials and technologies that will help you do the work yourself. If the insulation inside the room is carried out efficiently, then heating costs become minimal.

The walls that suffer the most are in corner apartments of high-rise buildings and in private houses. Having decided to take care of your apartment or house, you need to get acquainted with the peculiarities of the work and find out the technological nuances. We’ll talk about how to insulate walls from the inside in a private house.

We insulate houses from the inside

To create comfortable living conditions (preservation of heat, getting rid of damp, moldy surfaces), the walls of houses can be insulated both from the inside and outside, from the facade. Internal insulation is considered to be the most effective. Especially:

When taking care of insulating your home from the inside, you need to choose the right materials that are vapor-tight. The work must comply with special technology, otherwise, instead of insulating a private house or apartment in a high-rise building, you will become the culprit of its destruction: mold will appear due to condensation. The fact is that dew point may form- an increase in humidity in the room when the heating season begins leads to the appearance of droplets on the walls in places where joints and seams are not insulated.

How to choose the right insulation material for walls?

If you have to insulate walls from the inside, you will have to take care of the choice of material. There are special requirements for thermal insulation materials:

• expanded polystyrene and mineral wool;
• polyurethane foam and ecowool;
• penoplex.

It is these building materials that are used if you need to do internal insulation.

If you decide to insulate a private house from the inside with your own hands, try to learn more about the installation features. In addition to printed articles and Internet materials, you can use video tutorials that show in detail all the steps for installing insulation, both frame and frameless methods. Interested home owners can clearly track all stages of the work.

In the case where there are no special construction skills, it is best to carry out the work contact specialized companies, otherwise you will have to redo everything, and this will be additional material costs. Specialists carry out insulation work efficiently, quickly, following technology.

Application of mineral wool

You can insulate the walls with mineral wool. It is used most often, although such material cannot be called an ideal option. The point is that after some time mineral wool begins to absorb moisture, so it is impossible to avoid the appearance of damp places. When working with this material, you should do everything according to the instructions, not forgetting to process the joints. In addition, the walls themselves and the insulation must first be impregnated with antifungal compounds. Only in this way can the operation of the insulation be extended for ten years.

Before insulation with mineral wool, a metal frame is mounted on the wall. Plates are installed in the resulting cells, which must be compacted. The surface must be covered with plasterboard. When choosing mineral wool, do not forget that the usable area of ​​the apartment will decrease.

We insulate the walls from the inside using polystyrene foam

Expanded polystyrene has recently gained popularity as insulation. This material has:

• low specific gravity;
• minimal thickness, so installation does not require the installation of a frame;
• room humidity does not affect the quality of the material;
• The polystyrene foam is attached with construction adhesive. Can also be used dowels or liquid nails. But first, the joint areas are treated with polyurethane foam.

Penoplex is an environmentally friendly material for insulation

Penoplex, another name for expanded polystyrene foam, is an excellent material because it:

Polystyrene foam as insulation

The inside of the house can be lined with foam plastic. Its installation does not require the installation of a frame. Material produced in the form of panels, which are simply glued directly to the wall. As an adhesive composition, you can use the one that is usually used to glue ceramic tiles.

Glue is applied to the polystyrene foam, then, pressing slightly, mesh metal reinforcement is installed. The overlap must be at least 15 centimeters. This layer is then plastered or painted, then wallpaper is pasted. You can use ceramic or tiles for finishing.

The choice of insulation depends on the wall material

Are you tired of freezing in winter and have you decided to start insulating your apartment or private house? Please note that the choice of insulation will directly depend on what material the walls themselves are made of.

1. If the wall is made of brick, then polystyrene foam, expanded polystyrene and mineral wool will work more effectively in this case.
2. Walls based on foam blocks are usually insulated using polystyrene foam, penoplex or expanded polystyrene.
3. In wooden houses, it is effective to use penoplex and expanded polystyrene when insulating internal walls.
4. If the house is made of concrete, then each owner has the right to choose the material that he likes best, since there are no restrictions when choosing insulation.
5. For insulation of timber houses it is better to use ecowool, although you will have to install not only a vapor barrier, but also a sheathing.

Carry out insulation inside the house, following special rules. High-quality insulation can be done with your own hands if you listen to the advice of experts. First of all, this concerns the walls. When preparing them, you need to perform the following types of work:

• Using a hair dryer, spotlights, infrared lamps, air heaters, thoroughly dry the walls.
• Check the integrity of the insulating materials; if there are damages, they should be repaired. Such work is very important to protect the surface from dampness and steam.
• All seams that form between the floor slabs, as well as the heat-insulating layer, must be processed.

When preparing the surface, a number of specific preparatory works are performed, which require a special careful approach:

How much does it cost to insulate a house inside?

