Exterior plastering of aerated concrete walls. Plastering of aerated concrete walls indoors: wall plastering technology with installation instructions. The feasibility of using gypsum mixtures

But it differs from them in the composition of air bubbles inside.

Aerated concrete blocks are made of cement with a mass fraction of at least 50%.

Aerated concrete walls need external and internal finishing due to porosity and high level moisture absorption.

Features of aerated concrete

This building material has a cellular structure, which gives it special properties:

• good thermal insulation - in terms of characteristics, aerated concrete is comparable to wood;
• low mechanical stability, which leads to the appearance of cracks and chips over time;
• porous material is blown by air currents, which is why houses made of it without finishing are considered rather cold;
• unaesthetic appearance;
• high absorbency leads to corrosion of the material in winter, during frosts.

The special structure of aerated concrete blocks requires careful processing with finishing materials to improve it. quality characteristics. External plastering is carried out using special solutions that are selected for certain exposure conditions. environment. Proper plaster aerated concrete walls provides reliable protection base and its durability, and also allows you to give a more aesthetic appearance to the room.

How and with what to plaster aerated concrete indoors?

Regardless of the choice of type of plaster, finishing work must begin indoors. Changing the order and plastering the facade of the building will lead to excess moisture in room. The fact is that when steam leaves the room, especially in winter, condensate accumulates between the blocks and the finish, creating places with excess moisture. This is the main cause of cracks on the surface and shedding of the plaster. To avoid such troubles, you should first deal with the plastering of walls from gas blocks indoors. Experienced craftsmen distinguish two types of technology for plastering aerated concrete walls in a house:

• with full vapor barrier;
• maintaining and increasing the vapor permeability of the material.

The main element of plastering aerated concrete using the first technology is a polyethylene film. It is fixed between the layers of the solution, and the vapor permeability of the walls is reduced several times. Also used for vapor barrier oil paints, which are applied as finishing, and priming the base with special compounds.

The dependence of plastering technology from the inside on the outside

For exact definition approach to internal work you need to decide on the external plastering. The plastering of aerated concrete walls outside the room affects the method and sequence of actions for finishing the room:

1. When outer wall already has some kind of coating or is insulated with dense and vapor-tight materials, then moisture will accumulate in the walls. In this situation interior decoration carried out using materials with low vapor permeability. You also need to take care of reliable system ventilation, so that moisture does not accumulate in the corners of the room and on the windows.
2. When the aerated concrete facade is not covered with anything, or treated with porous heaters, such as mineral wool, then its vapor permeability is not impaired. In this case, it is necessary to first carry out work on the interior decoration of the room, and then move on to the outside.

Foundation preparation

The technology of plastering walls made of aerated concrete is practically no different from working with any other surface. First of all, you need to make sure that the walls are even, and if this is not the case, grind them with a planer or grater for aerated concrete. Many craftsmen skip this stage, but as a result, the cost of plaster increases, which is also used to level defects. Before applying primer aerated concrete walls wetted with water. For drier rooms, it is recommended to choose universal composition, and for the kitchen and bathroom - deep penetration primer. \

Building beacons are mounted on a dried surface, which will serve as a guide for successful plastering of the room. After installing beacons internal plaster aerated concrete walls will lie flat, and work will move faster.

The technology of finishing the facade of the building is somewhat different standards. First, the walls are cleaned of dust and leveled. Cracks and cracks are filled special glue for aerated concrete. After drying, it is necessary to apply a layer of primer for cellular materials. An important stage in the preparatory work for plastering the facades of buildings made of aerated concrete is the reinforcement of the surface with a mesh. When choosing the type of reinforcing mesh, it is necessary to pay attention to the fact that under the influence of an alkaline environment, the material from which it is made can dissolve. Experts recommend choosing fiberglass types.

Aerated concrete plaster (video)

How to plaster aerated concrete surfaces

To repair aerated concrete house served long years it is necessary to competently approach the choice of material for wall decoration inside and outside. Masters distinguish as many as four options for processing walls made of cellular material:

1. Gypsum plaster.
2. Cement-sand mortar.
3. Facade mixtures.
4. Drywall.

The last option is the so-called dry plaster. What drywall is better or plaster on aerated concrete walls - controversial issue. Surface plastering is a costly and time-consuming process. Working with GKL takes less time and, as a result, we get smooth walls. Procedure:

• vapor barrier of surfaces using a polyethylene film, membrane or glassine;
• installation of the crate for fastening the plasterboard;
• fastening drywall to the frame;
• puttying joints between sheets using sickle tape.

On a gas-concrete wall leveled in this way, any type of decorative finishes. What kind of plaster is better to plaster aerated concrete walls? To answer this question, it is necessary to know the specifics of the solutions and their interaction with the base material.

Disadvantages of different types of plasters

Gypsum plaster

To the main benefits gypsum mortar for the treatment of walls made of aerated concrete include:

• fast drying;
• high level of adhesion;
• no need to apply an additional smooth layer;
• the possibility of leveling the plaster for finishing.

Among the masters, Knauf Rotband, Bonolit and Pobedit Velvet are popular.

