Material for wall insulation from the inside without a frame. Instructions for insulating the internal walls of a private house

If you have to pay big sums for heating or the apartment is cold and damp, then there is an obvious problem that the heat is not retained inside. The most logical thing would be to insulate the wall in the apartment from the inside, and the common man associates this with complex installation work. However, it is not always necessary to use any special tools.

Pros and cons of insulating an apartment from the inside

Professional builders do not get tired of arguing about how to insulate the walls in an apartment. Some of them argue that insulating the inside is a waste of money, while others claim that insulating material works well. However, both of them agree that wall insulation from the outside is much more effective than from the inside.

But how to insulate a wall in an apartment for those who live in high-rise buildings, where thin walls freeze through and through in winter? After all, it is often simply impossible to insulate such a house from the outside. In addition, it is impossible to insulate houses in the historical center, if the apartment is located close to the elevator shaft, and many more reasons serve as contraindications to this type of insulation. Therefore, there is only one option, the pros and cons of which have long been known.

The disadvantages of insulation inside most often include:

on average, the area of an apartment is reduced by 0.5–2 square meters;
for the duration of the work, it is necessary to completely empty the room;
it is necessary to provide for many additional measures: ventilation, protection of the heat insulator, etc.;
the formation of fungus or mold.

The advantages of this type of insulation are:

low cost;
the ability to carry out work at any time of the year;
availability (you can carry out the installation yourself).

The good news is that if the insulation is carried out in compliance with all the rules, then most of the stated disadvantages can be avoided.

How to avoid destruction of the interior decoration?

Before you start to deal with the consequences of improper insulation, you should understand the causes of the problems.

At a certain temperature, water vapor condenses from the air. This temperature is called the "construction dew point", upon reaching which Condensation occurs on cooled surfaces, that is, water droplets.

According to the standards, the air temperature in residential premises should be at least 22 and not more than 27 degrees Celsius. In this case, the dew point is 10.7 degrees Celsius. Simply put, if you have insulated the walls and they have reached the dew point, condensation will surely appear. Where exactly it will be depends on many factors. For example, if it is cold outside, it will move further from the facade.

Condensation negates the effect of insulation, moreover, mold appears on the walls. So the number one task is dry walls. It is quite possible to achieve this, the main thing is to follow several rules:

for insulation choose the highest quality materials, when connecting the film for vapor barrier, seal the joints;
pay attention to the vapor permeability index of the insulation, the lower it is, the better. If the vapor permeability of the wall is higher than that of the heat insulator, then the steam will go outside;
when gluing insulation, it should not lag behind the wall. For this, it is best to use a comb;
place valves on windows to reduce humidity in the room;
calculate the thickness of the insulating layer taking into account the characteristics of the climatic zone. The insulation should be no thinner than this value;
before insulation treat the walls with a special compound which prevents the appearance of mold and mildew. Start insulating after the walls are dry.

It is worth considering that where the floors are connected to the load-bearing walls, it is impossible to carry out insulation. A heat insulator is applied to these places using a vapor barrier, then they are masked using false columns, etc.

How to choose a heater?

More and more new building materials are produced every year. Some of them are suitable for insulating apartments, but there are three proven insulation, the pros and cons of which are well studied:

mineral wool;
expanded polystyrene;
polyurethane foam.

Many of us have heard that it is possible to insulate an apartment from the inside with mineral wool. No wonder, because this stuff is pretty easy to work with: it is enough to lay it inside the plasterboard structure. Most often, the work is done quickly, the material is chosen the cheapest, vapor barrier is neglected. The result is appropriate: more harm than good. Ordinary rock wool rolls have a very low coefficient of thermal resistance.

The positive thing is that she seems to be "breathing". On the other hand, moisture penetrates through the cotton wool fibers to the dew point, and then it is absorbed into the material. Of course, there are more expensive and high-quality options, but if you insulate with ordinary cheap mineral wool, then it does not guarantee dryness.

To reduce the risk of moisture ingress, do not save on vapor barrier and glue with the highest quality glue. If smudges or, especially fungus, appear on the walls, then all the insulation work will have to be redone.

Expanded polystyrene

Expanded polystyrene is considered one of the best insulation for walls from the inside. It is increasingly used both in Russia and abroad. This material has all the necessary properties to displace mineral wool and become the most popular insulation of all.

Expanded polystyrene does not conduct heat well and does not absorb moisture, while it has a low vapor permeability. It easily copes with loads, can survive strong squeezes and tears, while it is very light and pliable: you can even cut with a knife. Therefore, the installation of insulation will not be a problem.