If you decide to create comfortable conditions in your private home yourself, it will cost much less than the services of specialized companies. On average, you will have to pay 450 rubles or more per square meter of insulation. The cost of a square will depend on what insulation material you used and what additional work had to be done before installing the insulation.

It should be noted that internal work on insulating a house is not always justified. It is better, of course, to do this outside the building. But if its implementation is impossible for various reasons, then the standards fully allow for insulation of walls in the interior of houses.

Of course, for the sake of comfort and warmth you will have to sacrifice square meters, since insulation materials “eat up” part of the area due to their volume. But, as they say, it is better to live in a slightly smaller house than in a cold and damp one.

Perhaps modern technologies will soon make it possible to make houses warm, saving space and at the same time eliminating condensation. For now, it is the technologies and materials listed above that make it possible to solve existing problems with heat conservation in a private home.

The problem of heat loss in private residential buildings has always existed. In some places, heat is lost uselessly through the roof, in other houses it is wasted through the foundation. However, the main part is spent through wall structures.

To this day, a pressing question for homeowners remains how to avoid unnecessary waste of thermal energy? Therefore, let’s try to figure out how to insulate a house, which material will best cope with the tasks.

Choosing thermal insulation

After constructing the frame of the building and laying the walls, an extremely important stage begins - insulating the housing. By selecting the most effective thermal insulation material, you can create the maximum barrier to useless heat transfer.

Currently, the most common insulation materials on the Russian market are: mineral wool, polystyrene foam, extruded polystyrene foam, glass wool, expanded clay, ecowool. Let's take a closer look at the features of each heat insulator.

An extremely popular material that has been successfully used as insulation for many decades.

The advantages of mineral wool are:

• low thermal conductivity coefficient ranging from 0.041 to 0.044 W/m3;
• good compressive density - up to 200 kg/m3;
• high fire safety - withstands exposure to elevated temperatures up to 1000 oC;
• excellent sound insulation.

Despite the obvious advantages, the material has a significant drawback - the ability to absorb moisture. Therefore, it is impossible to do without laying an external waterproofing layer during its installation.

In addition, for insulating walls from the inside, mineral wool is unlikely to be the best option, since it takes up too much useful volume.

The material is in wide demand in the domestic market on a par with the previous insulation, mainly due to its increased resistance to moisture. The thermal conductivity coefficient of polystyrene foam is an order of magnitude lower compared to mineral wool. However, the density suffers somewhat when compressed. The material does not resist mechanical stress very effectively. Therefore, polystyrene foam boards are easy to damage.

The density of foam plastic ranges from 11 to 35 kg/m3, depending on the brand. The compressive strength of the slabs is 0.05-0.16 MPa. The same bending quality of the material is 0.07-0.25 MPa. Thermal conductivity coefficient is 0.033-0.037 W/m3.

Advantages:

• does not need protection with moisture-repellent coatings;
• has little weight;
• acts as an effective heat and sound insulator;
• is one of the most accessible, relatively inexpensive solutions.

Among the disadvantages, it is worth noting the presence of a danger of fire of the material with the release of caustic, toxic smoke, causing harm to health when used at elevated temperatures.

In the past, the material was the most common basis for home insulation. However, the reason for the popularization of insulation was not so much its characteristics as the lack of more effective insulation materials.

Made from molten glass fibers. Hence the name of the material. It has decent thermal insulation qualities, which are only slightly inferior to mineral wool. Thermal conductivity ranges from 0.03 to 0.052 W/m3. Resistance to elevated temperatures reaches 450 °C.

The advantage of this solution is the absence of toxic fumes during fires. The disadvantages include inconvenient installation, significant shrinkage and increased hygroscopicity.

Belongs to the category of innovative cellulose-based insulation. Suitable for and outside. However, laying the material requires a special unit that combines the substance with water, forming an insulating mass of the required consistency. The dry insulation method does not allow the coatings to be insulated hermetically.

Material qualities:

• specific gravity – 25-75 kg/m3;
• thermal conductivity – 0.037-0.042 W/m3;
• the ability to accumulate moisture and its rapid evaporation without loss of insulating properties;
• effective absorption of sound waves;
• fire and environmental safety.

It consists of the smallest wood fibers, so it does not hide potential harm to health. As practice shows, the heat insulator does not emit toxic substances, prevents the development of mold and does not emit unpleasant odors.

The only drawback of insulation is the need to use specialized equipment.

Essentially, the material is insulating boards, the structure of which is formed by small plastic granules. To produce a sheet of extruded insulation, a blowing agent is mixed with granular particles under high pressure and temperatures. The result of production is colored or transparent slabs.

