Indoor aerated concrete wall plastering: wall plastering technology with installation instructions. How to plaster walls from gas silicate blocks? Decorative plaster for aerated concrete

The construction of houses from gas silicate blocks is one of the most promising areas in the field of private construction. In particular, aerated concrete blocks have become very popular, during the production of which special additives are introduced into the composition of the solution, causing abundant gas formation. As a result, aerated concrete has a pronounced open porous structure, which determines its significant advantages over other materials for masonry walls.

However, such a structure of aerated concrete also brings a number of difficulties in finishing the erected walls. This requires a special approach, both in terms of the sequence of work and the materials used. In addition, the plastering of aerated concrete walls inside the premises will also depend on their planned exterior finish.

What is the "capriciousness" of aerated concrete in matters of finishing, and in what ways can these problems be solved - this publication is devoted to these issues.

Features of aerated concrete

But on the materials for the work, you should go through in more detail.

The open porous structure of aerated concrete will not allow you to limit yourself only to filling the walls - a thin layer simply will not stay on such a surface. Therefore, even if the wall is laid out with the highest precision and does not require special adjustments to its plane, you still cannot do without plaster. And on the aerated concrete wall you will have to "throw" a layer of at least 5 mm.
Such a layer will be susceptible to cracking and shedding (the adhesive features of a highly porous structure are affected), if not reinforced with a reinforcing mesh. If on other wall materials the use of a reinforcing mesh is desirable, then in the case of aerated concrete this condition should be considered as mandatory. The mesh is best of all - fiberglass, resistant to an alkaline environment, so that over time it simply does not dissolve in the thickness of the frozen plaster mass.

The use of reinforcing fiberglass stacks is a prerequisite for high-quality plaster

Aerated concrete walls are distinguished by high moisture absorption. As experienced painters say, this material literally "drinks" water. It would seem that this is not bad for good adhesion, but it turns out just the opposite. Aerated concrete "sucks" moisture from the applied material, which causes its rapid drying, cracking and shedding - in the case of gypsum compositions, and disruption of the normal hydration of cement, if plasters based on it are used. In either case, the quality of the coating will be low, and the finish itself will be extremely short-lived.

It is important to find the right "moisture balance", otherwise the work will be of poor quality

On the other hand, excessive oversaturation of aerated concrete with water is also fraught with negative consequences. Yes, and such a wall is very difficult - the thrown solution begins to "creep", the layer becomes loose or heterogeneous, etc.

Which exit?

- you can use special plaster mix specifically for aerated concrete, intended for indoor finishing works... Their component composition, when properly mixed with water, in accordance with the instructions, is fully optimized for the characteristics of such a surface and sometimes does not even require preliminary priming of the surface. All this is necessarily indicated by the manufacturer in the instructions for use of the composition.

- the use of special deep penetration primers. Here, however, the balance is also important - the oversaturation of aerated concrete with impregnating compounds can lead to the opposite effect, since the absorbency of the surface for applying plaster on it is still important.

In both cases, professional masters do not advise to immediately give a thick outline - it is best to limit yourself to a minimum layer in which the reinforcing fiberglass mesh is embedded. This layer is not required a large number moisture, it is much easier with effort to "rub" into aerated concrete, and the reinforcement will create a solid base, without cracks. But after drying such a substrate, you can safely proceed to the main plastering on the lighthouses.

Video: the work of a master for plastering an aerated concrete wall

As already mentioned, the composition of the plaster mixture directly depends on whether it is necessary to leave its high vapor-permeable properties to the wall, or, conversely, to make it as difficult as possible for moisture to penetrate into the material.

In the first case, preference is often given to special gypsum-based plaster compositions, which often include light perlite sand. Usually, the instructions for the use of the composition indicate that it is combined with aerated concrete (gas silicate) walls. A classic example of such mixtures is Plaster or Osnovit - Gipswell plasters.

Manufacturers claim that for the application of such compositions, a reinforcing mesh is not even required. But in the case of aerated concrete, it is better not to ignore this moment.

Silicate based plasters are very well suited for aerated concrete, especially in terms of vapor permeability. However, such a wall decoration will significantly limit the owners in choosing a topcoat, since silicate mixtures are incompatible with many other organic-based decorative compositions - acrylic, silicone, latex, etc.
Cement-lime-based plasters have been developed especially for aerated concrete or similar surfaces. Their composition is optimized precisely for such surfaces that do not even require preliminary priming before plastering. An example is "Baumit HandPutz" plaster or a mixture from a set of a whole "ensemble" of mortars specially developed for aerated concrete "AeroStone".

The composition of such plasters includes cement, construction lime, special lightweight aggregates and plasticizing additives, fine-graded refined sand. Such a coating has good vapor permeability, and can be used for both external and internal work on aerated concrete.