Respectively, a thin layer of expanded polystyrene will solve the problem with insulation and will keep moisture out of the dew point. The only negative is that it does not protect against noise and is destroyed at temperatures above 80 degrees Celsius. The latter is usually irrelevant for the weather conditions in Russia.

Polyurethane foam

Polyurethane foam is the latest material that is designed to quickly and efficiently solve the problem of wall insulation from the inside. Moisture cannot penetrate the material, so it does not get wet. Moreover, it does not need to be glued, it is enough to spray on the wall. Thanks to this, seams and joints are not formed, even a room with curved corners will look perfect.

Of course, the material also has its drawbacks. Most often, the first thing consumers pay attention to is the price. Polyurethane foam - quite expensive insulation Moreover, the installation work is also expensive. In addition, if it catches fire, it will smoke heavily and release various toxic substances. When exposed to it, UV quickly decomposes into products that can cause enormous harm to health over several years.

Self-insulation of the wall from the inside

Since expanded polystyrene is an affordable and high-quality material, it will be used as an example. Before you start insulating the walls, you need to prepare their surfaces. Depending on whether the walls are covered with something or not, you need to carry out a few simple steps.

If the walls are already pasted over, painted or covered with finishing materials, then you should:

remove wallpaper or paint;
prime;
wait until the primer is dry;
putty;
let the putty dry.

If the walls are not covered with anything, then:

prime;
level the wall with plaster;
putty;
let the putty dry.

You can insulate the walls only after the putty is completely dry. It usually takes 2 to 6 hours, the exact time is indicated on the package. Then you should knead the glue, there is always an instruction on the mixture. Then take a notched trowel and apply glue to styrofoam, make sure the layer is even. Place the insulation in the desired position and check that there are no air pockets. The sealant is applied to the ends. Then, when all the sheets are ready, the glue should harden.

Now start applying the finishing coat:

apply a thin layer of mortar about 2-5mm thick;
until the mixture is solid attach reinforcing mesh; it should sink in the mixture, you can use a notched trowel. The mesh will protect the plastered walls from cracks;
apply the solution and level the surface with a spatula;
sand the wall every other day so that there are no irregularities. There will be a lot of dust, care should be taken to protect the respiratory system.

When installing, try to glue the sheets so as to avoid gaps. This will prevent moisture from entering the wall and prevent condensation from forming. If you still have gaps, use an installation tape to blow them out.

After completing the work, do not forget to regularly ventilate the room. Warming can lead to a violation of ventilation conditions that will harm your health. To maintain a healthy microclimate, ventilate rooms daily. Such care will definitely give results and the room will remain dry and warm.

Both builders and manufacturers of insulation materials argue about whether it is possible to insulate houses from the inside, but they all agree that in most cases, insulating walls from the inside will not be the best solution - if possible, it is better to do the outer thermal insulation of the house. However, if there is no choice, you should carefully study the features and rules for choosing and installing insulation so that the internal thermal insulation is effective, safe and durable. How to insulate the walls of the house from the inside and how to do it?

Inside the premises, walls can be insulated only in cases where the facade of the building cannot be changed or there is no access to the outer surface of the wall. It is recommended to avoid wall insulation from inside the house because it has a number of significant disadvantages:

The dew point is shifting towards the interior of the room. The wall begins to freeze through to its entire thickness, the cold meets warm air at the junction of the wall and the insulation, and condensation forms on its surface. This has many negative consequences: a fungus can develop on a wet wall, the effectiveness of the heat-insulating material decreases, it lags behind the wall, collapses; in addition, the decorative finish deteriorates.
The frozen wall loses its heat storage properties. It becomes difficult to control the temperature of the air in the room - it begins to warm up faster due to the operation of heating devices or the ingress of direct sunlight into the window and cool down faster when ventilated.

It is impossible to provide 100% thermal insulation, since it will not work to insulate the walls from the inside over their entire surface - there will be cold bridges at the intersection of the outer wall with the inner partitions.
The humidity in the room rises. This, again, promotes mold growth and is generally unhealthy. To ensure good air exchange, you will have to constantly ventilate the apartment, which will lead to an increase in heating costs.
The useful area of the apartment decreases - especially if, due to the climatic conditions in the region, it is necessary to install a thick layer of insulation for the walls of the house.
If the work on thermal insulation is not carried out before the start of the repair in the room, it is necessary to dismantle all the decorative finishes, which complicates the work and makes it more expensive.

The most dangerous consequence of internal thermal insulation is condensation inside the room, which leads to accelerated destruction of walls and deterioration of finishing materials. This can be partially avoided by accurately calculating the required thickness of the insulation layer and choosing the right material. Thus, insulating a house from the inside is expensive and unsafe, but sometimes inevitable.

