Internal plastering of aerated concrete walls: how to choose and apply a solution. Plastering walls made of aerated concrete indoors: wall plastering technology with installation instructions Do-it-yourself plastering walls made of aerated concrete

Repairs inside or outside the premises will not do without plastering walls and other surfaces. At the design stage it is necessary to familiarize yourself with the features of plaster, which are divided into types, they differ in characteristics and price. The right type of finishing material is half the battle, because Mixture characteristics can vary significantly., and what is ideal for one type of room may be completely unacceptable for another.

Some features of plaster

Plaster is a mixture that is used for surface treatment as a rough finish. What are the functions of the material? With the help of plaster, you can level the walls, repair cracks and other defects. Itself the structure of this solution is a coarse mixture, so after drying the surface will have rough surface. These effects can be easily eliminated in the future.

You can plaster walls of almost any type, concrete and wooden structures will be protected from the harmful effects of environmental factors. Various techniques and materials are used for plastering walls made of aerated concrete. Trends in the field of construction are developing in such a way that such building material as aerated concrete is becoming increasingly popular. It has a lot of advantages in comparison with concrete and brick construction.

The building, erected from aerated concrete, has increased energy-saving properties. This material is much lighter than traditional analogues, due to this fact, it is possible to reduce the cost of arranging the foundation and the construction time is significantly reduced. What kind of plaster is better to plaster the walls of aerated concrete blocks?

How to plaster aerated concrete walls?

One of the ways to finish walls made of aerated concrete is plastering. For plastering walls from blocks of cement-sand type - this is the best option. As for the process of applying the finishing layer, if desired, you can apply it directly to the wall. The same can be done with brick walls. However, some difficulties may arise in doing so.

The brick is small, so seams between bricks serve as a connecting element when applying plaster. In the case of aerated concrete, the situation is somewhat different, because the aerated concrete itself is large. This problem can be solved in several ways. Consider the main ones that are often used in practice.

Walls can be plastered both inside and outside the room. Both types of finishes have some features. When choosing a plaster, it is best to choose the one with the highest adhesion coefficient. This is to ensure the quality of adhesion of materials.

Preparatory work

Before applying a layer of plaster, the walls of aerated concrete are preliminarily prepared, this is necessary in order to ensure adhesion of materials. How is it done and what does this stage of surface finishing include?

First, you need pay attention to the seams between aerated concrete, they need to be well sealed, approximately 4 - 5 mm. The wall is leveled, and all defects that may occur, dust and other trace elements that reduce the quality of adhesion of materials, are cleaned. To clean the surface, you can use sandpaper, which will help to more thoroughly sand the blocks.

How to use the grid when plastering walls?

If you decide to use the third method of surface finishing, then you need to know what is used in this case. galvanized mesh. It is more durable, reliable and does not rust. As for the size of the grid cells, you should pay attention to the one in which the cells are small. After carrying out the preparatory work, it will be necessary to attach the grid directly to the wall. This must be done with ordinary nails. They are driven into the wall first by one third, after which the nail is bent, fixing the grid.

Particular attention should be paid to the edges of such a section, they usually stick out, before applying the plaster, all edges should be bent, then they will not stick out from under the plaster.

When the mesh is fixed, it is necessary to start applying the first layer of plaster. This is done in a way known as "spray", it is mainly used to fill grid cells with mortar. After it, several more layers of plaster will follow. This will necessarily be a primer layer, which must be kneaded by adding slag sand to the solution. The final layer will be the final layer, to prepare the solution for it, you must use fine sand.

All layers of plaster can be apply when the previous layer is not completely dry. This will reduce the time without reducing the strength and quality of the finishing layer.

Wall plastering mortar can be purchased ready-made, it is sold in a dry state. To prepare the mixture, you just need to add water. But, you can also prepare a cement-sand mortar yourself. In this case do not save on the quality of the cement itself, since the water-repellent ability of the plaster will suffer as a result. When plastering walls, a lot of tasks and requirements are solved, such as thermal insulation characteristics of the surface, water resistance, sound insulation, and so on.