If, in the plans of the owners of the house, to achieve the minimum vapor permeability of the walls from the inside, then they usually resort to the use of cement-sand plasters without the inclusions of lime or dolomite chips (flour). Naturally, the composition usually includes special plasticizing additives that stifle the adhesion of the created coating to a porous base.

All specialized mixtures for gas silicate surfaces have one common drawback - they are quite expensive, and with large volumes of work such internal plastering the walls will result in a hefty amount. But this is only a preliminary alignment, excluding finishing! Is it not possible to do something simpler, use more affordable mixtures or generally ordinary home-made plaster solutions, for example, based on cement and sand?

It is possible, but only an experienced craftsman can perform such a finish with high quality, whose long-term practice allows him to "by eye" determine the condition of the wall, and the need for its moistening or priming, and the exact component composition of the plaster. And without the experience of such work, making a mistake on an aerated concrete surface is as easy as shelling pears, and all the work will be done down the drain.

However, we can recommend one very interesting way of preliminary preparation. gas silicate wall to further. If everything is done in accordance with the recommendations, it will be possible to apply almost any plaster composition without fear of cracks, mortar creeping, its rapid drying, or, conversely, excessive waterlogging of the wall.

How can you properly prepare an internal aerated concrete wall for plastering?

For work, you will need the usual, the most inexpensive of all the glue in the store, for ceramic tiles, fiberglass mesh, deep penetration soil (normal, type Ceresit CT 17). And then it will be possible to plaster with any composition on a gypsum, cement, cement-lime and other basis. In particular, the usual cement-sand mixture is also quite suitable, even in a ratio of 1: 5.

It is quite difficult to determine in advance the amount of plaster mixture to put the wall in order, since it depends on the condition of the surface, its evenness, the presence and depth of level differences both vertically and horizontally. But our calculator will help to determine the amount of materials for the preparatory cycle.

It takes into account the conditions for priming the surface in two layers, with the dilution of the primer with water during the initial application, and the creation of a preparatory reinforced adhesive layer 5 mm thick. Calculations will show the result with a 15% margin "just in case" adopted by builders-finishers.

The calculation is carried out for rectangular surfaces, minus window and door openings.

Aerated concrete is gaining more and more popularity as construction material... And this is not surprising. Large block sizes can significantly reduce construction time, and the cellular structure retains heat, allowing you to reduce heating costs. But this material requires serious protection from moisture.

Aluminum powder is added to the basic solution from which aerated concrete is made. At one of the stages technological process, this component releases gas forming air-filled cells. In this case, the pores remain open, and moisture quickly accumulates in them.

Therefore, the material is protected from precipitation both at the stage of wall construction and after the "box" of the house is ready. The moisture accumulated in the autumn or spring time will also quickly go away under the influence of sunlight. But in winter this factor will be destructive. And over time, small cracks will appear on the walls, and then delamination.

In addition, aerated concrete has the following characteristics:

Low rates of thermal conductivity.
The strength depends on the foundation. If it shrinks strongly, then cracks will soon appear on the gas block.
Durability if the material is protected from water.
Fire and environmental safety.
Soundproofing properties.
High steam permeability, which makes homes comfortable, since internal vapors quickly escape to the outside, and do not accumulate in the premises.
High rates of moisture absorption, which forces the house to be faced with moisture-repellent materials.

When is it better to plaster aerated concrete walls?

Most often, plastering is chosen for finishing gas-block walls. But you should pick up right time to carry out the work, as well as a suitable composition. We will deal with the type of plaster for the facade a little lower, and now we will consider the time of finishing work.

Do not plaster immediately after construction. The walls are given time to dry completely and shrink. It is enough to wait a year. If this is not done, cracks will appear on the finish.
They select the warm season, when the night temperature does not go below 0 degrees. In such a situation, the moisture that the aerated concrete absorbs from the solution will quickly be released, and the finish will dry out.
To protect the walls in winter from moisture and frost, they are covered with deep penetration soil. Under such protection, the house will withstand the load of one frosty season without changes in its structure.
Plastic sheeting is also suitable as a barrier for unlined walls.

Is it necessary to pre-insulate the outside?

As mentioned above, walls made of this building material retain heat well. Therefore, with a competent calculation of the thickness of the structure, there is no need to insulate the house. It is better to do this by using the services of professionals. They take into account the climatic conditions of the region where the building is being erected.

You should not make the walls too thin so that they need to be additionally insulated, since it will be difficult to find insulation. The aerated concrete structure has high rates steam permeability, and if the thermal insulation does not cope with this task, then condensation will appear from the outside of the wall. This will lead to the destruction of aerated concrete and insulation.

