Plastering walls from aerated concrete inside a residential building is one of the best options preserve the heat-saving properties of the enclosing structures.

The use of aerated concrete blocks as building material- practically perfect option for low-rise housing. Private houses built from them have such advantages as low weight (and, therefore, do not require the construction of too strong foundations), low thermal conductivity and an affordable price. At the same time, an increase in the moisture content of blocks leads to a deterioration in its heat-saving characteristics, and to a heavier structure. To protect the walls, aerated concrete wall plaster is required - sometimes external, but most often internal.

Finishing features

When performing internal plastering of aerated concrete, it is worth considering the features of this material and the differences from more traditional brick, concrete and stone. First of all, this applies to the cellular structure of the blocks, which were originally considered a heater, and only then they began to be used for the construction of the walls themselves. Due to the open structure, which is the result of the addition of a special blowing agent (aluminum powder) to its composition, aerated concrete has high level vapor permeability. This characteristic is one of the main ones when choosing a material and finishing method.

Regardless of the choice of how to plaster aerated concrete, finishing work should begin from the inside, and only then deal with the facade of the building. Changing the order and performing first external, and only then internal finishing, leads to too high humidity in the room. Outgoing (especially when severe frost) steam condenses in the walls at the border of aerated concrete and finishing. The moisture created in this case can lead to cracks in the plaster and the falling off of its pieces. That is why the interior finishing work is performed in the first place.

Choice of method and material

While doing finishing works Plastering of aerated concrete walls is performed in one of two main ways. The meaning of the first is not only to preserve, but even to increase the vapor permeability of the blocks. The second, on the contrary, assumes complete vapor barrier. The advantages of maintaining vapor permeability lie in the creation of an optimal microclimate, and the option with insulating the walls - in the safety of the exterior finish, which is not affected by steam escaping from the building.

Unsuccessful options

It is not recommended to use cement mortar for plastering aerated concrete inside. The first reason is that smooth blocks do not allow the material to stick. The cement layer quickly falls off and the finishing has to be done again. Secondly, the best option for plastering blocks is considered to be a material with the same or greater vapor permeability index compared to aerated concrete. For cement, this characteristic is much lower, which does not allow maintaining normal conditions inside the building. For the same reason, the answer to the question whether it is possible to plaster expanded polystyrene or expanded plastic will be negative.

Besides, cement-sand mortar It has high humidity due to the significant amount of water required for its preparation. Aerated concrete structures with high rate water absorption, absorb liquid from the finishing material. The quality of the mortar, which requires uniform drying for curing, decreases, as does its ability to adhere to walls. As a result, cracks appear on the plaster, and its quality decreases, bringing the next repair closer.

You should not choose a special adhesive mixture for finishing aerated concrete inside. Despite the fact that it is designed taking into account the peculiarities of the material, it is advisable to apply the glue in a thin layer, which is not suitable for protecting against cracks. As soon as the vapor permeability of the block is broken, on the surface of a thin-layer plaster for aerated concrete from adhesive mixture will appear immediately;

• cracks;
• seam marks;
• and even mold.

Breathable finish

Choosing the option of finishing walls made of aerated concrete indoors while maintaining the natural vapor permeability of the material, they use plaster mixes on gypsum and gypsum putty. Due to the slaked lime and perlite sand in their composition, water vapor easily penetrates through the plaster layer. Another advantage of this option is that there is no need to prime the surface of the enclosing structures.

Slightly less often, mixtures containing a high content of such natural materials with a high degree of vapor permeability:

• chalk;
• marble;
• dolomite;
• limestone.

Their vapor permeability indicators are higher in comparison not only with the internal, but even with external plaster, and the dried solution is easily rubbed, acquiring ideal whiteness. The resulting coating has excellent durability and allows further finishing.

You should know: Due to the porous structure of concrete, it is recommended to putty it only after applying a primer. If this is not done, cracks will appear on the putty.