Cement-sand plaster

If this option was nevertheless chosen for finishing aerated concrete walls, then there are several ways to improve the composition for better interaction with the base. You can increase the adhesion if you add more to the standard mix recipe. cement mortar(for 100 kg of concrete you will need 8-10 kg of lime). The second option, which is acceptable, but still not recommended by the masters, is to add to cement-sand plaster mixes for processing aerated concrete (proportion 1:1). Among the leaders in sales of mixtures of this type are Baumit brand solutions and domestic Craps Extra-light.

Facade solutions

This type of mixture, in the case of aerated concrete, is suitable for both indoor and outdoor use. Key benefits of working with special plasters for aerated concrete:

• high adhesion rate;
• resistance to deformation and cracking;
• vapor permeability is equal to that of aerated concrete;
• pleasant view;
• does not require additional finishing work.

Do-it-yourself plastering of walls on aerated concrete is shown in the video below. With a competent approach to work and the study of materials, even a novice master can handle plastering a house from aerated concrete blocks.

The article popularly talks about the widely used building materials, lightweight concrete, the main characteristics and methods of finishing using traditional technologies, stucco house elements.

Aerated concrete wall plastering

Plastering of internal and external structures made of lightweight concrete is the most used method of protection against external influences. climatic conditions and giving the house an original respectable appearance, as well as internal comfort.

The prevalence of technology is due to the ability to inexpensively and on their own to carry out a set of works on the preparation and finishing of structures and achieve the desired results.

Special characteristics of aerated concrete blocks

Aerated concrete refers to cellular concrete, consists of quicklime, cement, sand and aluminum powder that forms gas. When mixing components and water, a reaction occurs with the release of gas, forming voids, the number of which determines the weight, density, thermal conductivity of concrete and areas of use:

• Concrete with a density of 300-400 (kg/m3) is used for thermal insulation.
• Density 500-900 (kg / m3) allows you to use for the construction of partitions and walls.
• With a density of 1000-1200 kg / m3, concrete is used to make load-bearing walls.

Concrete has gained popularity in housing construction due to its properties:

1. Low thermal conductivity allows it to be used as a heat insulating substance.
2. Frost resistance can reach 150 cycles, among lightweight concretes only expanded clay concrete has greater durability.
3. High fire resistance.

Of the negative qualities for construction, hygroscopicity can be noted, which means that aerated concrete needs to be coated.

The hygroscopicity of aerated concrete requires isolation from moisture.

Preparation of gas silicate blocks indoors for plastering

In aerated concrete, the amount of cement is up to 60 percent, in gas silicate - no more than 14, lime is twice as much, the rest is sand. The percentage matters, because the more cement, the higher the strength, and the base must be stronger than the coating, otherwise it will peel off. That is, the decoration of the house must be done with a lime-cement composition.

When finishing, you need to remember that the base must be stronger than the coating.

The main function of plastering surfaces from gas silicate blocks is the formation of a vapor-tight barrier and limiting the absorption of moisture. To improve the adhesion of the coating to the base, the structural elements are coated with a deep penetration primer, the first layer is applied generously, preferably with an airbrush, after drying it is necessary to paint over again.

After priming, given that the gas silicate composition of the base is weak, it is necessary to carry out reinforcement to prevent the appearance of cracks.

The rough layer of reinforcement is made of glue, on which the blocks were laid, experienced craftsmen use tile adhesive for this, as a cheaper composition.

The use of glue instead of a conventional solution is associated with polymer additives in the composition, providing strong bonding with a thin layer of the mixture.

After applying a thin layer of glue, 2-7 millimeters thick, a fiberglass mesh is embedded in it, which fixes the blocks and serves as a reliable base for the coating. The grid is superimposed on the applied glue with an overlap and is pressed with a spatula with teeth.

It is advisable to start applying the solution after 5-7 days, when reinforced layer gain strength.

Plastering of gas silicate blocks inside the building: technologies used

Protection of gas silicate structures occurs in three stages:

1. Plastering with lime-cement mortar.

2. Priming.

3. Putty.

A lime-cement or lime-gypsum mortar with a thickness of not more than one centimeter is applied to the reinforced surface.

The technology of manual plastering is common, if the wall is large and uneven, beacons are installed and the applied layer is equalized with a wide rule.

The solution is kneaded in a bucket, small tank or trough, water is poured into the poured mixture and stirred to the required consistency, you need to cook a little, gypsum sets in 20 minutes, cement needs a little more time, so the amount should be sufficient to produce during this time. You can level immediately after throwing, last step is a grout.

After finishing with a long rail, the evenness of the surface is checked, irregularities within 5-7 millimeters will be invisible.

Is it necessary to plaster the gas block from the outside

The need to protect the facade of aerated concrete is due to its properties:

1. Hygroscopicity will lead to the saturation of gas blocks with water, which in case of frost will cause the destruction of the structure.
2. Mechanical impact will cause chips, dents, cracks.
3. The material has a porous structure with open pores through which the circulating air carries away heat.
4. Rough aerated concrete house looks unrepresentative.

For aerated concrete structures, the danger is the accumulation of moisture inside the blocks, which freezes during temperature changes and destroys the block from the inside. Therefore, the protection of external surfaces is mandatory, the method of protection by plastering is widely used due to different reasons one of which is the low cost of this technology.

Applicable materials for outdoor work

For application protective equipment outside, substances are needed that have the following qualities:

• permeable to water vapor;
• not wet;
• with good grip;
• frost resistant.