If it is already necessary to carry out insulation, then such a material is chosen that can pass steam from the interior. According to the rules prescribed in State acts, the vapor transmission capacity from the interior walls to the exterior should be increased. Only in this case it will be comfortable to stay in the rooms, and mold and mildew will never settle on the walls.

Which mixtures are better for using?

When choosing a mixture for plastering gas-block walls, the following properties are noted:

Moisture repelling.
Good adhesion to the substrate.
Resistant to low temperatures.
Elasticity.
Decorativeness.

The assortment of building stores offers several types of plaster mixes. They all have positive and negative aspects to use. It is especially important to use for plastering aerated concrete suitable options... Therefore, we will consider each type separately.

Lime-cement

This is an example of a thin layer of lightweight plaster. It is used only for interior work. It is not worth it with ordinary cement mortar. It does not have the necessary characteristics to preserve the properties of our material. But with the addition of lime, everything changes:

The mixture adheres well to the substrate.
Apply in a thin layer.
The vapor permeability of the solution increases.
The finish is durable.
Inert to the appearance of mold fungi.
Affordable low cost.

There are, of course, several disadvantages:

The finished solution quickly hardens, therefore it is difficult to work with it, especially for a beginner.
Large consumption for square meter implies an increase in costs, even at a low product cost.
The solution is prepared independently, since only a dry mixture is sold.

Acrylic

This option is used for decorative facade decoration gas-block houses. It is applied in a thin layer, but it has a number of advantages:

durable;
elastic;
resistant to low temperatures;
the color retains its original brightness for a long time;
helps to strengthen the base in places where the load is increased;
repels moisture.

Despite the large number of advantages, there are such disadvantages that cause great doubts about the correct use of acrylic compositions for aerated concrete:

Low values of vapor permeability. Waterproofing is installed on the base, or a ventilation system is being built in the house.
The acrylic compound is highly flammable, so it is not suitable for wall areas near fire.
High price.

Silicate

Liquid glass-based compositions are excellent for both interior and exterior decoration. Such plaster is sold only in finished form... Stir thoroughly before use. The main advantages are:

vapor permeability;
moisture-repellent properties;
a large selection of textures;
affordable price.

But before plastering aerated concrete, it is worth studying the disadvantages that are here, like any other material:

Dirt and dust accumulate on the surface of the finish, which reduces the attractiveness of the coating.
A small selection of colors and shades.

Silicone

This option is made on the basis of silicone emulsions or resins. It is great for decorating facade walls. It has such undeniable advantages:

Hydrophobic (repels moisture, practically does not get wet).
Vapor permeability.
It is convenient to apply, therefore it is suitable for those who decide to do everything with their own hands.
Plastic.
Crack resistant.
It retains its original color for a long time.
Easily cleaned from dust and dirt.

Of the shortcomings, only the price is noted, which is an order of magnitude higher than the previous options. But is it worth saving your time and day if the material has so many advantages.

Cement-sand

The most famous and affordable version of plaster mixes, which is perfect for different reasons... But aerated concrete does not withstand the use of a cement-sand mixture. Everything is due to the lack of certain characteristics.

Is a cement mortar suitable for these purposes?

If a beginner gets down to business, then he should study all the subtleties of plastering aerated concrete. One of these nuances is the impossibility of using a conventional cement-sand mixture. The reasons for this are as follows:

Low steam permeability.
The solution contains a lot of moisture. The gas block quickly absorbs water and then gives it away for a long time, which increases the term of work. In addition, cement plaster with rapid evaporation of moisture loses its strength, as a result of which cracks appear.
Aerated concrete has a smooth surface, and the cement-sand mixture has low adhesion rates. Therefore, the solution does not adhere well to the base and can slip during operation. To avoid this, the walls are covered with a primer for aerated concrete, but this does not always help.

Add lime to the usual solution.
Mix a special mixture for aerated concrete and cement mortar in a 1x1 ratio.

And what about the glue for porous concrete?

A special adhesive mixture, which is intended for laying aerated concrete, should also not be chosen as a material for plastering walls. Although the glue was developed taking into account all the nuances of using a porous material, it is not suitable for plaster:

Apply only in a thin layer.
Designed for grouting.
Does not allow steam to pass through. Which leads to the appearance of condensation on the inner walls, and then mold.

Such material is used only for its intended purpose.