Vapor barrier finish

When choosing the finishing of aerated concrete indoors with the elimination of vapor permeability, that is, with complete insulation of the enclosing structures, one of the materials is polyethylene film. The easiest and fastest way to fix it on the walls is to lay it under one of the finishing layers. However, the speed and ease of installation does not matter if condensation forms on the structures finished in this way and the plaster swells. More suitable option in order to plaster aerated concrete inside the house, a sand-cement mixture will become, in the composition of which there are no additives in the form dolomite flour or lime. With its help, vapor permeability decreases several times, but the possibility of plaster peeling increases after a while.

Additionally, to reduce vapor barrier, without too much affecting the quality of the finish, will help:

• oil paint, which covers the walls on the final stage works;
• applying 3-4 layers of special composition as a primer for aerated concrete;
• using adhesives before applying the plaster. In this case, you can even do without the use of putty. Adhesives have the same properties and, in fact, replace it.

Features of work

To finish the aerated concrete with your own hands, you need to use the same tools that are needed for ordinary plastering. To prepare the solution plaster mix need special container- such as a plastic tank or a bucket made of the same material. They should be large enough to accommodate all the ingredients for the plaster.

Water is added to the dry mixture that is poured into the tank. The mixture is mixed to the desired state with a drill with a nozzle or a construction mixer. As a rule, it is possible to determine the proportions of material and liquid by the inscriptions on packages with building materials.

Plaster of aerated concrete walls is applied inside the room by "throwing" with the help such tools as:

• Master OK;
• plastering bucket;
• trowel.

The surface is rubbed with a trowel. And the excess solution from the wall can be removed with a half-scrubber. It is required to level the wall with the help of beacons, and to tighten the plaster mortar is the rule. Another tool that you cannot do without when performing work is a rail length from floor to ceiling. With its help, defects on the walls are checked - deviations of no more than 6-7 mm are considered permissible.

Plastering process

Having decided the question of how to plaster the walls of aerated concrete, they proceed directly to the performance of the work. They begin, like all surface finishing methods, with the preparation of the base. The blocks are cleaned of the mixture residues and the seams between them are closed. Before plastering aerated concrete indoors, a layer is applied to the porous surface.

Solutions for aerated concrete blocks, assuming the preservation of vapor permeability, also
they are able to pass steam, differing not only in high water-repellent properties, but also in the ability to strengthen the enclosing structures. The primer is required to be applied not in one layer, but in several. In this case, it must be taken into account that a new application is carried out only over a completely dried old one.

1. Anchoring the mesh for block reinforcement. Because of big size of each aerated concrete product, the value of their adhesion to finishing materials is small. And to increase the strength, reinforcement with a material is used, which contains an alkali-resistant fiber. Can be used for a gas block mesh "chain-link" with a small cell size. For its fastening, the use of 120 mm nails is required, which are well driven into aerated concrete;
2. If reinforcement is not used (it is necessary to decide whether a mesh is needed when plastering aerated concrete at the stage of choosing materials), the adhesion of the finishing layers to aerated concrete is ensured by grooves intersecting with each other, made by any suitable tools - for example, a hacksaw.
3. Application of the first layer of material (pre-selected, the better to plaster aerated concrete) on the mesh. In this case, the "spraying" technology is used, which ensures complete filling of the aerated concrete cells, and the leveling of the first layer is not carried out, which improves the adhesion to the next layer of plaster.

When applying the priming solution over the rough aerated concrete plaster, it is required to maintain the layer thickness at the level of 4–5 mm. The addition of slag sand to the primer is recommended. When applying the finishing plaster layer, it is advisable to use building material, which contains fine sand, which increases the smoothness of the blocks.

The construction of houses from gas silicate blocks is one of the most promising areas in the field of private construction. In particular, aerated concrete blocks have become very popular, during the production of which special additives are introduced into the composition of the solution, causing abundant gas formation. As a result, aerated concrete has a pronounced open porous structure, which determines its significant advantages over other materials for masonry walls.