Properties:

• practically complete absence of moisture absorption;
• the lowest thermal conductivity coefficient in comparison with any other common thermal insulators;
• ability to transmit light;
• frost resistance;
• lack of tendency to rot, mold development;
• highest compressive strength;
• It is considered an ideal option for thermal insulation of buildings both from the inside and for external work.

If we talk about the disadvantages of a heat insulator, then, just like ordinary foam plastic, the material suffers somewhat from fragility. Therefore, its installation and operation requires careful handling.

It is a loose insulation material. It has decent thermal conductivity and vapor barrier properties. Most often used for insulating floor coverings. Although it is ideal for insulating walls using the ring masonry method.

Expanded clay is characterized by moisture absorption at a level of about 8-20%. Due to the presence of a significant proportion of clay in the composition, it has increased sound insulation. Has high frost resistance. The thermal conductivity coefficient is 0.10-0.18 W/m3, which indicates decent thermal insulation qualities of the material.

The disadvantages of expanded clay include its tendency to generate dust, which complicates installation work, and the significant weight of the thermal insulation layer.

How slowly the insulation absorbs moisture, the longer it takes for it to be freed from it. Therefore, when laying expanded clay, it is necessary to provide in advance options for its vapor and moisture protection.

The choice of insulation directly depends on the method of work. There are several ways to externally insulate a home:

• ventilated facade systems;
• laying insulation under plaster.

The technology for creating ventilated facades involves installing insulation directly on the outer surface of the walls and insulating it with an airtight membrane. At a distance of 2-4 cm from the outer membrane, cladding in the form of siding, drywall, etc. is attached.

Material

The use of polystyrene foam in this case becomes unacceptable, since the presence of a ventilated space increases the likelihood of the material catching fire. The advantage of the insulation method is the possibility of laying inexpensive insulators in the form of mineral wool or glass wool, since here the heat insulator does not bear the load of the outer layer.

As for insulation under plaster, for this purpose insulation is laid on the surface of the wall. The insulator is secured with dowels or glued to a special mixture. Decorative plaster or primer is applied on top.

The insulation method involves the creation of a three-layer structure, when the selected heat insulator is laid between the inside wall and the outer cladding. The inner wall is connected to the outer wall with embedded anchors. The most common insulation materials here are polystyrene foam and mineral wool.

This method of insulating a house is one of the most effective. However, its main disadvantage is the ability to perform work only during the construction of housing.

Thermal insulation from the inside of the building is a less preferable option. Since in this case the “dew point” shifts towards the insulation, which leads to its getting wet. In addition, with this method of insulation, the area of ​​the rooms is noticeably reduced.

However, there are cases when creating an external thermal insulation coating for walls turns out to be impossible. For example, when the wall of a neighboring house is adjacent or the facade of a building is of cultural value. Therefore, insulation from the inside also has a right to exist.

What to choose?

If the inner plane of the walls will be plastered, the insulation can be mineral wool, ecowool or low-flammability foam. Before insulation, it is worth once again calculating the likelihood of exposure of the insulator to an abundance of moisture. With this method of insulation, condensation quickly destroys the insulation, its effectiveness decreases and there is a high probability of fungus appearing.

Eventually

What is the best way to insulate a house? The widest selection of heat-insulating materials for home insulation often leads to complete bewilderment of homeowners who dream of living in the most comfortable conditions. Some prefer glass wool, proven by practice and time. Others rely exclusively on advanced technologies.

Based on the beneficial properties of common materials, it is rational to use them in competent combinations. So, the most economical and at the same time quite effective solution for insulating the walls of a house will be a combination of the qualities of mineral wool, expanded clay, glass wool and polystyrene foam. It is better to isolate hard-to-reach places with ecowool, tightly filling any unevenness with the composition.

Expanded polystyrene boards are recommended for use in the most humid climates. The material retains its properties for decades under conditions of intense exposure to environmental factors. The components of the heat insulator do not react with atmospheric chemicals, which becomes an indispensable quality when insulating houses located in industrial regions.

If you have even the slightest opportunity to insulate the walls from the outside, do it. This is the best option, because insulating walls from the inside is a headache. There are only two correct and more or less acceptable options, and one takes up a lot of space, and the second requires significant costs during the winter. There is also a method suitable for insulating balconies and loggias. And that's all for now. All other options with polyurethane foam, liquid-ceramic thermal insulation, penofol and other materials only bring dampness and mold.

Insulating walls from the inside: what is the problem

Anyone who has insulated the external walls of a house or apartment from the inside - from the premises - is faced with the problem of the appearance of fungi, mold and high humidity. These consequences are natural, and appear regardless of the type of insulation that was used. You can get rid of moisture and fungi only by removing the internal insulation, making major repairs to the walls, treating them with antifungal compounds and plastering them.

Let's look at the reasons. The so-called dew point is to blame. This is the line where warm and cold air meet and where condensation results.