How to avoid condensation

If you still had to deal with internal thermal insulation, then before figuring out how to insulate a house from the inside, you need to understand whether negative consequences can be avoided. Dryness of the walls inside the house can be ensured by protecting the dew point from moisture.

For this you need:

Use a quality multi-layer waterproofing membrane. Plastic wrap will not work. In addition, it must be properly laid - with an overlap, with sealing of the joints.
Choose a heater with a minimum vapor permeability. If the material from which the walls of the house are made, this indicator will be higher, then the moisture formed between the insulation and the surface of the wall will not condense, but will come out.
Mount the insulation close to the wall. To do this, glue on it must be applied in an even continuous layer, and not with beacons.

Provide forced ventilation of the room, as well as install windows with air exchange valves.
Calculate the exact thickness of the insulation layer. It is impossible to focus on the average parameters, since it is possible to properly insulate the walls, only taking into account all the characteristics of a particular material, room and climatic features of the region.
Treat the wall to be insulated with antifungal and antibacterial agents. You can use a special antiseptic primer. You can start working only after the wall surface is completely saturated and dry.

When insulating an apartment from the inside, it is very important to get rid of all possible cold bridges. They are formed at the joints of the insulation plates and in those places where the wall is connected to the ceilings and internal partitions. To improve the efficiency of insulation, it is necessary to lay the thermal insulation material with an approach to the internal walls, floor and ceiling.

The choice of thermal insulation material and insulation installation technology

Mineral wool

It is not recommended to choose this material, since it will not work to insulate the wall in the apartment from the inside effectively enough with its help. However, cotton wool is the easiest to use and cheaper than other options, therefore, they often resort to using it.

Vata comes in two varieties:

rolls;
basalt slabs.

If there is no other choice, it is better to use cotton wool in the form of slabs - this insulation is denser, has better thermal resistance, and does not settle over time. The rolled type of cotton wool has a too high rate of vapor permeability, absorbs moisture well, so the walls insulated with it will probably get wet. However, the probability of moisture penetration under the insulation is also when using plates with a density of 75 kg / m3. You can reduce the risk of condensation by using a good vapor barrier and installing the insulation correctly.

Thermal insulation from the inside with mineral wool is carried out as follows:

At a distance from the wall surface, a frame is constructed from wooden battens or an aluminum profile.
The first layer of mineral wool is placed under the frame. It is necessary to glue it to the wall as tightly as possible.
The second layer of basalt wool slabs is laid between the frame slats with displacement of the joints relative to the first layer.
A layer of vapor barrier membrane is laid.
Drywall is mounted on the frame.

Due to the characteristics of the vapor barrier mineral wool, special attention must be paid when the internal insulation of the walls of the house is carried out. You cannot use plastic wrap, you need a more efficient vapor-tight multilayer membrane. It can be attached to a wooden frame with a stapler, always with an overlap; it is glued to the profile with double-sided tape.

The overlap when laying the membrane should be at least 100 mm, the joints should fall on the frame elements and be glued securely. The vapor barrier must go over surfaces adjacent to the wall. Places of contact of the membrane with surfaces should be additionally sealed. A liquid sealant is applied to a wall, pipe or other structure, then the membrane is pressed against the junction; after the sealant dries, the membrane is fixed with tape.

High-quality installation will reduce, but will not completely eliminate the risk of condensation when using mineral wool. It is better to consider other, polymer, types of insulation for the walls from the inside.

Expanded polystyrene and EPS

Expanded polystyrene, or polystyrene, is much better for insulating a wall in an apartment from the inside. This is facilitated by its following characteristics:

low thermal conductivity due to the presence of air in the cells of the material;
low vapor permeability and almost no hygroscopicity;
high strength, including compression and rupture;
small weight;
ease of processing with your own hands - you can cut the material with an ordinary knife.

Plain or extruded polystyrene foam of sufficient density, even with a relatively small thickness, will provide sufficiently effective thermal insulation of the room. It is recommended to choose it not only because of the ease of installation, but also since it can be used to insulate the apartment from the inside with its help most effectively: it does not allow moisture to pass through, so that condensation will not appear. The main thing is to properly glue the foam plates, sealing the joints and ensuring a tight fit to the wall.

When using expanded polystyrene for thermal insulation of residential premises, it is important to take into account some of its disadvantages. So, it practically does not protect against noise. In addition, when it burns, it releases toxic compounds into the air. Another disadvantage is the high cost of EPS, but it is compensated by the fact that you do not need to lay a vapor barrier membrane, and you will definitely not have to redo the insulation due to the destruction of the insulation, as in the case of improper installation of stone wool.

Polystyrene insulation for walls inside the apartment should have a high density - 25-30 kg / m3. Density can be determined by marking, which looks like "PSB-S-25", where 25 means the desired parameter.

