How to plaster walls from aerated concrete. How to plaster aerated concrete - the technology of applying plaster on aerated concrete walls. Self-finishing the facade with plaster

Since its inception in the construction industry, aerated concrete has been used exclusively as a heater. Later it began to be used for the construction of partitions. Then came the understanding that this material can be built bearing walls small low-rise buildings. At the same time, a problem arose - how and with what to plaster the walls of aerated concrete inside and outside the house. Since aerated concrete products leave the production line absolutely smooth, it is useless to plaster and putty them with ordinary solutions. These compositions on the surface of cellular blocks simply do not hold and slide.

It is also impossible to leave aerated concrete unprotected, since, due to its porous structure, it is susceptible to atmospheric influences and temperature changes. The cellular structure of this material endowed it with properties such as high vapor and water permeability. If the first property is useful when executing finishing works, then the ability to absorb moisture should be eliminated. This will help right choice plaster composition. Plastering technology must also be observed. Inside the house, plastering, puttying and screeding on the floor is possible only in warm time year, in the absence of rain and before facing the walls outside. If you do the opposite, and first close the facade, then evaporation from internal "wet" processes will concentrate in the pores of aerated concrete. Subsequently, this can lead to freezing of the supporting structures of the house, the appearance of mold, fungi, and the inner lining will peel off and fall off.

Material selection

For leveling and finishing walls made of aerated concrete blocks, it is best to use plaster mixtures designed specifically for such surfaces. This is indicated by the corresponding marking on the packages. The plaster composition must meet the requirements and provide:

• good vapor permeability and the ability to repel moisture;
• high adhesion to cellular materials and frost resistance;
• resistance to temperature changes, exposure precipitation;
• strength and density of the coating.

A special mixture for aerated concrete surfaces is more expensive than conventional solutions. However, the savings here are not justified. Better pay more than mess up wall structures and redo work. Manufacturers offer a large selection of cement-lime-based and gypsum-based materials. Each solution has its own characteristics due to the ratio of components and the presence of additives, additives. Responsible dry mix application recommendations are based on field trials and can therefore be trusted. quality product easy to plaster and without much practice.

Among the recommended formulations for internal works special attention deserves Rotband plaster from trademark Knauf. Represents the dry universal plaster mix consisting of plaster knitting and special additives. Plastering it is quite easy, even with your own hands, with a little skill. The main property of gypsum compositions is environmental Safety. They meet all regulatory requirements for use in residential buildings and public buildings.

Mixtures based on cement and lime components can be used both inside and outside. However, when deciding whether to plaster with cement mortar inside, conditions must also be taken into account. construction industry, and the circumstances of the future operation of the premises.

External plastering of aerated concrete walls

Walls aerated concrete outside can be plastered only after the completion of all "wet" processes inside the house. This is one of the main rules for the production of finishing works for buildings with load-bearing structures from cellular materials. Because the aerated concrete walls have the ability to "breathe", then it is necessary to plaster the facade with solutions endowed with a high level of vapor permeability. This level should be higher than that of the wall blocks themselves. If this condition is not met, then the plaster will delay the steam leaving the house. The walls inside and outside will become damp with all the ensuing consequences. For decoration can only be used special plaster for outdoor work. The facade finishing technology is as follows:

1. The preparation of the surface of the walls consists in cleaning them from dirt, glue or mortar influxes, sealing seams and large sinks, if any. At this stage, the facade is primed. To improve adhesion, it is necessary to plaster over the primer.
2. Reinforcement. This issue is resolved in each case separately. Some experts believe that it makes no sense to use a reinforcing mesh if thin-layer plaster for aerated concrete is used. Although for greater confidence and reliability of the future coating, it will not hurt to perform reinforcement. To do this, fiberglass meshes with high resistance to alkalis are used, planting them on building glue. Plaster mixtures for aerated concrete have an alkaline orientation.
3. Application of plaster solutions. The process is no different from the traditional execution. If necessary, use lighthouses. Plastering outside can be done manually or using small-scale mechanization (plastering machines or guns with semi-automatic control). The layer thickness is determined separately in each case and can vary from 7 to 15 mm.
4. To give the appearance of the house a more attractive look or a special personality, it is used decorative plaster or coloring. Facade paints are subject to the same requirements for the coefficient of vapor permeability.