Interior decoration

It is customary to perform internal wall alignment with plaster first. Thus, moisture that is absorbed from the solution will quickly leave the thickness of the wall. on internal walls made of aerated concrete do not differ much from plastering other surfaces. They adhere to this plan:

Preparation of the base. Removal of bumps and other irregularities. It is better to do this again when the walls are being erected, since in the future this leads to an increase in the waste of the solution.
Padding. It is advisable to choose a deep penetration soil, especially for rooms with high humidity such as a bathroom or kitchen. Never dilute the primer with water. This reduces the quality of the soil layer.
- help to control the thickness of the applied layer. The distance between elements is slightly less than the length of the rule.
Spray or brush on the first coat. The solution should not reach the top edge of the beacons.
Forming corners using a perforated profile with a reinforcing mesh.
Application of the second layer. The thickness will be narrower. The solution is also thrown, but immediately leveled out by the rule. At the same stage, beacons are removed.

If the surface will be painted or covered with wallpaper, then the surface should be made perfectly smooth. To do this, apply a finishing layer and rub it.

Outdoor

After the internal work is completed, they begin to beautify the facade. Be sure to check the dryness of the aerated concrete. Plaster applied on wet walls may peel off. It is also important to choose the weather conditions:

The optimum temperature is from +5 to +25 degrees Celsius.
Lack of wind.
Air humidity not more than 80%.
It is better to hide the walls from direct sunlight.

Wall preparation

Aerated concrete has a smooth, even surface, and therefore it is not necessary to level the walls additionally. But in the process of laying, sometimes small voids appear in the seams or chips on the blocks. They are sealed with the same glue on which the material was laid.

All flaws are filled with the solution and left to dry completely. Therefore, the treated areas are rubbed with a metal float in order to remove the protruding solution. Dust is removed with a brush or damp cloth, but make sure that the material is not too wet.

Padding

For priming the facade walls, deep penetration compounds are chosen. They create a strong film that prevents moisture absorption, but at the same time the steam passes through quietly. Also, an additional layer will increase the adhesion of the plaster and the base.

The soil is applied in several layers, depending on the climatic conditions of the area. To do this, use a roller or brush. The composition completely covers all walls without bald spots. If there are corners or other inaccessible places, they are processed with a small brush.

Plaster and reinforcement

Reinforcing mesh must be used, even if the layer is small, about 1 cm, and the base is well treated with soil. This will make the plaster layer durable and reliable. Select a fiberglass product that is alkali resistant.

Reinforcement and plastering are performed simultaneously, following this plan:

Cutting the mesh into strips.
Preparation of the solution, according to the instructions indicated on the package, if a dry mixture was purchased. The finished solution is simply mixed so that all components are evenly distributed.
A solution is collected on a wide spatula and evenly distributed over the surface, about 0.5 cm thick.
A special perforated profile with a reinforcing mesh is applied to the corner. The mesh is smoothed over the applied solution.
Then separate pieces of mesh are laid. Be sure to make a whip of 5-10 cm. The reinforcement is smoothed by immersing it in the solution. In places where it appears, add a little mixture and smooth it again.
The surface is treated in small areas with the expectation of full use of the ready-made solution.

After the entire facade is plastered, it is left to dry completely. There should be no flaws and protruding reinforcement on the surface.

Finishing layer

A decorative composition is chosen as a topcoat. The solution is either prepared according to the instructions, or mixed in a container. Apply with a wide spatula. The layer does not exceed 0.5-1 cm. At this stage, they work especially carefully, since the remaining flaws will be noticeable.

When the layer dries a little, rub it over and create either a smooth surface or texture, respectively. Then the layer should dry completely and only after that you can start painting, if necessary. , in this case, is as carefully selected as the mixture for plastering.

Plastering of aerated concrete walls is a justified measure. , like the foam block, despite all its advantages, the material is hygroscopic. This means that it absorbs moisture easily. Therefore, the aerated block house must be protected from the weather. If the gas block gets wet in the rain and then dries up, it will not lose its properties. And if it gets wet in winter, then the water accumulated in the pores of the 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: protecting aerated concrete outside from freezing, moisture, snow and other atmospheric precipitation is a necessary measure. During and during the winter storage (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 the external decoration of the facade - plaster for aerated concrete. The main thing is to create conditions for vapor permeability so that the aerated concrete "breathes".

Exterior decoration of aerated concrete house, in addition to protecting the blocks, allows:

to strengthen the heat and sound insulation of the walls;
eliminate the possibility of walls getting wet;
protect the house from sudden changes in temperature;
decorate the facade of the house (decorative plaster for aerated concrete).

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

Aerated concrete plaster

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

Cement-sand plaster for aerated concrete

Is it possible to plaster aerated concrete with cement mortar?

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

The reasons why it is impossible to plaster a house from aerated concrete with cement mortar:

Cement slurry has a lower vapor permeability index than aerated block. This is the most important reason why not use it. In the case of wall finishing made of aerated concrete, professionals have a rule, you can use only that finishing material that, in terms of vapor permeability, does not differ from the aerated concrete itself, or has a higher indicator than 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 insulation (polystyrene and expanded polystyrene) to insulate a house from aerated concrete.