Aerated concrete is a cellular type of concrete, has a porous structure. Therefore, buildings made of aerated concrete blocks easily absorb moisture. Accordingly, for their greater resistance to bad weather, the material requires protection. Among the most common methods is the use of plaster. Let us consider in more detail the features of plastering gas blocks, where to start, what tools will be required, what finishing technologies exist in this way.

Aerated concrete absorbs moisture very well, so you need to protect it

When to start finishing the walls of aerated concrete

The main distinguishing feature of aerated concrete is its increased hygroscopicity. Moreover, when the structure gets wet, when the temperature is above zero, negative consequences can be avoided - it will simply dry out, everything will be fine, but when water gets into the pores of the stone in winter, it freezes, respectively, expands, cracks may appear.

Given this, it would seem that the sooner the walls are plastered, the better. But this approach is wrong. It is ideal to carry out these activities for the next season, when the surfaces are completely dry after laying. Drying time depends on which mortar was used during masonry. For example, a joint made with a concrete-sand mixture will take longer to dry than one where the adhesive mixture was used, since it turns out to be much thicker.

Plastering is recommended for the next season

Another condition for finishing walls made of aerated concrete, which is recommended to be observed in order to achieve a high-quality result, is the need to do everything in warm weather. Experts call March-October the optimal time, when the air temperature is above zero. If this is not possible, it is necessary at least to cover the stone with a primer, cover it with plastic wrap, so that it will stand without losing its properties until it is completely finished. The most effective water absorption will be reduced by a deep penetration primer.

But sometimes there is no opportunity to postpone finishing work - it is required to carry it out immediately after the completion of the construction of the walls of the building. Here, experts recommend paying especially close attention to the composition of the solution. It must have good plasticity, vapor permeability, then moisture can freely go outside.

If you need to plaster immediately, then you need to carefully select the material

Which side to start finishing the gas block building

There are three options for where to start covering aerated concrete wall blocks. Each has its own characteristics, and only one is considered correct. In particular, you can start:

1. outside;
2. from within;
3. simultaneously from both sides.

Experienced builders recommend starting to plaster outside only when the dwelling is located near water bodies. The primary task here is to protect aerated concrete from water and wind. Under other circumstances, the method of processing from the outside is not suitable - if you plaster the stone from the outside, all moisture will go inside the house, which may cause cracks, and the drying process of the joints after the masonry is completed will be significantly delayed. In addition, the stone itself may begin to break down. Plastering walls made of aerated concrete indoors will help to avoid the above problems - this method is considered the most preferable due to its effectiveness. The third method is considered the most unpopular way to finish walls made of aerated concrete - despite the good properties of vapor permeability, having "blocked" moisture from both sides, it will have nowhere to go, which sooner or later will lead to the detachment of the finishing mixture from the block itself, and subsequently - even destruction of the latter.

Plastering only needs to be done on one side.

Sequence of work

Plastering aerated concrete blocks contains three stages. Before plastering aerated concrete, it is necessary to apply a special primer with a brush or roller, designed for building materials that absorb moisture well. The greatest efficiency is achieved by applying the solution evenly, that is, there should be no dry spots. After the end of this stage, the primer should be absorbed and dry.

At the second stage, a special reinforced mesh resistant to alkaline components is fixed by means of self-tapping screws. The mesh is fixed at a certain distance from the stone - there must be free space between them.

The final, third, stage is directly plastering walls from aerated concrete. Here it is important to choose materials whose vapor permeability properties are higher than those of aerated concrete itself. It is possible to increase the service life of the surface, while maintaining its attractive appearance, in a year by covering it with a water repellent.

The material for plaster must be chosen with greater vapor permeability than that of aerated concrete

How to plaster - requirements, nuances

Aerated concrete plaster will become of the highest quality, it will not have to be re-made in a short time if the composition of the mixture meets certain requirements, and the packaging contains special markings. Among other things, it must be characterized by:

1. resistance to cracking, drying out, fading;
2. increased ductility without compromising strength;
3. good adhesion to porous types of concrete;
4. water-repellent properties;
5. high level of vapor permeability.

Compliance with such criteria is especially important when applied outside the building.

Even taking into account the large number of different types of modern plaster mortars, only a few have these characteristics, therefore, the following are most often used when processing aerated concrete.

