Do-it-yourself wall insulation from the inside with polystyrene foam. Detailed instructions for insulating walls from the inside with polystyrene foam

Wall insulation from the inside with polystyrene foam has gained wide popularity due to the excellent thermal insulation of the material. Expanded polystyrene can be used to insulate a room both inside and outside.

It is possible to insulate with polystyrene foam from the outside and from the inside, this insulation is popular due to its qualities and low price.

Characteristics of expanded polystyrene

Extruded polystyrene foam is a product of mixing polystyrene with a substance based on carbon dioxide and light freons.

This mixture is heated and passed through a special apparatus - an extruder. This equipment contributes to good mixing and foaming of the mixture. This composition is then formed into sheets which, when solidified, form a light porous material.

Wall insulation with polystyrene foam is much more effective than with polystyrene foam. This is due to the fact that expanded polystyrene has a granule size of 2-8 mm, interconnected by heated steam. Extruded polystyrene foam is subjected to heat treatment while still in a liquid state, due to which the material acquires a solid solid structure.

Expanded polystyrene has the following properties:

Technical characteristics of expanded polystyrene boards.

Low thermal conductivity: 0.03 W per 1 cc. Such a high ability to retain heat is due to the fact that this material consists of 90% of the air in the cells.
Ability to withstand heavy loads: 35 tons per 1 sq.m.
Resistant to temperature extremes, humidity, precipitation, direct sunlight.
Chemical resistance: does not rot, is not destroyed by insects and rodents.
Does not pass moisture, which eliminates the occurrence of mold and swelling.
Low vapor permeability. Wall insulation with polystyrene foam eliminates the use of vapor barriers.
Fire resistant.
Long service life: up to 50 years and above.
Environmental friendliness. Expanded polystyrene is widely used not only in construction, but also in the food industry. Containers and disposable tableware are made from this material.

Currently, the technique of erecting hollow walls has gained popularity. Its essence lies in the fact that a sheet of insulation is inserted into the cavity of the supporting structures. This allows you to save building materials, and also increases the performance of the building. In this case, the insulation lasts much longer, as it is hidden from the aggressive effects of the environment.

Partitions inside the house are rarely insulated with polystyrene foam, since in any case they are inside a warm room.

On a wall insulated with polystyrene foam, the installation of electrical outlets is undesirable.

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Preparing walls for thermal insulation

Figure 1. Scheme of insulation using expanded polystyrene inside the building.

Insulation of walls from the inside is done when it is impossible to do it from the outside. For example, when the facade of the house has a great historical significance or a lot of decor. In other cases, it is advisable to insulate the room from the outside, since internal thermal insulation reduces the volume of the room.

Internal thermal insulation has a scheme, as in Fig.1.

To work, you will need the following tools and materials:

spatulas;
paint roller and brush;
perforator;
rubber mallet;
dowels;
mounting knife and pencil;
building level;
glue;
container for adhesive liquid;
painting net;
primer;
antifungal agent;
expanded polystyrene sheets, at least 5 cm thick.

Wall insulation begins with surface preparation. First you need to dismantle the old wallpaper or other finishing material. The old and plinth should also be removed to insulate the wall as low as possible.

Traces of mold should be removed with sandpaper. In the presence of irregularities and cracks, the wall must be leveled with plaster and puttied.

After the putty has dried, the surface should be coated with an antifungal agent. The next day, the walls are primed. This is done for good adhesion of the finishing material to the wall and to prevent the appearance of fungi. When performing this procedure, it is recommended to ventilate the room.

To prevent the accumulation of condensate, it is necessary to lay a waterproofing substrate before installing the insulation.

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Insulation of internal walls: instructions

Figure 2. Scheme of fastening polystyrene foam to the wall with dowels

Insulation with polystyrene foam from the inside can be done in two ways:

fixing sheets to the wall with dowels;
laying tiles on glue.

The scheme of the first method is shown in fig. 2.

The insulation begins to be fixed from the bottom up from the corner. The plate is set vertically and pressed against the wall to be insulated, and the end of the sheet against the side wall. Holes are drilled through the insulation with a perforator, into which the dowels will be hammered.

Then plastic dowels are inserted into the holes, and nails are hammered into them. The dowel cap should tightly press the sheets of insulation and not rise above its surface.

The second row is laid close to the bottom. To get a smaller sheet of insulation, it is cut with a knife. The gaps between the sheets are sealed with mounting foam, but not with adhesive tape.

The second method of insulation is performed using glue, the best option of which is Ceresit. This adhesive composition has good adhesion with polystyrene foam, drywall and other finishing materials.