The figure on the left shows the situation with the dew point if the wall is not insulated. It is located somewhere in the thickness of the wall, depending on the temperature and humidity, it shifts first to one side, then to the other, but is always located quite far from the inner surface. In this case, moisture accumulates in the wall and freezes. In the spring, as it thaws, it evaporates, and evaporates into the atmosphere. If dampness is observed in the room, it is for a short time and at the level of sensations.

The photo in the center shows a situation where the wall is insulated from the inside. In this case, condensation falls in the insulation, or, if this is not possible (expanded polystyrene is used, for example), at the boundary of the insulation and the wall. Even if the wall freezes and the condensation turns into ice, in the spring it will begin to melt, the insulation, wall material and finishing will become wet. Since there is a large distance to the outer surface facing the street, moisture dries very poorly in this case, which “comes out” in the form of dampness, mold and all the accompanying delights.

And the third option is to insulate the wall from the outside. In this case, the dew point is in the insulation. How to get it out of there is another story (make a ventilated facade or choose the right vapor permeability of materials), but for our topic it is important to understand that in this case the wall inside the room will definitely be dry and warm.

To summarize, we can say, if possible, insulate from the outside. Insulation of walls from inside premises has to be done only in a few cases:

• if they are not allowed to be insulated from the outside (the building is a historical monument or prohibited by local authorities);
• if the wall goes into the joint between two buildings;
• the wall opens into the elevator shaft.

But before you start this work, thoroughly inspect the floor, ceiling, and windows. Sometimes most of the heat escapes not through the walls, but through these surfaces, and it is easier to insulate them (in the sense of less hassle with the dew point).

Correct internal insulation of walls in a house or apartment

There are only two ways to insulate indoor walls from the inside and avoid problems with dampness:

• recreating a multi-layer wall (place a half-brick wall with insulation at some distance);
• Heat the wall and then insulate it.

These options work, but, as you can see, they “eat up” a significant amount of space and cost a lot of money. In each specific case, it is necessary to consider what kind of insulation and how much is needed, but the wall pie remains the same.

Second wall

At some distance from the main wall, a second wall 10-12 cm thick is installed. Between the two walls, a layer of insulation, which is required for these conditions, is attached to the inner one. In this case, there should be a ventilation gap of at least 3 cm to the outer wall. In total, this entire structure will be 20-25 cm away from the main wall. It will “eat up” a considerable area.

As you can see, in this case the dew point can be located inside the insulation or on the inner surface of the wall facing the street. To be able to remove the formed moisture, you can make forced ventilation by installing one or two exhaust fans.

Since in this case the insulation will get wet, it is necessary to choose one that is not afraid of moisture. These are polyurethane foam, polystyrene foam, foam glass. You can also use some types of stone wool, but only those that are not afraid of moisture (there are some).

Thermal insulation material must be fastened simultaneously with the construction of the walls. They laid it out to a certain height and secured the thermal insulation. It’s inconvenient to work, but there is no other choice.

Electrical heating

The idea of ​​this method is to move the dew point inside the wall when insulating a concrete or brick wall internally. To do this, it must be heated. The easiest way is to attach an electric heated floor mat. At some distance from it, insulation is installed, on top of which there is a finishing layer.

In this case, there are no problems with moisture removal, and much less space is required to install the system: from 8 cm (with a ventilation gap of 3 cm and an insulation thickness of 5 cm).

With this method, the thermal insulation material can be of any kind. To install it, first a sheathing is made, then a counter-lattice, and then a suitable insulation is attached to it.

Option for insulating a balcony from the inside

In the case of a loggia and a balcony, the situation is often completely different. If the authorities do not allow the installation of a wall, they require that the existing reinforced concrete screen be left; it is cut off from the warm air by careful thermal insulation made of extruded polystyrene foam (EPS).

In this case, it is better to make the insulation excessive than at least slightly insufficient. The total thickness is divided into two layers. They are laid without a gap (preferably with locks), and so that the seams of the first layer overlap the sheet of the second. There should be no through access of warm air to the screen.

It is necessary to approach the issue of insulating the floor and ceiling of the loggia/balcony very carefully and ensure tightness at the junction of them with the walls. Also pay attention to how the glazing will be installed: there may also be problem areas: the joint with the screen, walls, insulation of the part above the frames. All of them must be well finished, excluding the possibility of contact of warm/cold air. In this case there will be no problems. Even .

September 7, 2016
Specialization: Capital construction work (laying a foundation, erecting walls, constructing a roof, etc.). Internal construction work (laying internal communications, rough and fine finishing). Hobbies: mobile communications, high technology, computer equipment, programming.

I know various ways to improve the energy efficiency of your home with your own hands. However, their use in a city apartment is limited by the design features of a panel high-rise building and the lack of equipment for high-rise work. Therefore, most often it is necessary to insulate the room from the inside.