Silicone plaster is perfect for finishing aerated concrete outside.

Silicone plaster for aerated concrete has the most advantages. Resistant to adverse weather conditions, has good vapor permeability, water repellency, and is easy to apply. There are no disadvantages of this type in operation, except for its high cost, which is nevertheless compensated by the long service life of the coating.

The second place belongs to silicate plaster for aerated concrete, which has a suitable level of vapor permeability, low water absorption. The main disadvantages are a small color palette plus the loss of the initial attractiveness of the silicate appearance when dust enters.

In third place is plaster based on cement with lime. It also has the necessary qualities to cover this type of structure.

Plastering aerated concrete can be carried out with a mixture based on cement

Often, gypsum mixture is also used in such houses. Its advantages: it dries quickly, subsidence is excluded, there is no need to apply a finishing layer of plaster, in addition, you can make the surface as smooth as possible. However, the solution has its drawbacks. This includes average vapor permeability characteristics, susceptibility to rapid wetting from precipitation, in addition, spots may appear during its operation.

In addition, acrylic solutions are used for processing. Their rather significant advantage is strength, but one must also remember about the disadvantages - low fire resistance, which is why it is used only in certain rooms, a relatively low level of vapor permeability. To prevent condensation from accumulating in the pores of aerated concrete, experts recommend using additional ventilation or internal waterproofing.

Having studied the characteristics of all the materials presented, everyone can independently choose how to plaster aerated concrete.

Aerated concrete finishing scheme

Tools Used

Plastering of aerated concrete walls is carried out by means of tools used in the processing of other surfaces. Beating off the protruding parts of the walls, making them smoother, installing notches where they are needed, is done with a plaster hammer or hatchet. The deep penetration primer is applied with a special brush (brush). You will also need a plumb line (it helps to install beacons to cover the desired surface with a solution), a building level, a square, metal shears, a puncher, a hacksaw, and other standard tools. Regarding lighthouses, there are several options. The first is to purchase specialized metal beacons in a hardware store, fortunately, their choice is now quite wide.

Before starting work, you should prepare all the necessary tools

The second, “old-fashioned”, method is to use improvised means: even blocks of wood, pipe trimmings, and other suitable “details”. Thanks to the beacons, the plane is perfectly flat, the angles are correct. The listed tools will come in handy if the plastering of aerated concrete walls is done manually.

Special equipment can provide faster uniform application. The method is more expensive financially, but this is fully compensated by the quality of the end result: due to the implementation of plastering under pressure, the bonding of the solution to the surface of aerated concrete is quite strong.

Machine plastering is a bit more expensive

Coating Technology

The technology for finishing walls with plaster for aerated concrete is quite simple - it is performed in four steps:

1. preparatory stage, where, before plastering aerated concrete, it is leveled, thus reducing the consumption of the solution;
2. padding;
3. coating with a thin layer of plaster of aerated concrete walls, which will continue to act as a base when fixing the reinforced mesh;
4. mesh reinforcement (to prevent cracks).

For reinforcement, a metal or fiberglass mesh is used. Moreover, special attention during its installation must be paid to windows and doors - places where the most significant load.

Having fixed the grid, the plane is covered with a finishing layer of plaster, and when the coating dries, the so-called grout is performed, that is, the surface is relieved of bumps, roughness, and other minor defects.

Before plastering aerated concrete, the wall should be leveled

Features of finishing aerated concrete

Starting to cover aerated concrete with plaster, you should take into account the features of this material. First of all, experts recommend avoiding the traditional combination of cement and sand. The corresponding coating can crack, fall off over time, and it also contains a lot of water, which has a devastating effect on the walls themselves.

When plastering gas blocks, a prerequisite is the intended purpose of all means specifically for cellular material.

Experts recommend not using cement mixtures for finishing aerated concrete.

It is also important to start work on the exterior cladding of the facade, when all the “wet” interior work has already been completed, then condensation can be avoided inside the walls. Moreover, the thickness of the plaster layer inside the building should be twice as large as the outer one, otherwise the water vapor will remain inside the blocks, they will become damp. This is the only difference between carrying out these works inside and outside - the technology itself remains unchanged.