Glue should be applied to the wall, not to the Styrofoam! To do this, with a notched trowel, the adhesive mixture is applied pointwise or in stripes to the surface, and then a sheet of insulation is applied to this area. The glue hardens very quickly, so the sheet should be mounted within 10 minutes.

For reliable fastening, the sheets can be fixed with dowels. 5 dowels are enough for one layer of material: 4 in the corners and 1 in the center.

Home... How many associations arise when thinking about it. This is the peace that comes when you find yourself in its cozy rooms. This is also an opportunity to soak in a warm bed on a cold winter Sunday. This is also a favorite hobby that awaits after work. But in order to bring all this to life, you need to work hard. To begin with, a house must be purchased or built. And if you decide to build, you will definitely have to insulate. This is a whole science, which we will talk about now. By entering in the search line the query “do-it-yourself wall insulation with polystyrene foam video”, you can study the entire technological sequence of such work and even put it into practice. And how nice it will be later to realize and tell friends and relatives that you yourself have done such a difficult job as insulating the walls with polystyrene foam!

Benefits you get by insulating your home

Why is it considered that it is so necessary to insulate the house? Yes, because there are many reasons for that.

By limiting the process of heat transfer, the insulation layer will protect your home from cold in winter and heat in summer. Thus, in severe frosts you can save on heating, and in the summer heat the house will always be cool. And you don't need air conditioning.
It is worth walking through the private sector, as insulated houses immediately catch the eye. And all thanks to the fact that current materials and technologies allow not only to insulate housing, but also to give it an attractive appearance.
One of the properties of modern heaters is their ability to protect the house from the effects of the external environment, which leads to an increase in the life of the building.
Modern materials for wall insulation protect houses from fungus and mold.

Why is it better to insulate a house with polystyrene foam?

In order to answer this question, it is necessary to find out what this material is.

After analyzing the information on the Internet, you can find out that polystyrene foam is used mainly as a heater. It is environmentally friendly, but most importantly, it has good thermal insulation properties. Compared to other materials, a 3-centimeter layer of expanded polystyrene is the equivalent of 10 centimeters of wood, 106.5 centimeters of reinforced concrete, 25 centimeters of foam concrete, or 42.5 centimeters of brick. In addition, the material is an effective sound insulator and has a low level of vapor permeability.

Expanded polystyrene is a material that is 98% air distributed in small cells obtained by foaming polystyrene with pure hydrocarbon and heating it with steam of a certain temperature. As a result of the passage of this technological chain, polystyrene balls increase in volume, while increasing the volume of the entire material by 50 times. Becoming more resilient due to the air filling them, the balls stick together under the influence of steam. As a result, we have a very light, durable, non-deformable insulation material.

As mentioned above, expanded polystyrene is an environmentally friendly material. This means that it is safe for both the environment and human health. When working with expanded polystyrene, no additional protective equipment is required; during operation, it also does not emit any harmful substances.

When describing the properties of this insulation, the word "reliable" would be the most appropriate. Expanded polystyrene is a really reliable material on which cracks do not appear, microbes, bacteria and mold do not take root. It does not rot and allows the room to breathe. Therefore, it is possible to insulate the walls with polystyrene foam from the inside.

One of the very valuable qualities that this material possesses is its fire resistance and self-extinguishing ability. In this case, gases of the same composition are released as when wood is burned.

And only prolonged exposure to ultraviolet rays, as well as certain chemicals - such as acetone, alcohol and kerosene - can damage the expanded polystyrene.

Based on the foregoing, we can conclude that expanded polystyrene meets all the requirements to be considered a priority option when choosing a material for home insulation.

Wall insulation from the outside with expanded polystyrene

Do-it-yourself wall insulation with polystyrene foam from the outside is a simple process. And even those who have never done any construction work can figure it out. However, for everything to be done well, it will take some effort.

Warming should begin with the preparation of the walls of the house. To do this, it is necessary to remove all unnecessary (grilles, air conditioners), remove peeled plaster, repair cracks, trying to make the wall as even as possible.

Next, the wall must be coated with a primer. To avoid slipping of the first layer of insulation, the so-called basement profile is attached to the bottom of the wall (at a distance of 30-40 centimeters from the ground) with the help of special dowels. After that, you can proceed directly to the installation of insulation. Its masonry is made similarly to brick. In order to prevent the formation of "cold corridors", a distance of no more than 2-3 millimeters should be left between the insulation plates. Particular attention should be paid to the corners. Here it is necessary to lay the plates in such a way that a jagged dressing is obtained. Upon completion of the masonry, the insulation must be closed (so that the sun's rays do not fall on it) and left in this form for 12-24 hours for the glue to dry. After additional fastening with dish-shaped dowels, the walls are plastered - the last stage of insulation work.

You can see how this work is done on the Internet by entering the query "polystyrene foam wall insulation outside the video" in the search box.