Cement-sand mortar has a high moisture content. To mix the components into the sand-cement mixture, you need to add water. It is also obvious that aerated concrete, having a significant moisture absorption rate, will tend to absorb this water from the solution. This, in turn, reduces the quality of the mortar applied 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 foil to ensure even drying. So why should he behave differently on the wall? The primer saves the day, 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 there any need for such savings that will significantly reduce the speed of work, and the finished surface will not be 100% of high quality.

Plaster mortar has poor 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.

The adhesion index (adhesion, adhesion of surfaces) can be increased 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 construction cement-lime mixture KREPS Extra-light (240 rubles / 25 kg), Osnovit Startwell T-21 (208 rubles / 25 kg), Baumit HandPutz 0.6 (300 rubles / 25 kg).

compulsory application of a finishing layer. Because it is difficult to make a smooth surface using a sand-cement mixture.

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

Also undesirable. Despite the fact that it was developed taking into account the specifics of aerated concrete, it is intended for application in a thin layer and the formation of seams, and not for external wall decoration.

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

Gypsum plaster for aerated concrete

Advantages of gypsum-based plaster:

high drying speed;

no shrinkage of the solution;

the ability to make a smooth surface;

no need to apply a finishing layer.

Disadvantages of gypsum plaster:

mediocre vapor permeability;

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

quick wetting during rain or snow;

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

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

Facade plaster for aerated concrete

The most effective material for plastering exterior and interior walls made of aerated concrete. Plaster for facade works has a number of characteristics, including the vapor permeability indicator, which is identical to that of aerated concrete (for most types of plasters), good adhesion to the base, beautiful appearance.

When choosing what to plaster aerated concrete, it is best to stop at a high-quality special mixture. In addition, the use of facade plaster makes it easier to decorate aerated concrete house with your own hands.

What 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 plaster application thicknesses (minimum and maximum);

adhesion to the substrate (at least 0.5 MPa);

resistance to low temperatures;

resistance to cracking;

pot life of the solution. 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, in this matter it decides not the last role, but also not the key one.

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

Material prepared for the site www.site

When can aerated concrete walls be plastered?

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

There is no need to rush to the cladding either. After laying aerated concrete, the walls should dry well. That is why aerated concrete walls are plastered 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, Ceresite ST-17 (549 rubles / 10 l).

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

According to the craftsmen, 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 late March to early October.

From which side do you need to start finishing the house from aerated concrete?

We will carry out comparative analysis several popular options for the order of execution of wall decoration.

Option 1
First, the exterior decoration 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 picks up moisture. However, this is not the case, even after standing without protection (but primed) the whole winter, the gas block will "give back" the accumulated moisture in the spring. And if it is closed from the outside, where will the vapors be directed? That's right, inside the room. This will not only increase the drying process and delay the execution of interior decoration, but 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, in the process of finishing work, the pores of the aerated concrete block are partially closed. And if you first plaster them from the outside, the accumulated water vapor will simply have nowhere to go. Moisture settling inside the block will contribute to its destruction. Plastering walls made of aerated concrete indoors will avoid this situation.

After the plaster has touched the inner walls and has dried well, you can start finishing the outer walls.

Option 3
Simultaneous interior and exterior finishes

The method is the least preferred. Moisture, which will be "pulled" by the gas block both from the outside and from the inside, will not be able to get out quickly.

Despite the fact that aerated concrete plaster has good vapor permeability, the rate of this process is not so high. This 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.

In theory, each of the options is eligible for implementation. But, the second 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 this correctly, without prejudice to the aerated concrete to allow moisture to pass through.

Plastering of aerated concrete blocks does not fundamentally differ from performing work of a similar type on other materials. The putty application technology differs in only a few details, which will be emphasized.

Internal plaster of aerated concrete walls

Technology of finishing aerated concrete with plaster indoors - sequence of works:

1. Preparation of the base

It starts with leveling the walls - removing irregularities is done using a planer or aerated concrete grater. This work is recommended to be performed even at the stage of building a house, but many 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 applied layer. In turn, this is fraught with plaster flaking and cracks.

2. Application of the primer

There are often recommendations that the primer should be diluted 1 to 1 with water. reduces its ability to increase surface adhesion. There are more reliable ways to save money. For example, remove dust from a surface by applying clean water to it. Apply water with a brush or roller as if it were a primer. And then, after drying, a primer is applied.

The choice of a 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 / 5 l). For the bathroom and kitchen, it is advisable to use a deep penetration soil, for example, Prospectors (450 rubles / 10 l).