If you take into account the recommendations of experts, aerated concrete will serve you for a long time.

Thus, we see: with all its advantages, the building material is still quite fastidious and requires special treatment. And in order for it to retain its useful properties to the maximum, a number of measures must be taken. But following the above recommendations, it will prove to be a very reliable material, last a long time, and the home will be cozy and comfortable.

Video: Aerated concrete plaster, base preparation

Video: Aerated concrete putty and plaster

Exterior and interior plastering of walls made of gas silicate blocks has become a widespread type of finishing work due to the widespread use of this material in the construction of individual and multi-apartment residential buildings. Gas silicate products provide good thermal protection of the premises, significantly reduce the load on the foundation, but the plastering technology requires knowledge of the purpose and behavior of each component involved in this process. Otherwise, the strength of the coating on the plastered wall will be less than expected.

Subtleties and tasks of plastering on gas silicate

The task of proper wall plastering is important specifically for gas silicate blocks, because due to their specific structure they have a very high degree of vapor permeability. Saturation of the entire mass of the material with water vapor during the season of severe frosts will lead to the destruction of its structure by the expansion of ice crystals.

To reduce the intensity of the process to an optimal value that does not pose such a risk, and to establish a comfortable balance of humidity and temperature in the house, the brand of plaster used should be used.

As an example, we can give the characteristics of a typical plaster mixture, summarized in the following table:

On the packaging of its products, the manufacturer indicates recommendations on the possibility of application to certain surfaces. Usually on the front in large print it is indicated whether this composition is intended to plaster.

Fundamental points

In order to perform its function in full, it is necessary to comply with some requirements. They are associated with the characteristics of the material, which also appear after it is laid in the wall structure.

Depending on the planned deadlines for the completion of all construction work, the following points are taken into account:

1. Permissible humidity, which is inherent in gas silicate products at the exit from the production line, is up to 30%. The procedure for drying the entire array takes at least 1 cycle of operation, therefore, after the first winter, the blocks tend to have large or small cracks. Before the start of finishing work, the laid out box of the building is kept, if possible, for about 1.5 years. If such a period is unacceptable, then it is better to plaster these walls inside the house first, so that the moisture has the opportunity to evaporate through the outdoor area accessible to air movement.
2. The appearance of cracks can also be caused by shrinkage of the foundation. Before plastering the walls, you need to let the house settle for 1 - 2 cycles of freezing - thawing of the soil. Otherwise, the cracks in the plaster will turn out to be deep into the main material of the walls and cosmetic rubbing is no longer enough.
3. Air circulation from the outside is provided using the operational capabilities of the ventilated facade of the house. Facing with various types of panels (stone, wood, siding) or the use of well brickwork creates conditions for the constant removal of moisture vapor through a specially left air gap.
4. Do not use moisture-proof extruded polystyrene foam as an external insulation. It will trap condensate at the border of contact with the masonry.
5. The problems of high humidity in individual rooms in a residential building should not be solved only by plastering blocks and selecting a composition with exceptional characteristics. In the future, the walls in this room can be additionally protected with moisture-resistant tile adhesive or finish coatings (tiles, waterproof paint or vinyl wallpaper).

One of the options for the appearance of defects on gas silicate blocks 1-2 years after laying is visible in this photo:

The reason for the destruction is that a material such as aerated concrete needs reliable protection from aggressive environmental influences and destructive forces:

• mechanical damage;
• precipitation;
• ultraviolet;
• direct ingress of water;
• weathering.

The porous material intensively absorbs water, which, expanding upon heating or freezing into ice, breaks the cellular structure.

The means of protection will be waterproofing the basement, covering with a layer of plaster (outside and inside the building), arranging external thermal insulation.

The efficient operation of gas blocks is largely determined by the consistent and high-quality creation of an internal vapor-tight plaster barrier.

Stages of plastering aerated concrete

Plastering of walls from gas silicate blocks should begin with thorough impregnation of the entire area of ​​\u200b\u200bthe wall with a special primer. Unlike, which has a closed porous structure, open pores are formed in the material during production, since fine aluminum chips are added to the base solution as an additive. It is the main gas generator when reacting with the lime present in the liquid mixture.