The main types of mixtures for finishing aerated concrete outside:

• Acrylic for aerated concrete, strengthen loaded structures, plinth.
• Silicate, include liquid glass;
• Silicone, based on organosilicon polymers, well suited for facades, but high price;
• Gypsum mixture;
• Lime-cement composition.

Do-it-yourself internal plastering of a gas block: a feature of the work

Due to the high hygroscopicity of the material, plastering inside the house has its own characteristics.

Plastering surfaces must necessarily include the process of reinforcement. It is recommended to use a fiberglass mesh that does not collapse in an alkaline environment.

The surface should be painted over with a deep penetration primer twice.

Apply a thin layer of plaster with a thickness of about 5 millimeters and drown the mesh in it. After drying, apply the main layer using beacons.

What is the best plaster

If vapor permeability is required for kitchen, bathroom or sauna rooms, mixtures of gypsum with perlite sand are used. Silicate is also suitable, however, it should be noted that such mixtures are incompatible with acrylic, silicone, latex materials.

For use on aerated concrete, cement-lime mixtures can be used, which do not require a primer on the walls.

Set of tools

Finishing aerated concrete surfaces requires the following tools:

1. Spatulas.
2. Scraper to remove dirt and debris.
3. Metal brushes.
4. Hammer, for knocking down irregularities, protruding mortar.
5. Sandpaper.
6. Brushes, rollers for priming.
7. Master OK.
8. Tank for mixing solution.
9. Mixer for preparing the solution.
10. Falcon, a shield where the mixture is applied.
11. Grater for grouting.
12. Poluterok.
13. The rule is to align the corners.

How to plaster: work progress

Ready-made mixtures are great for finishing, but have a high cost, therefore, for do-it-yourself work, a wall preparation technology is offered, after which you can safely use any composition.

For preparation, you will need tile adhesive, fiberglass mesh, deep penetration primer. It is necessary to level all the chips and cracks with a composition for laying aerated concrete blocks, then remove dust and debris from the wall with a cheek and paint over with a deep penetration primer twice.

The tile adhesive is diluted and applied to the surface with a thickness of 5 millimeters, the mesh is pressed on top with a notched trowel. When the layer is completely dry, plaster is applied in the usual way, any solution can be used.

The cost of this technology will be an order of magnitude less than when using ready-made plasters.

How long can you move on to the next stages of wall decoration

After the end, the beacons are removed, the resulting dents are subsequently sealed with putty.

To move to the following types finishing, it is necessary to wait for the walls to dry completely at a constant temperature. Drying will take about a month in the warm season so that temperature changes do not lead to cracking or peeling. It is undesirable to speed up the process; if necessary, a heater is used.

Interior and exterior decoration of the house milestone construction works, the quality of which depends on the durability, comfort of living and aesthetic appearance of the house. For finishing works there are many modern materials and technology, but traditional methods do not lose popularity and are relevant at the present time. These methods allow you to achieve the desired results at low cost and labor intensity.

Useful video

Aerated concrete is increasingly being used in private construction, competing with traditional brick. Such houses are much warmer, and it takes less time to build. By technical specifications aerated concrete differs markedly from other materials, and these differences must be taken into account when choosing exterior finish for walls. Plastering is considered the most popular option, and in order for the coating to correspond as closely as possible to the base material, you need to choose the right composition.

Let us consider in more detail the types of facade plasters for aerated concrete and the right technology their application.

Aerated concrete has a cellular structure with open pores, which provides not only thermal insulation properties but also high vapor permeability. Thanks to this quality, an optimal microclimate is created inside the house, the accumulation of condensate is excluded, and the risk of mold development is minimized.

But there is a downside: open pores increase the hygroscopicity of the material, and the absorbed water destroys the cells when it freezes. For this reason, the exterior finish must be waterproof in order to reliably protect the walls from moisture, and have a vapor permeability not lower than that of aerated concrete, so as not to impede the release of fumes.

Important! According to the standards prescribed in SP 50.13330.2012, in heated houses, the vapor permeability of materials should increase from the inner to the outer layers. Only under these conditions is it possible normal functioning load-bearing structures. Since this parameter varies in the range of 0.11-0.23 mg / (m h Pa) for aerated concrete, the plaster composition must be selected with a vapor permeability of at least 0.12 mg / (m h Pa).

Additionally, facade plaster must have the following qualities:

• high adhesion to the base material;
• frost resistance (at least 35 cycles);
• increased compressive strength;
• weather resistance;
• decorative.

In principle, aerated concrete surfaces can be operated without protective coating, but after a few years, the external attractiveness will disappear: the blocks will darken, peeling will appear, mold may develop. So it's best to do it right away. facade decoration and then only periodically update the coating with painting.

Prices for aluminum stairs

Aluminum ladder

Types of plasters for aerated concrete

The most common and most budgetary plaster for outdoor use is cement-sand. But since its vapor permeability is only 0.09 mg / (m h Pa), it is not at all suitable for aerated concrete structures. Other types of plaster mixtures, such as mineral, silicate and silicone, have the necessary parameters. Let's consider the characteristics of each of them in more detail.