3. Installation of beacons

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

4. Throwing "fur coat"

This is the name of the method of applying the first layer of plaster. The work is carried out from the bottom up. Next, you need to lean the rule on the lighthouses and align (stretch) 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. Treatment of 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 bridges of cold, it is advisable to remove them at this stage, and seal the places (recesses after dismantling) with mortar.

6. Forming corners

For the device and reinforcement of the outer corners, it is used perforated corner with mesh.

7. Finishing

Grouting (if necessary) and painting of aerated concrete walls are performed. In the case of wallpapering, no finishing is required.

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

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

How to plaster aerated concrete walls correctly - video

Exterior wall plaster made of aerated concrete

Decorative plaster the facade of the house can provide for the application of plaster for external use in a thick layer (thick-layer finishing) or in several layers (thin-layer plaster).

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

Outside plastering technology:

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

priming the surface;

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

reinforcement of plaster with mesh;

How to properly reinforce plaster

As a reinforcing layer, a metal mesh with small cells can be used, for example, a steel mesh with a wire diameter of 0.1 mm, and a cell pitch of 0.16x0.16 mm (average price is 950 rubles / m2 = 2 850 rubles / roll) or fiberglass mesh (for example, reinforcing fiberglass mesh with a cell pitch of 50x50 mm (approximate price of 17.60 rubles / sq. m = 880 rubles / roll).

The mesh is fastened with an overlap of 50 mm. At the same stage, the corners of the building are formed using a perforated corner with a mesh. The mesh helps prevent cracks in the plaster due to building shrinkage. Thus, the plaster of the facade made of aerated concrete 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 mesh in areas of high voltage, near windows and doors.

Advice. Fastening the mesh to a dry wall will have no effect, because the mesh will be fixed to the base with self-tapping screws. In the case of its installation on a 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 is completely dry. Otherwise, it may fall off under the weight of the second layer. Insofar as this method provides for a thin-layer application of the solution, you will need to wait 3-4 days. The thicker the layer, the more. You can check if the layer is dry with water. If you splash 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 factors environment(from moisture, snow, rain).

applying a second layer of plaster. This layer is considered leveling, therefore increased attention pays attention to the evenness of application and the formation of a smooth surface;

application of the third (finishing) layer of 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 exterior paints are used. For example, Nova-Fasad (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 water repellent. This is a special solution that professionals recommend to be applied one year after staining, after the end of all facing work. The water repellent will give any surface additional water-repellent properties. A special water repellent for aerated concrete "Neogard" (350 rubles / 1 liter) has proven itself well.

Aerated concrete putty

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

Ready-made silicate plaster, for example, Baumit SilikatTop Kratz Repro 3.0 mm (RUB 3,700 / 25 kg)

Silicone plaster, for example, Baumit SilikonTop (3300 rubles / 25 kg)

Acrylic plaster, for example, Ceresit CT 77 (3800 rubles / 25 kg)

Front "fur coat" Weber.pas akrylat or Weber.pas akrylat Fur coat 615С 1,5mm (1800 rubles / 25 kg)

Conclusion

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

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

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

The gas block is a compact and lightweight building material. Its laying during the construction of walls does not require special skills, which allows people without special construction education to build warm and inexpensive housing with their own hands. At the same time, this material is very "capricious" in terms of decoration.

Features of aerated concrete in terms of plastering

Features of aerated concrete are in the technology of its production. It is the only building material that has shallow passages that pose two major problems for the walls:

easily blown by medium-strength wind;
have high vapor permeability.

The first problem is solved by finishing the walls both inside and outside the premises, and therefore the question "whether it is necessary to plaster the walls from aerated concrete blocks" disappears by itself. High vapor permeability can be handled only with the proper use of finishing technologies.

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

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

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

How to plaster aerated concrete

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

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

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

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

The plaster mortar is applied directly to the wall, which has been pretreated with a penetrating primer with sawn-through gaps with a chainsaw (gaps are necessary for better adhesion of the mortar to aerated concrete).
Plastering of the wall is carried out on a plaster grid, planted on a special glue, which has become fashionable lately.

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

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

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

Here you need to use:

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

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

Calculation of material consumption

Starting work on applying the plaster layer, it is important not to be mistaken with the amount of purchased material. Immediately, we note that it is absolutely impossible to calculate exactly how much of what is required - you cannot take into account all the differences in the surface of the wall in height, as well as the presence of a vertical in it. But, with a slight error in any direction, the calculations can be done.

You should start by determining the area that you want to plaster. To do this, multiply the length of each wall by its height and add the results together. Subtract the area of doors and windows from the resulting number. The final result is multiplied by the average thickness of the plaster, as a result of which we get the amount of solution in m 3.