Today I will tell you what types of insulation for walls from the inside are available, how to properly install them and complete the final interior decoration.

Advantages and disadvantages of internal insulation

The greatest scope for engineers and insulation specialists opens up when it is necessary to insulate a private house. There you can install heat-insulating material indoors, on the facades of the building, and even build multi-layer walls with insulation inside.

As for a city apartment, and especially one located on a high floor, the choice of solutions is limited. You will have to fix insulation for the walls indoors or use expensive high-altitude equipment. The last option is unacceptable for independent implementation, so most people resort to the first.

I would like to note a few more disadvantages of internal insulation, because of which experts are not very willing to resort to it:

1. When thermal insulation material is placed internally, the dew point shifts, and moisture can condense under the insulation (between the enclosing wall and the additional wall), causing the appearance of fungus. In addition, due to constant wetness, the enclosing structure will collapse faster.

1. The insulating layer inside the room prevents the wall from warming up by accumulating thermal energy. As a result, thermal inertia decreases, that is, the microclimate inside the room will depend more on the air temperature outside.
2. The thermal insulation layer has a multi-layer structure, and for effective operation it is necessary to use insulation with a thickness of at least 10 cm. Therefore, the insulating pie reduces the already not very large usable area in a city dwelling.
3. The technology for installing insulation on the internal surfaces of walls does not allow high-quality joining of slabs on walls and floors, so cold bridges often arise in these places, reducing the effectiveness of thermal insulation.
4. Some types of thermal insulation materials emit chemical compounds hazardous to humans into the air, which accumulate in living spaces.

However, internal insulation also has its advantages:

• no need to use climbing equipment, aerial platforms or scaffolding;
• thermal insulation work can be done at any time of the year, regardless of the outside air temperature;
• Insulation measures can be combined with the process of decorative finishing of the apartment, which will save a certain amount of money.

To make the most of the advantages and minimize the disadvantages, you need to choose the right thermal insulation material for the job. Therefore, in the next section I will talk about the types of insulation for walls from the inside.

Choice of insulation

Before determining the best insulation, I will list the possible options that can be used to insulate an apartment:

1. Mineral wool. An effective and environmentally friendly insulation material, which is often used in private construction.
2. Polyurethane foam. Sprayed polymer foam, which, covering the walls of the apartment, forms a homogeneous waterproof thermal insulation layer that well protects the room from heat loss.
3. Thermal insulation paint. The downside is the very high price.
4. Expanded polystyrene. Sheet cellular insulation, which has excellent technical characteristics in terms of use for internal insulation of an apartment, but is very cheap.

In my opinion, the optimal choice would be polystyrene foam, or, as it is popularly called, polystyrene foam (although this is not very correct). In addition to the low price, which I have already mentioned, this thermal insulation material has several additional advantages, which I will describe in the table below.

Characteristic	Description
Good heat-retaining properties	The material has a very low thermal conductivity coefficient, so for effective thermal insulation of a city apartment it is enough to use sheets with a thickness of 5, maximum 10 cm.
Hydrophobicity	Insulation made from sealed polystyrene cells practically does not absorb water, so during installation and operation it does not require additional waterproofing.
Light weight	Thermal insulation does not place a large load on the building envelope.
Antiseptic	The material has antiseptic properties; mold, fungi and other microorganisms do not develop on its surface and inside.
Durability	Subject to operating conditions, the insulation retains its properties for at least 30 years.
Easy to install	Expanded polystyrene is easily mounted on insulated surfaces without the use of complex engineering equipment.

Of course, construction foam polystyrene sheets are not without their drawbacks, but they are entirely justified by the affordable cost.

So, as we found out, foam made on the basis of polystyrene (labeled PS) using the non-press method (labeled B) is best suited for the job. To increase fire safety, it is necessary to purchase insulation with fire retardants added to the raw material mass (marked C).

As for density, a material with a density of 25 kg per cubic meter is suitable for thermal insulation of walls indoors, since after installation it will not experience external mechanical loads.

The photo shows wall insulation with fire-fighting properties with a density of 25 kg per cubic meter.

Let me sum it up. For internal wall insulation, you need to use polystyrene foam PSB-S-25. The manufacturer of the material is absolutely not important.

• all granules of the material are approximately the same size;
• the length, width, and most importantly - thickness, of individual sheets of polystyrene foam must match;
• foam plastic should not emit unusual odors that indicate a violation of the production process;
• The packaging of the material must be marked, and along with expanded polystyrene, the seller must provide the necessary technical documentation.