Mineral

Mineral-based plaster is inexpensive and easy to make with your own hands. The main disadvantage is the limited range of colors, but since this coating lends itself well to dyeing, it is not so great. a big problem. Ready mixes contain lime, white cement, marble chips and other fillers, as well as some additives that improve the quality of plaster. Home-made mixtures are most often made from cement, lime paste and sand, or only from sand and lime. It is worth noting that sand-lime solutions have low water resistance, and direct exposure to precipitation is detrimental to them.

silicate

In silicate plaster, liquid potash glass acts as a binder. Such compositions are more convenient to apply, are not afraid of moisture and perfectly pass evaporation, which allows them to be successfully used for finishing aerated concrete walls as a topcoat.

Silicate plaster - photo

The color range is quite limited, but, again, this drawback is easily eliminated by staining. Silicate plaster goes on sale in a ready-to-use form, and at a cost slightly higher than dry mineral mixtures.

Silicone

The basis of silicone plaster are silicon-organic polymers. She possesses the best performance compared to other types of plasters: it does not absorb water, it is easy to apply, it is resistant to weathering, vapor permeable and does not lose its visual appeal for a very long time. In addition, such a coating remains elastic, and does not become cracked during shrinkage of aerated concrete blocks. Silicone plasters are also sold ready-to-use, have many color options. Due to the presence of special fillers, silicone plasters make it possible to create a varied texture of the coating. The only negative is the high price of the material, so not everyone can afford such a finish.

Acrylic

But acrylic plasters for aerated concrete can only be used under the condition of enhanced waterproofing with inside walls and good ventilation premises. This is due to the low vapor permeability of the material, which is closer to cement-sand compositions. If you do not provide sufficient protection to the internal surfaces, water vapor will begin to accumulate in the thickness of the walls and provoke peeling of the finishing layer.

Popular types of plaster mixtures for aerated concrete blocks

Prices for various types of decorative plaster

Decorative plaster

Technology of plastering aerated concrete facades

Conditions for work

It is possible to plaster the facade of aerated concrete only after all the “wet” processes inside the room are completed and the surfaces are completely dry. This applies not only to plastered and painted walls, but also to screeds on the floor, the moisture from which evaporates very actively. The blocks themselves must also be dry - the maximum allowable humidity is 27%. If you plaster wet walls, the intense release of water vapor will cause peeling of the coating.

It is recommended to perform plastering of external walls at a temperature of +5…+30 °C, while relative humidity air should not exceed 80%. If for some reason it is not possible to complete the exterior finish before the onset of frost, it is necessary to treat the entire area with a deep penetration primer. The best option- primer Ceresit ST-17, applied in 2 layers. Such protection will be enough until spring, when the weather conditions will allow you to start plastering.

Advice. Cannot be applied plaster compositions in the heat, strong wind and exposed to the walls of direct sun rays. These factors contribute fast drying solution, and he does not have time to firmly grasp the base. As a result, the emergence of many small cracks and peeling plaster.

Deep penetration primer prices

Deep penetration primer

Surface preparation

As a rule, walls made of aerated concrete blocks are quite even and smooth, so they do not need to be specially leveled. If there are deep chips or dents, you need to seal them with the glue that was used when laying the blocks.

To do this, knead a little glue (you can mix it with the dust formed when sawing the blocks), collect it with a narrow spatula and fill the recesses. Remove excess and allow the solution to dry. In the same way, empty seams between the blocks are closed. When the glue dries, the walls need to be rubbed to remove minor flaws. Use a metal flat grater for this. Finally, brush off dust from the entire surface.

Padding

For priming aerated concrete walls under plaster, deep penetration compounds with strengthening properties are used. They create a very strong elastic film that allows water vapor to pass through, but does not allow the material to absorb water. Additionally, such primers increase the adhesion of the base and finishing layer. Popular means: Knauf Grundiermittel, Siltek E-110, Aerated concrete-contact-1.

The primer is applied in 1-3 layers, depending on the climatic conditions of the area. For example, in dry and warm regions, one coat of primer is enough, and in areas with a damp climate, coastal areas, three coats are needed. To apply the composition, use a roller or a wide paint brush. Primed with a continuous layer, evenly distributing the composition over the base. in the corners and hard-to-reach places use a narrow brush so that there are no dry areas left.

Plaster and reinforcement

It is not necessary to reinforce a layer of plaster up to 10 mm thick if the walls are well primed. With a greater thickness, reinforcement is indispensable, and for this, a fiberglass mesh with mesh sizes of 3x3 mm is used. The mesh must be alkali-resistant - this will ensure high durability and strength of the finishing layer. This information is indicated on the packaging, so when buying a mesh, pay attention to this item.

Step 1. Prepare a plaster solution. The proportions of water and dry mixture are in the manufacturer's instructions, so read it carefully before starting work. For kneading, take a clean container, pour the indicated volume of water with a temperature of + 15 ... + 20 ° C. Add dry ingredients and stir construction mixer at a speed of 400-800 rpm. Allow the solution to brew for 5-7 minutes and mix again.

Construction mixer price

construction mixer

Step 2 They take a wide metal spatula, put a solution on the edge and apply it on the wall in an even strip. The spatula must be held at an angle to the surface and not pressed too hard, so the composition will be distributed most evenly. The layer thickness should not exceed 5 mm.

Step 3 A grid is laid on top of the solution, straightened, and then gently deepened into the plaster, rubbing with a spatula over the surface with effort. If necessary, add the solution in small portions and again rub well. After fixing the grid, apply the solution to the next section and repeat all over again. The mesh must be overlapped by 40-50 mm to avoid cracks at the border of adjacent sections.