However, such a structure of aerated concrete also brings a number of difficulties in finishing the erected walls. This requires a special approach, both in terms of the sequence of work and the materials used. In addition, the plastering of aerated concrete walls inside the premises will also depend on their planned exterior finish.

What is the "capriciousness" of aerated concrete in matters of finishing, and in what ways can these problems be solved - this publication is devoted to these issues.

Features of aerated concrete

But on the materials for the work, you should go through in more detail.

• The open porous structure of aerated concrete will not allow you to limit yourself only to filling the walls - a thin layer simply will not stay on such a surface. Therefore, even if the wall is laid out with the highest precision and does not require special adjustments to its plane, you still cannot do without plaster. And on the aerated concrete wall you will have to "throw" a layer of at least 5 mm.
• Such a layer will be susceptible to cracking and shedding (the adhesive features of a highly porous structure are affected), if not reinforced with a reinforcing mesh. If on others wall materials the use of a reinforcing mesh is desirable, then in the case of aerated concrete, this condition should be considered as mandatory. The mesh is best of all - fiberglass, resistant to an alkaline environment, so that over time it simply does not dissolve in the thickness of the frozen plaster mass.

The use of reinforcing fiberglass stacks is a prerequisite for high-quality plaster

• Aerated concrete walls are distinguished by high moisture absorption. As they say experienced painters This stuff literally "drinks" water. It would seem that this is not bad for good adhesion, but it turns out just the opposite. Aerated concrete "sucks" moisture from the applied material, which causes its rapid drying, cracking and shedding - in the case of gypsum compositions, and disruption of the normal hydration of cement, if plasters based on it are used. In either case, the quality of the coating will be low, and the finish itself will be extremely short-lived.

It is important to find the right "moisture balance", otherwise the work will be of poor quality

On the other hand, excessive oversaturation of aerated concrete with water is also fraught with negative consequences... Yes, and such a wall is very difficult - the thrown solution begins to "creep", the layer becomes loose or heterogeneous, etc.

Which exit?

- you can use special plaster mixes specifically for aerated concrete, intended for interior finishing work. Their component composition, when properly mixed with water, in accordance with the instructions, is fully optimized for the characteristics of such a surface and sometimes does not even require preliminary priming of the surface. All this is necessarily indicated by the manufacturer in the instructions for use of the composition.

- the use of special primers deep penetration... Here, however, the balance is also important - the oversaturation of aerated concrete with impregnating compounds can lead to the opposite effect, since the absorbency of the surface for applying plaster on it is still important.

In both cases, professional masters do not advise to immediately give a thick outline - it is best to limit yourself to a minimum layer in which the reinforcing fiberglass mesh is embedded. Such an interlayer does not require a large amount of moisture, it is much easier to “rub” it into aerated concrete with effort, and the reinforcement will create a solid foundation, without cracks. But after drying such a substrate, you can safely proceed to the main plastering on the lighthouses.

Video: the work of a master for plastering an aerated concrete wall

As already mentioned, the composition of the plaster mixture directly depends on whether it is necessary to leave its high vapor-permeable properties to the wall, or, conversely, to make it as difficult as possible for moisture to penetrate into the material.

• In the first case, preference is often given to special gypsum-based plaster compositions, which often include light perlite sand. Usually, the instructions for the use of the composition indicate that it is combined with aerated concrete (gas silicate) walls. A classic example of such mixtures is Plaster or Osnovit - Gipswell plasters.

Manufacturers claim that for the application of such compositions, a reinforcing mesh is not even required. But in the case of aerated concrete, it is better not to ignore this moment.

• Silicate based plasters are very well suited for aerated concrete, especially in terms of vapor permeability. However, such a wall decoration will significantly limit the owners in choosing a topcoat, since silicate mixtures are incompatible with many other organic-based decorative compositions - acrylic, silicone, latex, etc.
• Cement-lime-based plasters have been developed especially for aerated concrete or similar surfaces. Their composition is optimized precisely for such surfaces that do not even require preliminary priming before plastering. An example is "Baumit HandPutz" plaster or a mixture from a set of a whole "ensemble" of mortars specially developed for aerated concrete "AeroStone".