Tools and materials

In addition to polystyrene foam, the following additional materials are required:

1. Primer for concrete with antiseptic properties.
2. Adhesive for foam plastic.
3. Plastic dowels with wide caps.
4. Polyurethane adhesive for foam plastic.
5. Fiberglass alkali-resistant mesh.
6. Reinforcing corners.

The tools you will need are a hammer drill (since you will have to drill a large number of holes in the concrete wall) and graters for working with cement-containing glue (need with smooth and jagged edges). And, of course, a standard set of plumbing tools - a hammer, wire cutters, scissors, and so on.

Insulation technology

How to insulate walls from the inside using polystyrene foam? The instructions, which are outlined below, consist of several sequential steps, which are shown in the diagram:

Step 1 - Preparing the Walls

I always start by preparing the insulated surfaces for work:

1. I install the necessary engineering communications. Most often we are talking about air conditioner air ducts and electrical wiring. Less often – about water supply and sewerage:
   • The air channels connecting the internal and external blocks of split systems must be laid in pre-made grooves, insulated with polyethylene foam shells, and then puttied flush with the main wall.
   • Electrical wiring should also be laid inside the groove. There is another option - fix the wires on the wall surface in polymer fireproof channels, and then make recesses in the foam where the wires will be hidden.
   • Water pipes with detachable connections cannot be hidden in the insulating layer and concrete walls, as they may leak. It is necessary to use only plastic products connected by gluing or soldering.
   • In general, sewer pipes should only be laid in an open way.

1. I eliminate defects in reinforced concrete walls. They must be sealed before gluing the foam:
   • Small cracks should be filed down using a grinder and a diamond wheel, and then sealed with polyurethane foam. After hardening, cut off the excess composition with a knife flush with the wall.
   • Large defects should be repaired with cement mortar. If a piece of reinforcement is visible inside the recess, it must be cleaned with sandpaper to remove traces of corrosion, and then coated well with a rust converter.

1. I clean the wall of mortar residues, debris and dust. Be sure to use a hammer drill or a hammer with a chisel to eliminate sagging mortar, which may interfere with the leveling of the polystyrene foam boards. Dust can be removed with a brush.

1. I prime concrete walls. It is better to do this in two layers:
   • Dilute the primer with clean water in a ratio of 1 to 1 and treat all insulated walls with it. If the amount of work is large, it is better to use a sprayer.
   • The second layer is applied after the first has partially dried. In this case, there is no need to dilute the primer, and for application it is better to use a paint brush, with which you thoroughly rub the primer liquid into the walls.

1. I am marking the walls. It is necessary to mark the horizontal and stretch the guidelines along which the polystyrene foam will be glued:
   • At a height of about 52 cm from the floor (50 cm is the width of the expanded polystyrene sheet), it is necessary to make a notch, and then through this mark, using a water or laser level, draw a strictly horizontal line along which the first row of slabs will be glued.
   • Drill a hole near the ceiling near the corner of the room into which to drive a metal rod. After this, at a distance of 11-12 cm from the wall, tie a rope to it and hang a weight on it. It will hang strictly vertically.
   • Install a similar rod near the floor, then tie a rope to it so that it continues to hang vertically.
   • Repeat the operation at the opposite corner of the wall.
   • Pull a horizontal one between two vertical ropes. This will serve as a guide for leveling the slabs. It can be moved up and down along the guides installed in the corners.

Step 2 - Installation of insulation

Installation of thermal insulation sheets is carried out in the following sequence:

1. I am preparing the adhesive composition. For this, a pre-purchased dry mixture is used. Mixing the solution:
   • A strictly defined amount of water (indicated on the glue package) is poured into a clean bucket or trough, where dry powder is added.
   • The mixture is mixed using a low-speed drill and a mixer attachment.
   • After mixing, the solution must stand for about 5 minutes for a chemical reaction to begin between the additives and plasticizers included in the glue.
   • After the required pause, the finished glue is mixed again.

1. If necessary, I cut sheets of polystyrene foam. The beauty of this material is that you do not need to use complex or expensive equipment to process it:
   • The necessary parts are separated from the pieces of insulation using a hacksaw or a sharp stationery tool.
   • For cutting, you can also use a special nichrome wire, which is heated using an electric current. In this way, you can cut polystyrene foam not only crosswise, but also lengthwise.
   • After trimming, the edges must be treated with a foam float (with holes) or coarse sandpaper.

1. I coat the polystyrene sheet with glue. This should be done immediately before installation on the wall, but in this paragraph I will tell you about the general rules:
   • First, you need to form a bead of glue along the edges of the slab about 2 cm thick. In this case, you need to ensure that the cement composition does not get on the end of the polystyrene foam (where the seam between the tiles will be).
   • Then you need to put 2-3 lumps of glue in the middle of the sheet, which will hold the slab on the wall.
   • Carry out control gluing. Place the slab against the wall, press it down, and then tear it off. The spread glue should cover at least 40-60% of the polystyrene foam board (the exact figure is indicated in the thermal insulation documentation).