To increase the life of the painted coating and maintain comfortable conditions indoors, it is recommended to use water repellents.

Interior wall plastering

It is necessary to plaster the internal surfaces, observing the technology and the sequence of work. The procedure itself is standard, as well as outside. The main requirements relate to the compositions used. Gypsum-based mortars are most often used, less often cement mortars with the addition of slaked lime. But both those and others on the marking should have recommendations for plastering on aerated concrete. Interior finishing will be carried out only on a carefully prepared surface. It is cleaned of excess glue or masonry mortar, dirt is removed, seams are sealed. Before plastering, apply several layers of primer. A material intended for aerated concrete should be used, which has increased water-repellent and reinforcing properties, is approved for use in indoor areas. The technology is as follows: each subsequent layer of primer is applied after the previous one has completely dried.

If a decision is made to plaster on a reinforcing mesh (this the best option and more reliable), then glass fiber products with increased resistance to alkalis should be used. The grid must be firmly and evenly fixed to the plane. Sometimes, instead of reinforcement, notches are made on aerated concrete, which also help to better grip the inner surface and finishing material. Then you can plaster, apply a rough layer of the composition is recommended by the "spray" method. It would be good to use a plaster gun or machine so that the mixture is supplied under pressure and evenly distributed over the reinforcing mesh. At the beginning of the setting of the plaster mass, it is smoothed and primed again. This is followed by the process of applying the finishing layer for wallpapering or painting. Can be plastered with textured decorative compositions recommended for covering walls made of aerated concrete.

Indoor plastering of aerated concrete walls is one of the topical issues in the construction of aerated concrete blocks. The fact is that the material needs to be plastered for a number of reasons, the main of which are the cleanliness and smoothness of the surface, since without additional measures the finishing layer will not hold well. To make it clearer, all these nuances should be understood in detail.

Aerated concrete blocks are characterized by ease of use: the material is warm and light. This facilitates their trouble-free cutting to obtain the required dimensions. However, a completely logical question may arise, why do we need aerated concrete plaster? The fact is that the blocks have a smooth surface, which will not allow you to properly fix the finishing layer. In this case, the choice of plaster mixtures for a gas block should be approached very carefully. Plastering walls from the inside allows you to solve the following tasks:

• protects the surface from sudden temperature fluctuations;
• provides a good level of adhesion to other materials;
• improves thermal insulation characteristics;
• provides vapor permeability;
• protects against moisture.

It should be borne in mind that aerated concrete, like foam concrete, has a cellular structure. Therefore, plastering must be carried out in compliance with the technology. Otherwise, air circulation is disturbed, which leads to a deterioration in the properties of the material. Plastering of aerated concrete walls outside the premises is also necessary. The outer finish protects against the effects of precipitation and the accumulation of harmful gases and dust.

When to plaster?

The gas block, due to its porous structure, easily absorbs moisture, so it must be immediately protected from such a negative impact. If the building material gets wet, there is nothing critical in this. However, you should not allow freezing of water in the block. As a result, cracks may simply appear, the strength will decrease, and there is no need to hurry with the cladding. After the masonry is completed, the walls must dry. Therefore, aerated concrete walls must be plastered only in heat. If the blocks are not laid on a special adhesive mixture, due to which a seam of small thickness is provided, the drying time increases.

There are situations when in the warm season it is not possible to perform finishing work. In this case, the walls are covered with deep penetration soil, which will reduce moisture absorption. In addition, it is recommended to cover the walls plastic wrap. If you follow the advice of the masters, then it is best to finish the walls of aerated concrete during the period when the temperature at night does not fall below 0˚С. Depending on the region, these temperature indicators correspond to the time from the end of March to the beginning of October. From the above, we can conclude whether it is necessary to plaster aerated concrete walls.

Types of plaster mixes

Before you figure out how to plaster aerated concrete walls, you need to decide on the materials that are suitable for these purposes. Building mixtures can be purchased ready-made or kneaded independently immediately before application. To prepare a high-quality solution, it is necessary to use a filler, which is used as sand, gravel, sawdust or stone chips and a binder ( slaked lime clay, gypsum, cement). Water is added to these components. Cement-sand plaster and mixtures, which use slaked lime, cement and sand, are prepared on construction site. To date, clay is used quite rarely.