Wall insulation from the inside with expanded polystyrene

When performing insulation inside the house, almost the entire sequence of actions described above is performed.

The walls are prepared: the wallpaper is removed, the walls are leveled, puttied, antifungal liquid is applied to them. After the last wall has dried, they are primed.
Insulation is glued onto the prepared walls, starting from the bottom. Glue is applied to the wall, after which the tile is laid. At the end of the masonry, the fastening must be duplicated with dowels along the edges of the tile and in the center. Finally, the tile is given 3-4 days to dry, and then you can start finishing.

Watch a video on the Internet for the request “do-it-yourself wall insulation from the inside with polystyrene foam video” so that the work is understandable and easy to do.

In order to live in a wooden frame house, it was possible to live comfortably not only in the summer season, but also all year round, you will need high-quality insulation of the walls of the house. It is best to insulate the walls with polystyrene foam (styrofoam). It’s worth saying right away that penoplex and polyurethane foam are the same thing, it’s just a kind of polystyrene foam. It is interesting that such material can be used for both frame and brick houses, and the insulation is fixed in the same way both there and there.

Features, pros and cons of the “wet” and “dry” method of warming a frame house

As you might guess, wall insulation with polystyrene foam by the “dry” method assumes that the insulation will be applied immediately during the construction of the house, the voids are filled with a dry method.

This method has one significant drawback: dust particles that will fly away from the insulation can subsequently adversely affect human health. Penoplex and polyurethane in themselves are safe materials, they will not harm a person, but it’s still worth being careful.

The scheme of warming a house from a bar with the help of penoplex

Usually, polyurethane foam is applied “dry” when the construction time is running out and the insulation for a frame or brick house needs to be fixed as quickly as possible. As for the brick structure, then in it the thermal insulation with foam plastic is usually carried out “wet”. What is meant by it?

Penoplex is first mounted in the grooves of the walls, and then it needs to be dried for 2-3 days.

If the weather conditions are unfavorable, then the time may well be needed even longer. Of course, in the conditions of extremely tight deadlines for the construction of a brick or frame house, such terms are a very big minus.

In general, here you need to choose: either mount the penoplex in a “dry” way and save time, or vice versa. But in any case, even from a purely technological point of view, “wet” foam insulation is preferable to “dry”. This must be taken into account.

Scheme of the device for dry insulation of a frame house

Preparation of walls for insulation with polystyrene foam

Wall preparation is the most important step. It includes the following work:

The walls of a frame house must be well prepared before insulation

Wall alignment. It should be said right away that the walls of a frame or brick house should be actually perfectly even. The fact is that penoplex is a relatively fragile material. Any unevenness can simply lead to the fact that the insulation tiles will crack and the entire thermal insulation effect will be virtually destroyed. Experts recommend that plastering of walls be carried out in such a way that, as a result, the height difference (along with possible irregularities, chips, cracks) does not exceed 3 centimeters. This applies to both frame and brick houses;
After plastering, it is not worth rushing to lay the foam plastic: the thermal insulation should adhere to the wall as best as possible. To do this, the surface of the latter should be slightly rough, in which case the material will lie better than if the wall is completely flat. Moreover, it should be borne in mind that polyurethane foam cannot simply be inserted into the crate of the facade of a brick or frame wooden house, as is the case with other types of material: it will be mounted using special glue. Naturally, it will be more problematic to glue insulation on a smooth glossy wall surface than not rough;
If the walls of the building were painted on the outside with a coloring compound that has a zero vapor permeability index, then the layer of such paint must be completely cleaned (when the surface of a wooden frame or brick house is insulated with foam, the vapor barrier must be carefully monitored). After the paint layer has been cleaned, the surface must be primed without fail (a primer literally costs a penny in any construction market, so you definitely shouldn’t feel sorry for it). By the way, if we are talking about the internal insulation of a frame or brick house, then here it will no longer be necessary to prime the walls. But in any case, you should not forget about the vapor barrier;
Checking whether the surface needs to be additionally primed is quite simple: you need to run your palm over the surface. If a chalk mark remains on the hand, then the surface must be primed again. Here, we can say, the following rule applies: there is never too much primer. Especially when it comes to the walls of a brick or frame house. And in itself, foam insulation, as noted above, does not imply fastening: only glue;
If during manual contact the surface crumbles, even if only slightly, then the surface must be cleaned again with a conventional brush, and then, again, a primer layer must be applied. Shedding is a rather serious problem, which can later lead to trouble.

After stripping the surface of the paint, it must be primed without fail.