Step 4 In the corners, special perforated profiles are attached with a mesh fixed at the edges. To do this, apply the solution to the very corner, level it with a spatula in height, apply corner profile and press gently. Then, like a mesh, they deepen into the plaster and level the surface with a spatula. They are placed not only on the outer and inside corners but also around the perimeter of window and door openings.

Corners and mesh should never protrude above the plane of the wall. The surface must be flat, smooth, without visible defects. Now you need to let the solution dry well. Drying time depends on the composition of the mixture and weather conditions, on average it ranges from 3 to 7 days.

Finishing layer

Knead the solution for the finishing layer and apply it with a wide spatula to the surface. The thickness of this layer varies between 4-10 mm. Special care is required here, since all defects will remain in sight. When plastering adjacent squares, the formation of stripes along the edges should be avoided, all excess must be immediately removed with a spatula.

When the plaster has sufficiently set, but not yet completely hardened, proceed to the grouting of the walls. For this, it is most convenient to use a polyurethane grater, but a metal grater is also suitable. The grater must be applied flat to the surface, pressed, and smooth the plaster layer in a circular motion. You should not press too hard, so as not to leave scratches and dents.

After grouting, it is necessary to wait for the plaster to dry completely, and only then proceed to the final stage - painting. You can also apply decorative structural plaster by applying it in a thin layer on the prepared base.

Video - Facade plaster for aerated concrete

Plastering walls made of aerated concrete is a justified measure. , like the foam block, despite all its advantages, the material is hygroscopic. This means that it easily absorbs moisture. Therefore, a gas-block house must be protected from the weather. If the gas block gets wet in the rain and then dries, it will not lose its properties. And if it gets wet in winter, then the water accumulated in the pores of aerated concrete will freeze and expand. This is fraught with the appearance of small cracks that spoil the view, as well as the occurrence of more serious damage.

Conclusion: protection of aerated concrete from the outside from freezing, moisture, snow and others precipitation- necessary measure. During and during winter conservation(if necessary), this function can be performed by a film stretched over the walls. During the operation of the house, it can be any facing material for exterior finish facade - plaster for cellular concrete. The main thing is to create vapor permeability conditions so that the aerated concrete "breathes".

The exterior finish of aerated concrete houses, in addition to block protection, allows:

• strengthen the heat and sound insulation of the walls;
• eliminate the likelihood of wetting the walls;
• protect the house from sudden changes temperature;
• decorate the front of the house decorative plaster for aerated concrete).

One of the most popular ways to exterior finish an aerated concrete house is to apply plaster. Therefore, questions often arise, for example, how and with what to plaster aerated concrete, which we will try to answer as fully as possible. Let's spend comparative review characteristics of the best mixtures for facade decoration, as well as describe the technology of plastering walls in the form of step-by-step instructions understandable to beginners without construction experience.

Plaster for aerated concrete

Summarizing the experience of builders and owners of aerated concrete houses, we can conclude that three types of finishing materials are used for plastering aerated concrete walls:

Cement-sand plaster for aerated concrete

Is it possible to plaster aerated concrete with cement mortar?

No. Regardless of whether the gas blocks were laid on cement or on glue. In general, it is highly undesirable to plaster aerated concrete with cement mortar, because aerated concrete is very smooth and the mortar does not adhere to it, and it also strongly absorbs water from the mortar.

Reasons why it is impossible to plaster an aerated concrete house with cement mortar:

• The cement mortar has a lower vapor permeability than the gas block. This is the most important reason why you shouldn't use it. In the case of aerated concrete wall decoration, professionals have a rule that only one can be used. finishing material, which, in terms of vapor permeability, does not differ from the aerated concrete itself or has a higher indicator compared to it. Only in this case, the optimal microclimate of the aerated concrete house will be maintained.

Note. For the same reason, it is undesirable to use rigid heaters (polystyrene and expanded polystyrene) for insulating a house made of aerated concrete.

• Cement-sand mortar has a high moisture content. To knead the components in the sand-cement mixture, you need to add water. It is also obvious that aerated concrete, having a significant rate of moisture absorption, will tend to absorb this water from the solution. This, in turn, reduces the quality of the applied mortar and its ability to adhere to the wall. After all, concrete gains strength only if it dries evenly and slowly.

Remember, the foundation must be periodically moistened and covered with a film to ensure uniform drying. So why should it behave differently on the wall? The primer saves the situation, but not much. The appearance of a cobweb of small cracks on the plastered surface of aerated concrete cannot be avoided.

Note. In order to save money, you can mix a cement-sand mixture and a special mixture for finishing aerated concrete blocks in a ratio of 1 to 1. But is such savings needed, which will significantly reduce the speed of work, and the finished surface will not be 100% of high quality.

• Cement mortar for plaster has low adhesion. It cannot provide high-quality adhesion to aerated concrete. One of the reasons can be considered the weight of the solution and the presence of large impurities in its composition.

You can increase the adhesion index (adhesion, adhesion of surfaces) by adding lime to classic recipe cement mortar (proportion: 8-10 kg of lime per 100 kg of concrete).