As for ready mixes for plastering, they are supplied in dry bags. They include:

• cement;
• gypsum;
• sand;
• fillers.

Such mixtures are divided into cement and gypsum, which have their own properties and features in application. Cement-based compounds have a longer drying time, are subject to cracking and sedimentation. Plaster on aerated concrete is applied in a layer 5-10 mm thick.

What mixture to choose?

All mixtures listed above have different properties and when applied to a building material, they act differently. But the question of which plaster is better to plaster aerated concrete walls remains open. First, consider what is used to protect the outer walls, which are constantly affected by precipitation, wind and temperature. As a rule, these are mortars based on cement and sand. They have proven themselves in constant contact with moisture. But the question is - can they be used for plastering aerated concrete? Due to the porous structure, the gas block quickly absorbs moisture, as a result, the cement simply does not have time to gain the necessary strength.

To plaster aerated concrete walls with cement mortar, you need to do it right, i.e. with technology. To prevent moisture from the building mixture from being absorbed into the block, the surface must be prepared. For this purpose, it is covered with several layers of a deep penetration primer, with each layer being completely dry before applying the next. Before applying the plaster, the surface of the wall is wetted. To avoid cracking, it is recommended to use a mesh.

How to plaster aerated concrete inside the house? Gypsum mortars, unlike cement mortars, dry faster, and the surface is less prone to cracking. Mixtures based on gypsum are used for partitions and internal walls, since such compositions are of little use for external use due to the constant influence of moisture. Ready plaster mixtures contain various additives and fillers in their composition, due to which the surface is endowed with resistance to cracking and negative influences.

If there is a choice between the finished mixture and the one made before use, then it should be taken into account that the properties of dry plaster are more predictable. In the process of production of such compositions, the moisture content of the sand, the quality of the cement, the accuracy of all components are controlled. As for mixtures that are prepared on site, it is quite problematic, if not impossible, to check the quality of cement. The main disadvantage of dry plasters is the high cost.

Preparatory activities

To fully answer the question of how to properly plaster an aerated concrete surface, it’s worth starting with the tools that you need to work. In fact, the tools used are the same as for applying traditional plaster mixture. To prepare the solution, you will need a container, which can serve as a plastic bucket or tank. By volume, they should be sufficient to stir all the components.

After pouring the dry mixture into the container, add water. To mix the solution, use a construction mixer or a drill with a nozzle. To achieve the required consistency, the proportions of water and material are determined according to the inscriptions on the bags with dry plaster. To work, you will need the following tools:

• Master OK;
• plaster ladle;
• trowel.

Plastered aerated concrete is rubbed with a grater, while the excess mortar is removed with a trowel. Beacons are used to level the surface, the solution is pulled together using the rule. An obligatory tool for checking defects on the surface of the walls is a long rail from floor to ceiling. The maximum deviation should be no more than 7 mm.

Plastering the surface from the inside

After deciding how to plaster aerated concrete, proceed directly to the workflow. As with any other type of finish, you first need to prepare the surface. Gas blocks need to be cleaned of residues masonry mixture and close the seams. As already noted, a primer is applied before plastering. Internal plastering of aerated concrete walls consists of the following steps:

1. Reinforcing mesh attachment. To increase the strength of the rough finish, you can use a chain-link mesh with a small mesh size. In addition, a reinforcing material with alkali-resistant fiber is added to the composition of the mixture. The mesh is fastened with nails 120 mm long, which are well driven into the aerated concrete wall.
2. If the reinforcement process is not expected, it is necessary to make special grooves for better adhesion of the surface of the block with finishing materials. For these purposes, any suitable tool such as a hacksaw.
3. Applying the plaster mixture on the reinforced base. In this case, they resort to applying the mixture by spraying, when the voids of aerated concrete are completely filled. The first layer of plaster is not leveled, which will provide better adhesion.

A primer must be applied over the rough layer of plaster. It is recommended to add slag sand to the priming solution. It is desirable to apply the finishing layer of plaster using building mixtures with fine sand in the composition, which allows you to get a smoother surface. At the end of the process, the already dried solution is smoothed to make the surface as even as possible. As a rule, smoothing is started 24 hours after application. To make the surface smoother, the blocks are sprayed with water.

