Features of plaster walls made of aerated concrete inside and outside the premises. Features of internal plastering of aerated concrete walls How to properly plaster aerated concrete walls

Aerated concrete blocks have become a trend in individual development. Increasingly, they are also used in multi-storey construction, when internal and external walls are laid out of them in frame-block buildings.

Attention: this material deals with aerated concrete. In construction, another material with a similar name is used - gas silicate concrete (gas silicate). This is a completely different material both in terms of components and characteristics. It contains very little cement, only 14%. Therefore, all recommendations for aerated concrete blocks are unacceptable for him - there is practically no adhesion to cement-sand mixtures.

Gas block - compact and lightweight construction material. Its masonry during the construction of walls does not require special skills, which allows people without special construction education to build warm and inexpensive housing with their own hands. At the same time, this material is very “capricious” in terms of finishing.

Features of aerated concrete in terms of plastering

Features of aerated concrete lie in the technology of its production. It is the only building material that has through shallow channels that create two serious problems for walls:

• easily blown by moderate winds;
• have high vapor permeability.

The first problem is solved by finishing the walls both inside and outside, in connection with which the question “do I need to plaster walls from aerated concrete blocks” disappears by itself. High vapor permeability can only be managed with the proper use of finishing technologies.

Here, even minor mistakes due to ignorance of the nuances of finishing work can have fatal consequences. For example, its durability directly depends on the order of plastering the walls inside and outside the building, which will be discussed below.

When preparing to plaster the surface of walls made of aerated concrete blocks, the following points must be considered:

• Even the densest aerated concrete under concentrated blows, for example, with a hammer on a chisel, breaks off and cracks. Therefore, the preparation of such walls for plastering is significantly different from the same work in relation to brickwork.
• The presence of open pores in aerated concrete blocks does not allow the use of putty for wall decoration - its thin layer simply does not hold on to them, although the quality of the surface allows this method to correct small errors in their installation. Therefore, it is necessary to plaster with a layer of at least 5 mm.
• The low adhesive properties of porous structures, which include aerated concrete, require the mandatory use of either expensive primers or fiberglass reinforcing mesh (other materials dissolve in the alkaline environment of the cured plaster).
• The high vapor permeability of the material dictates the following order of work on plastering walls: first, the plaster is carried out indoors, and then, after the inner layer of the mortar has dried, outdoors. If the sequence is reversed or work is carried out simultaneously from two sides, then moisture will be locked inside the wall, which will destroy it during frosts.

How to plaster aerated concrete

How to plaster aerated concrete walls inside the house? There is no single answer to this question. If you buy ready-made plaster mixtures, then there are no problems, except for the financial component. On sale there is always dry plaster on a different basis:

• lime and cement - the most popular mixture for plaster aerated concrete walls;
• liquid glass (silicate mixture) - the cheapest type of dry mortar, but incompatible with decorative plaster based on acrylic, silicone, latex;
• silicone - the highest quality plaster mix with, of course, the highest price;
• cement and mineral chips, which replaces the sand.

For reference: there are also acrylic mixtures on sale, but they are better used for decorative plaster.

Buying ready-made plaster will seriously affect the family budget, so you need to consider options for preparing the solution yourself. So what kind of plaster is better to plaster aerated concrete walls? There are two blocks of answers, depending on the type of prepared adhesion of the wall to the plaster.

1. The plaster mortar is applied directly to the wall, pre-treated with a penetrating primer with slots sawn with a chainsaw (the slots are necessary for better adhesion of the mortar to aerated concrete).
2. Plastering of the wall is carried out on a plaster mesh, planted on a special glue, which has become fashionable lately.

In the first case, it is necessary to take into account the features of the material:

• the presence of cement and lime in the composition;
• porosity;
• high vapor permeability.

Such an unusual combination of properties near the wall immediately crosses out cement mortar with sand from the list of mixtures. It adheres very poorly to such a surface even when applying a high-quality primer.

Here you need to use:

• gypsum with light perlite sand;
• gypsum with lime;
• lime with cement, fine sand, aggregates and plasticizer.

In the second case, any combination of mortar components is allowed, including cement and sand in a ratio of 1 to 5.