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

Necessary tools for work

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

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

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

construction (bubble) level;
steel brush or scraper (also called "cutting");
container for the preparation of plaster;
a hacksaw for metal or a chainsaw;
falcon;
trowel, has other names - trowel, plaster blade;
half-scraper;
grater;
malka;
trowel;
a set of spatulas.

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

Surface preparation

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

all general construction and assembly work for floor installation, installation of door and window blocks, etc .;
walls are cleaned of old plaster, paint, wallpaper and whitewash;
wall blocks are being repaired (if necessary);
various kinds of pollution are removed.

Attention: the technology for performing the above works is described in detail in the material "Preparation of surfaces for plastering".

The next, most important stage of work when plastering aerated concrete is to ensure adhesion (adhesion) of the plaster to the wall. There are two options: to apply the mortar to the primed wall or to the plaster mesh. The second option is gaining popularity, so let's take a closer look at it.

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

The step-by-step instructions are not very complicated.

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

The diluted glue is poured onto the dried primer with a trowel. The work is carried out from the bottom up, along the width of a little more than a roll of reinforcing mesh. The layer thickness after leveling should be within 5 mm.

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

The mesh cut to length, flush with the ceiling, is embedded in the glue, and then the same is done below, near the floor. A spatula with 5-6 mm notches, the plaster mesh is pressed as deeply into the glue as possible. Work is carried out from top to bottom. At first, the movements of the spatula can be chaotic, and in the final stage, strictly horizontal. This is necessary for the formation of horizontal ordered stripes with a height of about 5 mm from the glue squeezed out through the mesh, which will serve as an ideal connecting element between the wall and the plaster mortar.

Glue surface gaps are not allowed. Work is carried out in turn on each mesh sheet. Each subsequent mesh should overlap the previous one by 10 cm. For ease of joining, several vertical stripes are drawn along the edge of the strip treated with glue with a spatula (subsequently, in the process of work, they should be converted into horizontal stripes).

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

When, after laying, you can start plastering

When building a house from aerated concrete, you should not rush to finish the walls both inside the building and outside. Even when placed on glue, the blocks will still shrink - this is their property. There is no need to explain what will happen to the plaster on the shrinking wall - continuous cracks and a complete replacement of the plaster layer.

Experts say that after the wall has been erected, it is necessary to wait 7 months, and only then begin plastering work. However, this recommendation cannot be accepted. Simple wall construction does not lead to their shrinkage - there is no pressure on the blocks. Only after the roof has been erected, a full-fledged shrinkage process begins. Therefore, the countdown should be carried out from the moment the roofing work is completed.

Plastering technology

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

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

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

The soil is put in a thicker solution (approximately like bread dough) and a different ratio of cement and sand - 1: 5. It is applied after the spray is completely dry. The thickness of the primer should not exceed 2.0 cm. It is applied to the wall with a trowel. Then the rule is aligned. Finishing soil treatment is carried out with a trowel. They can work left and right, up and down. If the soil layer is more than 2 cm thick, then the correct solution is to apply twice.

But if such wetting occurs in winter, then this can lead to the development of a destructive process. The fact is that freezing water tends to expand, and therefore small cracks will appear in the blocks, which will not only spoil the appearance of the facade, but also significantly weaken the supporting structure.

The process of preparing walls, made of gas silicate or aerated concrete blocks, for applying cement-based plaster

Facade plaster is the best choice for aerated concrete

Of all the options present on the modern construction market, namely facade plaster is exactly the material that most closely matches technical specifications aerated concrete. It has optimal vapor permeability, excellent adhesion and attractive appearance. Therefore, such aerated concrete plaster will the best choice for finishing walls lined with gas blocks.

Let's consider its main advantages over analogues:

High vapor permeability, which allows gas blocks " breathe».
The minimum amount of water required to mix the mixture. This indicator should not exceed 0.2 liters per 1 kilogram.
Resistant to low temperatures.
Excellent adhesion.

Resistant to cracking.
Long pot life of the solution.

What plaster is not suitable for aerated concrete and why

One of the most popular types of plaster is a cement-sand mixture. However, it is completely unsuitable for working with gas blocks. Regardless of what material the blocks themselves were laid on (glue or cement), the use of this finishing material is unacceptable for the following reasons:

Vapor permeability of cement is lower than that of aerated block... This is the main reason why you should refrain from using this type of plaster.

Moisture content is also an important indicator for gas blocks... In a cement-sand mortar, it is increased, since its mixing requires the addition of a fairly large amount of water. Since aerated concrete is characterized by high moisture absorption, it will absorb water from the solution, which can not only destroy the structure of the blocks themselves, but also reduce the quality of the plaster solution.
Cement slurry is characterized by low adhesion rates... This is due to the large weight of the solution and the presence of large impurities in its composition.