Installation of expanded polystyrene plates on the inner wall is carried out as follows:

The surface of the wall is cleaned, primed and dried.
Insulation plates are glued in rows with an offset of the joints. It is advisable to use polyurethane glue, which is applied to the entire surface of the expanded polystyrene board.
Additionally, the plates are fixed with special plastic dowels.
The joints are sealed with silicone sealant, large gaps are filled with polyurethane foam.
Reinforcing fiberglass is laid on top of the insulation with an overlap. On top of it, you can lay plaster for decorative finishing. Another option is to immediately glue drywall instead of reinforcement.

There is another installation method. On the long ends of the PPS plates, grooves in the form of corners are selected. Two plates are joined, the seam is sealed. Then a wooden board is inserted into the groove. The resulting structure is fixed to the wall with self-tapping screws. This method is more convenient, since in this case it is possible to insulate the room faster and more economically. In addition, the boards can be used as a frame for attaching drywall.

Should I consider other options

There are also more modern insulation for walls from the inside - polyurethane foam, thermal insulation plaster, foamed polyethylene and even ceramic-based thermal paint. Among them, only the first material is worthy of attention; other options are actually of little use for insulating an apartment from the inside. Polyurethane foam is an ordinary foam, similar to assembly foam, which is applied to the insulated surface using a special sprayer.

The material is good because it reliably adheres to any surface, penetrates into all cracks, is monolithic and vapor-tight. It quickly solidifies and does not form any cold bridges. However, polyurethane foam is quite expensive, and you won't be able to work with it on your own.

Thus, if it is necessary to insulate the walls from the inside, it is best to use expanded polystyrene. This heat insulator has the most suitable characteristics, and it is not difficult to install it with your own hands. Subject to the technology of insulation, it will effectively protect the house from the cold.

September 7, 2016
Specialization: Capital construction works (foundation laying, wall erection, roof construction, etc.). Internal construction work (laying of internal communications, rough and final finishing). Hobbies: mobile communications, high technologies, computer technology, programming.

I know different ways to improve the energy efficiency of a home with my 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 you have to insulate the room from the inside.

Today I will tell you what heaters are for the walls from the inside, how they are correctly installed and the final interior decoration.

Advantages and disadvantages of internal insulation

The greatest scope for engineers and insulation specialists opens up in the case when it is necessary to produce thermal insulation of a private house. There it is possible to mount heat-insulating material indoors, on the facades of a building, and even erect 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 the insulation for the walls inside the room or use expensive high-rise equipment. The latter option is unacceptable for independent implementation, so most resort to the first.

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

With the internal placement of heat-insulating material, the dew point shifts, and moisture can condense under the insulation (between the enclosing and additional wall), becoming the cause of the appearance of fungus. In addition, due to constant wetting, the enclosing structure will collapse faster.

The insulating layer inside the room does not allow the wall to warm up, accumulating thermal energy. As a result, the thermal inertia decreases, that is, the microclimate inside the room will depend more on the air temperature outside.
The insulating 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 cake reduces the already not very large usable area in a city dwelling.
The technology of installing insulation on the inner surfaces of the walls does not allow high-quality joining of plates on the walls and interfloor ceilings, therefore, cold bridges often appear in these places, which reduce the effectiveness of thermal insulation.
Some types of thermal insulation materials release chemical compounds that are dangerous to humans, which accumulate in the living room.

However, internal insulation has its advantages:

you will not have to use climbing equipment, aerial platforms or scaffolding;
thermal insulation work can be done at any time of the year, regardless of the air temperature outside;
insulation measures can be combined with the process of decorating the apartment, which will save a certain amount of money.

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

The choice of insulation

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

Mineral wool. Effective and environmentally friendly insulation, which is often used in private construction.
Polyurethane foam. Sprayed polymer foam, which, covering the walls of the apartment, forms a homogeneous waterproof heat-insulating layer, which well protects the room from heat loss.
Heat insulating paint. The downside is the very high price.
Expanded polystyrene. Sheet cellular insulation, which has excellent technical characteristics from the point of view of use for internal insulation of an apartment, but at the same time it is very cheap.

In my opinion, expanded polystyrene will be the best choice, or, as it is popularly called, polystyrene (although this is not very correct). In addition to the low price, which I 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 coefficient of thermal conductivity, therefore, 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 of sealed polystyrene cells practically does not absorb water, therefore, during installation and operation, it does not need additional waterproofing.
Light weight	Thermal insulation does not put a lot of stress on the building envelope.
Antiseptic	The material has antiseptic properties, mold, fungi and other microorganisms do not develop on its surface and inside.
Durability	If the operating conditions are observed, the insulation retains its properties for at least 30 years.
Ease of installation	Expanded polystyrene can be easily mounted on insulated surfaces without the use of sophisticated engineering equipment.

