Plaster of aerated concrete walls. Internal plastering of aerated concrete walls: how to choose and apply a solution. What mixture to prefer as facade plaster

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 exterior and interior finishing due to porosity and high levels of 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 there are two types of plastering technology aerated concrete walls in the 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 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 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 the primer, aerated concrete walls are 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 the beacons, the internal plaster of the aerated concrete walls will lie flat, and the 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, a coat of primer for cellular materials must be applied. An important milestone preparatory work for plastering the facades of buildings made of aerated concrete is the reinforcement of the surface using 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. Main positive points 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.

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, opportunity 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. There are various types of finishes, but the most common is plaster. Let's try to figure out how to plaster aerated concrete inside the house.

Plaster options for finishing walls made of aerated concrete

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

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

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

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

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

Wall decoration inside the house can serve two purposes:

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

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

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

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

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

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

To disadvantages gypsum mixtures relate:

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

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

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

Interior decoration of the house from aerated concrete

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

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

In conclusion, I would like to remind you that regardless of how to plaster aerated concrete, compliance with the technological regimes indicated by the contractor plaster mixture, is directly related to the quality and durability of the work performed. 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.

One of the popular wall materials used for the construction of private houses is aerated concrete. But despite its fame, very often fatal mistakes are made at the stage of finishing an already built house, due to which the natural microclimate of an aerated concrete house is disturbed. And before starting detailed description the process of processing the facade, you need to figure out why such misconceptions are born, how to avoid them and what kind of facade plaster for aerated concrete should be.

A little about aerated concrete

To understand the issues of finishing, let's move away from this topic a bit in order to understand how important it is to do everything right and what affects the cladding technology. To do this, you need to plunge into the technology of block production. And if you briefly describe its description, then special additives are introduced into the finished cement-sand mortar, the result of the reaction of which is the formation of a porous structure. If we consider in more detail the body of gas silicate concrete, we can see not only microvoids, but also many tubules that dot them, forming an “open” cellular structure, which has a mass positive properties, such as:

• high heat capacity. It is provided not only by the porous body of the blocks, but also by their precise geometry, which allows the use of a minimum butt joint from a special adhesive composition, which does not allow the formation of "bridges" of cold;
• noise isolation;
• not susceptibility to various fungal formations;
• The "open" structure of the concrete creates a unique atmosphere inside the building - it will keep you cool in summer and warm in the cold season. But if you break this natural system vapor permeability, for example, illiterate plaster walls made of aerated concrete, then the house will be stuffy, and condensation will begin to accumulate on the walls, which will lead to mold.

But the cellular structure of aerated concrete blocks also has certain disadvantages:

• a high degree of water absorption leads to the rapid destruction of the walls without the possibility of recovery. Therefore, waterproofing is given Special attention;
• the structure, consisting of open pores, is very well ventilated, which makes the house quite cold, even despite good system heating;
• heterogeneity of the body of blocks, even the most high density makes them susceptible to mechanical influences, which are imprinted in the form of large chips and potholes.

But is it necessary to plaster aerated concrete blocks or is it necessary to install a more solid cladding? Of course, the ventilated facade system is perfect option for decorative protection of walls, but if you choose the best way to plaster aerated concrete outside and follow the technology, then this method of finishing will be no less effective.

When is the best time to plaster gas silicate walls

Aerated concrete belongs to the family of cellular concrete, so it has some of its general properties, namely shrinkage. This phenomenon is inevitable, and if finishing is done earlier than six months later, then its cracking is inevitable.

But as we remember, aerated concrete does not like water, therefore, after the walls are erected, rhinestones need to be treated with a deep penetration primer, which reduces water absorption. For reinsurance, you can cover the walls with polyethylene.

The rest of the plastering is best done in the summer, but if the planned finishing falls on a colder period of the year, then it is allowed to be carried out when the temperature at night does not fall below 0 0 C.

The quality of the erected structure of aerated concrete directly depends on the sequence of production of finishing outside the premises and inside. Consider possible ways analyzing their advantages and disadvantages.

Method 1 - parallel plastering inside and outside the house

The production of such a finish is very convenient from a technical point of view, and saves a lot of time. But if we consider this method from the other side, then it is less preferable, since the quality is lost and the characteristics of a newly built house suffer.