Do-it-yourself insulation of a frame house with polystyrene foam

Insulation with polystyrene foam may involve fixing the material in the following ways:

Glue is used first:

After gluing the tiles, it is necessary to wait at least 3 days for the tile adhesive to set as securely as possible. By and large, it is not a problem to withstand such a period: it is unlikely that a person will quickly paste over all the outer walls of the building on their own.

After the glue has set, you can already proceed with the additional fastening of the insulation with dowels. The number of dowels is easy to calculate: for every square meter of wall area there should be at least 5 pieces of dowels.

As for the length of the dowel, the rule also applies here: they must enter the wall with their main part (up to the cap) by at least 5 centimeters. Less is impossible, since tiles of thermal insulation material can simply slide off.

In this case, then it is not recommended to use dowels at all: let the insulation rest on one glue. The dowels themselves should be centered with a slight indent.

What else you need to know when insulating a house with polystyrene foam:

Possible errors in insulation

Reinforcing mesh on polystyrene must be laid

The most important mistake that people make when insulating houses is the lack of a reinforcing mesh between the laid insulation and the decorative part of the walls. Its presence is a guarantee that the heat-insulating material will last for a long time, and will perform all the functions assigned to it.

The mesh must be selected with a density index of 140 to 160 grams per 1 square meter. In this case, we are talking about frame houses, and not any others.

From above, it should also be covered with a second layer of adhesive, and the surface itself should also be almost perfectly flat. Here you can talk about several important nuances:

The vertical stripes of the grid may not overlap, but the horizontal stripes must, and the overlap should be no more than 10 centimeters;
The corners of the facade must be reinforced, for which either perforated plastic or a corner is used (if the corner is metal, then it must be galvanized to avoid corrosion in the future).

Another common mistake is that the insulation of the walls of the house is carried out very quickly, in haste. Often this is expressed in the fact that the glue is simply not allowed to dry completely and properly “grab” both the insulation itself and the walls of the building.

To strengthen the corners of the facade, perforated plastic is usually used.

Wall insulation from the outside with polystyrene foam must necessarily assume that the adhesive base is kept for at least 3 days - this is even a law, not a rule.

Expanded polystyrene wall insulation is a very good material in itself, but its improper use can send all the work down the drain, especially when it comes to a wooden house.

Scheme of the principle of operation of insulation in the wall of the house

As for the finish, it can be very different. Today, for example, decorative plaster is often used. Of course, it is impossible to immediately apply plaster to the insulation: the reinforcing mesh indicated above must be available.

You should not forget about the primer in this case either. In general, any subsequent stage in the external insulation of the walls of the house should always involve a primer. If you do not use it, the wall will begin to crumble over time, the insulation will quickly become unusable, and all work will need to be done again.

On the other hand, initially you need to carefully calculate everything: any material for such work, its quantity, must be calculated with a margin of 10-15%. If then there is not enough material, then you will have to stop all work.

Video

You can watch a video that talks about it. how to properly insulate the walls of the house using polystyrene foam.

No matter what material your house is built from, foam wall insulation polystyrene will not be a waste of money, since there is never a lot of insulation, and the warmer the walls of the house, the more comfortable and cozy it will be in it in the winter.

Investing in the insulation of a house structure is the most profitable investment of money both at the construction stage and during the operation of the building. If you spend excess money on building cladding, foundation strength, you will not be able to get your money back. The money invested in insulation will return to you very quickly in savings on heating costs at home.

Expanded polystyrene - an effective and easy-to-install insulation

Expanded polystyrene as a heater is in great demand, and summer residents and builders use it. Styrofoam insulates not only the walls of private houses, but you can also often see foam insulation of the outer walls of apartments in multi-storey buildings.

PPS is an environmentally friendly material that is harmless to health. As evidence for this, the use of PPS as a container for packaging food products (styrofoam trays, trays) can serve.

Low vapor permeability is often called a disadvantage of polystyrene, but most vapor-permeable heaters also have the property of water absorption, insulated walls with such heaters become damp due to the accumulated moisture of the heat-insulating material.

Expanded polystyrene is a low-flammable and self-extinguishing insulation. Styrofoam itself does not burn well, more often it does not burn at all. If another material burns near the Styrofoam, it will melt, releasing toxic gases into the air. For this reason, expanded polystyrene is recommended to be used for insulating walls made of non-combustible materials, for example, brick, stone, foam concrete walls.

For insulation of wooden houses, burning ceilings, foam frames, it is better not to use it. This insulation does not dampen, does not exfoliate, this material has a stable strength, for many decades its thermal insulation properties have not deteriorated. In work, it is easy to process: it is well sawn, cut and glued. In terms of cost and effectiveness, foam plastic is the leader among other thermal insulation materials.

