Than aerated concrete is plastered inside the house. Technology of plastering walls from gas silicate blocks Plastering of internal walls from gas silicate blocks

External and internal 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 apartment buildings. Products made of gas silicate provide good thermal protection of premises, significantly reduce the load on the foundation, but the technology of plastering 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 gas silicate plaster

Task correct plastering walls are 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 material with water vapor during the severe frost season will lead to the destruction of its structure by the expansion of ice crystals.

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

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 for the possibility of applying to certain surfaces. Usually on the front part it is indicated in large print whether this composition is intended for plastering.

Principal points

In order to fulfill 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 has been laid in the wall structure.

Depending on the planned completion date of all construction works take into account the following points:

The permissible humidity, which is inherent in gas silicate products at the exit from the production line, is up to 30%. The drying procedure for the entire massif takes at least 1 cycle of operation, therefore, after the first winter, blocks tend to appear 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 first plaster these walls inside the house so that moisture can evaporate through the external area accessible to air movement.
Cracking can also be caused by foundation shrinkage. 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 be deeply embedded in the main material of the walls and cosmetic rubbing will no longer be enough.
Air circulation outside is provided by using the operational capabilities of the ventilated facade of the house. Cladding with various types of panels (stone, wood, siding) or the use of a well brickwork, creates conditions for permanent removal of moisture vapor through a specially left air gap.
Do not use moisture-proof extruded polystyrene foam as an external insulation. It will retain condensation at the border of contact with the masonry.
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 topcoats ( tiles, waterproof paint or vinyl wallpaper).

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

The reason for the destruction is that a material such as aerated concrete needs reliable protection against aggressive effects. environment and destructive efforts:

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

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

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

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

Stages of aerated concrete plastering

Plastering walls made of gas silicate blocks should be started with a thorough impregnation of the entire wall area with a special primer. Unlike, which has a closed porous structure, during production, open pores are formed in the material, since fine aluminum crumbs are added to the base solution as an additive. It is the main gas generator for the reaction 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.

The primer impregnation can be applied generously without gaps along the entire wall using a spray gun or roller, as in this photo:

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

Reinforcement

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

During laying, gas silicate blocks form a fairly flat plane, which, if necessary, can be additionally leveled with a float with an abrasive nozzle, therefore, a sufficient thickness of the plaster layer is from 2 to 7 mm. A flat mesh is laid in it.

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 for reinforcement internal plaster walls made of gas silicate blocks, discussed in this video:

Requirements of plastering technology

The external plastering work on the blocks begins only after the completion of the finishing work on the wall from the inside of the house, the completion of the wet mortar processes for the installation of floor screeds, plaster, and putty work.

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

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

The decision of how to plaster the gas silicate is made taking into account the following factors:

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 multi-layer wall must increase from the inner layer to the outer or be a comparable value.
A solution from a dry plaster mixture (for gas silicate blocks) must be prepared strictly according to the manufacturer's instructions indicated on the product packaging. The mixing container is taken of a sufficient size, maintaining the recommended proportions and water temperature with accuracy. The amount of added water is strictly dosed, since subsequently it is undesirable to dilute the swollen plaster mixture with an overly thick consistency that has been kept for the allotted time, and too liquid solution will drain off. Stirring evenly until smooth is best done with an electric drill with a special attachment.
In addition to strength, for external plasters, one should pay attention to the indicators of frost resistance and elasticity. Outside temperature changes create preconditions for cracks to appear in too rigid monoliths. We should not forget about the flammability class of the material - resistance to fire is an important indicator of the safety of a house.

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

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

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

Saving on cheap materials or on their quantity often leads to bad consequences. It can be argued with confidence that this is usually not a matter of bad building materials, but their misuse. If there is a need to plaster the gas silicate blocks of the outer walls, then this should be done using only specially provided materials for such types of work.

Indoor repairs are carried out in several stages. When conducting renovation works it is important not to forget about plastering concrete walls with inside... Plaster for aerated concrete plays an important role, even when it comes to work in panel buildings modern layout... 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.

The 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 consists in the fact that aerated concrete plaster is carried out in such a way as to achieve vapor permeability in concrete walls due to the unique qualities of the material. Builders advise against 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 disguise 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. In this case, the microclimate in the room 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 choice of a certain composition of mixtures for carrying out repair and finishing work on the walls of the building. To do this, it is necessary to do the 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. Also, there won't be any in the wall.

Vapor barrier

In order to treat the inner wall and increase the vapor barrier at least tenfold, specialists 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 polyethylene film under the layer of plaster. But experienced builders are not advised to carry out such work, since the film can peel off from the plasters and walls due to the appearance of condensation.

What materials and tools are used?

It all depends, first of all, on the task set by the customers and specialists. For its implementation, building materials are selected that can correctly interact with aerated concrete and have the property of vapor permeability. Professionals recommend processing the inner surfaces of the walls from blocks of a mixture with gypsum, sand and lime. Also, builders use tools that include chalk or marble.