Of course, sheet building polystyrene foam is not devoid of drawbacks, however, they are fully justified by the affordable cost.

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

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

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

To summarize. For internal wall insulation, you need to use PSB-S-25 expanded polystyrene. The manufacturer of the material is absolutely irrelevant.

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

Tools and materials

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

Antiseptic concrete primer.
Foam adhesive.
Plastic dowels with wide caps.
Polyurethane foam adhesive.
Fiberglass alkali-resistant mesh.
Reinforcing corners.

From the tools, you will need a perforator (since you will have to drill a large number of holes in a concrete wall) and graters for working with cement-based glue (needed with even 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 foam plastic? The instruction, which is outlined below, consists 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:

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

I eliminate defects in reinforced concrete walls. They must be repaired before gluing the styrofoam:
- Small cracks should be sawed off with 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 emery paper from traces of corrosion, after which it should be well smeared with a rust converter.

I clean the wall from the remnants of the solution, debris and dust. Be sure to use a perforator or a hammer with a chisel to eliminate the build-up of the installation mortar, which can interfere with the leveling of the expanded polystyrene plates. Dust can be removed with a brush.

Dirt 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 the walls to be insulated with it. If the volume of work is large, it is better to use a spray bottle.
- The second layer is applied after partial drying of the first one. In this case, the primer does not need to be diluted, and for application it is better to use a scrubber, with which to carefully rub the primer liquid into the walls.

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

Step 2 - Installation of insulation

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

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

If necessary, I cut sheets of expanded polystyrene. The beauty of this material is that you don't need to use complex or expensive equipment to process it:
- The necessary parts are separated from the pieces of insulation using a hacksaw or sharp clerical.
- For cutting, you can also use a special nichrome wire, which is heated with an electric current. Thus, you can cut polystyrene foam not only across, but also along.
- After trimming, the edges must be processed with a foam trowel (with holes) or coarse sandpaper.

I spread a sheet of polystyrene with glue. This must be done immediately before installing on the wall, however, in this paragraph I will tell you about the general rules:
- First, it is necessary to form a roller around the edges of the slab with a thickness of about 2 cm from the glue. At the same time, it is necessary to ensure that the cement composition does not fall on the end of the expanded polystyrene (where the tile seam will be).
- Then you need to put 2-3 lumps of glue in the middle of the sheet, which will hold the plate on the wall.
- Carry out test gluing. Place the slab against the wall, press down and then tear off. The distributed glue must cover at least 40-60% of the expanded polystyrene board (the exact figure is indicated in the documentation for the thermal insulation).

I glue sheets of expanded polystyrene. The work starts from the bottom row, which is mounted strictly along the drawn line and continues from top to bottom:
- Insulation plates at the inner and outer corners are installed using the gearing method. This means that the slab of the upper row should hang over the slab of the lower one and so alternately up to the very top.
- The vertical seams on the bottom row must not line up with the seams on the top. They should be displaced relative to each other by at least 15 cm.
- Vertical seams should not be a continuation of the window and doorway. In the corners, specially cut L-shaped parts should be installed.
- It is better to start gluing the second and subsequent layers after the first row of foam boards in the room is glued and the glue has hardened for at least a day.

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 are subject to sealing.
- If the gap between the plates is large, you first need to insert a small piece of expanded polystyrene 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 clerical knife.

I fix the expanded polystyrene with dowels with hats. I used a dowel with a plastic driven core, which has a lower thermal conductivity:
- A ruler is installed on the perforator in such a way that, after passing through the foam and glue, the drill is buried into a 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), in order to securely hold the thermal insulation, it is enough to use 2-3 dowels per sheet of expanded polystyrene.
- After making a hole, a dowel is inserted into it, and then the core is clogged in such a way that the cap is slightly recessed into the expanded polystyrene foam, without rising above the surface.

Step 3 - Reinforcement

Finishing of expanded polystyrene with a reinforcing mixture is performed as follows:

Window and door blocks are being designed. For this, special parts are used that are glued to the window trim or door block. The scheme of work is as follows:
- The surface of a window or door block is cleaned of debris, dust and residues of adhesive solution, if it somehow ended up there.
- The door trim or window block is degreased using any alcohol-containing solution.
- Reinforcement corners are trimmed to the desired length at an angle of 45 degrees so that they can be docked together.

A strip of protective paper is removed from the adhesive layer, after which the reinforcing corner is glued to the door or cone block.
After that, a small layer of glue is applied to the slope of the window or door, a mesh is applied to it, connected to the corner, which is then embedded in the glue with a trowel to work with plaster mortar.
The outer corners of the window and doorway are made out. For this, perforated corners with a mesh installed on both sides are suitable. They also need to be pressed into the previously applied glue and smoothed with a trowel.