The final step is Painting works that involve the use of paints. Materials in this case are selected with a high degree of vapor permeability. After the surface is painted, it is recommended to apply a water repellent, which will increase the durability and strength of the finishing layer. Lifetime interior decoration depends on many factors. One of the main ones is the quality of the materials used, i.e. should be based on cost. The characteristics of the gas block are no less important, because on the surface Low quality even a good finishing mixture will not hold well.

Exterior wall plastering

The most budgetary and common plaster for outdoor use is cement-sand. However, the mixture is not suitable for aerated concrete due to low vapor permeability. For these purposes, mineral, silicate or silicone facade plasters are used. They have nearby required characteristics: vapor permeability identical to aerated concrete, good adhesion, have a beautiful appearance. They start plastering the facade only after the completion of all processes, as a result of which moisture is released inside the room, and the surfaces are completely dry. Gas blocks must be dry, and as much as possible permissible humidity is 27%. If this figure is too high, the water vapor that will escape to the outside will cause peeling of the finishing layer. Facade plaster for aerated concrete should be endowed with the following qualities:

• frost resistance;
• high adhesion to the base;
• increased compressive strength;
• weather resistance;
• decorative.

Plaster for exterior finish can be applied to the walls of the house in a thick layer (thick layer) or thin (thin layer). Thin-layer plaster is characterized by the fact that the material is applied in several layers with a thickness of not more than 10 mm. After preparing the surface and covering with soil, a thin layer of plaster (up to 5 mm) is applied and reinforced with a mesh.

For reinforcement, metal (wire diameter - 0.1 mm, mesh size - 0.16 * 0.16 mm) or fiberglass mesh (mesh size - 50 * 50 mm) is used. Its installation is carried out with an overlap of 50 mm. In addition, the corners of the building are formed, for which a perforated corner with a mesh is used, which prevents the appearance of cracks due to shrinkage of the building. Using a spatula, the mesh is sunk into the applied mixture. Reinforcing material must be installed at the locations of doors and windows. Then the plaster layer is leveled and waiting for it to dry. The second layer is considered leveling, so you need to strive to create the smoothest possible surface. After applied finishing layer and the surface is rubbed with subsequent grouting. It remains to cover the building outside with paint, apply textured plaster and a hydrophobizer.

Aerated concrete is a popular building material that produces strong, durable, warm and resistant to various negative impacts buildings. It has an acceptable cost, and construction with its help can be done by one's own hands, even for beginners. After the construction of the house, it is necessary to decide what materials will be used for finishing work. Initially, the walls are covered with high-quality plaster, so it is important to figure out how to plaster aerated concrete outside and inside the house, as well as how to do this work correctly.

Important! It is not allowed to use the same material for exterior and interior work, since it is important that the resulting coatings are resistant to the existing operating conditions, and they differ significantly on the street and inside the house.

Types of plaster for aerated concrete

Plasters are presented on the market in numerous forms. Not all varieties are suitable for aerated concrete, therefore, the parameters of each material must first be studied, after which it is selected desired option for outdoor use or for indoor use.

Important! Plaster for outdoor use must have high thermal insulation parameters, resistance to moisture and temperature changes, and at the same time must provide good sound insulation and have an attractive appearance.

There are several of the most popular plasters used for aerated concrete. Each option has its own characteristics, so it is important to study the parameters of any type before making a specific choice.

cement plaster

This material is considered to be in demand for carrying out different types works, but it is considered unsuitable for aerated concrete. This is due to the fact that smooth walls are obtained from it, on which cement mortar does not adhere well. Also, aerated concrete has a specific feature to absorb moisture from the solution. Cement plaster has a vapor permeability that is lower than that of walls, so if you use it for finishing work, the microclimate that is installed in residential premises can significantly deteriorate.

Also, the cement mortar has a low adhesion to the surface of aerated concrete. Often, to increase this parameter, lime is added to the composition. If, nevertheless, this particular material is chosen for outdoor work, then a special finishing layer is certainly applied after the plaster has dried, allowing you to get a perfectly smooth surface.

Important! If the vapor permeability of aerated concrete is impaired, this can cause various cracks, mold or traces of seams.

Adhesive for aerated concrete

A special adhesive mixture is presented on the market, designed for application to walls made of aerated concrete. She possesses optimal composition to work with this material, however, its main purpose is the connection of individual blocks, so it is used at the joints.