Any technology for plastering walls made of aerated concrete implies significant evaporation of moisture. Of course, most of it will be weathered with the help of natural and artificial ventilation, but the bulk of the moisture will fall on the walls. Simultaneously carried out plaster from the outside will clog it on certain time, which is undesirable.

Method 2 - when the exterior finish is carried out first

It is more logical to initially finish the walls of aerated concrete from the outside in order to prevent their destruction under the action of atmospheric phenomena. But this is not entirely true, if this is done, then the vapors will be directed inward, which is highly undesirable.

But even overwintered primed walls will easily give up moisture and all vapors in the spring, without destroying the structure. But if a house is being built near a body of water, then priorities change, and under such circumstances, you first need to protect the walls from the street from exposure to abundant moisture.

Method 3 - when interior decoration is carried out first

Of the proposed options, this one is the best, because the volume of moisture formed during the finishing will freely come out through the non-clogged pores of aerated concrete. After the plaster is completely dry, you can safely proceed to the cladding of the facade.

Treating the walls with a deep primer with this method of finishing will not interfere with the removal of excess moisture.

What mixture to prefer as facade plaster

Market building materials replete with a huge range of plaster mixtures intended directly for the processing of aerated concrete. If you believe the manufacturers, then they are all the best in their field. But this is far from true. Tabled Characteristics of Major Groups plaster compositions help you decide.

All vapor-permeable plaster, except for mineral, is available as a ready-mix. In this regard, studying the characteristics various kinds pay attention to the setting time. The longer it is, the easier it will be for beginners to apply the mixture.

But still, the preparation of a conventional cement plaster composition is much more profitable from an economic point of view. Therefore, all inexperienced builders are tormented by the question: “is it possible to plaster aerated concrete with cement mortar?”. The answer is unequivocally no, for the following reasons:

• low adhesion with a gas silicate surface;
• high humidity, which is detrimental to such cellular walls;
• low coefficient of vapor permeability, which will not allow moisture to escape.

Some craftsmen even manage to mix concrete mortar with a plaster mixture in pursuit of profit. But instead they get a lot of problems and the need for large Money to remedy the consequences.

Self-finishing the facade with plaster

There is nothing clever about how to plaster aerated concrete as competently as possible. Next is the matter of technology. Plastering can be carried out using several technologies:

• thin layer;
• thick layer.

There is no particular difference in them, the choice is yours, depending on which way it will be more convenient to apply the plaster.

Training

In both cases, before finishing, you need to prepare the base.

Stage 1. The walls are cleaned with a stiff brush from dirt.

Stage 2. Defects in masonry joints are eliminated with an adhesive composition.

Stage 3. If there are potholes in the blocks, they also need to be “patched” with the same masonry adhesive or mounting foam.

Stage 4. Beacons are mounted on nails - a profile along which alignment will occur.

Stage 5. The base of the walls is primed with a hydrophobic composition with a surface 2–3 mm thick.

Stage 6. After it dries, a composition for a 5 mm reinforced cloth is applied.

Stage 7. A reinforcing mesh (fiberglass or metal) is fixed on the walls with an overlap of 5 cm. It is better to do this with a solution than with self-tapping screws. Since in the first case, the grid will become one with the wall and, accordingly, will “sit down” together with aerated concrete, preventing the appearance of small cracks plaster layer. By the same principle, they are installed and fixed plastic corners. Only after the reinforcing plaster has dried can it be continued.

Thick plaster surface

When carrying out plastering using this technology, it is meant to apply one layer sufficient to perfectly level the wall - at least 10 mm.

Stage 1. Dilute the plaster mixture in a small amount.

Stage 2. The composition is thrown onto the walls.

Stage 3. The plaster is aligned with the beacons by the rule.

Stage 4. After plastering the entire surface of the walls, wait until it is completely dry and only after that you can paint as desired.

Thin-layer plaster surface

Plastering walls using multi-layer technology is also not difficult and is more suitable for beginners.

Stage 1. The first layer is applied in 3-4 mm on aerated concrete. Only after it has completely dried can you continue further.

Stage 2. The applied plaster is considered to be leveling, so special attention should be paid to evenness. Again, we are waiting for complete drying - about 3-4 days.