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

I perform continuous reinforcement of the wall surface with fiberglass:
- 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 for the width of one roll of fiberglass mesh.
- After distributing the glue, the fiberglass mesh is pressed against the wall surface and embedded in 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 canvases 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 onto another wall at a distance of 10 cm. When smoothing it, it is necessary to work only with the blunt end of the float, making movements outward so as not to break the mesh.

I leave the wall to dry. It is necessary to dry it not until the strength is completely gained, but only by 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 dampening the surface to ensure proper dehydration of the solution.

Step 4 - decorative finishing

Now you can proceed to the next step:

I clean the surface of the wall with a float. In no case should this be done with sandpaper, since you can tear the mesh installed on the expanded polystyrene. You can only act with the end of the plaster float, cleaning off the influx of mortar.

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

I level the wall with finishing putty. This composition will eliminate the slightest unevenness of the base and prepare the walls for further painting or wallpapering. After the putty hardens, you need to clean the walls.
Dirt walls. The primer at this stage will reduce the absorbency of the surfaces and improve adhesion to paint or wallpaper glue.

After that, the final decorative finish can be carried out.

Summary

Now you know how to increase the energy efficiency of your own apartment with the help of expanded polystyrene. By the way, this material is quite versatile, so you can use it to insulate the attic from the inside with your own hands. You can learn more about this technology in the video in this article.

You can leave your opinion on the information contained in the material in the comments.

Master of Architecture, graduated from the Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.

The issue of internal insulation causes a lot of controversy and has its ardent opponents. But there are those who believe that this option will help make the building more comfortable to live in. Both sides are right. In every situation there is a reason for adopting a particular position. But before choosing this method for the interior decoration of a private house, it is worth carefully weighing the pros and cons, studying the features, and choosing a safe insulation.

When is it relevant

Insulation of the walls from the inside certainly allows you to increase the thermal performance of the house. But this is an unconventional technology, because they usually try to do it. However, there are situations when there is no other way out.

Internal thermal insulation is recommended only when it is impossible to carry out external insulation

Also, the option is relevant for apartment buildings. It helps not only to improve the comfort of your home, but also to prevent the occurrence of such troubles as mold or mildew.

Problems

This method has a number of disadvantages. It is for this reason that the method has many opponents. Insulating walls “from the inside” can cause the following problems:

The walls are not protected from the cold. The supporting structure of the building continues to be in contact with the outside air. This can lead to its gradual destruction. Cracks will begin to appear on the surface. This event not only does not protect the outer wall from the cold, but also takes away part of the heat from it, because before the insulation, part of the heat from the room heated the wall, and now this flow is blocked.
Condensation falling out. It forms on a cold surface when it comes in contact with warm air. Heating technicians call the place of condensation the dew point. The main task of thermal insulation is to move the dew point outside the wall. Insulation "from the inside" provides a dew point shift to the border between the wall and the insulation. This process is hidden, so the owners of the house do not notice it. But humidity will be an excellent condition for the multiplication of various microorganisms.
Reducing the area of \ u200b \ u200bthe premises. Modern types of insulation have good efficiency. But science has not yet come up with such a good material that its thickness is minimal. To insulate the house from the side of the room, you will need from 5 to 10 cm of insulation. This eats up the area quite strongly. It is not so noticeable to the eye, but if you calculate the losses for the entire building, the figure turns out to be significant.

With internal insulation, the dew point shifts to the border between the wall and the insulation

Therefore, before deciding on the internal insulation of the walls of the house, we recommend that you think carefully about the listed problems. In this case, ignorance does not absolve from responsibility, since the result of inattention will make itself felt in the first years of operation.

Material selection

The technology allows you to use different types of insulation. Each of them has its own characteristics, advantages and disadvantages. Most often, the following options for wall insulation from the inside are used:

Styrofoam;
extruded polystyrene foam (Penoplex type);
mineral wool;

Styrofoam

Polyfoam is inexpensive and has good efficiency. In most cases, 5 cm will be enough to ensure a comfortable microclimate. It allows you to perform work quickly, without complex processing and additional tools.

Polyfoam is an inexpensive and effective heat insulator

But this material has significant drawbacks:

low strength;
flammability;
poor vapor permeability - foam can turn a house into a real greenhouse.

Extruded polystyrene foam

The closest relative of foam is extruded polystyrene foam (Penoplex type). It is very similar in appearance, but has an orange color instead of white. It is also worth noting that it has greater strength and durability. But such disadvantages as flammability and poor vapor permeability have not gone away. Such wall insulation will not allow it to breathe and will require an additional ventilation device.