The material is applied in a thin layer, therefore it is not considered suitable for forming the outer layer on the walls of aerated concrete. It will not be possible to make the best out of it. protective covering, as well as its cost is considered quite high, so it is not advisable to use it for these purposes.

Gypsum plaster for aerated concrete

This material has many advantages for use on aerated concrete walls. Its pluses include:

• fast drying, so after the layer hardens, you can quickly proceed to subsequent finishing work;
• the coating does not shrink;
• with proper application of plaster on aerated concrete, the formation of a perfectly smooth surface is guaranteed;
• at the expense High Quality material, there is no need to apply a top coat after the layer has dried.

But this material is not without certain significant shortcomings. These include:

• not too good vapor permeability ();
• to obtain a quality mixture requires enough a large number of water;
• if moisture or snow gets on the coating, which is not protected by any additional layer, it will quickly get wet;
• often ugly and clearly visible spots appear on surfaces, therefore, for an attractive appearance of aerated concrete walls, you need to use special coloring compositions to eliminate them.

Important! Even with many disadvantages, gypsum mortar is considered relevant for use on aerated concrete walls, but is usually used for interior decoration in rooms with a low humidity index.

Special facade plaster designed for aerated concrete

There is a special material for aerated concrete walls on the market, used for both outdoor and indoor use. The advantages of using it for a house built from aerated concrete include:

• a good indicator of vapor permeability, equal to the vapor permeability of the building material itself;
• excellent appearance of the resulting coating;
• good adhesion to aerated concrete.

It is this material that is most often chosen for finishing a building made of aerated concrete. It provides a high-quality, uniform and durable layer with interesting view. But this material has a rather high cost, so a lot of money is spent on finishing the whole house. For internal walls, the use of gypsum mortar is considered optimal.

Competent choice of plaster for walls made of aerated concrete

When choosing a material intended for plastering aerated concrete walls, the basic requirements and criteria that it must meet are taken into account. To get really high quality and optimal coverage, plaster must have:

• good indicator of vapor permeability;
• resistance to low and high temperatures;
• resistance to exposure to significant humidity;
• resistance to the appearance of cracks, mold or other negative factors on the created surface;
• the duration of the viability of the solution, and this factor is most important for people who independently perform the process of applying plaster, and at the same time do not have experience with such solutions.

Important! For each buyer, an additional important parameter is the cost of the solution, and it must correspond to its quality and properties, but it is not recommended to pay attention to the most affordable material, since it will not have optimal properties for use on aerated concrete walls.

When is plaster applied to aerated concrete walls?

Aerated concrete is considered a specific material, characterized by good moisture absorption, therefore, immediately after the construction of the structure, it is recommended to take care of protecting the walls from water. Wetting of the material is not considered critical, but it is impossible for the moisture in the aerated concrete to freeze, as this can cause cracks or weaken the walls.

Important! However, one should not rush, since after building a house from aerated concrete, it is recommended to give the material time to dry thoroughly.

Plaster is applied to aerated concrete only in the warm season. If applied during operation cement mixture, then its drying time is considered significant, and this is due not only to its parameters, but also to the fact that a layer of sufficient thickness is certainly created.

If it is not possible to apply plaster in the warm season, then the walls will certainly be covered with a special primer, and it is important to choose a means of deep penetration. The resulting layer reduces the water absorption of aerated concrete. It is allowed to cover the entire structure with polyethylene or other similar material.

From what part of the house does the finishing of the aerated concrete building begin?

There are several options that determine the sequence of actions required to repair a house built of aerated concrete. These include:

• First exterior finish, and after internal. Experts assure that, first of all, it is necessary to protect the building from various negative atmospheric factors that can adversely affect the condition of the house made of aerated concrete. It is not permissible for the walls to gain a large amount of moisture. However, on the other hand, water vapor will accumulate in a house closed from the outside, which will negatively affect the duration of its drying, and there may also be difficulties with internal finishing work. This option is considered preferable for houses built on the banks of various rivers or lakes.
• First, interior finishing work is carried out. This option involves the partial closure of the pores in the walls of the structure of aerated concrete. After interior finishing, it is not allowed to immediately carry out exterior work. The fact is that this can lead to the fact that a large amount of water vapor accumulates in aerated concrete blocks, so moisture will settle in the walls of the house, which can cause their destruction. Therefore, the exterior decoration of walls made of aerated concrete is carried out only after the plaster has completely dried inside the house.
• Simultaneous execution of works. This method assumes that both internal and external finishing processes are immediately implemented. This method is considered the least popular, and this is due to the fact that moisture does not have time to leave the aerated concrete blocks.