Cement-lime plaster can be purchased as a ready-made dry mix. For example, dry building cement-lime mixture CREPS Extra-light (240 rubles / 25 kg), Startvell T-21 (208 rubles / 25 kg), Baumit HandPutz 0.6 (300 rubles / 25 kg).

• obligatory application of the final layer. Because it is difficult to make a smooth surface using a sand-cement mixture.

Is it possible to plaster aerated concrete with aerated concrete glue?

Also undesirable. Although designed with the specifics of aerated concrete in mind, it is intended for thin layer application and jointing, not for exterior wall applications.

Violation of the vapor permeability of aerated concrete will lead to such problems as cracking of the finishing layer, the appearance of traces of seams (disappear after drying), the appearance of mold.

Gypsum plaster for aerated concrete

Advantages of plaster based on gypsum:

• high drying rate;

• non-shrinkage of the solution;

• the ability to make a smooth surface;

• no need for a top coat.

Disadvantages of gypsum plaster:

• mediocre vapor permeability;

• greater, in comparison with a special mixture, the water content required for mixing the mixture (10-15 liters per bag);

• getting wet quickly during rain or snow;

• the likelihood of spots on the surface that have to be painted over.

Despite the disadvantages, plastering the walls with gypsum is an acceptable option for finishing aerated concrete. Well proven: gypsum vapor-permeable highly plastic plaster mixture Pobedit Velvet G-567 (previously Pobedit-Egida TM-35 for 320 rubles / 25 kg.), Knauf Rotband (360 rubles / 30 kg) and Bonolit (290 rubles / 30 kg).

Facade plaster for aerated concrete

Most effective material for plastering exterior and internal walls from aerated concrete. Plaster for facade works has a number of characteristics, including the vapor permeability index identical to that of aerated concrete (for most types of plasters), good adhesion to the base, beautiful appearance.

When choosing how to plaster aerated concrete, it is best to focus on a high-quality special mixture. In addition, the use of facade plaster simplifies the finishing of an aerated concrete house with your own hands.

What kind of plaster is better to plaster aerated concrete walls?

There are a variety of ready-made mixtures for plastering aerated concrete walls on the market. To do right choice, you should pay attention to the characteristics of the plaster:

• vapor permeability;

• the required amount of water for mixing the mixture (no more than 0.2 liters per 1 kg of the mixture);

• boundary values ​​​​of the thickness of the plaster (minimum and maximum);

• adhesion to the base (minimum 0.5 MPa);

• resistance to low temperatures;

• crack resistance;

• solution pot life. The more, the easier it is for beginners to work with it.

And only when choosing between two equivalent mixtures, one should be guided by the price, it decides not the last role in this matter, but not the key one either.

According to reviews, plastering of aerated concrete walls outside the premises is popular among users - a dry mix with plasticizers Ceresit CT 24 (380 rubles / 25 kg), leading in terms of price / quality.

The material was prepared for the site www.site

When can aerated concrete walls be plastered?

Since aerated concrete easily absorbs moisture, it is better to protect it from getting wet immediately. We repeat, it is not critical if the material gets wet, but you should not allow moisture to freeze in the gas block. This can lead to its weakening and the appearance of unwanted cracks.

Haste in facing is also useless. After laying aerated concrete, the walls should dry well. That is why the plastering of aerated concrete walls is carried out only in warm time of the year. In the case of using a concrete-sand mortar as a binding element when laying aerated concrete blocks, the drying time increases, since such a seam is several times thicker than a seam made with a special adhesive mixture.

If it is not possible to finish the house during the warm season, you need to cover the walls with any deep penetration primer. For example, Ceresit ST-17 (549 rubles / 10 l).

The primer will reduce water absorption. It is also desirable to cover the walls with polyethylene left over from packing pallets with aerated concrete.

According to the masters, the most preferable time for finishing work is the period when the night temperature exceeds 0 °C. For middle lane Russia, this time is from the end of March to the beginning of October.

From which side should you start finishing the house from aerated concrete?

Let's spend comparative analysis several popular options for the order of execution of wall decoration.

Option 1
First, the exterior of the house is made of aerated concrete

There is an opinion that the most important thing is to protect the gas block from the street, because. it absorbs moisture. However, this is not so, even after standing without protection (but primed) for a whole winter, the gas block will “give up” the accumulated moisture in the spring. And if it is closed from the outside, where will the vapors be directed? That's right, indoors. This will not only increase the drying process and delay the interior decoration, but is also fraught with the appearance of cracks inside the room.

Option 2
First, the interior decoration of the house is made of aerated concrete

With this approach, the pores are partially closed in the process of finishing work. aerated concrete block. And if they are plastered first from the outside, the accumulated water vapor will simply have nowhere to go. Settling inside the block, moisture will contribute to its destruction. Plastering the walls of aerated concrete indoors will avoid this situation.

After the plaster has touched the interior walls and dried well, you can start finishing the exterior walls.

Option 3
Simultaneous finishing inside and outside the house

The method is the least preferred. The moisture that the gas block “pulls” at the same time from the outside and from the inside will not have the opportunity for a quick exit at all.

Despite the fact that plaster for aerated concrete has good performance vapor permeability, the speed of this process is not so high. Which is especially critical in the cold season (at night temperatures below zero). In this case, water vapor will settle in the form of condensate and, as a result, can lead to peeling of the plaster layer from the aerated concrete. In practice, this option will lead to the destruction of the gas block as quickly as possible.