Penoplex is stronger than polystyrene and lasts longer

Is it possible to carry out internal insulation with expanded polystyrene? Yes, you can. But you need to prepare for the negative consequences and eliminate them in time. This option is more suitable for bricks or lightweight concrete. Wood for walls is usually chosen precisely for its ability to breathe. Polyfoam or polystyrene foam will easily block air flows and negate all the advantages of wood.

Mineral wool

Such insulation is widespread. It costs relatively little more, but it has a high vapor permeability. It is recommended to choose basalt mineral wool, which is produced in hard slabs. It is easy to install, does not burn, and has a fairly high strength.

But you should carefully place the insulating layer inside the room. This material has a low moisture resistance. Cotton wool perfectly absorbs water, after which it practically ceases to perform its direct functions. For reliable protection against moisture, a vapor barrier should be provided on the warm air side and waterproofing on the cold side.

Fiberboard

The walls of the house can be insulated from the inside. The option does not guarantee that the difficulties listed above will not appear in the future, but it has the following advantages:

good thermal insulation and sound absorption;
unattractiveness to insects and rodents;
good resistance to moisture and temperature extremes;
ease of processing, you can use any tools;
easy installation;
convenience for wiring.

Fiberboard is resistant to temperature extremes and high humidity

Material selection criteria

Insulation of the walls of the house from the inside must meet the following criteria:

environmental friendliness;
safety;
fire resistance (for materials that are unstable to high temperatures, select the appropriate finish);
durability;
efficiency, low thermal conductivity;
good resistance to moisture (or the presence of additional protection against it).

The material for internal thermal insulation must have good vapor permeability

It is also worth checking the vapor permeability. How to insulate a house for years to come? Consider good ventilation. Without this, the building will suffer from high humidity and microclimate disturbances. The problem can be solved, but you need to think about it at the initial stage.

Technology

For a private house, two methods of securing the material are used. Both are relevant:

on glue;
on the frame.

The second option allows you not to level the carefully insulated surface. In addition, it allows you to easily attach finishing materials. For example, for cladding with drywall, in any case, you will need to build a frame. You can insulate the wall under plywood or plaster. Then there is no need to use a frame. The choice of installation method for insulation largely depends on the method of further finishing. Be sure to consider what foundation is required.

Fastening with glue

The surface must be thoroughly cleaned of dirt, grease and dust, otherwise this can significantly reduce the quality of adhesion of the heat-insulating material to the base. Further work is performed in the following order:

level the surface, knock down protrusions, cover up cracks and depressions;
treat the surface with an antiseptic composition;
apply a layer of primer;
the sheet is glued, the adhesive is applied with a roller to the wall and material;
allow the glue to dry;
fix the material to the wall with dowels.

Expanded polystyrene sheets and mineral wool slabs are fixed in a checkerboard pattern. After fixing the insulation, you can start finishing.

Fastening to the frame

This option can be called more time consuming, but also more reliable. It allows you to protect the insulation from mechanical stress. This is especially true when using fragile foam.

Before starting work, the wall is cleaned of dirt and treated with an antiseptic. After that, you need to build a good frame from wooden bars or a metal aluminum profile. The racks are fastened to the wall with self-tapping screws. The step of the elements is selected depending on the width of the insulation. For mineral wool, such a step will be required so that 58 cm remains in the light.For polystyrene and polystyrene foam, the distance in the light should be exactly 60 cm.

After installing the frame, the insulation is laid between the racks. The joints between expanded polystyrene and the frame are filled with polyurethane foam. After that, you can start finishing.

When performing work on any of these technologies using mineral wool, it is important not to forget about moisture insulation. The waterproofing is attached directly to the wall before the cotton wool is installed, and the vapor barrier covers the material and protects it from internal steam. The fastening of the layers is usually done with a construction stapler. The overlap of the material along the length must be at least 10 cm.

If you properly insulate the house from the inside, you can significantly reduce the energy consumption for heating (especially in the northern regions). Therefore, it makes no sense to economize on this aspect. This article will discuss in detail how to do this procedure with your own hands.

You can endlessly talk about the advantages of facade insulation. However, this technique is not always available (for example, if the exterior of the building has already been completed). In such cases, you have to do work inside the house.

We are trying to find the advantages of the method

This technique has few positive qualities:

Simplicity - all work can be done without any problems with your own hands, because there is no need to create large "forests".
The ability to carry out work regardless of the season. Correct external insulation should be carried out at positive temperatures, in the absence of precipitation and low humidity. Work inside can be carried out under any conditions
Availability. You can do the work gradually. This is convenient in cases where a person does not have the opportunity to immediately start large-scale work, and he plans to insulate the most important premises with his own hands, and not the entire building.