Material consumption calculation

Starting work on applying the plaster layer, it is important not to make a mistake with the amount of material purchased. We note right away that it is impossible to absolutely accurately calculate how much of what is needed - it is impossible to take into account all the differences in the wall surface in height, as well as the presence of a vertical in it. But, with a slight error in any direction, the calculations can be done.

You should start by determining the area that needs to be plastered. To do this, multiply the length of each wall by its height and add the results together. Subtract the area of ​​doors and windows from the resulting number. We multiply the final result by the average thickness of the plaster, as a result of which we obtain the amount of mortar in m 3.

For reference: the last multiplier is the average result of adding the thickest and smallest layers of plaster, which is determined during the installation of beacons.

Necessary tools for work

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

• stepladder (you can prepare a special portable platform - goats);
• Phillips screwdriver or screwdriver;
• metal profiles for lighthouses;
• roulette;
• plumb;
• a rule with a level 2.0-2.5 m long;
• scissors for metal (Bulgarian);
• a hammer:
• paint brush (spray gun or roller);
• priming bath;

Attention: experienced professionals use two rules. Short, no more than 1.5 m, - it is more convenient to level the applied plaster, long - to check the quality of the work performed.

• construction (bubble) level;
• steel brush or scraper (another name is "cutting off");
• container for the preparation of plaster;
• hacksaw or chainsaw;
• falcon;
• trowel, has other names - trowel, plastering spatula;
• trowel;
• grater;
• malka;
• trowel;
• set of spatulas.

Attention: details about the purpose of each tool and their photos can be found in the material "".

Surface preparation

Plastering of aerated concrete walls indoors should begin with surface preparation. From quality preparatory work depends largely on the durability of the plaster. Many years of experience shows that the work should be carried out in a clear sequence:

1. all civil construction and installation work installation of the floor, installation of door and window units, etc.;
2. walls are cleaned of old plaster, paint, wallpaper and whitewash;
3. wall blocks are being repaired (if necessary);
4. various kinds of contaminants are removed.

Attention: the technology for performing the above works is described in detail in the material “Preparing Surfaces for Plastering”.

The next, most important stage of work when plastering aerated concrete is to ensure adhesion (adhesion) of the plaster to the wall. There are two options here: apply the solution to the wall treated with a primer or to the plaster mesh. The second option is gaining popularity, so let's consider it in more detail.

To work, you need to buy a primer deep penetration for aerated concrete (Ceresit), tile adhesive (for ceramic products - Knauf, Eunice 2000, etc.) and fiberglass plaster mesh.

The step by step instructions are not very complicated.

• Two layers of a penetrating primer are applied to the wall. For the first layer, in order to saturate aerated concrete with moisture, the soil is diluted with water in a 1: 1 ratio. On the second layer, its consumption should be in the range of 150-180 g/m 2 . All known methods can be used to apply the solution: roller, brush, garden sprayer, compressor, etc. The second layer is applied only after the first layer has completely dried.

• Diluted glue is thrown onto the dried primer with a trowel. Work is carried out from the bottom up, a little more than a roll of reinforcing mesh in width. The layer thickness after leveling should be within 5 mm.

Attention: dilute tile adhesive and work with it in strict accordance with the instructions printed on the package.

• The mesh cut along the length, close to the ceiling, is melted into the glue, and then the same is done below, near the floor. With a spatula, with teeth 5-6 mm long, the plaster mesh is pressed as deep as possible into the adhesive. Work is carried out from top to bottom. At first, the movements of the spatula can be chaotic, and in the final stage - strictly horizontal. This is necessary for the formation of horizontal ordered strips about 5 mm high from the glue squeezed out through the mesh, which will serve as an ideal connecting element between the wall and the plaster solution.

Adhesive surface gaps are not allowed. The work is carried out in turn for each mesh web. Each subsequent mesh should overlap the previous one by 10 cm. For ease of joining, several vertical strips are drawn with a spatula along the edge of the glued strip (subsequently, in the process of work, they must be converted into horizontal stripes).