For finishing work, specialists use plastering tools. The mixture is prepared in an appropriately sized container. The solution is mixed using a mixer or. Thin-layer aerated concrete plaster is applied to the blocks with a trowel or trowel. Surfaces are rubbed with a float. The poluter is used to remove excess mixture. The surface of the blocks inside the walls is leveled with beacons. Aerated concrete plaster is pulled together by the rule between the guides. The builders determine the quality of the work performed by the rail.

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

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

Aerated concrete walls need external and interior decoration due to porosity and high 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;
the porous material is blown through 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 frost.

The special structure of aerated concrete blocks requires careful processing with finishing materials to improve its quality characteristics. External plastering is performed using special solutions that are selected for specific environmental conditions. Correct plastering of 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 the type of plaster, you need to start finishing work indoors. Changing the order and plastering the facade of the building will lead to excess moisture in the 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 surface cracks and plaster shedding. To avoid such troubles, you should first tackle the plastering of the walls from the gas blocks indoors. Experienced craftsmen there are two types of plastering technology aerated concrete walls in the House:

providing complete vapor barrier;
preservation and increase of vapor permeability of the material.

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

Dependence of inside plastering technology on external finishing

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

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

Preparation of the base

The technology of plastering walls made of aerated concrete practically does not differ from work 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 plane or a grater for aerated concrete. Many craftsmen skip this stage, but as a result, the costs of plaster increase, which is also used to level defects. Before applying the primer, aerated concrete walls are moistened with water. For drier rooms, it is recommended to choose a universal composition, and for the kitchen and bathroom - a deep penetration soil. \

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

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

Aerated concrete plaster (video)

How to plaster aerated concrete surfaces

In order for the repair of an aerated concrete house to serve for many years, it is necessary to correctly approach the choice of material for decorating the walls inside and outside. Masters distinguish as many as four options for processing walls made of cellular material:

Gypsum plaster.
Cement-sand mortar.
Facade mixtures.
Drywall.

The last option is the so-called dry plaster. What is better drywall or plaster on aerated concrete walls is a controversial issue. Plastering a surface is a costly and time-consuming process. Working with gypsum board takes less time and, as a result, smooth walls are obtained. Procedure:

vapor barrier of surfaces using polyethylene film, membrane or glassine;
installation of the lathing for fastening the gypsum board;
fastening drywall to the frame;
putty of joints between sheets using serpyanka tape.

Any kind of decorative finish can be applied to the aerated concrete wall leveled in this way. What 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

Name	Flaws
Cement	Low level of adhesion in relation to the gas block
	High moisture content
	The vapor permeability index is lower than that of the aerated block, therefore, the cement mortar can only be used when used for interior decoration of vapor-proof materials (plastic film, etc.)
Gypsum	Gains moisture during snow and rain
	Stains on the plaster
	Low vapor permeability
Facade	The only drawback of this type of plasters is their high cost.

Gypsum plaster

The main advantages of a gypsum solution for treating aerated concrete walls include:

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

Knauf Rotband, Bonolit and Pobedit Velvet are popular among the craftsmen.

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. Grip can be improved by adding more cement mortar(for 100 kg of concrete, 8-10 kg of lime will be needed). The second option, which is acceptable, but still not recommended by the masters, is to add a mixture for processing aerated concrete to the cement-sand plaster (1: 1 ratio). Among the leaders in sales of mixtures of this type are solutions of the Baumit brand and the domestic Craps Extra-light.

Facade solutions

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

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

Plastering walls on aerated concrete with your own hands is demonstrated in the video below. With a competent approach to work and the study of materials, even a novice master will cope with 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 the best solution. Active use of aerated concrete in modern construction due to the low cost of blocks, low specific gravity, high thermal insulation properties, the possibility of machining hand tool, high fire safety.

However, after the completion of the main construction work, the question inevitably arises of further internal and exterior decoration Houses. Exists different kinds finishes, but plaster was the most widespread. Let's try to figure out how to plaster aerated concrete inside the house.

Plaster options for aerated concrete walls

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

High vapor permeability;
The ability is very fast and in large quantities absorb moisture;
Fragility.

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

Cement - sand;
Plaster;
Facade.

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

Wall decoration inside a house can serve two purposes:

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.
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 let's consider which material will be most suitable for plastering your particular house.

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

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

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

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

The disadvantages of gypsum mixes include:

Low vapor permeability;
A fairly large volume of water is required to mix the mixture;
High adhesion of dried plaster to atmospheric precipitation and moisture in general.

Despite the above disadvantages, plastering aerated concrete with gypsum is quite acceptable.

Facade. This type of plaster mix is optimal for aerated concrete plastering inside and outside the premises. 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 aerated concrete house

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

The plaster mixture must have good vapor permeability parameters, at least equal to the parameters of aerated concrete;
To prepare the working mixture, an excessive amount of water should not be used.
The selected mixture must have a high coefficient of adhesion to the substrate;
The ductility of the plaster should ensure the walls are resistant to cracking;
The frost resistance of the selected mixture must correspond to the climatic conditions;
The time before 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.