The purpose of the primer in this case is to close the surface pores, prevent active absorption of moisture from the plaster solution (give it sufficient time for uniform hardening), and ensure high adhesion for strong adhesion to the surface.

Impregnation with a primer can be applied liberally without gaps over the entire wall using a sprayer or roller, as in this photo:

Attempts to replace special compounds with simple spraying with water, as a rule, give a poor result in terms of the strength of the resulting plaster - the material absorbs moisture very quickly, and if it is soaked in a large amount of water, it will not give it back.

Reinforcement

To prevent subsequent cracking of the plastered surface, to maintain the integrity of a monolithic seamless solid mass - this is the task facing. In building mixtures based on cement or gypsum, there is a pronounced alkaline environment, so fiberglass must be resistant to this category of substances.

During laying, gas silicate blocks form a fairly flat plane, which, if necessary, can be easily further leveled with a grater with an abrasive nozzle, therefore, a sufficient thickness of the plaster layer is from 2 to 7 mm. It has a flat grid.

On walls of a large area (height), it may be necessary to level the plane with plaster vertically or horizontally. Then it is advisable to choose a more durable coarse mesh, as in this photo:

A flat mesh is pressed onto a thin (1 mm) layer of plaster or glue, which is covered with another layer of plaster mixture. The total thickness of the resulting coating should not exceed 1 cm.

Advice on how to determine the need to reinforce the internal plaster of walls made of gas silicate blocks is discussed in this video:

Requirements for the technology of applying plaster

External plastering work on the blocks is started only after the completion of the finishing work of the wall from the inside of the house, the completion of wet mortar processes for the installation of floor screeds, plaster, puttying work.

All the moisture evaporating during these operations comes out not so much through ventilation and other openings (drafts are harmful here), but is actively absorbed by the surrounding materials and then tends to the outside through the pores of the gas silicate walls.

If the walls on the facade of the building are plastered prematurely, then the made external protection in the cold season will be collected at the border of plaster and aerated concrete, freeze and tear off the plaster layer (shooting, peeling).

The decision on how to plaster gas silicate is made taking into account such factors:

1. Cement-sand mortar is poorly suited for this purpose for the following reasons: poor adhesion due to rapid loss of water (a primer will not always help); a significant decrease in the vapor permeability of aerated concrete (violation of the microclimate inside the house). For exterior decoration, the use of a cement-sand mixture prepared according to the usual recipe is simply unacceptable. This leads to a violation of the basic rule - the vapor permeability of a multilayer wall should increase from the inner layer to the outer one or be a comparable value.
2. A solution of a dry plaster mixture (for gas silicate blocks) must be prepared strictly according to the manufacturer's instructions indicated on the product packaging. A mixing container is taken of sufficient size, maintaining with accuracy the recommended proportions and water temperature. The amount of water added is strictly metered, since subsequently it is undesirable to dilute the swollen plaster mixture with an overly thick consistency, which has been aged for the prescribed time, and a too liquid solution will drain. Uniform stirring to a homogeneous mass is best done with an electric drill with a special nozzle.
3. In addition to strength, for exterior plasters, attention should be paid to frost resistance and elasticity. Outside temperature fluctuations create the prerequisites for the appearance of cracks in too rigid monoliths. We should not forget about the flammability class of the material - fire resistance is an important indicator of home safety.

Estimated consumption of the necessary materials and approximate prices for determining the budget structure are shown in the table:

The approach than plastering gas silicate blocks inside is simpler - for this purpose there is a wide range of gypsum compounds for interior work, which do not need to resist weather conditions.

You should not refuse the procedure to plaster the room from the inside, limiting yourself to making a thin coating from one putty. The effort expended should form a full-fledged wall covering.

Saving on cheap materials or on their quantity often leads to bad consequences. It can be confidently asserted that the problem is usually not in bad building materials, but in their improper use. If there is a need to plaster gas silicate blocks of external walls, then this should be done using only specially provided materials for such types of work.