How to plaster aerated concrete walls inside the house when reinforcing the wall with plaster mesh and tile adhesive? This combination of reinforcing mesh with adhesive allows the use of any type of plaster currently used in construction.

When, after masonry, you can start plastering

When building a house from aerated concrete, one should not rush to finish the walls both inside the building and outside. Even put on glue, the blocks will still shrink - this is their property. What will happen to the plaster on the wall that has shrunk does not need to be explained - continuous cracks and a complete replacement of the plaster layer.

Experts say that after the construction of the wall, it is necessary to wait 7 months, and only after that start plastering work. However, this recommendation cannot be accepted. The simple erection of walls does not lead to their shrinkage - there is no pressure on the blocks. Only after the construction of the roof begins the full process of shrinkage. Therefore, the countdown should be carried out from the moment the work on the construction of the roof is completed.

Plastering technology

How to plaster aerated concrete walls indoors? The technology for plastering aerated concrete walls indoors is the same as for other types of walls.

For reference: in the vast majority, beacons for aerated concrete walls are not installed. This is due to the even surface of the wall after laying the blocks - the strict geometry of the material and a thin connecting seam make it easy to withstand the vertical. Beacon guides are used only in case of loss of verticality, which occurs as a result of foundation settlement. The process of installing them on the wall is described in the work "".

• The solution is mixed in small portions.
• Before work, the plaster should “rest” for several minutes.
• When applied to a bare wall, plastering work is carried out in three layers, on a mesh with glue - in two (primer and coating).
• The solution for spraying is prepared in a ratio of 1: 2 to the consistency of sour cream.
• Plastering starts from the bottom left corner. Lead from bottom to top, left to right. The thickness of the spray is 4-5 mm. It is applied with a trowel by sharply throwing a small amount of mortar onto the wall.

• The soil is placed with a thicker solution (about like bread dough) and a different ratio of cement and sand - 1:5. Apply after complete drying of the spray. The thickness of the soil should not exceed 2.0 cm. It is applied to the wall with a trowel. Then the rule is aligned. The final processing of the soil is carried out with a trowel. They can work left, right, up and down. If the soil layer exceeds 2 cm in thickness, then the correct solution is to apply twice.

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. Active use of aerated concrete in modern construction due to the low cost of blocks, low specific gravity, high thermal insulation properties, the possibility of machining hand tool, high fire safety.

However, after completing the main construction works the question of further interior and exterior decoration of the house inevitably arises. 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 a number of additional rules during finishing work. These disadvantages of aerated concrete include:

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

The first two disadvantages have a particularly important effect on aerated concrete plaster. It is the high level of adhesion that 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. It is possible to provide an optimal microclimate in an aerated concrete house only if the vapor permeability finishing material equal to or greater than 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 of optimal strength parameters by cement plaster is possible only if it dries slowly and evenly.
3. Low adhesion and high specific gravity of the 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.

The disadvantages of gypsum mixtures include:

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

There is currently 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 good vapor permeability parameters, 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 mix 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.

What plaster for aerated concrete fit better of everything, and how to apply it correctly - owners of buildings made of aerated concrete blocks often face these questions. In order to qualitatively plaster walls, you need to understand all the nuances of not only building mixtures, but also the material itself.

Aerated concrete - what is it and what is it eaten with

Blocks are made from cement, lime, water, quartz sand and aluminum powder. All components are mixed and fed into the autoclave under pressure. There, the mixture foams due to the reaction of alkali with aluminum, and a porous material is formed, which is becoming more and more popular every year in low-rise construction. The material is light, but at the same time strong enough. It is easy to use, since an ordinary saw is used for sawing it.

Besides, aerated concrete blocks are not subject to reproduction of a mold and a fungus, being an environmentally friendly material. Aerated concrete has poor thermal conductivity, therefore, in a building built using this technology, it will always be cool in summer and warm in winter. Although aerated concrete blocks are a popular material in construction, they are still a little capricious. The fact is that they quickly absorb moisture, which must be taken into account when carrying out finishing work. Aerated concrete plaster always starts from the inside of the building. This is due to the fact that the moisture contained in the building mixture must have time to evaporate before the exterior of the building is finished.