Choosing foam for facade insulation

For external wall insulation with foam plastic, a material 50 mm thick of the M25 brand is suitable. Such a heater in terms of heat-insulating qualities can replace 50 cm brickwork. This is quite enough for climatic conditions in most regions of Russia. This type of polystyrene foam can provide sufficient vapor permeability (in this respect it is better than 10 cm polystyrene of the same grade M25, or 50 mm M-35). A wall insulated with this insulation will not suffer from accumulated moisture, and at the same time create a favorable environment for the development of bacteria, fungi and mold.

Preparing walls for foam insulation

Before starting the insulation with polystyrene foam, it is necessary to carry out work on the preparation of the outer walls. In this case, it is necessary:

Cut down or otherwise remove slightly protruding parts (structural elements protruding beyond the facade will have to be separately glued with insulation).
Repair all potholes, the foam should fit snugly against the wall.
Clean the wall surface of peeling paint or loose plaster so that the old coating does not fall off along with the sheets of thermal insulation material.
The loose surface of the wall should be primed with a special compound or, if the wall is in very poor condition, the plaster should be cleaned to the very surface of the wall.

After all these works have been completed, you need to check how equal the wall is, and, if necessary, level it with a solution that is used when installing foam sheets.

Long nails with wide hats are sometimes used for fixing foam plastic to the wall. But it is better if the insulation boards are glued to the wall. To do this, you can use the universal Flisenkleber glue manufactured by Knauf or other modern adhesives.

Before pasting, the walls must be prepared, first of all, cleaned of dirt and moistened (this can be done using a garden sprayer). Styrofoam should also be moistened. Glue "Fliesenkleber" is plastic and has good adhesion (that is, it can stick to any surface). You need to dilute the glue in a plastic container using a stirrer and an electric drill.

How to insulate slopes and doorways

Window and door openings during the installation of the thermal insulation system require special attention, as they can create cold bridges. It is not recommended to insulate openings with polystyrene foam; polystyrene foam insulation will reduce openings by 10 cm both vertically and horizontally.

To solve this problem, you can use materials such as plastic lining and mineral wool. The slope needs to be cut off a little - by 3 cm, after that we apply a layer of waterproofing, and mineral wool on top of it. We cover the entire resulting structure with a clapboard. But the insulation of slopes and doors should be done only after the walls have been thermally insulated with foam plastic and a decorative finish has been made. And the sloping of the slope must be carried out even at the preparatory stage before the walls are pasted over.

Fastening polystyrene foam to walls

Do-it-yourself wall insulation with polystyrene foam is performed in the following sequence.

The walls are puttied with a special solution, on which the foam will be laid. The layer can be made not continuous, but the denser it is, the better.
We apply glue to the plates with a spatula with teeth (8 mm wide) along the entire perimeter in zigzag lines and also in the center. Glue must cover at least 40% of the surface of the foam board. It must be remembered that the adhesive after application retains adhesive properties for 10 minutes, so the plate must be installed within 10 minutes.
We install sheets of insulation to each other as tightly as possible. The installation is carried out "in a row" (that is, the plates of the next row are shifted relative to the previous one). This method of laying the insulation increases the strength of the heat-insulating layer, and prevents the formation of through cracks. More efficient stacking of foam sheets in both horizontal and vertical orientations. In this case, the dressing of the seams goes along the length and along the height of the wall surface.
After installation, the plates are fixed with special plastic dowels in the amount of 5 pieces (one in the center, 4 at the corners of the plate). To install the dowel, drill a hole in the wall through the insulation 40-50 mm deep.
After installing the fasteners, proceed to the finishing work. A layer of glue is applied to the surface of the insulation in strips, a mesh is applied to it, which is rolled with a roller so that it is completely drowned in glue. Then the grid is closed with another layer of glue. Decorative plaster is applied after the adhesive has completely dried.

Insulation of the facade of the building with foam plastic

Can walls be insulated from the inside?

Insulation of the house with expanded polystyrene can be carried out not only from the outside, but also from the inside of the room. The external method of installing thermal insulation is more efficient and safer. Internal wall insulation should be done very carefully and strictly in accordance with the installation technology of the thermal insulation system. With internal wall insulation, the dew point shifts and condensate can collect on the walls, which leads to the formation of mold, the destruction of the heat-insulating layer and the supporting structures themselves. The inner heat-insulating layer isolates the walls from the heating system, moisture accumulates in them and, as a result, the most unpleasant consequences arise.

But not everything is as bad as it seems at first glance. If you properly equip the internal thermal insulation system, you can avoid all these terrible consequences.

The main thing when installing the internal heat-insulating layer is to pay serious attention to vapor barrier and do not forget about ventilation.

Insulation of the wall from the inside with foam

Before you start insulating the wall from the inside with foam, a primer layer is applied to the surface of the wall. For this, experts recommend using an antifungal acrylic primer for deep penetration interior work.