The composition of such plasters includes cement, construction lime, special lightweight aggregates and plasticizing additives, fine-graded refined sand. Such a coating has good vapor permeability, and can be used for both external and internal works on aerated concrete.

• If, in the plans of the owners of the house, to achieve the minimum vapor permeability of the walls from the inside, then they usually resort to the use of cement-sand plasters without the inclusions of lime or dolomite chips (flour). Naturally, the composition usually includes special plasticizing additives that stifle the adhesion of the created coating to a porous base.

All specialized mixtures for gas silicate surfaces have one common drawback - they are quite expensive, and with large volumes of work, such internal plastering of walls will result in a hefty amount. But this is only a preliminary alignment, without taking into account finishing! Is it not possible to do something simpler, use more affordable mixtures or generally ordinary home-made plaster solutions, for example, based on cement and sand?

It is possible, but such a finish can only be performed with high quality experienced master, to whom his long-term practice allows "by eye" to determine the condition of the wall, and the need for its moistening or priming, and the exact component composition of the plaster. And without the experience of such work, making a mistake on an aerated concrete surface is as easy as shelling pears, and all the work will be done down the drain.

However, you can recommend one very interesting way preliminary preparation gas silicate wall to further. If everything is done in accordance with the recommendations, it will be possible to apply almost any plaster composition without fear of cracks, mortar creeping, its rapid drying, or, conversely, excessive waterlogging of the wall.

How can you properly prepare an internal aerated concrete wall for plastering?

For work, you will need the usual, the most inexpensive of all the glue in the store, for ceramic tiles, fiberglass mesh, deep penetration soil (normal, type Ceresit CT 17). And then it will be possible to plaster with any composition on a gypsum, cement, cement-lime and other basis. In particular, the usual cement-sand mixture is also quite suitable, even in a ratio of 1: 5.

It is quite difficult to determine in advance the amount of plaster mixture to put the wall in order, since it depends on the condition of the surface, its evenness, the presence and depth of level differences both vertically and horizontally. But our calculator will help to determine the amount of materials for the preparatory cycle.

It takes into account the conditions for priming the surface in two layers, and with the dilution of the primer with water during the initial application, and the creation of a preparatory reinforced adhesive layer 5 mm thick. Calculations will show the result with a 15% margin "just in case" adopted by builders-finishers.

The calculation is carried out for rectangular surfaces, minus window and door openings.

Recently, aerated concrete has been used in the construction of private houses. The material has earned wide recognition due to its positive qualities... Such material is produced in rather voluminous blocks of light weight, so construction is being carried out at a rapid pace.

Peculiarities

The foam material perfectly retains heat, therefore, you can significantly save on insulation.

The abundance of pores allows the blocks to "breathe". The bad news is that they absorb moisture. If in the warm season the water dries up without consequences, then in frost the moisture absorbed into the building material will inevitably lead to the formation of cracks.

Plastering aerated concrete will prevent the penetration of water into the block, preserve its integrity.

For high-quality performance of work, it is necessary to take into account the features inherent in the material being processed. Not all aerated concrete blocks are the same - their structure may differ. For example, the outer surface is different.

Plastering sawn aerated concrete is possible without pretreatment. The formed block has a smooth hydrophobic layer on the outside. It is problematic to apply plaster on such a surface - to increase adhesion, you need to grind the treated side with a wire brush.

We must not forget that the degree of vapor permeability increases in the direction from the inner surface to the outer, therefore, the facade finishing should be done twice as thin as the inner coating.

Before plastering aerated concrete walls after construction, at least six months must pass... During this time, the walls will completely dry out, they will wear out excess moisture falling into the blocks during the construction of the structure.

The outer surfaces of the walls can be plastered decorative materials, compositions for subsequent painting can also be used. Exterior decoration sometimes serves as additional insulation. In cold climates, plastering plays a significant role in keeping indoor warmth.