Lime, acrylic or silicate - what to choose

The main advantage of aerated concrete blocks is their ability to "breathe". For this reason, plaster for aerated concrete should not clog the pores of the material. In addition, as already noted, the material strongly absorbs moisture, which can lead to cracking. Therefore, it is forbidden to use in the process, which in most cases are used for rough finishing work.

Choose mixtures that can preserve the microclimate of the room, pay attention to compositions specially designed for cellular concrete. Some experts suggest using mixtures in the finishing of aerated concrete that create a vapor barrier. In this case, the life of the building is increased due to the fact that the blocks are saturated with moisture as much as possible.

In modern practice, the following types of materials are used:

• Lime (cement-lime) compositions. The most popular blends on the market. They have not only excellent vapor permeability, but also good adhesion, and are resistant to low temperatures. The most popular manufacturers Knauf, Prospectors, Founding and Volma.
• Acrylic plasters. An expensive type of finish, which without fail requires the arrangement of good waterproofing before application. Judging by the reviews and recommendations of experts, preference should be given to such brands as Ceresit, Baumit, Bolix.
• silicone blends. Perhaps the ideal material for interior decoration. They are crack-resistant, but quite expensive. Outstanding representatives - ceresite and Baumit.
• silicate plasters. They are generally used for exterior finish. They are made on the basis of potassium liquid glass, and the most famous brands are such as Caparol, Baumit, Ceresit.
• Gypsum mixtures. With their help, it is easy to create a perfectly flat surface, but their only drawback is that they do not tolerate high humidity, therefore, they are categorically not suitable for bathrooms and require a mandatory one. Good mixes are offered by campaigns such as Knauf, Velvet, Bonolit.

Surface preparation is the key to a quality finish

The plastering of walls from gas silicate blocks must be carried out in compliance with the technology, otherwise in the future it will be possible to get a surprise - cracking of the plastered surface. At the very beginning, inspect the surface for the presence of large chips and residues of glue, with which the masonry was carried out. A planer is suitable for you, with which all these influxes are combed. After cleaning the surface, treat it with a primer. To save money, we do not recommend diluting the finished solution with water, it is better to moisten the wall with a wet roller, and then treat the surface with a primer. In dry rooms, a simple primer is used, but in wet rooms it is replaced with a deep penetration composition.

To create a reliable and durable surface, the internal plastering of aerated concrete blocks must be carried out on a reinforcing mesh. For these purposes, you can use a galvanized or fiberglass version. Attach it to the surface with nails or dowels. We install beacons on top of the grid, on which plastering work will be carried out. Lighthouses are installed strictly according to the level at a distance of 130-160 cm from each other. This length is considered optimal for work, but some masters may choose it depending on personal preferences and experience. There are ready-made versions of galvanized steel beacons in the store, or you can make them yourself from a plaster mixture.

When choosing a reinforcing mesh, it is worth giving preference to a material with small cells.

Applying mortar to the wall - how to accurately follow the technology

After completing all the preparatory work, proceed to the lining of the gas silicate. The first step is spraying - this is a method of applying a rough layer of plaster. A small amount of the mixture is thrown onto the surface with a layer of no more than three millimeters. Further work is stopped until the solution sets. The next step is to apply the base layer. This process is called primer and consists in applying the plaster mixture to the surface with a spatula or other tool. This fills all the space between the beacons. After that, take the rule. It is applied strictly horizontally to the beacons at the very bottom, and then gradually, making zigzag movements, you need to lift it up.

During alignment, a mortar will remain on the tool, which must be removed and thrown onto the wall over the main mass or in those places where depressions have formed. The alignment process is repeated until the rule is clean. After the mortar has set, beacons must be removed from it (if they were not made of plaster). The cavities remaining after this are covered with a plaster solution flush with the entire surface. Then the surface is given time to dry, after which it is necessary to apply the last layer, called a veneer. Its essence is to create the most even surface, so its thickness does not exceed 1-3 mm.