Renovation inside the premises is carried out in several stages. When carrying out repair work, it is important not to forget about plastering concrete walls from the inside. Plaster for aerated concrete plays an important role, even when it comes to work in modern panel buildings. As a rule, concrete slabs have an uneven surface, and this defect cannot be corrected with putty alone. Block coverage is necessary for a number of reasons. These include the smoothness and cleanliness of the wall surface.

Ways

For plastering the internal surfaces of a building, during the construction of which aerated concrete was used, two methods are used. The first method is that plastering on aerated concrete is carried out in such a way as to achieve vapor permeability in concrete walls due to the unique qualities of the material. Builders do not recommend using mortar and cement and sand for finishing blocks indoors. Aerated concrete blocks instantly absorb liquid, after which they become covered with cracks. It will not be easy to mask the irregularities that have appeared even after priming the vapor-permeable wall.

Some specialists are engaged in plastering gas blocks using a different method - vapor barrier. At the same time, the indoor climate will be the same as in reinforced concrete buildings. The only difference is that such plastering will be more reliable.

Promotes vapor permeability of the walls

The components contained in aerated concrete contribute to the vapor permeability of the building material. However, this factor requires the selection of a certain composition of mixtures for repair and finishing work on the walls of the building. To do this, it is necessary to perform plastering in such a way that the inner wall is vapor-permeable or, on the contrary, vapor-proof. In a house with such a wall, the microclimate will self-regulate. In addition, they will not be in the wall.

vapor barrier

To process the inner wall and increase the vapor barrier at least ten times, experts apply a solution, the thickness of which should reach two and a half centimeters. The plaster contains cement and other ingredients. Sometimes, for this purpose, workers put a film of polyethylene under a layer of plaster. But experienced builders are not advised to carry out such work, since the film can peel off plasters and walls due to condensation.

What materials and tools are used?

Everything depends primarily on the task that customers and specialists have set for themselves. For its implementation, building materials are selected that can properly interact with aerated concrete and have the property of vapor permeability. Professionals recommend treating the inner surfaces of the walls of the blocks with a mixture of gypsum, sand and lime. Builders also use tools that include chalk or marble.

For finishing work, specialists use tools for plastering. The mixture is prepared in containers of the appropriate size. The solution is mixed with a mixer either. Thin-layer plaster on aerated concrete is applied to the blocks with a trowel or trowel. Rubbing surfaces is carried out using a grater. A half-ter is used to remove excess mixture. The surface of the blocks inside the walls is leveled with beacons. The aerated concrete plaster is pulled together by the rule between the guides. Builders determine the quality of the work carried out with a rail.

Aerated concrete has long been loved by private developers for its excellent performance and very attractive cost. However, before starting construction from it, you need to study all the "pitfalls" in this matter in order to build a high-quality and durable structure. So, when planning the finishing, it is important to know how to plaster aerated concrete inside the house, and what materials are prohibited. What are the reasons for such restrictions and what kind of finish is ideal for gas silicate blocks, we will consider below.

Features of finishing aerated concrete walls

Before you plunge headlong into the issue of finishing the walls, you must first understand the structure of gas blocks, from which the quality of the future home will completely depend.

The main way to obtain this cellular material is the introduction of special additives into the composition of the concrete solution, which, when reacting, form air bubbles that tend to break out. They simply streak the aerated concrete body not only with voids, but also with thin channels, forming a surface that resembles natural pumice in its texture. Such a structure has excellent positive properties with the correct final processing of blocks:

• high sound absorption coefficient;
• good level of thermal insulation;
• "breathing" walls create a unique microclimate in the room, keeping warm in the winter season and cool even in the most intense heat;
• the porous structure of aerated concrete is not subject to the emergence and maintenance of colonies of fungal and other microorganisms, which, as a result of their vital activity, destroy walls.

The porous structure of aerated concrete

But despite these wonderful performance characteristics, aerated concrete also has disadvantages due to its structure:

• the porous structure is subject to increased water absorption, which is fraught with the rapid destruction of blocks;
• products with the highest density index, and, accordingly, strength, do not differ in resistance to mechanical stress, leading to spalls and cracks;
• the heterogeneous structure, which retains heat so well, is very sensitive to wind. Unprotected bare aerated concrete walls are strongly blown, and it is cold inside them, even despite a well-organized heating system.