For aerated concrete, you should choose a plaster with optimal parameters. Finishing material is obliged to protect the walls from destruction on both sides.

Due to the porosity, the aerated concrete received such characteristics as thermal insulation and vapor permeability.

Correctly executed finishing:

• helps to maintain useful qualities blocks;
• does not allow condensate to accumulate inside the pores;
• prevents mold and unwanted damage.

Types and compositions

It is impossible to finish aerated concrete walls with ordinary cement mortar. Standard solutions have too high a density and therefore do not adhere well to blocks. Due to poor adhesion, after a short time, cracks appear on the walls, which leads to peeling of the plaster layer and exposing the walls.

Special "breathable" mixtures with a so-called vapor-permeable base:

• pass steam freely;
• create a positive indoor climate;
• protect walls from moisture accumulation inside them.

The following requirements are imposed on plasters for finishing aerated concrete:

• resistance to precipitation and ultraviolet light, to rapid and frequent changes in outdoor temperature;
• sufficient density;
• possessing high adhesion;
• the presence of vapor permeability;
• compressive strength;
• good thermal insulation;
• decorative appearance.

Good plaster meets all of the listed requirements. It is easy to apply, looks great and lasts a long time on the walls.

If the facade is not processed, the aerated concrete will first darken, then it will begin to deform, and its outer part will flake off.

Exterior plasters differ from those used for interior decoration of aerated concrete blocks. The former are more expensive, the latter are cheaper. The main difference lies in the moisture resistance of the hardened mixture. If for external walls this indicator is essential, then for interior decoration you can do without it. The exception is plaster for rooms with high humidity such as bathrooms.

By their composition, facade plasters are divided into the following types:

• acrylic;
• silicone;
• silicate;
• lime-cement.

None of the species can be considered ideal - each species has its own strengths and weak sides... For example, the vapor permeability of acrylic-based plaster is low, but it has excellent decorative properties. The finish is thin-layered, but very durable. The layer retains a flawless structure for a long time.

It is advisable to use acrylic plaster when applying good insulation to internal walls.

The basis of silicate plaster intended for aerated concrete is liquid potassium glass. The vapor-permeable coating is resistant to moisture, perfectly resists abrasion and dirt. Durability is a quarter of a century. The disadvantages include the limited color gamut.

Silicone compounds contain organosilicon polymers and resins. The coating is very durable. Unlike other types, silicone plaster retains its elasticity after hardening. Cracks do not appear on the finishing layer even after the blocks have shrunk. Due to fillers, plaster is given various colors and shades.

The advantages have a significant impact on cost - silicone compounds are the most expensive.

Lime-cement mortars are characterized by vapor permeability and strength. They lack elasticity and water resistance. The problem is solved by introducing special additives into the mixture., and experimenting with fillers, you can get different colors.

Ready-made mixtures are equipped with everything you need - they can be used without preliminary preparation and introduction of improving components.

For internal work, completely different compositions are used. At the heart of the plaster for the treatment of aerated concrete indoors, there is gypsum.

Before starting work, the blocks should be primed.

The plaster is applied on a leveled surface, free from build-ups, dirt and dust.

The work is performed in several stages:

• padding;
• applying the first layer of plaster;
• installation of a reinforcing mesh;
• applying a second layer of plaster.

Wallpaper can be glued to the treated wall after the material is completely dry... Decorative finishing can be done on request. The decor appears when fillers in the form of marble chips or perlite are introduced into the gypsum mixture. Covered gypsum solution the wall can be painted.

Preparation

It is very important that the aerated concrete walls are prepared for the application of the finishing layer.

Despite the fact that the outdoor and interior walls are used in different conditions, there are General requirements according to their preliminary processing:

• both inside and outside the walls should be even;
• for both sides, the plaster should be selected with the maximum adhesion capacity;
• applying the solution to the mesh is desirable on both sides;
• the master will need a container for mortar, a trowel, a plastering bucket, a grater.