After all these steps, smooth the surface with a grater. After wetting the wall with water, leave it to dry completely, after which you can proceed to. When plastering on aerated concrete, special attention should be paid to the formation of corners. To do this, use metal or, which are attached to the surface and then plastered. If it is not possible to purchase them, then take a small spatula and apply the solution to the surface on one side. After the mixture has hardened, remove the excess with a knife and carry out the same procedure on the other side of the corner. Clean the surface if necessary.

As you can see, the interior of aerated concrete is not such a big deal. It remains only to decide how to plaster aerated concrete inside the house. Usage quality materials will allow you not to worry about the reliability of the finish, only from time to time you will need cosmetic repairs.

Plastering aerated concrete walls requires special materials and the correct application process. In the case of using unsuitable materials or not observing the process of applying the plaster, it will not last long and will quickly begin to collapse and peel off.

Briefly about aerated concrete

Aerated concrete is a building material that is used to build the walls of a building. Preferably produced in blocks measuring 400x200x600 mm (dimensions may vary depending on the manufacturer).

Aerated concrete is produced from components such as:

• Cement.
• Quartz sand.
• Lime.
• Water.

By mixing the above components with aluminum powder, hydrogen is released, which increases the crude solution several times. When concrete hardens, a large number of hydrogen bubbles create its porous structure.

Advantages and disadvantages of aerated concrete

Advantages:

• Good thermal and sound insulation.
• The blocks are light weight and easy to handle.
• Environmental friendliness of the material.
• High fire resistance.

disadvantages:

• Exterior finishes are a must.
• Brittleness of the material.
• High price.

The use of aerated concrete in construction can significantly reduce time and financial costs, since its laying does not require special skills, and its thermal insulation properties save on insulation.

Wall preparation

Since aerated concrete walls have a smooth surface, plaster does not adhere well to them. Regardless of whether the exterior or interior plaster of aerated concrete walls needs to be prepared before finishing. It is also worth knowing that aerated concrete has a high vapor permeability, this fact must be taken into account when plastering walls from this material.

Preparation of aerated concrete walls for plastering is carried out as follows:

After the walls are prepared and reinforced, you can start plastering. It should be borne in mind that after reinforcing the walls with glue, it is necessary to wait a few days, since the glue, when dried, has poor water absorption and the plaster may lag behind.

Technology

The technology of plastering walls made of aerated concrete consists of the following steps:

1. Wall preparation.
2. Wall priming. It is recommended to use a primer based on acrylate siloxane.
3. Wall reinforcement. To reinforce the walls, I use a fiberglass mesh that is resistant to stretching and has high tensile strength.
4. Installation of beacons. Beacons are installed at a distance of no more than 120 cm from each other. The use of beacons allows you to perfectly evenly plaster the walls. If the walls are even beacons can not be used.
5. Application of the first layer of plaster. The first layer of plaster is applied with a methodical ladle or trowel, after which it is leveled with a wide spatula or wooden lath at least 1 meter.
6. Applying the second coat of plaster. For the second layer, it is necessary to use finishing plaster; it has fine sand, which allows you to hide the flaws of the first layer. The second layer is applied in the same way as the first one, only more carefully aligned.
7. Seam grouting. A few days after applying the plaster, you can produce grouting. Grouting is done with a wooden trowel, after slightly moistening the wall with water. Rub the seams, in a circular motion, slightly pressing the grater against the wall.

After grouting the walls are ready and can be applied decorative plaster or wallpapering. Finishing work on plastered walls must be done only after they have completely dried.

The choice of lining for aerated concrete

Plaster mixtures for aerated concrete walls must have the following properties:

• Good durability.
• Weather resistance.
• Good waterproofing properties.
• High vapor permeability.
• Elasticity.
• Good adhesion to walls.

This is one of the main criteria for plastering aerated concrete walls for interior and exterior decoration.

Wall cladding made of aerated concrete can be made with the following materials:

It is important to use plaster designed for aerated concrete walls. The use of other types of plasters in the future may lead to their peeling.

Conditions for working with facing material

For high-quality and durable wall plastering, it is necessary to adhere to the following conditions:

1. Sequence plaster first external then internal.
2. Perform wall plastering can be carried out after the end of all wet screeding, puttying, etc. The walls must be thoroughly dried after previous work.
3. Wall plastering can be produced at a temperature of +5 +30 degrees. In no case should work be carried out at sub-zero temperatures, as the plaster will fall off.