Important! Although modern high-quality plasters have good vapor permeability, they dry out for a long time, and this is especially important if the finishing of aerated concrete walls is planned for the cold season, so it is advisable to leave the process until the warm season.

Aerated concrete wall finishing technology

The use of plaster for interior decoration of a house built of aerated concrete is simple and clear process. It is divided into successive stages:

• Foundation preparation. It is important to eliminate significant irregularities on aerated concrete walls. To do this, they are polished with a planer or a special grater. It is allowed to skip this stage, however, in the process of work, a large amount of plaster will be needed, which will significantly increase the cost of finishing.
• A good quality primer is applied. It is not recommended to mix this remedy with water, as this action will lead to a deterioration in the quality of the material. Before applying the primer, it is necessary to clean the base from dust, for which the walls are washed with plain water. The primer is applied after the walls of aerated concrete have completely dried. A specific type of primer is selected in accordance with the particular room you have to work in. For standard rooms, which include a bedroom or a hall, you can choose an inexpensive and universal material, but for the bathroom or kitchen, a blue penetration agent is purchased.
• Installation of beacons. The next stage involves the installation of beacons on the walls of aerated concrete. They are presented in special metal structures, providing a perfectly even coating of plaster. They are usually mounted using a small amount of plaster solution. The distance between them is left in accordance with the width of the rule that will be used to level the solution. In the course of work, it must be used building level, which guarantees the evenness of the fixation of the beacons.
• Plaster preparation. In the process of creating a solution, you must strictly follow the instructions that are attached to the material by the manufacturer. In this case, obtaining the optimal mixture with the desired consistency and uniformity is guaranteed.
• Applying plaster by spraying. It is this method that is used to form the first layer of plaster. The procedure is performed from the bottom up, and the mixture is thrown over the entire surface of the base. Next, the resulting layer is extruded using the rule. When voids form, they must be filled with mortar. It is important that the material does not peel off, because if this happens, the plaster is removed and then re-applied.
• Processing the resulting layer. It is performed only after the mixture has dried. Further, the coating is slightly moistened, for which it is recommended to use a spray gun. Then it is carefully leveled and beacons are removed. The resulting empty spaces are filled with plaster.
• High-quality and even corners are created. For perfect results, special perforated corners made of metal, equipped with mesh on the sides.
• Finishing walls made of aerated concrete. After the final drying of the layer of plaster, finishing begins. To do this, the walls are covered with paints or other finishing materials.

Thus, the process of plastering aerated concrete walls is a fairly simple process that is easily performed by every home owner.

Important! Get perfect result work is possible only with strict adherence to the basic rules and compliance with correct sequence actions.

How to plaster aerated concrete walls outside?

Exterior finishing work for a house made of aerated concrete involves the creation of a sufficiently thick layer. Therefore, several layers are usually applied at once, and reinforcement is also performed. The whole process is divided into stages:

• aerated concrete walls are being prepared, and this process involves the elimination of large transitions and irregularities, which will positively affect the cost of purchasing finishing materials;
• coating the surface with a primer;
• applying plaster, and the thickness of the first layer should not exceed 5 mm;
• reinforcement is made in advance purchased metal mesh equipped with small cells;
• a layer of plaster is leveled along a fixed grid;
• a second layer of material is applied after the first one dries, and it is important to pay much attention to proper leveling and obtaining a smooth and smooth surface of aerated concrete walls;
• a third layer is applied, which, if necessary, is wiped after drying;
• the resulting coating is painted or covered with textured plaster;
• it is treated with a water repellent, and it is usually applied a year after finishing, and the main purpose of this tool is to protect the walls of aerated concrete from moisture.

Video: aerated concrete plaster

Thus, applying plaster on walls made of aerated concrete is a simple process. It is easy to perform both inside and outside the house. To obtain a high-quality result, it is important to carefully study the instructions, as well as clearly follow the sequential steps. Other important point creation perfect coverage for aerated concrete walls, it is the right choice of the plaster itself, which must comply with the operating conditions available on the street or inside the house. The article - "" may also be useful.