In order for the plaster to fit well on the gas blocks, the latter should be evenly moistened... For this, the usual tap water and the simplest sprayer.

If there are chips or cracks, then you will have to pick up a trowel and use a solution to eliminate the flaws. The cementitious mortar will be an excellent restorative material if the recesses are first primed.

With the help of beacons, the surface of the walls of the room is displayed in one plane, after which you can start performing the main work.

First, finishing is carried out inside the premises and only then outside - in otherwise excessive moisture builds up inside the house.

Application technology

From correct execution technology depends on the appearance of the treated walls and the durability of the decorative layer.

Below is the sequence of processing the outer surfaces of aerated concrete walls.

First you need to inspect the blocks: eliminate all irregularities, clean the cracks, expand and putty with ordinary mortar.

They act in the same way when identifying chips and potholes in each gas block. The listed preparatory work you can do it yourself - it's not difficult at all.

Those who dare to do basic work with their own hands without the appropriate skills need:

• acquire tools;
• follow the technology for performing plastering;
• not be afraid of heights (part of the time will have to be spent at a decent height in the forests);
• have free time;
• have physical strength.

In order for the plaster to fit well and not lag behind, the gas blocks are primed after cleaning with a metal brush.

A special primer is required - it must contain acrylatesiloxane. This ingredient protects the wall from moisture and increases adhesion. At the same time, the composition does not interfere with the "breathing" of the gas block.

The priming operation in accordance with the technology should be carried out in dry weather and temperature environment about +15 degrees. It is advisable to process the walls from the side where there is no direct sunlight.

The next step - mesh tension - is started after the final absorption of the primer.

A mesh made of alkali-resistant material is suitable for gas blocks... Any other material will simply dissolve over time, which will negatively affect the service life of the finishing layer. On the wall, a fiberglass reinforcing mesh is fixed with self-tapping screws so that a small space remains between it and the wall.

Plastic plaster, specially designed for aerated concrete, is applied to the prepared wall in dry warm weather. Mixes for foam building material are quite expensive, but they repel moisture and allow air to pass through. The plaster is applied to the blocks with a wide trowel.... The result should be an even thin layer, the thickness of which is approximately 8 mm.

The processing does not end there. A water repellent is applied to the plaster... After it has been absorbed, it is time to run final finishing... Optionally, it can be decorative plaster or paint. In both cases, the formulations are distinguished by "breathing" properties, guaranteeing the unimpeded passage of vapors from the inside to the outside.

Processing aerated concrete walls inside the house begins in the same way as outside. The inspection is carried out in the same way, and significant deficiencies are canceled. Before puttingty the surfaces, the leveled wall is primed.

Interior decoration performed with special plaster, which includes gypsum and perlite sand.

After completing the work, the walls become uniform, smooth, without the slightest visible defects. The plaster consumption is low, because the layer is applied very thin. This eliminates the need for long-term alignment, which is also important.

Painting interior walls should be produced with paints specially designed for aerated concrete. They can be applied to both ordinary plaster and decorative. Painted surfaces look great - decorative trim retains its original appearance for a long time.

A house that is made of a material such as aerated concrete has many differences from houses in the construction of which foam concrete or brick was used. Aerated concrete is lightweight artificial stone, which has a porous structure and high thermal insulation performance, and this suggests that the plaster for aerated concrete is not used ordinary.

So what kind of plaster should be used when exterior decoration houses made of aerated concrete blocks? What kind of solution should it be, and why can't you use ordinary mixtures?

You guessed it, to complete outdoor protection walls, use ordinary cement-sand plastering solution it is forbidden. The reason for this prohibition is that ordinary plaster lower vapor protection parameters than aerated concrete blocks that make up the building.

There is an unspoken principle that any multi-layer breathable wall structure must be built in such a way that each subsequent layer has a higher vapor permeability than the previous one. The closer to the street - the greater the porosity.