You should also be aware that for buildings made of foam concrete, foam plastic cannot be used for exterior decoration, since it does not have vapor-permeable properties, and the accumulated moisture between the wall and the insulation will contribute to its delamination.

Interior and exterior decoration

The process of plastering exterior and internal walls consists of the following steps.

Internal plaster:

• Initially, the walls of the building must be carefully prepared. Clean them from the remnants of the mortar, paints, bituminous stains, dust and dirt. If necessary, the walls can be washed with soap and water. It is also necessary to seal all the seams and joints of the blocks with a special putty.
• After the putty has dried, you can prime the walls. The primer must be compatible with the applied plaster. The primer is applied evenly with a roller or brush, in two layers without missing a single section of the wall. After about three hours, the primer will dry and you can start the process of plastering the walls.
• Initially, it is necessary to apply the starting layer of the solution made according to the manufacturer's instructions, which are indicated on the package. The solution is evenly applied to the wall surface with a metal float or spatula.
• After the first layer is dry you can apply the finish in the same way. A day later, the dried plaster is rubbed with a wooden float, after wetting the wall with water.
• At the final stage the plastered wall can be painted with vapor-permeable emulsion paint.

External plaster:

• Exterior wall decoration must be made strictly with materials that have vapor-permeable properties. Same as for internal plaster, it is necessary to clean the walls and remove all cracks, chips, etc. This can be done using tile adhesive. Temperature environment at the time of plastering work should be from +10 to +25 degrees.
• After preparing the walls, it is necessary to strengthen the fiberglass reinforcing mesh. You can strengthen the mesh with glue or wood screws. The mesh prevents the mortar from running off and keeps it well on the wall, and also avoids cracks due to the shrinkage of the plaster.
• The next step is the application of plaster. The plaster is applied in the same way as for interior decoration. You should know that it is necessary that the vapor transmission capacity of the plaster be higher than that of aerated concrete. If necessary, you can install beacons to level the walls.

  You should also know that the thickness of the outer layer of plaster should be less than half that of the inner one.

  The leveling of the plaster is done with a wooden lath.

• When the plaster dries, it is necessary to grout the seams and flaws. After 48 hours, the plaster will dry and the final stage of finishing work can be carried out.

Therefore, we can conclude that finishing a building made of aerated concrete is an expensive pleasure, but saving on materials will lead to much disastrous consequences and high financial costs.

Plastering of aerated concrete walls with cement-sand mortar

In order to save aerated concrete walls, it is possible to plaster with a cement-sand mortar, this is done as follows:

• First you need to prepare the walls: to do this, it is necessary to remove dust, dirt and glue residues from them, and then prime them.
• The next step will be to reinforce the walls with fiberglass mesh and the usual cheapest tile adhesive. With a spatula or metal float, the adhesive is applied to the primed surface of the wall, after which the mesh is applied. After that, the applied mesh must be smoothed horizontally with a notched trowel. When the glue dries, a surface with grooves will be obtained, which will contribute to good adhesion of the cement-sand plaster.

  Thus, in addition to reinforcing the wall, the seams of the blocks are smoothed out and small irregularities in the wall are removed, and the glue grooves will prevent the plaster from slipping when it is applied. A fiberglass mesh will help prevent cracks when the plaster shrinks.

• After the glue has completely dried, you can start plastering the wall. To do this, it is necessary to mix the cement-sand mortar with a ratio of 1: 3 and throw it onto the wall with a ladle. After that, with a long rail, with light movements to the left to the right, distribute the solution evenly along the wall; this procedure must be repeated until the wall becomes even.
• When the walls are completely plastered and dry, you can start grouting, after which the walls will be ready for further finishing, wallpapering or applying decorative plaster.

Plastering of bare walls made of aerated concrete with a cement-sand mortar is unacceptable, since it does not have good enough adhesion and will slip, and cracks will appear when it dries.