The construction of houses from gas silicate blocks is one of the most promising areas in the field of private construction. In particular, it has become very popular aerated concrete blocks, 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. A special approach is needed here, both in terms of the sequence of work and the materials used. In addition, the plastering of aerated concrete walls inside the room will also depend on their planned exterior finish.

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

Features of aerated concrete

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

• The open porous structure of aerated concrete will not allow you to limit yourself to only puttying the walls - a thin layer simply will not hold on to such a surface. Therefore, even if the wall is laid out with highest precision and does not require special adjustments to its plane - you still can’t 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 prone to cracking and shedding (the adhesive features of the highly porous structure affect), if it is 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 - fiberglass, resistant to alkaline environment, so that over time it simply does not dissolve in the thickness of the hardened plaster mass.

• Aerated concrete walls are distinguished by high moisture absorption. As experienced painters say, this material 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, which causes it to dry out quickly, crack and shed - in the case of gypsum compositions, and a violation of the normal hydration of cement, if plasters based on it are used. In both cases, the quality of the coating will be low, and the finish itself will be extremely short-lived.

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 mortar begins to "creep", the layer becomes loose or inhomogeneous, etc.

Which exit?

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

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

In both cases, professional masters do not advise immediately to give a thick sketch - it is best to limit yourself minimal layer, in which a reinforcing fiberglass mesh is recessed. Such a layer does not require a large amount of moisture, it is much easier to “wipe” it into aerated concrete with an effort, and the reinforcement will allow you to create solid foundation, no cracks. But after drying such a substrate, it will be possible to safely proceed to the main plastering along the lighthouses.

Video: the work of an aerated concrete wall plastering master

As already mentioned, the composition of the plaster mixture directly depends on whether it is necessary for the wall to leave its high vapor-permeable properties, or, conversely, to make it as difficult as possible for moisture to penetrate 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 use of the composition indicate that it is combined with aerated concrete (gas silicate) walls. Classic example similar mixtures - plasters "Plaster" or "Osnovit - Gipswell".

Manufacturers claim that the application of such compounds does not even require a reinforcing mesh. But in the case of aerated concrete, this point is better not to be ignored.

• Silicate plasters, based on, are very well suited for aerated concrete, especially in terms of vapor permeability. However, such wall decoration will significantly limit the owners in choosing finish coat, since silicate mixtures are incompatible with many other organic-based decorative compositions - acrylic, silicone, latex, etc.
• Especially for aerated concrete or similar surfaces, cement-lime-based plasters have been developed. Their composition is optimized specifically 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 designed for AeroStone aerated concrete.

The composition of such plasters includes cement, building lime, special light aggregates and plasticizing additives, fine-grained purified sand. Such a coating has good vapor permeability, and can be used for both external and internal work on aerated concrete.

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

All specialized mixtures for gas silicate surfaces have one general disadvantage- they are quite expensive, and with large volumes of work such internal plastering walls will result in a fair amount. But this is only a preliminary alignment, without taking into account finishing! Is it possible to do it easier, use more affordable mixtures or generally ordinary home-made plaster mortars, for example, based on cement and sand?

It is possible, but only experienced master, to which his long-term practice allows "by eye" to determine the condition of the wall, and the need for moisturizing 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 in vain.

However, we can recommend one very interesting way pre-training gas silicate wall to the next. If everything is done in accordance with the recommendations, it will be possible to apply almost any plaster composition without fear for the appearance of cracks, the mortar slipping, its rapid drying, or, conversely, excessive waterlogging of the wall.

How can I qualitatively prepare an internal aerated concrete wall for plastering

To work, you need the usual, most inexpensive of all presented in the store, glue for ceramic tiles, fiberglass mesh, deep penetration primer (normal, Ceresit CT 17 type). 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 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 determine the amount of materials for the preparatory cycle.

It takes into account the conditions for priming the surface in two layers, moreover, 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 the 15% margin "just in case" accepted by builders-finishers.

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

Currently, such building material as aerated concrete is becoming more and more widespread. For the construction of a low-rise building, it is optimal solution. The active use of aerated concrete in modern construction is due to the low cost of blocks, low specific gravity, high thermal insulation properties, opportunity machining hand tools, high fire safety.