Taking into account all these negative circumstances, we can conclude that aerated concrete walls need to be finished. But it must be done as competently as possible so as not to disturb the microcirculation inside the walls, which can lead to destructive processes.

Vapor permeability

The porous structure, which has been talked about so much, has another property - good vapor permeability, which is the key to the durability of any structure made of cellular concrete.

In the process of life, people release a large amount of all kinds of moisture into the atmosphere. Just imagine how the air is saturated with it when ironing, washing, drying clothes, cooking or taking a bath. Of course, part of the vapors formed is removed using artificial and natural ventilation, but the main volume falls on the walls. In its pure form without finishing, aerated concrete perfectly passes moisture without retaining it inside its body.

Another thing is if there is a facade and interior cladding, and it is required for such wall material. Therefore, both finishes should complement each other, organizing the maximum natural removal of moisture.

For example, a ventilated facade system was chosen as an external finish. In this case, the provided ventilation gap does not disturb the natural balance of moisture in the aerated concrete wall, leaving complete freedom for the vapors to escape. Under such circumstances, any plaster for aerated concrete can be used.

Ventilated facade - the best type of exterior finish for aerated concrete walls

In the case of a wall insulation device, you need to pay attention to the characteristics of the base material. For example, mineral wool fully complies with the requirements - it insulates with high quality and does not prevent the removal of moisture. As in the previous example, the steam circulation is not disturbed and the wall remains dry, so any plaster mixture can be chosen.

How to maintain natural moisture balance

But often, for one reason or another, facade decoration is arranged to bypass the basic rules, or, even worse, the insulation was made with foam sheets (its vapor transmission capacity is almost zero) without a ventilation gap. This leads to the accumulation of moisture in the thickness of the wall, which eventually manifests itself in damp corners, the collection of condensate in the room - and these are the first harbingers of the appearance of fungal mold.

The consequence of violation of the vapor permeability of aerated concrete walls

Such a serious defect can be corrected only by using materials for interior decoration, whose ability to pass vapors is much lower than that of aerated concrete. This shielding method will prevent the accumulation of moisture inside the walls. Best to use:

• paints with a special composition;
• waterproof wallpaper;
• cement-sand plaster mortars of dense consistency.

But in this case, the importance of a high-quality ventilation device is significantly increased so that the accumulated moisture does not settle on the walls and inside the room, forming a greenhouse effect.

In order not to complicate the construction process, it would be most correct to initially produce interior decoration. After all, the repair involves a large amount of evaporated moisture, which simply needs to go outside, and it is best if it does this through the “bare” gas silicate walls.

And one more small nuance regarding the timing of the processing of walls made of aerated concrete blocks. Any cellular materials shrink well, which, in turn, negatively affects any fine cladding - this usually manifests itself in cracking and peeling of the decorative layer.

Therefore, it is recommended to carry out both internal and facade finishing processes at least six months after the complete erection of the building box and the roof device. It is best to plan this stage of construction in the spring - summer period. As mentioned above, the interior decoration is carried out first, after the end of all processes, in a month you can start processing the facade.

What plaster to prefer for interior decoration

As noted above, aerated concrete blocks are characterized by a high degree of water absorption, which can lead to excessive drying of the applied layer of plaster. This is especially evident on gypsum compositions and cement-based mortars - fast drying, cracking and shedding. If, on the other hand, we go from the opposite, and unnecessarily saturate the wall with water, then it will simply be impossible to plaster it, since the applied layer will not be held on the aerated concrete base.

Choosing the right materials will help solve this problem:

• primers of deep penetration with a special composition. When applying them, the main thing is not to overdo it and not oversaturate the surface of the wall with moisture. Therefore, before use, read the instructions and follow them strictly;
• special mixtures intended for plastering exactly gas silicate blocks. Their composition perfectly protects such “capricious” porous surfaces. But this is subject to the dilution of the plaster in the correct proportions with water. Only following the instructions for use from the manufacturer will help not to make a mistake in this matter.

But that's not all. The cellular surface does not have good adhesive qualities. For this reason, it is initially necessary to apply a rough layer of plaster with a thickness of at least 5 mm. But even this finish is prone to cracking and flaking. To prevent this, a plaster mesh is used. Fiberglass or polyurethane sheets are best preferred due to their excellent alkali resistance and long service life. Only after applying such a reinforced plaster layer and its complete drying, you can safely proceed to the fine finish.