As an exception, it is possible to allow all layers to have a given indicator of the same level, but this is not encouraged.

For work with aerated concrete blocks you should use exclusively special facade plaster for aerated concrete, which is called that.

How to plaster aerated concrete

Plastering aerated concrete walls is done as follows: apply facade plaster for aerated concrete blocks to the walls. This material is a special porous plaster mixture that has high vapor-permeable properties.

It is advisable to apply the plaster to the mesh so that it does not crack and fall off when it dries.

Plaster, which is used for finishing buildings made of aerated concrete, must have the following necessary qualities:

• bulk weight - about 0.8 kg / dm³;
• fraction within 2 - 4 mm;
• it must be a light plastering mortar belonging to group P I plasters;
• resistance to compression pressure - class CS I;
• low coefficient of water absorption;
• fire resistance - class A1.

The plaster mixture used for finishing the facade of aerated concrete houses should have good plasticity indicators, it should be easy to process and should be applied over the base. This plaster can be applied in a layer not more than 1.5 cm thick at a time.

Having hardened, given plaster must have good water-repellent properties.

However, nevertheless, it must realize a good transmission capacity with respect to water vapor, and in addition, it must easily cope with the detrimental effects that adverse weather conditions have.

How to plaster aerated concrete video

It should be said right away that plastering work on aerated concrete are not easy and not cheap.

If you have already firmly decided to perform plastering work in a house made of aerated concrete, then use only suitable materials... Do not forget that this is the guarantee that your work will be of high quality, and the plaster will delight your eye for many years.

Approach to plaster internal surfaces aerated concrete walls are somewhat different from similar works on brick and concrete walls.

From this article, you will learn what exactly is worth considering when plastering aerated concrete, how to correctly solve the issue of vapor barrier, and which mixture is best to use. There will also be a step-by-step consideration of the do-it-yourself sequence of work, corresponding the right technology aerated concrete plaster and the ratio of the proportions of the solution.

There are two options: to use materials for a vapor-permeable finish, which will not interfere with the original properties of the gas block, or to use a vapor-barrier finish, which significantly reduces the vapor permeability coefficient of the material.

The first option is good in that the vapor permeability of the walls of the house contributes to the fact that the microclimate in the building will constantly self-regulate, as a result of which life in it will be as comfortable as possible, you will not need to worry about dampness, the formation of fungi or mold on the inner surface of the walls.

By artificially reducing vapor permeability, you will lose all this, but you will get a more durable layer. facade plaster at home.

The fact is that it is the steam escaping from the inside of the house through its walls that is the main reason for the cracking of the outer plastering in the cold season.

This happens due to the "dew point" - when steam, the temperature of which is lower than the air temperature, condenses on the surface of the wall under the layer of external plaster, freezes, and provokes delamination of the cladding.

The choice of the type of plaster mix lies entirely on your shoulders. You should approach it as responsibly as possible, and be fully aware of what exactly you want to receive and what you donate in return.

Reviews of builders responsible for plastering walls from aerated concrete blocks indicate that most customers prefer the option of a vapor-permeable finish.

1.2 Which plaster is better to use?

As you can see from the above, there are two types of plaster mixes for performing work on the walls of aerated concrete inside the building - vapor barrier and vapor permeable.

Vapor-permeable plaster mixes include gypsum-based mixes in proportion. The best option possessing best ratio prices and quality, is the plaster mix "Pobedit Egida TM35", it includes lime.

Aegis TM35 (lime) has all the properties that should be inherent in a high-quality mixture for aerated concrete - minimum weight, high adhesion properties, and strength of the hardened layer.

This mixture is based on gypsum (lime) and perlite sand; it also contains slaked lime, which guarantees the maintenance of optimal vapor barrier characteristics of the walls of the house.

If no additional wall cladding is planned after the plaster layer (painting of the plaster layer is quite common design solution today), then it is worth giving preference to the mixture "Aegis S50", which includes lime.