However, after completing the main construction works inevitably raises the question of further internal and outdoor decoration at home. Exist different kinds finishes, but it was plaster that was most widely used. Let's try to figure out how to plaster aerated concrete inside the house.

Plaster options for finishing walls made of aerated concrete

In addition to the above advantages, which ensured the popularity of such a building material, it also has disadvantages that require the implementation of a number of additional rules during the finishing work. These disadvantages of aerated concrete include:

• High vapor permeability;
• The ability to very quickly and in large quantities absorb moisture;
• Fragility.

The first two disadvantages have a particularly important effect on aerated concrete plaster. Exactly high level adhesion significantly complicates the process of finishing both inside the house and outside. There are three options for plastering walls made of aerated concrete:

1. Cement - sand;
2. plaster;
3. Front.

It is important to note that no matter what material you choose for plastering, the finishing of aerated concrete walls should begin with interior work. This is due precisely to the high vapor permeability of aerated concrete. When performing external plastering, the humidity of the room increases significantly, which can adversely affect the quality of internal work.

Wall decoration inside the house can serve two purposes:

1. Maintaining or even increasing the vapor permeability of aerated concrete. This option is used if the main purpose of finishing is to create an optimal microclimate in the house.
2. Complete vapor barrier. This option is used if the outer surface of aerated concrete is also plastered; in this case, the release of steam to the outside is minimized, which has a positive effect on the durability of the external plaster.

Now consider what material will be most suitable for plastering your particular home.

Cement - sand plaster. Often, many people ask themselves: is it possible to plaster aerated concrete with cement mortar? Wall decoration with such material is highly undesirable for the following reasons:

1. The vapor permeability index of cement is significantly lower than that of aerated concrete. Provide an optimal microclimate in aerated concrete house is possible only if the vapor permeability of the finishing material is equal to or exceeds the performance of aerated concrete.
2. With significant indicators of moisture absorption, aerated concrete will intensively absorb moisture from sand - cement mortar, and this will significantly reduce the quality of the plaster, since the acquisition cement plaster optimal parameters strength is possible only under the condition of slow and uniform drying.
3. Low adhesion and high specific gravity solution exclude the possibility of its reliable adhesion to the material.

Gypsum. Plastering aerated concrete inside the house with gypsum has both advantages and some disadvantages. The benefits include:

1. 1. Fast drying;
2. 2. No shrinkage;
3. 3. Ability to obtain a smooth surface;
4. 4. With skillful plastering of aerated concrete walls, you can avoid applying the finishing layer. It is unlikely that the quality of the surface will allow tinting, but wallpapering is quite acceptable.

To disadvantages gypsum mixtures relate:

1. Low vapor permeability;
2. A fairly large volume of water is needed to knead the mixture;
3. High adhesion of dried plaster to precipitation and moisture in general.

Despite these shortcomings, plastering aerated concrete with gypsum is quite acceptable.

Front. This type of plaster mixture is optimal for plastering aerated concrete indoors and outdoors. The vapor permeability indicators of such a composition correspond to those of aerated concrete blocks, they are characterized by high adhesion, and they also have good aesthetic properties after drying.

Interior decoration of the house from aerated concrete

Currently, there are a large number of ready-made dry mixes for wall plastering. When choosing a material for carrying out plastering works the following factors must be taken into account:

1. The plaster mixture must have parameters good vapor permeability, at least equal to the parameters of aerated concrete;
2. An excessive amount of water must not be used to prepare the working mixture.
3. The selected mixture must have a high coefficient of adhesion to the base;
4. The plasticity of the plaster should provide the walls with resistance to cracking;
5. The frost resistance of the selected mixture must correspond to climatic conditions;
6. The time until the start of setting of the newly prepared mixture, in other words, the time during which the prepared mixture has sufficient plasticity to be applied to the base.

Currently, Ceresit CT 24 is confidently leading in the market of dry mixes for plastering aerated concrete, with a huge variety of choices, in terms of price-quality ratio.

In conclusion, I would like to remind you that regardless of how to plaster aerated concrete, compliance with the technological regimes indicated by the performer of the plaster mixture is directly related to the quality and durability of the work being done. Do not neglect the preparation of the base. Preliminary removal of various masonry irregularities will allow you to significantly reduce the layer of applied plaster on aerated concrete, and, consequently, its consumption.