Pour the primer in a small amount into a specially prepared container and evenly apply it to the surface of the wall with a roller. An antifungal primer is good because it eliminates fungal and mold spores and prevents their reappearance.

Walls should be treated in a well-ventilated room, for safety when working with a primer, it is advisable to use a special mask to protect the respiratory tract from the toxic components present in the primer.

After processing, let the wall dry for a day, and lay the waterproofing to protect the insulation from getting wet, and only then proceed to laying the foam.
We begin to lay the insulation boards from the bottom farthest corner. We apply a foam sheet tightly to the wall and to the floor, make a hole in the center, and enter the wall by 5-6 cm, drive an umbrella into the resulting hole (the umbrella cap should fit snugly against the foam), then for reliable fixation we drive the dowel into the middle of the umbrella. For one foam slab, 5-6 umbrellas will be required. We press the subsequent sheets tightly against each other, leaving no gaps between them. In addition, the sheets of insulation should fit as tightly as possible to the surface of the wall.

The most difficult moment is laying the last sheet in a row, since you will have to adjust the pieces of insulation to size. For cutting foam boards, you can use a knife or a hacksaw, but the pieces must always be obtained with smooth edges.

When the foam is laid, you should do the seams. The gaps between the plates must be eliminated. Gaps up to 5 mm are blown with foam, and gaps larger than 5 mm are laid with pieces of foam (a thin layer of foam must first be applied to the pieces).

After installing the foam boards, a vapor barrier is made. This step must be performed with internal wall insulation.

When the installation of the vapor barrier is completed, we proceed to finish the surface of the wall.

First of all, we hide the seams formed between the plates and the hats of the umbrellas. We use some adhesive for this.

We apply a solution (2 mm in thickness) to the joints of the sheets and apply a reinforced tape, about 50 mm wide. The tape should not have folds, so it must be well stretched, along the entire length of the seam, the tape should be in one piece.

We apply the tape to the beginning of the seam, press it with a spatula and move on. When pressing on the tape, an adhesive solution will come out, which will hide the tape. Umbrella hats are covered with a mixture of using tape. Now you should wait until the mixture dries.

We take a reinforcing mesh, and cover the entire surface of the wall with it (we glue the mesh onto the same adhesive mixture). A small section of the wall, equal in width to the reinforcing mesh, is covered with an adhesive mixture. We impose a grid from top to bottom and hide under a layer of glue with a spatula. The mesh should be without folds, well stretched. We overlap the next row of the grid so that it overlaps the previous row by 5 cm. The mesh must be completely hidden behind a layer of adhesive solution so that it is not visible. After the laying of the grid is over, we smooth out all the bumps. Let the solution dry and process the surface of the wall with sandpaper. Now you can start decorating.

Internal wall insulation with foam

Styrofoam insulation is the most economical and easiest way to insulate. To create a high-quality thermal insulation system using foam boards, no special professional skills or sophisticated equipment are required. Foam boards are light in weight, so the cost of their transportation is minimal. Expanded polystyrene is a cheap and very effective insulation that is in great demand.

How to work with expanded polystyrene when insulating the wall of a building from the inside, its main advantages and disadvantages, how to prepare a wall for thermal insulation, stages of work.

The content of the article:

Insulation of walls from the inside with expanded polystyrene is one of the simplest and at the same time reliable ways to preserve heat in residential and non-residential premises. Every year, the thermal insulation service increases in price, but for many categories of our fellow citizens it is still in demand. Among the huge variety of insulation materials on the market, expanded polystyrene does not lose its relevance, because each of us is well acquainted with it. We will analyze what other advantages it has, and also consider the features of its use for internal wall insulation.

Features of thermal insulation of walls from the inside with polystyrene foam

The main problem in carrying out internal work can be called the phenomenon of increasing freezing of the insulated wall. This is due to the fact that the dew point, which acts as the center of condensate accumulation, shifts to the inner edge of the structure, and sometimes even comes to the surface. The spread of condensate leads to the destruction of not only the finishing layer, but also the wall itself. The result is high heat loss and high humidity in the room.

Traditional expanded polystyrene is produced by manufacturers in the form of even, smooth and dense sheets, the dimensions of which can be either 100 by 100 or 100 by 50 cm.

The installation of this material requires the utmost attention. But you still can't get rid of the problem of joints. The main solution should be the tightest possible fit, and the ends of adjacent sheets are coated with sealant for a better connection with each other.

The master applies a solution for fixing this material in a special way. Traditional cakes, which are suitable for outdoor work, are not suitable for internal thermal insulation. They will lead to the appearance of gaps in which condensate will subsequently accumulate. Therefore, when it is necessary to insulate the walls from the inside with polystyrene foam, the adhesive mixture is applied to the entire sheet and its uniform distribution is achieved. This will ensure that it adheres securely to the wall surface.