Aerated concrete is a modern building material that resembles foam concrete in structure, but differs in air bubbles located inside. The hollow structure of aerated concrete absorbs moisture well, which requires external finishing of the material. The better to plaster aerated concrete walls is discussed in the proposed article.

For the manufacture of material are used:

• quartz sand - the basis of the mixture;
• lime;
• cement;
• water;
• aluminum powder is added during the manufacturing process of the material. Acts as the main blowing agent and gives the material a specific structure.

Tip: When purchasing aerated concrete, it must be borne in mind that the pores of the blocks, unlike foam concrete, are open. This determines the features of its application and finish.

Comparative characteristics of foam concrete and aerated concrete are presented in the table:

When plastering external surfaces of aerated concrete, its high hygroscopicity must be taken into account.

This requires the use of non-standard plasters, which over time will not lead to:

• Cracking of the internal and external surfaces of the building, as in the photo.

• The appearance of traces of masonry after fog or rain, which worsens the visual parameters of the walls.
• Change of technical characteristics.

• An increase in indoor humidity.
• The appearance of mold in the corners of the rooms.

To finish the exterior surfaces, special facade plasters are used. A particular danger for aerated concrete slabs is temperature extremes and severe frosts.

During operation, a certain amount of liquid begins to accumulate inside the structures, which will expand when it freezes and can greatly damage the structures of the structure. It is possible to plaster aerated concrete bases only with mixtures that have good water-repellent properties that do not prevent moisture from evaporating from the walls.

For exterior finishing of aerated concrete, the plaster must have:

• Good adhesion parameters.
• High compressive strength.
• Frost resistance.

Tip: Owners of buildings made of aerated concrete blocks should take into account that the exterior wall decoration is carried out only after all internal facing work has been completed. Otherwise, when carrying out “wet” interior finishing work, the walls will absorb a significant amount of moisture, which will subsequently begin to evaporate.

If a exterior facade will be finished before applying the internal plaster, with its intensive evaporation, the external plaster layer will peel off from the surface of the aerated concrete. After interior decoration premises, it is possible to clad the walls of the house from the outside with special compounds with the highest vapor permeability.

Advice: It is impossible to plaster facades using standard cement-sand mixtures due to their insufficiently high vapor permeability properties.

Plaster for gas concrete

For wall finishing, a vapor-permeable plaster for aerated concrete is used, which passes water vapor well, does not get wet, with good adhesion to the surface of the blocks and high frost resistance.

Lime-cement plaster

All the necessary properties are inherent in light thin-layer plasters, specially created for finishing surfaces made of aerated concrete. An example of such plaster can be - Baumit HandPutz for do-it-yourself wall decoration, produced in bags weighing 25 kilograms.

Its main physical properties are shown in the table:

Tip: Before plastering aerated concrete with this plaster, it is necessary to spray the previously cleaned wall surface with Baumit Vorspritze mortar.

Material selection

To choose which plaster is better to plaster aerated concrete walls, you need to purchase a plaster composition that meets the characteristics:

• good vapor permeability;
• the optimal volume of liquid for mixing the mixture: for one kilogram of the mixture - no more than 0.2 liters of water;
• certain values ​​​​of the minimum and maximum thickness of the plaster;
• good adhesion with a base of at least 0.5 MPa;
• resistance to negative temperatures;
• high resistance to cracking;
• long pot life of the mixture, the larger it is, the easier it is to work with the solution, especially for beginners.

The procedure for plastering walls made of aerated concrete

Before starting work, it is better to get acquainted with the video in this article.

Advice: Building blocks from cellular concrete are quite even with almost imperceptible seams. Use for leveling surfaces plaster solutions not necessary. It is enough to apply only a thin layer of the mixture.

The wall plastering instruction suggests the following work procedure:

• Surface primer. A composition specially designed for aerated concrete, the surface of which actively absorbs moisture, is applied with a brush or roller.

• A reinforcing mesh is mounted, which is attached to the surface with self-tapping screws (see How to fix a plaster mesh to a wall).

• The walls are finished with a thin layer of plaster.

Properly selected plaster mixes for aerated concrete blocks allow you to make your home not only beautiful, but also warm, preserving all its positive characteristics for a long time.