Theoretically, each of the options has the right to be implemented. But the second one is correct.

How to plaster aerated concrete walls with your own hands

We figured out the question of whether it is possible to plaster aerated concrete. Now it is important to understand how to do it correctly, without prejudice to aerated concrete to let in moisture.

Plastering of aerated concrete blocks has no fundamental difference from the performance of works of this kind on other materials. The putty application technology differs only in a few details, which will be emphasized.

Internal plaster walls made of aerated concrete

The technology of finishing aerated concrete with plaster indoors - the sequence of work:

1. Foundation preparation

It begins with the alignment of the walls - the removal of irregularities is done using a planer or grater for aerated concrete. This work is recommended to be done at the stage of building a house, but many people neglect this, saving time. In principle, this stage can be omitted, which will lead to a significant increase in the consumption of the mixture and an increase in the thickness of the coating layer. In turn, this is fraught with flaking of the plaster and cracks.

2. Applying a primer

Often there are recommendations that the primer should be diluted with water 1 to 1. This is fundamentally wrong, because. reduces its ability to increase surface adhesion. There are better ways to save money. For example, remove dust from the surface by applying clean water to it. Water is applied with a brush or roller as if it were a primer. And then, after drying, a primer is applied.

The choice of primer depends on the purpose of the room to be finished. For a corridor or hallway, any universal primer is suitable, for example, Unis (250 rubles / 5l). For the bathroom and kitchen, it is advisable to use a deep penetration primer, for example, Prospectors (450 rubles / 10 l).

3. Installation of beacons

Beacons, as the name implies, determine the thickness of the application of the solution. They are set to the width of the rule. The accuracy of the installation is determined by the building level.

4. Throwing a "fur coat"

This is the name of the method of applying the first layer of plaster. The work is done from the bottom up. Next, you need to base the rule on the beacons and align (extend) the sketched layer along them. If voids appear, they must be repaired immediately. The main thing is that the plaster does not peel off from the base. If this happens, you need to remove the plaster, treat the surface with a primer and apply the solution again.

5. Processing the first layer

After the first layer of plaster has dried, it must be slightly moistened (with a spray gun) and leveled. Since the beacons serve as cold bridges, it is advisable to remove them at this stage, and seal the places (recesses after dismantling) with mortar.

6. Forming corners

A perforated corner with a mesh is used to arrange and reinforce the outer corners.

7. Finishing

Grouting (if necessary) and painting of aerated concrete walls is carried out. In the case of wallpapering, finishing is not required.

For paint for aerated concrete, requirements are also put forward regarding vapor permeability. Such properties are possessed by interior paints based on PVA, latex, acrylic emulsions, on organic solvents and cement paints.

An example is ESKARO AKZENT (antibacterial paint, 325 rubles / 0.9 kg). At the same time, for rooms with high humidity, special paints should be used, for example, AquaNova Premium (282 rubles / 2.8 kg)

How to plaster aerated concrete walls - video

External plastering of aerated concrete walls

Decorative plastering of the facade of the house may involve the application of plaster for outdoor use in a thick layer (thick-layer finish) or several layers (thin-layer plaster).

Consider a multilayer version of applying thin-layer facade plaster for aerated concrete. Its feature is the creation of three thin (no more than 10 mm) layers.

Technology for applying plaster outside:

• wall preparation. Includes leveling the surface to reduce the consumption of the mixture and the thickness of its application;

• surface priming;

• applying a thin layer of plaster mixture (up to 5 mm). Its purpose is to serve as a basis for attaching the grid;

• reinforcement of plaster with mesh;

How to properly reinforce plaster

Can be used as a reinforcing layer metal grid with small cells, for example, steel mesh with a wire diameter of 0.1 mm and a cell pitch of 0.16x0.16 mm ( average price 950 rubles / sq.m = 2,850 rubles / roll) or fiberglass mesh (for example, reinforcing fiberglass mesh with a cell pitch of 50x50 mm ( approximate price 17.60 rubles / sq.m. = 880 rubles / roll).

The mesh is attached with an overlap of 50 mm. At the same stage, the corners of the building are formed using perforated corner with mesh. The mesh helps prevent cracks in the plaster due to shrinkage of the building. Thus, the plaster of the aerated concrete facade will not be covered with a web of small cracks. The mesh is sunk into the applied solution with a spatula. It is especially important to install the grid in places of high voltage, near windows and doors.

Advice. Mounting the mesh on a dry wall will not give any result, because the mesh will be fixed to the base with self-tapping screws. In the case of its installation on the solution, it forms a monolith with the solution, and will move with it.

• alignment of the plaster layer on the grid;

Next, you need to wait until the first layer dries completely. Otherwise, it may fall off under the weight of the second layer. Because the this method provides for a thin-layer application of the solution, it will take 3-4 days to wait. The thicker the layer, the more. You can check if the layer is dry with water. If you spray on the wall and the water is absorbed, then it's time to get to work.

Note. When the plaster dries, it must be protected from the influence of environmental factors (moisture, snow, rain).

• applying a second layer of plaster. This layer is considered leveling, so increased attention paid evenness of application and the formation of a smooth surface;

• applying the third (finish) layer of the plaster mixture, followed by grouting if necessary;

• painting a plastered aerated concrete wall or applying a textured plaster mixture, for example, Pobedit-Bark beetle (340 rubles / 25 kg).