1. I glue sheets of polystyrene foam. Work begins with the bottom row, which is mounted strictly along the drawn line and continues from top to bottom:
   • Insulation boards at internal and external corners are installed using the gearing method. This means that the slab of the top row should hang over the slab of the bottom and so on alternately to the very top.
   • The vertical seams of the bottom row should not coincide with the seams of the top row. They must move relative to each other by at least 15 cm.
   • Vertical seams should not be a continuation of the window and door opening. Specially cut L-shaped parts should be installed in the corners.
   • It is better to start gluing the second and subsequent layers after the first row of foam plastic boards in the room has been glued and the glue has hardened for at least a day.

1. I seal the seams between the foam sheets. This is done using polyurethane glue. This operation eliminates the appearance of cold bridges in the insulating layer, which worsen the heat-retaining properties of the walls. The operation is performed taking into account the following features:
   • Seams with a thickness of 1 mm or more must be sealed.
   • If the gap between the plates is large, you first need to insert a small piece of polystyrene foam there, and only then fill everything with polyurethane foam.
   • The foam dispenser should be positioned so that it fills the entire thickness of the gap, and is not just on top.
   • After hardening, the protruding parts of the glue are cut off flush with the insulating layer using a stationery knife.

1. I secure the polystyrene foam with dowels with caps. I used a dowel with a plastic driven core, which has a lower thermal conductivity coefficient:
   • A ruler is installed on the hammer drill so that after passing through the foam and glue, the drill is buried into the reinforced concrete wall to a depth of 6 cm.
   • Holes are drilled through the foam. Considering that the insulation will not experience wind loads (as on the facade of a building), to reliably retain the thermal insulation, it is enough to use 2-3 dowels per sheet of polystyrene foam.
   • After making a hole, a dowel is inserted into it, and then the core is driven in so that the cap is slightly recessed into the polystyrene foam, without rising above the surface.

Step 3 - Reinforcement

The finishing of polystyrene foam with a reinforcing mixture is carried out as follows:

1. Window and door blocks are designed. For this purpose, special parts are used that are glued to the window trim or door block. The scheme of work is as follows:
   • The surface of the window or door block is cleaned of debris, dust and remnants of the adhesive solution, if it somehow ended up there.
   • The door trim or window block is degreased using any alcohol-containing solution.
   • The reinforcing corners are cut to the required length at an angle of 45 degrees so that they can be joined to each other.

• A strip of protective paper is removed from the adhesive layer, after which the reinforcing corner is glued to the door or door block.
• After this, a small layer of glue is applied to the slope of the window or door, a mesh connected to the corner is applied to it, which is then embedded into the glue with a trowel to work with the plaster mortar.
• The outer corners of the window and door opening are formed. Perforated corners with a mesh installed on both sides are suitable for this. They also need to be pressed into the pre-applied glue and smoothed with a smoothing iron.

• At the corners of window and door openings, gussets are glued to the walls - pieces of mesh measuring 20 by 40 cm at an angle of 45 degrees to the horizontal.

1. I perform continuous reinforcement of the wall surface with fiberglass mesh:
   • Glue is applied to the surface of the foam, after which it is evenly distributed over the entire surface of the wall from ceiling to floor using a notched trowel. You need to cover the wall with glue to the width of one roll of fiberglass mesh.
   • After spreading the glue, the fiberglass mesh is pressed to the wall surface and embedded into the reinforcing mixture with a plaster float.
   • A small amount of glue is additionally applied on top, which is distributed over the surface of the insulation so that the mesh is completely hidden by the solution.
   • Adjacent mesh sheets are mounted overlapping each other at a distance of 10 cm.
   • In the inner corners of the room, the mesh should be positioned so that it runs up to another wall at a distance of 10 cm. When smoothing it, you need to work only with the blunt end of the grater, making outward movements so as not to tear the mesh.

1. I leave the wall to dry. It is necessary to dry not until it has fully gained strength, but only 75%, so that the surface can be cleaned (more on this in the next section). If the room temperature is too high, I recommend slightly moistening the surface to ensure proper dehydration of the solution.

Step 4 - Decorative finishing

Now you can move on to the next step:

1. I clean the surface of the wall with a float. Under no circumstances should you do this with sandpaper, as you can tear the mesh installed on the polystyrene foam. You can only operate with the end of the plaster float, clearing off the build-up of mortar.

1. I measure the wall using a rule to detect and eliminate irregularities. Problem areas must first be marked with a pencil, and then additionally sealed with a reinforcing compound.
2. I putty the surface with starting putty. After the reinforcing layer has completely dried (the exact time required for this is indicated on the glue package), it should be puttied with starting putty to eliminate minor defects in the base.