At present, Ceresit CT 24 is confidently leading in the market of dry mixes for aerated concrete plastering, 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, adherence to the technological regimes specified by the performer of the plaster mixture is directly related to the quality and durability of the work carried out. Preparation of the base should not be neglected either. Preliminary removal of various unevenness of the masonry will allow you to significantly reduce the layer of applied plaster on aerated concrete, and, consequently, its consumption.

Plastering of aerated concrete walls requires special materials and a correct application process. If unsuitable materials are used or if the plastering process is not followed, it will not last long and will quickly deteriorate and flake off.

Briefly about aerated concrete

Aerated concrete is building material, which is used to erect the walls of the building. Preferably produced in blocks of 400x200x600 mm (dimensions may vary depending on the manufacturer).

Aerated concrete is produced from components such as:

Cement.
Quartz sand.
Lime.
Water.

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

Advantages and disadvantages of aerated concrete

Advantages:

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

Flaws:

Exterior finishing is imperative.
The fragility of the material.
High price.

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

Preparing the walls

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

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

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

Technology

Aerated concrete wall plastering technology consists of the following stages:

Preparing the walls.
Priming the walls. It is recommended to use a primer based on acrylatesiloxane.
Reinforcement of walls. For wall reinforcement, I use a fiberglass mesh that is resistant to stretching and has a high tensile strength.
Installing beacons... Beacons are installed at a distance of no more than 120 cm from each other. The use of beacons allows you to perfectly even plaster the walls. If the walls are even, beacons can be omitted.
Application of the first layer of plaster. The first layer of plaster is poured with a methodical bucket or trowel, after which it is leveled with a wide spatula or a wooden lath of at least 1 meter.
Application of the second layer of plaster... For the second layer, it is necessary to use the finishing plaster, it has fine sand, which allows you to hide the flaws of the first layer. The second layer is applied in the same way as the first, only it is smoothed more carefully.
Grouting. A few days after the application of the plaster, it is possible to produce grouting... Grouting is done with a wooden float, after slightly moistening the wall with water. Rub the seams, lightly pressing the grater against the wall in a circular motion.

After grouting, the walls are ready and can be applied decorative plaster or glue wallpaper. Finishing work plastered walls must be made only after they have completely dried.

The choice of facing for aerated concrete

Plaster mixes for aerated concrete walls must necessarily have the following properties:

Good durability.
Resistance to atmospheric influences.
Good waterproofing properties.
High vapor permeability.
Elasticity.
Good adhesion to walls.

These are one of the main criteria for aerated concrete wall plaster for interior and exterior decoration.

Aerated concrete wall cladding can be made with the following materials:

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

Working conditions with facing material

For high-quality and durable wall plaster, you must adhere to the following conditions:

Consistency plaster first external then internal.
Plaster walls can be carried out after the end of all wet screed, puttying, etc. Walls must be thoroughly dry after previous work.
Plastering walls can be produced at a temperature of +5 +30 degrees. In no case should work be carried out when sub-zero temperature as the plaster will fall off.

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

Interior and exterior decoration

The process of plastering external and interior walls consists of the following stages.

Internal plaster:

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

External plaster:

Exterior wall decoration must be made strictly with materials that have vapor permeable properties. Just as for internal plaster, it is necessary to clean the walls and remove all cracks, chips, etc. This can be done with tile adhesive. The ambient temperature at the time of plastering work should be from +10 to +25 degrees.
After the walls have been prepared, the fiberglass reinforcement mesh must be reinforced. You can strengthen the mesh with glue or wood screws. The mesh prevents the mortar from dripping and holds it well on the wall, and also avoids cracks when the plaster shrinks.
The next step is the application of plaster. Plaster is applied in the same way as for interior decoration. You should know that it is necessary that the vapor transmission capacity of the plaster is higher than that of aerated concrete. If necessary, you can install beacons to level the walls.
You should also know that the thickness of the outer layer of the plaster should be two times less than the inner one.
Plaster leveling is done with a wooden lath.
When the plaster dries up, it is necessary to grout the joints and flaws. After 48 hours, the plaster will dry and you can carry out the final stage of finishing work.

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

Plastering of aerated concrete walls with cement-sand mortar

In order to save aerated concrete walls, you can plaster cement-sand mortar this is done as follows:

Initially, you need to prepare the walls: for this, it is necessary to remove dust, dirt and glue residues from them, and then prime.
The next step will be to reinforce the walls with fiberglass mesh and the usual cheapest tile glue. With a spatula or metal trowel, glue is applied to the primed surface of the wall, after which a mesh is applied. After that, the attached mesh must be smoothed horizontally with a notched trowel. When the glue dries, you will get a grooved surface that will promote good adhesion of the cement-sand plaster.
Thus, in addition to reinforcing the wall, the seams of the blocks are smoothed out and small irregularities in the wall are removed, and the glue grooves will prevent the plaster from sliding during its application. And the fiberglass mesh will prevent cracking when the plaster shrinks.

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

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

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