Gypsum plaster is a good option for plastering aerated concrete walls. But at the same time it has a number of disadvantages in front of the facade:

The vapor permeability of such compositions leaves much to be desired.

Manifestation white bloom- efflorescence

In case of snow or rain, such compositions are characterized by rather quick wetting.
On such a surface, spots may appear that need to be painted over.
Contains more water than specialized plaster mixes for aerated concrete.

The best time to apply plaster

Considering that aerated concrete has a high water absorption, it needs to provide good protection against wetting. As mentioned above, the wetting of this building material is not critical, if frost is not predicted at the same time. In any case, after laying the walls, you need to give time to dry. It is enough to wait about a month and you can apply the plaster mixture.

Ideally, aerated concrete house facade plastering is done during the warm season. If it is impossible to carry out these heat works, then the walls should be covered with a deep penetration primer. It will reduce water absorption rates. It is also advisable to protect the walls using polyethylene left over from the packaging of aerated concrete pallets.

Masters advise to carry out work during a period when the air temperature at night does not drop below zero degrees. Thus, walls can be plastered from the end of March to the beginning of November.

How to properly plaster the walls of a house from aerated blocks

One of the main misconceptions is that the main task of plaster is to protect the walls from the outside. The only problem is that if such walls are not primed, then with the arrival of spring they will "give back" the accumulated moisture. And since there will be a layer of plaster outside, all the moisture will go inside the house. As a result, cracks in the interior walls are possible.

Advice! The priority of protecting external walls exists only if the construction of a house takes place in close proximity to the sea, lake or any body of water.

Simultaneous finishing of interior and exterior walls is also unacceptable. The fact is that in this case, the moisture that the gas block will somehow pick up in itself, in this case, simply will not have any way out. And its subsidence inside the block will only accelerate the processes of its destruction.

Yes, aerated concrete plaster has good vapor permeability. But still they will not be enough for quick moisture removal.... And this becomes especially critical when the average air temperature at night drops below zero. As a result, the gas block will begin to deteriorate quickly.

Considering all of the above, it should be noted that the most beneficial and the right option is like this: first applied internal plaster, and after the drying of this layer - the outer... In this case, the moisture accumulated inside the aerated concrete blocks will have an outlet to the outside, which will not bring negative consequences for the building itself.

How to carry out interior decoration

Consider the sequence of work on interior decoration aerated concrete walls:

Preparatory stage... First of all, the walls must be properly prepared: leveled, for which a special plane for aerated concrete is used.

Apply a primer... Some masters suggest diluting the primer with water in a 1 to 1 ratio, which is incorrect, since it negatively affects the adhesion of the material. The primer composition is selected depending on the purpose of the room. For example, if deep penetration soil is required for the kitchen or bathroom, then any universal material can be taken for the hallway.
Installing beacons... They allow you to adjust the thickness of the applied solution. They are arranged according to the width of the rule, and the accuracy is controlled by means of a level.
Throw in a starting layer or "fur coat"... Work should be carried out from the bottom up. Next, we describe the rule for beacons, leveling the resulting layer. When voids are formed, they immediately close.

We carry out the processing of the first layer... After the applied plaster dries, it is necessary to moisten it with a spray gun, and then level it. In this case, it is advisable to dismantle the lighthouses, since they are cold bridges. The recesses formed after them are immediately sealed with a solution.
Form corners... To create even and strong outer corners, a perforated corner should be used, which is installed on a small section of the mesh and covered with a compound.

Apply the finishing layer... Grouting is done if necessary, then paint can be applied to the walls. Finishing of the walls is not carried out if they are subsequently covered with wallpaper.

Since the paint is also characterized by certain indicators of porosity, it is necessary to approach its choice with all care. Good options are compositions based on latex, PVA, acrylic emulsions, cement and paints based on organic solvents.

How to plaster walls outside

How to plaster aerated concrete outside? The best material for such finishing is decorative facade plaster. There can be two application options:

A high build finish where the material is applied in one thick coat.
Several coats require thin-layer plaster. This option for wall decoration will be discussed below. It involves the application of a finishing material, no more than 10 mm thick.

External plaster is applied as follows:

The preparation of the wall is in progress. It is about leveling the surface, which is done in order to reduce material consumption.
Before plastering, the wall must be properly primed.
After that, a starting layer of the mixture is applied. In thickness, it should not exceed 5 mm.

The finishing layer is reinforced metal mesh having small cells. It is overlapped by 50 mm. At this stage, the corners of the house are also formed, for which a perforated corner is used. The main task of the mesh is to prevent the formation of cracks in the plaster layer, which can occur during the shrinkage of the building.
A spatula is used to "sink" the mesh in the solution.