We analyze all the shortcomings

As for the negative aspects, there are plenty of them:

A significant reduction in the area of \ u200b \ u200bthe premises, especially if interior decoration is planned. Of course, you can make a small thickness of the thermal insulation layer, but this will negatively affect the efficiency.

Tip: Choose the right insulator size. In order not to be mistaken with the choice, take a look at online calculators or calculate the recommended thickness of the insulator with your own hands.

Condensation begins to form under the insulation at a faster rate. This is due to an incorrect dew point offset. How to fix this consequence with your own hands will be discussed in the next paragraph.
When insulated indoors, the walls will practically stop warming up. They will not participate in protecting the house from the cold, and most importantly, their operational period will begin to decline.
If you create frames inside the premises for laying the insulator, then this will inevitably lead to the formation of so-called "cold bridges". As a result, the effectiveness of the insulation will decrease.

From this picture, you can easily understand the principle of this term.

The dew point is the place where moisture that comes out of the air begins to condense. This situation inevitably leads to the destruction of the walls (brick suffer the most) and the insulation material. Thermal insulation from the inside encourages the dew point to move closer to the room. However, the situation can be improved if a set of measures is taken:

Purchase insulators with very low vapor permeability and moisture absorption. As a result, moisture that accumulates inside the room will practically not get into the walls.

Tip: the most suitable option for this criterion is foamed polyurethane foam. However, its cost is relatively high.

When laying the insulator with your own hands, avoid joints. Even the smallest gaps will encourage condensation.
Install a one-sided conductive vapor barrier. You can use a special membrane film.
Arrange the layers of thermal insulation in the order of increasing vapor permeability. That is, those materials for which this indicator is minimal should be located inside the room.

Step by step we disassemble the process of warming

The theoretical aspect has been studied, now it is time to practice. Most of the operations described below can be done without any problems with your own hands, even without having special skills.

How to properly prepare the surface

Preliminary procedures are the most time consuming and critical stage. You will need to do the following:

Deal with the wiring. If it is inside the walls, it must be brought out. For this, junction boxes are located and wires are led from them to the outside (connection is made through special terminals). With external wiring (which is placed in special cable - channels) it is even easier - you just need to disassemble it.

Important! In the absence of skills in working with an electrician, it is better to invite a specialist in order to prevent fatal mistakes.

The next step is the leveling of the rough surface (the process of dismantling the finish is not considered). If the walls are brick or concrete, then a small layer of cement screed will help. Defects in wooden surfaces can be removed with a planer.
Further, dust and dirt are removed. In this case, the surface must not be wetted!
Now you need to thoroughly dry the walls to prevent mold and mildew. To do this, use thermal guns or convectors. These devices should work until all moisture has completely evaporated.
Then you should cover the surface with antiseptics, especially when it comes to a wooden structure.
When the impregnations are completely dry, a vapor barrier material is attached to the surface using a special moisture-resistant glue.

Create a strength frame

Now you need to build a frame of bars (their size should be no less than the estimated thickness of the insulating layer). In a wooden house, they are fixed immediately onto large self-tapping screws. For brick and concrete buildings, you will have to pre-drill holes and install a dowel - nails in them.

The distance between the bars is made to the size of the selected insulation - this makes the work easier. In addition to vertical logs, several more horizontal ones are installed, with a step of 1-1.5 meters. They are needed to ensure the maximum rigidity of the frame.

Insulator laying

The only thing left is to put the heat-insulating material into the niches that have appeared with the help of special glue. The following models are actively used for internal insulation:

Styrofoam. The cheapest analogue, which is characterized by low efficiency. It is permissible to use it only with an impressive wall thickness, or in warm regions.
Mineral wool. It is recommended to use the basalt variety, since it has a low thermal conductivity (in this segment it is second only to penoplex).
Penoplex. The most advanced thermal insulation material to date. It is very lightweight and therefore very easy to stack.

When laying, the presence of cracks is unacceptable. It is best to do two layers in a checkerboard pattern, as all joints will be reliably hidden.

Consider alternative options

The options presented above are not the only ones that are suitable for this task. 2 more methods are actively used:

Warm plasters - a special mixture is simply applied to the surface. Only suitable for thick brick or aerated concrete walls. There is no need for the construction of the frame and preliminary preparation.
Foamed polyurethane foam. It is applied like polyurethane foam. When using it, it is unnecessary to lay a vapor barrier material, since good adhesion to the surface is necessary. A frame is created with a large step (1-1.2 m). Polyurethane foam is sprayed into it and subsequently covered with some kind of sheet material.