1. I level the wall with finishing putty. This composition will eliminate the slightest unevenness in the base and prepare the walls for further painting or wallpapering. After the putty has hardened, you need to clean the walls.
2. I prime the walls. Primer at this stage will reduce the absorbency of surfaces and improve adhesion to paint or wallpaper glue.

After this, the final decorative finishing can be carried out.

How to competently solve the issue of insulating a building, house or cottage after completion of the main construction work? Any experienced builder will answer unequivocally: not only external insulation is necessary, especially if the building is made of brick and other materials that conduct heat well.

Causes of moisture

In the winter season, with the onset of frost, the walls of our houses freeze. In a correctly calculated wall thickness, the transition point from sub-zero to positive temperatures, called the dew point, is located inside the wall and condensation does not occur. That is why they used to build houses with walls made of stone no less than 80 cm thick. Today, with the use of the latest construction technologies and innovative materials, it has become possible to build houses with thinner walls, but such buildings require the installation of additional thermal insulation structures.

The question arises: should insulation be carried out from the outside or inside?

The issue of exterior finishing disappears when the house is made of timber and does not require external finishing. If the house is made of stone, then it would be more competent to insulate the facade, but this does not exclude carrying out internal work.

There is the only exception - the internal insulation of the walls of an apartment in a multi-storey residential building, where the use of any type of thermal insulation material will not give tangible results.

How to insulate a house yourself

If you decide to abandon facade insulation, then how to insulate the house from the inside to avoid condensation? After all, it is this that leads to the appearance of fungal formations and the destruction of thermal insulation materials. Every owner needs the entire thermal insulation internal structure to work efficiently and functionally. There are several widely used home insulation technologies.

The insulation of a log or timber house has its own characteristics. The thermal conductivity of wood compared to stone is, of course, lower, and wood retains heat well, however, when walls are insulated from the inside, moisture can form between the inner surface of the wall and the surface of the insulation. To avoid this, create an air gap to blow through the wood and insulation. Technically, the problem is solved using a frame lathing made of wood with a frame width equal to the width of the insulation boards. The lathing is mounted at a distance of several centimeters from the wall to ensure a ventilation effect.

From the side of the wall, a windproof membrane is pulled over the frame, which performs a dual function: it protects the air gap from being blocked by the fibers of the insulation and limits excess air movement inside the insulation. In this case, it is more advisable to insulate walls from the inside using natural, environmentally friendly materials. There is a wide selection of mineral wool insulation; the most famous manufacturers in Russia are URSA, ISOVER, ROCKWOOL, KNAUF and others. On the room side, the insulation is hermetically covered with a material that provides protection against steam penetration into the internal layers of the heat insulator.

The technology for insulating concrete or stone walls is similar to the previous design, but in this case it is necessary to provide a larger number of technological openings for air intake. Much more condensation will appear than in the first case, and the air gap must be wide enough for intensive ventilation. In fact, it is necessary to build an additional internal wall.

When carrying out thermal insulation work indoors, you must understand that natural physical processes will affect the entire structure. This work requires a competent professional decision.

As a result, several main conclusions can be drawn:

• When installing thermal insulation on the inside of the walls of a house, the dew point inevitably moves to the inner surface of the wall. This will happen even taking into account the correct calculations of the thickness of the heat insulator. As a result, the service life of the entire thermal insulation structure is reduced.
• The thermal insulation structure must include a vapor barrier membrane. As a result, it is necessary to resolve the issue of normalizing humidity in the room (increasing costs for heating and ventilation systems).
• Indoor insulation reduces the volume of rooms.
• Since the entire structure is installed inside the house, the issue of human life safety becomes the most important. It is important to understand which insulation material best satisfies this requirement. Materials made from natural raw materials are the best choice. Soft slabs or rolls of mineral wool, which have high heat-protective and sound-proofing properties, are well suited. All materials that have good vapor permeability and are capable of absorbing moisture will lose their functional properties over time.
• The use of expanded polystyrene or polystyrene foam, as materials that practically do not absorb moisture, is more profitable. In this case, it is necessary to consider a tight fit of the plates to each other. The main disadvantage of this option is that it is a completely synthetic material, and they will have to breathe.
• Today there is a lot of talk about polyurethane foam, which hardens when applied to the surface and, of course, gives strong adhesion to the inner surface of the wall. Condensation does not form, but to carry out the work it is necessary to construct technological formwork. This process is quite long, and the wall does not breathe.

There are many wall insulation materials, there is plenty to choose from, but the right decision must be made. People will live, work and breathe in this house.

Video tutorial on internal insulation of a room

You can insulate your house from the inside yourself. To do this, it is better to familiarize yourself with the video material:

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