Stage 3. The final step - coating finish surface, which can later be overwritten if necessary.

Stage 4. After the previous application has dried, the walls can be painted.

To increase the life of the plaster, it is necessary to treat it with a water-repellent solution. It will extend the life of the plastered surface by almost two times. Especially the use of such compounds is relevant in areas with high humidity.

As you can see, plastering the walls yourself is not so difficult. On the first 10 m 2 you will develop your style of application, after which the process will go much faster.

Plastering of aerated concrete surfaces is a necessary measure due to the fact that the porous structure of the material allows moisture to pass through well, and this is unacceptable for the durability of any residential building. Aerated concrete bricks have high hygroscopicity. Therefore, facade plaster for aerated concrete is applied in without fail, preferably in two layers, and with preliminary protection of the walls with a primer and antiseptics.

Any atmospheric precipitation is the risk of wetting the walls of gas blocks, which, after drying, can begin to collapse, becoming covered with microcracks inside and outside the house. And this risk increases markedly in winter time, because the water in aerated concrete, when frozen, will expand and burst the building material, violating its monolithic structure.

Before plastering the facade and side walls of the house, especially in winter, the outer surface must be protected from moisture with a polyethylene film. After obligatory plastering, any surface can be fixed to the surface finished with mortar decorative material for outer cladding facade.

Purpose of finishing outside:

1. Increasing the heat and noise insulation of the building and premises;
2. Minimization of the probability of wetting the walls with precipitation;
3. Protection of external surfaces from contrasting outdoor temperatures;
4. decorative feature.

The application of plaster is the most common method of finishing facades and walls made of aerated concrete due to its relative cheapness and ease of execution. But even such a simple process requires study, so a small overview of the characteristics of the plaster compositions used in construction for outdoor work and the methods of plastering aerated concrete surfaces will be useful.

Three types of practical and cheap building materials for wall decoration are common, therefore, how to plaster aerated concrete should be decided after studying all the options:

Cement-sand mortar

1. This is the most common internal plaster mixture for builders, but it is not recommended to use it for plastering gas blocks from the outside, since the gas brick does not hold cement well. And, if a primer or fiberglass mesh can be used on the walls inside the house to hold the plaster cement-sand mortar, then these methods are not suitable for working outside due to the constant exposure to temperatures and precipitation. It is undesirable to protect gas blocks with a cement-sand mortar, since gas blocks immediately absorb moisture from the mixture. The reasons for the ban are as follows:
   1. The cement-sand mixture has a lower vapor permeability coefficient than aerated concrete. And the most important rule of the plasterer is to use a material whose vapor permeability coefficient is the same as this indicator or greater than that of aerated concrete;
   2. Expanded polystyrene or polystyrene is not recommended to insulate the house for the same reason.
2. The plaster applied on aerated concrete on cement contains a lot of water, since it is kneaded on it. Aerated concrete is initially produced with a high moisture absorption coefficient, so moisture from the solution will quickly get inside the wall, leveling the adhesion, layer quality and strength of aerated concrete blocks, because the main condition for the strength of concrete is slow setting and hardening;
3. Cement-sand mortar has low adhesion, that is, adhesion. Therefore, for plastering internal walls, lime can be added to the mortar in proportions of 1:10 (lime - cement);
4. Cement mortar must be closed finishing layer plaster, as the starting layer will be rough.

Construction adhesive mixture

1. Construction adhesive is a very expensive solution, and it is impractical and uneconomical to apply it in a large layer instead of plaster;
2. When plastering aerated concrete blocks with a building adhesive mortar, the vapor permeability of aerated concrete will decrease, since the glue does not pass air well. As a result of clogging of the pores in the blocks, the material may begin to crack, mold may appear in poorly dried places, local peeling of the adhesive plaster is possible.

Gypsum for aerated concrete

The positive aspects of plastering with gypsum mortar:

1. Gypsum plaster mixture quickly sets and dries;
2. Gypsum mortar does not shrink;
3. Even a thin plaster surface will be smooth;
4. For such plaster, a finishing decorative layer is not needed.