  For painting aerated concrete, only paints for outdoor use are used. For example, Nova-Facade (590 rubles / 7 kg), Gasbetonbeschichtung from Dufa (2674 rubles / 25 kg), ROLPLAST Gordianus (3700 rubles / 10 kg), Dyotex (concentrate, 5500 rubles / 15 kg).

• application of a hydrophobic agent. it special solution, which professionals recommend applying a year after staining, after all facing works. The water repellent will give any surface additional water-repellent properties. A special water repellent agent for aerated concrete "Neogard" (350 rubles / 1 l) has proven itself well.

Aerated concrete putty

When deciding how to putty aerated concrete, you need to know that there are three types of finishing materials on the market that are similar in purpose, but differ in their composition. All this, facade plaster for aerated concrete, sold in the form ready mix. It is intended for thin-layer finishing of the plastered surface.

Ready-made silicate plaster, for example, Baumit SilikatTop Kratz Repro 3.0 mm (3700 rubles / 25 kg)

Conclusion

Consistently performing work on plastering walls made of aerated concrete and using only vapor-permeable materials, it is possible to provide a reliable finish that will decorate the facade of the house for more than one year. And scheduled repairs will be reduced to periodic painting, to restore the color of the paint and eliminate small cracks.

Internal and external plastering of gas silicate blocks is one of the most common methods for finishing walls made of this material. When doing these works, many people forget that it should be done a little differently than ordinary brick or monolithic concrete surfaces.

Since aerated concrete houses easily absorb moisture, they must be plastered.

Stucco errors

For example, a case that needs to be considered in order to understand what the consequences may be if there are errors in the execution of aerated concrete walls.

For exterior decoration, the use of conventional cement-sand mortar is simply unacceptable. This is due to the same vapor permeability and leads to a violation of the main rule, which says that any multi-layer breathing wall must have a vapor permeability that increases from the inside out from layer to layer, or at least be commensurate.

The plaster mixture for walls containing is sold in the form of a dry powder with special additives that help meet the following performance characteristics:

If you leave a house made of aerated concrete to winter not plastered, then on next year he will “please” with a network of cracks.

• vapor permeability (the most important factor);
• water resistance (no less important and protects the blocks from getting wet);
• good frost resistance;
• high adhesion (the ability to tightly adjoin the blocks);
• resistance to mechanical damage;
• elasticity (prevents the appearance of cracks during precipitation and in the process of expansion-compression at temperature differences outside);
• heat resistance (increases the ability to withstand the effects of fire, i.e. increases fire safety the entire building).

Before the beginning plastering works required preparatory work. Clean the wall surface from dust, dirt, bituminous stains or an old layer of plaster, paint.

The plaster solution for gas silicate blocks must be prepared following the instructions on the package in strict order. To begin with, the mixture can be poured into a container of sufficient size, observing the proportions in quantity and weight. For 1 kg of the mixture, 0.20 liters of water is usually required. It is very important to correctly add the required amount of water, since it is undesirable to dilute plaster mixtures of too thick consistency, and it is simply inconvenient to use too liquid plaster. A mixture of ideal consistency should be something like a cream.

Stucco mixtures can be mixed manually, but it will be more convenient, better and faster if you use a drill with a special nozzle.

Step-by-step instruction

It is necessary to plaster walls from gas silicate blocks in the following sequence:

Facade finishing takes place in three stages - priming, plastering and painting.

1. The wall is coated with a special primer, which is made from acrylate siloxane, which has strengthening and hydrophobic properties.
2. A fiberglass mesh is attached to the wall, which is resistant to alkali solutions and has a surface density of 200 g/m³. It must have high resistance to tensile loads and must not stretch.
3. Having previously installed the guide beacons, the solution is evenly applied to the wall. This is done using a plastering unit, trowel or bucket. The thickness of the plaster layer should not exceed 1.5 cm. If the plaster mixture is applied in 2 layers, then each layer should be within 7 - 9 mm.
4. Still fresh plaster is leveled with a plaster lath, the excess is removed with a wooden grater.
5. After letting the surface dry a little, it is rubbed off.
6. Not earlier than after 48 hours, the walls are covered with specially designed vapor-permeable paints, for example, ATLAS ARKOL S or FASTEL.

All tools must be thoroughly rinsed with water immediately after completion of work, otherwise the remaining plaster will harden and its removal will take a lot of time and effort.

The quality of the plaster layer is checked using a long rail (from floor to ceiling), which is applied in several places both horizontally and vertically. The presence of irregularities and protrusions relative to the plane of the rail is immediately noticeable. The allowable error is 5-7 mm, as it is imperceptible to the ordinary eye.

In order to increase the service life of the facade, top coat can be additionally treated with a layer of water repellent. But before applying, you must wait until the house dries as much as possible. That is, this can be done after 1 - 1.5 years after the completion of all finishing work (external and internal). The applied layer of water repellent should be as thin as possible.

Summing up, it is clear that plastering aerated concrete is not cheap, as many people think. Saving on materials can lead to disastrous consequences, as was shown in the example at the beginning of the article. Here we can confidently say this: the point is not in bad building materials, but in their incorrect and inappropriate use. And if a decision is made to plaster gas silicate concrete, then it is necessary to do this using only materials suitable for these works.