In order to economically and correctly distribute the adhesive solution, we use a special needle-type paint roller. It seems to pierce the surface of the material, which gives a more reliable connection. It is for this method of fastening that it is important to ideally prepare the working wall plane. Ordinary cement mortar is not very suitable for these purposes.

It is advisable to acquire mixtures that form a moisture-proof layer. The same applies to anchor fastenings - instead of them, T-shaped profiles should be preferred, which will be fixed not only to the floor, but also to the ceiling. This is necessary, especially in cases where mesh reinforcement will be applied over the insulation.

Advantages and disadvantages of wall insulation with polystyrene foam

Among the many advantages that wall insulation from the inside with polystyrene foam has, we will focus on the following:

The cheapness of the material, which makes it available to a wide range of users.
According to its characteristics, it is not inferior to expensive and fashionable heaters.
Polyfoam has excellent thermal insulation properties.
Very simple and accessible in terms of installation.
The material is lightweight.
It is easy to dock during insulation, simply removing the excess with a knife.
Characterized by durability.
Maintains a comfortable temperature.

And that is not all. Customers may ask if classic foam is suitable for arranging a heat-insulating layer. Of course, yes, but extruded polystyrene foam for wall insulation from the inside surpasses traditional foam in its qualities: it has higher strength, is easy to install, because it does not crumble and can be cut with an ordinary sharp knife, it has a lower water absorption, which guarantees it a long and efficient operation.

Among the negative qualities of such a heater, experts note the following:

Expanded polystyrene can be called, without exaggeration, a rather fragile material.
When warming, they need to provide additional ventilation in the room.
The material should be protected from direct sunlight, the action of which leads to its scattering.
Refers to combustible materials and, in addition, releases toxic substances when ignited.

Despite the fact that, according to manufacturers, the operational period of expanded polystyrene can reach 10-20 years, much depends on the observance of technological nuances during installation. If it was somehow violated, the service life will immediately decrease.

One of the dangers is the appearance of fungal mold on the walls of rooms insulated with foam. It serves as a source of allergic manifestations. This happens because the dew point shifts to the middle of the wall, and dampness and humidity come into the house behind it.

Styrofoam fire releases dangerous and toxic gas. Despite the fact that the material does not burn, it begins to melt under the influence of high temperature. In this case, not only suffocating black smoke enters the air, but also a gas called phosphene, which causes paralysis of the respiratory tract.

The technology of internal insulation of walls with expanded polystyrene

After you have chosen the technology for attaching polystyrene foam and calculated all the costs, you can begin insulation work. It is necessary to observe a number of nuances that can affect the quality of the finished coating. Experts do not recommend saving on materials or skipping individual work from the technological chain.

Preparatory work before insulation from the inside of the walls

First of all, the wall to be insulated must be leveled. Even an unskilled builder understands that on an uneven surface one should not expect high-quality fastening of the insulator and all subsequent layers. Ultimately, this will lead to heat loss and inefficient spending.

If we are talking about a newly built building, then the wall should be plastered first. After that, it is treated with primer paint and any irregularities are repaired with putty. In other cases, the same actions will be required, only without the mandatory application of a plaster solution.

It's a different story when it comes to renovations. Until the moment you insulate the walls from the inside with polystyrene foam with your own hands, be sure to remove the old paint or wallpaper. After that, each wall is carefully diagnosed for the detection of recesses, cracks or chips in the concrete.

Any defects are eliminated with plaster mortar or store putty. In some cases, you can resort to mounting foam. After that, the surface is carefully leveled. As soon as the working wall is completely flat, it is again treated with ground paint.

However, before laying the foam sheets, we still need to take care of waterproofing. This is explained simply: in any case, at low air temperatures outside the building, moisture will pass through the wall and get on the insulation, under its influence, polystyrene foam loses its characteristics, and over time it simply begins to rot. The waterproofing material will just serve as protection against moisture.

After the waterproofing is installed, proceed to the installation of insulation. If in former times its sheets were fastened necessarily using screws and dowels, then modern industry has simplified this process. There are special adhesive solutions that greatly facilitate installation work.

Thus, the main requirements that must be met before the start of thermal insulation:

The surface should be as flat and dry as possible.
The wall must be separated from the heat-insulating layer by waterproofing and vapor barrier.
The insulation itself should not have slots, joints or any gaps.
It must have the maximum moisture resistance.

From the tools you need to prepare such as a knife, sandpaper, gloves, a hammer, a puncher, a pencil, a ruler corner, a container for diluting glue and other liquids.