Flaws:

1. The vapor permeability coefficient leaves much to be desired;
2. Large water consumption;
3. Any atmospheric precipitation moistens gypsum plaster to the entire depth of the layer;
4. Due to too good adhesion, colored spots may appear on the surface due to the penetration of mineral dyes in the composition of aerated concrete into the gypsum layer.

Gypsum or alabaster is considered the most effective composition for plastering aerated concrete surfaces outside and inside the house. This mixture for finishing facade works has a vapor permeability coefficient, the same as aerated concrete, excellent adhesion, attractive appearance.

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

There are special mixtures for working on aerated concrete. It is preferable to use mixtures with the following properties:

1. High or medium vapor permeability;
2. Not more than 200 ml of water per 1 kg of the mixture for its mixing;
3. Minimum and maximum thickness a layer of plaster (the greater the difference, the better);
4. Index of adhesion with the main surface - ≥ 0.5 MPa;
5. Resistance to low temperatures;
6. Crack resistance;
7. Long working solution life.

Conditions for plastering aerated concrete surfaces

Carrying out plaster work warm time year suggests a rainy season, but wetting aerated concrete blocks is not as critical as freezing moisture inside them. Therefore, it is better to protect the aerated concrete dwelling with moisture-proof films at any time of the year, since the walls may simply not have time to dry in the fall before frost.

The newly erected walls of the house must dry out before they are plastered, therefore both construction and plastering on aerated concrete should be carried out in the summer. Due to the fact that the first row of gas bricks is usually laid on cement-sand mortar, the drying time of the walls increases, and this circumstance must be taken into account when calculating technological processes.

Applying two or three layers of primer to aerated concrete will significantly reduce its water absorption. The practice of building private housing has shown that best time for the construction of aerated concrete walls of the building - the season when the temperature at night does not fall below 0 ° C.

There are three options for finishing aerated concrete surfaces, taking into account the order of finishing work:

1. First held exterior finish. Private developers mistakenly think that first of all it is necessary to protect the house from the outside so that the walls do not get wet from rain and snow. But even wet in the fall, but primed aerated concrete in the spring will quickly dry at positive temperatures. With walls covered with plaster, moisture in winter will only evaporate inside the housing, which will not only extend the drying time of the walls, but also affect the occurrence of cracks on the internal walls of the house;
2. The first is interior decoration. With such an organization of the process, the moisture accumulated in aerated concrete has only an outlet to the outside, and the possibility of cracks will be minimal. Therefore, this finish option is considered the most correct;
3. Exterior and interior decoration is carried out simultaneously. This option is the worst of all three. Moisture in gas blocks is clogged, and its slow evaporation will lead to cracks, mold, and peeling of the plaster layer.

Internal plastering technology

Before plastering the walls, they must be leveled with a special planer, grinder or grater on aerated concrete. Leveling will help save on the thickness of the plaster layer - if you apply too thick a layer, the plaster may begin to crack or even peel off.

Sanded walls should be primed, but it is not recommended to dilute the primer with water. Then metal beacons are attached to the walls - 2-3-meter perforated ribbed corners that determine the thickness of the plaster layer. The corners are attached to plaster or alabaster, the distance between them is determined by the width of the rule or the widest spatula. The verticality of the fastening is checked by level.

On the walls for aerated concrete, the plaster is applied from the bottom up, and leveled with the rule. Voids and irregularities are filled with mortar using a smaller spatula. After an hour and a half, when the first layer of the solution has set a little, it is moistened with a spray bottle, and leveled with a wide spatula (rubbed). It is desirable to remove lighthouses before this operation, as they can serve as the point of occurrence of "cold bridges". Internal corners are aligned and reinforced with the same beacons, the outer corners are reinforced with a metal perforated corner without ribs, and a fiberglass mesh. After the last layer has completely dried, the wall must be rubbed.

If the interior walls are to be painted, it is recommended to use a paint with good vapor permeability, for example, acrylic, water-based or PVA-based paints, as well as those based on organic solvents.

How to plaster aerated concrete inside the house updated: January 23, 2017 by: Artyom

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 other precipitation is a 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 the best mixes for finishing the facade, and also describe the technology of plastering walls in the form step by step instructions understandable to beginners with no 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 external and internal walls of aerated concrete. Facade plaster 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.

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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 the warm season. 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 work 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. Ground 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 a 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 as a ready-made mixture. 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.