The best plaster mixes

Having figured out a little about what parameters the finishing mixture should meet, let's look at its most popular and effective types:

• plaster compositions based on silicates, namely "liquid glass". They are perfectly combined with aerated concrete surfaces, especially in terms of vapor permeability. But there is a small "but". Such plaster mixtures are incompatible with many types of fine finishes, for example, based on acrylic, latex, silicone;
• gypsum plasters with perlite sand. They are ideal for aerated concrete wall surfaces, as indicated on the packaging. Any material for finishing is suitable for them;
• plaster mixtures on a cement-lime basis with the addition of optimizing additives. Such compositions were invented specifically for finishing cellular material, even without a preliminary primer. The internal plaster of walls made of aerated concrete of a similar plan has not only excellent adhesive properties, but is also applicable for both rough and finish finishes.

The use of such plaster compositions is ideal for gas silicate walls and, if desired, you can use them to apply a leveling layer yourself. Like all specialty materials improved for one application, these mixtures come at a very high cost, which in the end adds up to a decent amount.

But there is an alternative that will economically resolve the issue of internal plastering - the use of a conventional cement-sand mortar in a ratio of 1:5. But it must be used with extreme caution in relation to aerated concrete surfaces and not overdo it with the addition of water to the working mixture.

The process of self-interior plastering

Even if you decide that indoor plastering of aerated concrete walls will be done by craftsmen, it will not hurt to know the process of its implementation. After all, even professionals can sometimes make mistakes, and control from the outside will help to avoid annoying shortcomings.

Preparing for plastering

The algorithm of the process for preparing walls for plastering is quite simple in execution, in which it is impossible to make a mistake. Therefore, you can do it yourself. This will require:

• or plastic 100-120 cm wide;
• adhesive for ceramic tiles;
• deep penetration soil;
• notched trowel with 5-6 mm teeth.

Stage 1. Carefully inspect the walls for construction "jambs". For example, cracks and chips are subject to putty with alignment to the general level of the walls. For these purposes, a regular repair mortar is suitable, however, if it is not needed so much, then it is best to use an adhesive specifically designed for aerated concrete.

Stage 2. After drying the restored parts, go over all the walls with a stiff brush to remove dirt and dust.

Step 3. Apply primer in one coat. You can do this in a way convenient for you, for example, using a roller or brush. To reduce the consumption of the primer solution, experienced builders will use conventional sprayers. If there are none at hand, then you can just as well use an old model of a vacuum cleaner, the principle of which is to blow air. Only after high-quality drying of the first layer, you can start applying the second.

Stage 4. When the primer is completely dry, you can safely dilute the glue, according to the instructions and cut the plaster mesh into strips, the length of which should be equal to the height of the walls.

Stage 5. Starting from the bottom, pour the prepared glue onto the wall, gradually moving up. The thickness should be approximately equal to a layer of 5 mm, and the width should be slightly larger than the width of the mesh.

Step 6 Apply a strip of stucco and press it firmly into place on the wall. Now you can level the adhesive layer with a notched trowel so that the direction of the grooves runs horizontally. This improves adhesion to both the wall and future plaster.

Applying plaster

After the reinforced layer is completely dry, you can safely proceed to the main plastering process.

Stage 1. Wielding the building level, profiles are exposed - beacons.

Stage 2. The working solution is mixed according to the instructions. If the choice fell on the traditional cement-sand composition, then it is taken in a ratio of 1: 5, a plasticizer is added and kneaded to a thick consistency.

Alignment of the solution on the beacons

Stage 3. A solution is thrown between the two beacons along the entire height of the wall. Using the rule, the resulting layer is leveled to the required level of smoothness. Once again, attach the rule to the wall and check if there are gaps between them. If there is, add a mortar and level it, no - fine, plaster all the walls in a similar way.

The described plastering technology is quite simple and even an inexperienced master can successfully use it. The main thing is that it is correctly chosen how to plaster the walls of aerated concrete inside the house.