This material, although it has a slightly lower vapor conductivity, due to the presence of 2.5% concentration of polymer impurities in the composition, guarantees maximum strength and whiteness of the walls, since the mixture is based on lime and gypsum with a fraction size of 60 to 90 μN, which is 30-50 percent less than products in the same price range.

The category of vapor barrier plaster mixes includes materials that include a large number of polymer admixtures are plastic plaster, which has gained wide popularity in recent years.

This also includes ordinary cement-sand plaster, the composition of which does not contain additives in the form of lime, or dolomite flour. To ensure maximum vapor barrier (reduction of steam permeability by 11-12 times), it is required to apply a composition of sand-cement plaster with a thickness of 2-2.5 centimeters. For large areas can be used plastering station for sandy cement mortar... Since plastering the walls with a cement-sand mortar of a room is not an easy task.

There are also more radical inexpensive ways to reduce the vapor conductivity of aerated concrete walls, for example, a lining under a layer of plaster with ordinary plastic film, but this way not recommended for use due to the fact that delamination of the finish from the walls may occur due to the formation of condensation on the surface of the film.

The cost-effective option of vapor barrier plaster for interior walls aerated concrete house is the composition of the usual inexpensive gypsum mix together with vapor barrier primers such as "Pobedit Grunt-Concentrate" and the like.

To achieve the desired effect, you will have to prime the walls of the aerated block 3-4 times, which will reduce the vapor permeability of plaster 10 millimeters thick by almost 5 times.

It is also worth considering the surface finish of the room, for example, plaster, painted oil paint, loses in steam transfer about 30% per composition, gluing wallpaper, especially fleece, contributes to a similar effect.

2 Required tools and work technology

The composition of the tools by means of which the plastering of the inner surfaces of the walls from the aerated block is performed does not differ in any way from the tools for similar work on other surfaces.

You will need a container in which the plaster mixture will be stirred.- a plastic or metal bucket or tank, the main thing is that the size is suitable. For high-quality stirring, a drill with a mixing attachment is required, so it is quite difficult to bring the mixture to the desired consistency with your own hands - clots and lumps will form.

The ratio of the proportion and composition of the dry mix and water are indicated by the manufacturer on each package, do not neglect these recommendations, as they may differ for different plasters.

A mixture of plaster is poured onto aerated concrete using a trowel or a special plastering bucket. Leveling and plastering is carried out with a wire and spatulas.

If you need to apply a thick layer of plaster, over 1 cm, to the wall, it is recommended to purchase plaster beacons for plastering, which greatly simplify leveling and plastering with mortar. You can rub the surface with a plaster float or ordinary fine sandpaper.

If the walls are covered with a thick layer of plaster, then it is necessary to use a reinforcing mesh, which will strengthen the finishing layer and prevent it from cracking and peeling.

Also, the mesh improves the adhesion of the solution and the aerated block, as a result, it is much easier to apply the mixture to the wall surface. It is best to use plaster fiberglass meshes with a mesh size of 5 × 5 mm.

Stages of work:

1. We prepare the surface - we clean the walls from dust, glue residues, and any dirt. Oil stains are degreased with alcohol or gasoline. If the stain cannot be processed, then it is necessary to gouge it out of the gas block, and the resulting unevenness should be repaired with plaster mortar.
2. The walls are covered with a layer of primer. The number of layers is determined by the technology and the requirements for the vapor permeability of the walls, while, to apply the next layer, it is necessary to wait until the previous layer is completely dry.
3. If necessary, a reinforcing mesh is mounted on the walls. The mesh should be installed tightly, without sagging - this is best done using dowels with wide heads.
4. A rough layer of plaster mixture is applied. The mortar is evenly sprayed on the wall with a trowel, and leveled with a rule.
5. After setting the rough layer, it is covered with a primer and carefully leveled.
6. After the rough layer has completely solidified, the wall is plastered finishing mixture, which is leveled with a spatula.

After two days after application finishing putty you can start decorative finishing work.

2.1 Analysis of the features of the plaster of aerated concrete walls (video)