Instructions for mounting polystyrene foam on the walls

You should start with the calculations of the necessary material. The value of the height of the walls is taken and multiplied by the width. From the value obtained, it is necessary to subtract window and door openings, but add a small tolerance due to slopes. As for the type of insulator, it is not at all necessary to chase the thickest foam. It will be enough to make a choice in favor of the 10-centimeter PSB-S-25.

As for the glue, it is worth giving preference to a special one that is designed for such materials. Although it costs more, it will be able to provide the necessary result, namely, a heat insulator securely fixed on the wall. To carry out work on the reinforcement of polystyrene foam, you will need a separate type of glue, so you will also have to worry about this in advance.

From other materials and devices, we need special umbrella dowels, which provide additional fastening to the wall. By the number of them, you need to take about 5 pieces for each attached sheet. The length of the fastener should be 2 times thicker than the thickness of the sheet itself. To carry out the reinforcement of glued polystyrene foam, you need to stock up on a mesh with cells of 5 by 5 cm. Corners and slopes will be glued with special paint corners.

If such a cycle of work will be carried out for the first time, then it is better to take care of a small excess of materials. This will insure against the need for repeated trips to the store.

Do-it-yourself insulation of internal walls with polystyrene foam is carried out in the following order:

A new sheet of material is taken, on which a layer of glue about 10 mm thick is spread. The composition must be distributed evenly over the entire area.
It is necessary to glue products to the wall in a checkerboard pattern, like laying bricks. The size of the gaps should be minimal.
After gluing, we will fasten the sheets with dowels-umbrellas. They are driven into each corner of the slab, and one is attached in the very center. This can be done immediately for each glued product or in total for all. In this way, it is possible to achieve a tight fixation of the heat insulator.
Now you can proceed to the reinforcement stage. There is another rule here: in order for the mesh to hold well, it must be filled with a thick layer of glue. Before gluing, you can slightly moisten the wall by spraying it. For reinforcement, you should buy a mesh with a certain density index, not less than 140 g / m 2.
After you fix the mesh to the foam, it is smoothed over its entire area. At all corners of the product are attached with the same glue protective corners.

It is necessary to carry out all types of insulation work at a temperature of at least + 5 ° С. Be sure to achieve complete drying of the wall, as well as an acceptable level of humidity. At each stage, the surface must be dried, for which you can use heaters or heat guns, building hair dryers.

Final finishing of the wall insulated with polystyrene foam

Giving the final appearance to the insulated wall is the last stage of the work. This process can be attributed to the longest and most laborious in the entire algorithm. Since a single layer of plastering is not enough, work can be carried over to the next day. The last layer must be made as neat and even as possible, since with its help we create a base for high-quality wall decoration.

After the leveling layer dries, it is cleaned with sandpaper in order to eliminate all irregularities. The wall is covered with primer paint, which is able to provide perfect adhesion between the heat insulator and the finish coat.

Plastering work on an insulated wall should begin with the choice of a mixture that is designed to cover polystyrene foam materials. Among the most famous products are Ceresit, Worth, Ecomix. They are a universal mass that forms a protective layer on the insulation. The mixture is used not only for leveling the wall, but also for gluing the grid. The material consumption will be approximately as follows: 4 kg per 1 m 2 for the mesh and 6 kg for the protective final layer.

The use of a mesh is necessary so that the leveling mass can adhere to the surface of the expanded polystyrene. The denser the product, the stronger the whole structure will turn out, but it will be more difficult to paste over the corners with it. To glue the corners, we cut a strip of mesh with a length equal to the length of the slope and a width of 30 cm. The universal mass is smeared with a spatula on the corner, after which a piece of mesh is applied and ironed thoroughly.

To install the mesh, it is cut into pieces of about 1 meter. The mass is applied to the work surface, the product is applied to it and smoothed from top to bottom, as well as in the direction from the center of the wall. In the process of smoothing on a spatula, you need to take a little mixture to completely close the structure. This is how each vertical strip is glued, and the joints are made according to the “overlap” principle, so that each one partially enters the neighboring one.

After the mesh dries, it is grouted. To do this, you need a plastic grater, on which a piece of emery cloth is fixed. It is necessary to overwrite counterclockwise, with careful circular movements.

It remains to fix the leveling layer, for which we will use the same universal mixture. The mass is thrown onto the wall with a spatula, while its thickness should be approximately 3 mm. The dried finish layer is subject to grouting, in the same way as in the case of the mesh.

Its grouting should be done no earlier than one day, but no later than four days after application. It is at this stage that the surface becomes as smooth and even as possible. Now it can be painted with colored primer paint, based on the preferences of the customer.

How to insulate walls from the inside with polystyrene foam - look at the video: