We plaster walls from aerated concrete with our own hands. Stucco walls of gas silicate blocks: the choice of mixture and finish

Often, developers have a question how to plaster aerated concrete from the outside. Before starting work, it is recommended to determine the important characteristics and, based on this, choose the best finish.

Aerated concrete plaster must meet the basic requirements - the mixture is tight to the surface and has good adhesion. The finishing layer is durable, frost-resistant while having the right level of vapor permeability and water repellent.

When to do plastering work

External plastering is recommended after finishing work in the building. It is generally accepted that if you do not protect the surface of gas blocks from the street, it will absorb moisture. This is not so, primed walls can stand without a protective layer for the whole winter, when the climate changes in spring, moisture from the surface will evaporate. In the opposite case, when the house is processed from the facade, evaporation fumes will be directed inside the room, which will lead to the appearance of dampness.

Note! An exception is the option of building a house on the seashore or pond. When it is required to protect the external walls from the influence of humid climate and winds.

Before plastering, the walls of the gas blocks should dry well. If during the construction process a cement mortar was used, which has the ability to absorb moisture. For this reason, exterior decoration during the rainy season will not be effective. But especially dangerous for the walls is cold water, which then turns into ice. In the process of melting, the structure of aerated concrete begins to collapse.

Facade insulation

If the building is properly insulated, then you can quickly heat the room and save money on heating costs. Insulation from the outside is recommended to be done with mineral wool, polystyrene foam, polystyrene foam or other options. For example, insulation and plastering the facade of a house can be replaced by building an additional brick wall or treated with liquid polyurethane foam.

Types of plasters

There are several types of plaster that are suitable for processing aerated concrete walls. There are certain requirements for the composition of the mixture for outdoor work.

The material must be permeable and at the same time its coefficient should be higher than that of the treated surface - aerated concrete or sealant.
The plaster must be resistant to frost and temperature changes.
To prevent cracking, the applied layer must be flexible.
Plaster should have strong bonded qualities with aerated concrete.

Mineral

How to plaster aerated concrete walls? Professionals and private builders recommend the use of mineral-based plasters. They are among the thin-layer compositions specially created for aerated concrete finishing. Such solutions are made with their own hands, they have an affordable cost, good vapor permeability and low weight.

The finished compounds include such components:

lime;
white cement;
marble chips and other fillers.

The color palette of such plaster mixes is limited. They can be easily painted; the only caveat is the use of vapor-permeable coloring compounds. Painting is able to protect the coating from moisture, because a humid environment can destroy mineral plasters.

Silicate

The basis of this type of building plaster is potassium water glass, which is a binder component.

Advantages of the silicate mixture:

Ease of application;
Resistance to moisture;
Vapor permeability;
If necessary, painted in any color;
Acceptable price;
Long service life (up to 25 years);
Decorative qualities.

Silicone

It is better to plaster aerated concrete blocks with facade silicone plaster. It has high technical and operational characteristics, surpasses other plaster mixes.

The advantages of silicone plasters include:

water repellent properties;
building material is easily applied by hand, without the involvement of specialists;
plaster has a high degree of resistance to atmospheric phenomena and vapor permeability;
Long service life;
Fillers have a different texture;
The material is elastic.

Acrylic

The material has high decorative qualities and durability. A big disadvantage of acrylic plaster for processing aerated concrete and other cellular textures is the low level of vapor permeability. For this reason, condensation forms in the inner layer of the plastered surface. As a result, under such an impact, surface deformation occurs - peeling and cracking.

Cement-sand

Cement plaster is not suitable for the treatment of external aerated concrete surfaces. For what reasons, this popular building material is not suitable:

The solution is not fixed on a smooth surface of aerated concrete due to insufficient adhesion properties. The mixture has a high density and high weight;
When applying a cement mortar to the surface, aerated concrete absorbs moisture, weakening adhesion of materials. As a result of such rapid drying, the integrity of the layer is destroyed;
Low vapor permeability of cement mixtures - inconsistency with building standards, and violation of optimal microclimatic indicators in residential premises.

If cement plaster is used for interior work, it will protect aerated concrete walls from the penetration of steam.

Important! Expanded polystyrene and polystyrene are not recommended for use for surface treatment of aerated concrete.

Gypsum plaster

Plaster, which includes gypsum, has the following positive qualities:

dries quickly;
the solution does not shrink;
the mixture goes smoothly;
no topcoat required.

Cons of stucco wall gypsum:

average vapor permeability;
more water is required compared to special mixtures, about 10-15 liters per 1 bag of 25 kg;
the surface will quickly get wet after rain and snow;
spots appear on the surface that need to be painted over.

Front

The mixture is most effective for processing both external walls and indoors, the material is easily applied with your own hands. Plaster has a number of positive qualities - good adhesion to the base, attractive appearance. In particular, the material has vapor permeability indices identical to those of gas blocks. When choosing plaster for the construction of aerated concrete, it is better to choose a quality special mixture, this will simplify the process of decorating the house.

If there is a choice of plaster or drywall, which is better for aerated concrete inside the house. The following facts should be taken into account: walls made of gas blocks are smooth, and they do not require alignment. Accordingly, the plaster will be cheaper, the solution will lie in an even and beautiful layer.

Do it yourself

We plaster aerated concrete on the outside with plaster intended for outdoor use. There are two options for applying the mixture - a thick layer or several thin layers, which are applied no more than 3 layers and not more than 1 cm each.

Work order:

the surface is prepared for plastering - pollution is removed;
then you should do the hanging of the surface with your own hands along the lighthouses;
spray is applied - the first layer of plaster coat;
the primer is applied and leveled;
cutting corners;
slope finish;
a coating layer is applied;
the surface is overwritten.

Technology work outside

If necessary, a heater is mounted for blocks under the plaster.
Wall preparation - surface leveling to reduce material consumption and application thickness.
Before you start plastering the walls, aerated concrete should be treated with a primer. For this, compositions intended for the fine-mesh structure of materials are used.
Application of a thin layer of plaster mix for aerated concrete surfaces - up to 5 mm. This base will serve to attach the mesh.

It should immediately be noted that it is unacceptable to plaster aerated concrete blocks from the outside with adhesive solutions. Because the glue does not fulfill the tasks. In order to protect and level the surfaces, it is recommended to use specially designed mixtures that meet all operational requirements.

When work is done on plastering the facade of aerated concrete, it is recommended to follow some rules, which are described below.

after the building is erected, it is necessary to withstand a certain period of time so that internal moisture evaporates naturally;
brand of plaster should be suitable for outdoor use;
sequence of repair work - first inside the house, after outside;
the temperature regime should correspond to +8 to +30 С0 - for outdoor decoration;
Building regulations, the observance of which should be taken into account in relation to increasing the thermal conductivity Each mounted or applied material to the gas block should be considered.

Reinforcement

To the question whether it is necessary to reinforce the plaster, and whether a mesh is needed. The answer is simple, since the layer of plaster coating of aerated concrete can vary from 5 to 15 mm. If the layer exceeds 10 mm, a metal mesh with a fine texture of the cells is used as the reinforcing layer. For example, a mesh with a wire diameter of 0.1 mm and a mesh size of 0.16 x 0.16 mm, or fiberglass mesh with 5x5 cm cells, is suitable.

You need to mount the grid with an overlap of 5 cm, for the corners of the house use perforated corners with a grid. This method will help prevent cracking on the plaster after the building shrinks. It is better to install the mesh in the applied solution with a spatula. A particularly important point is the installation of the grid in places with a high level of voltage - the area of \u200b\u200bwindows and doors.

Advice! If you attach the net to a dry surface, the result will be zero. Because the mesh needs to be fixed to the wall using self-tapping screws, and then apply a layer of mortar. Otherwise, the non-fixed mesh will move along with the putty.

Work order:

Align the plaster layer with the mesh using vapor permeable plaster.
It is necessary to wait until the first layer is completely dry. Otherwise, it will fall away under the weight of the next layer. This technique provides for a thin layer application of the mixture. It will take three to four days to wait for complete drying. Accordingly, the thicker the layer, the more wait for it to dry. Checking whether the surface has dried is carried out using water. Splashing liquid onto the surface, it was quickly absorbed - this means that it is time to begin further work.
A second layer of plaster is applied, which is considered to be leveling. Therefore, the layer should be even and smooth;
A third finishing layer of plaster is applied and, if necessary, it will require subsequent grouting.
Painting the surface with materials for outdoor use or applying putty.
Water repellent treatment. Experts recommend applying this solution 12 months after staining and completing all work on the facade cladding. Water repellent gives any coating additional water repellent properties.

Note! When the plaster layer dries, it must be protected from the influence of such undesirable environmental factors as moisture, snow, rain.

Putty

When deciding whether it is necessary to putty aerated concrete, it is recommended to learn about the types of building mixtures. There are 3 types of varieties of products on the market that are designed for finishing. By and large, this is facade plaster intended for thin-layer finishing of an already plastered surface, differing only in composition. Ready mixes are sold in buckets and come in silicate, silicone and acrylic.

Important! Performing work on plastering the house from the outside, it is recommended to use only steam-passing building materials. This will provide not only a reliable finish, but will serve as a decoration for the building.

Aerated concrete blocks today are incredibly in demand - and not only in private construction, but also in the construction of frame-block multi-storey buildings. The products are compact, lightweight, easy to install, which allows a person to build a warm and inexpensive housing with their own hands.

However, raising the walls and bringing them under the roof is not all. You need to know exactly how to plaster aerated concrete inside the house, and understand by what principle the internal plaster is generally selected. These issues became the topic of this article.

The principle of selection of plaster to the base

Both aerated concrete and gas silicate concrete are classified as cellular concrete. There is an opinion that this is one and the same, but there is still some difference between them.

In both materials, there is a combination of two cement-lime binders. However, their percentage is different, resulting in a material with completely different strength characteristics.

Leveling coatings for aerated concrete

In aerated concrete, up to 60% of cement is present, and the rest is lime and sand. In gas-silicate products, cement is only 14%, almost twice as much lime, and many times more sand. It is clear that if there is so little cement, then the strength of the products is not the same. In general, gas silicate concrete is no longer a structural material, but insulating.

Perhaps now you have a question: "What does the internal wall plaster have to do with it?" And despite the fact that it is selected depending on the type of base, and in order not to have problems with the coating, you need to know exactly what and what can be combined. Crucial here are the characteristics of the binder.

Note! Cement, or rather products and solutions based on it, always has greater strength than lime and gypsum. When creating multi-layer screeds, the following principle must be observed: the base must always be more durable than the coating - otherwise, it will inevitably peel off.

From the above it is not difficult to conclude: if there is no - or almost no cement in the blocks, then the internal plastering of the walls, and especially the external, cannot be made, for example, with cement-sand mortar (see Optimum ratio of cement to sand for plaster ) It can be used for gas blocks, since they have a high percentage of cement, and the wall surface has sufficient strength.

You can even use not special purchased mixtures, one of which we see in the photo, but to knead the solution yourself. Only you need to keep in mind that the plaster should not be made as for heavy concrete or clay bricks - in the proportions of 1: 3, when a solution of the M150 brand is obtained.

Plastering the internal walls of aerated concrete is carried out with a solution of half the strength: M75. For its manufacture, cement M400 is taken, and mixed with sand 1: 5.

With an increase in the grade of cement, its amount in the solution should decrease to 1: 6, or even to 1: 6.7 - this is the arithmetic. Everything is done quite simply, and the lower price of self-mixing plaster will save significantly on finishing work.

How to plaster gas silicate

Now, as for the gas silicate wall, in which there is very little cement. Accordingly, such a plaster, as for aerated concrete, is not suitable for it. However, it is impossible to infinitely reduce the amount of binder in a solution - you can only replace part of it with another binder that is less weak in strength.

In gas silicate blocks there is a large percentage of lime, and it is most logical if it is also present in the plaster. That is, the most ideal option for plastering such walls would be lime-cement plaster. Making it yourself is more difficult, as lime mortar should be present in the solution.

It is much easier if the stucco of the house inside is produced with a purchased mixture. And by the way, if it is suitable for gas silicate, then it is suitable for aerated concrete (and not vice versa). Manufacturers often orient plaster mixes on both materials, which means that in addition to cement, lime is also present in them.
Sometimes the instructions on the package say that the mixture can be used for all cellular concrete. This means that they can also be applied to foam concrete walls, which include cement only from binders. Just keep in mind that there are also cementless varieties of foam blocks made on the basis of lime.
Like gas silicate, this material is also more likely a heater than a structural material. Foam blocks, in which there is absolutely no cement, are used for the construction of interior partitions. They can also be plastered, but only in the solution should not be cement.

It should be noted that silicate plasters are the best option for leveling walls of gas and gas silicate blocks, calcareous foam blocks, as well as silicate bricks. But since they contain liquid glass, and they are very corrosive, they are not used for residential premises - only in production shops and on building facades.

The appropriateness of using gypsum mixtures

The plaster inside the house having lime surfaces can be made of gypsum or lime-gypsum mixture. In principle, they are suitable for all types of substrates, but there is one thing here, and it concerns walls built of cellular concrete.

Given their high vapor permeability, and the similar property of gypsum, it is not always advisable to use plaster based on it, indoors:

Here it is already necessary to consider the structure of the wall decoration as a whole, and oddly enough, you need to focus on the option of exterior decoration. Suppose, outside the cellular concrete walls will be monolithically lined with brick, clinker tiles, or stone, or plastered on polystyrene foam.
Due to their poor vapor permeability, these materials will trap moisture in the thickness of the walls, giving it no way out. In this case, it is necessary to use only cement plaster inside, or provide such a decorative coating that will become an obstacle to steam.
For example: if it is paint, then alkyd; if wallpaper, then vinyl or cork. Yes, the same tile or stone, any lining with insulation - all this will not allow porous walls to be saturated with moisture.
In which case, the internal plastering of walls of aerated concrete, or other cellular material, can be performed with a gypsum mixture? There are only two options. The first is when the exterior walls are aligned on the base base with plasters with a high degree of vapor permeability: silicate, silicone, special for cellular concrete.
The second option is a ventilated facade. When there is an unobstructed outlet for steam and condensate from the outside of the wall, the internal plastering of the walls, like their finishing, can be done as you like. But we note that if the facade is insulated, then the insulation boards should be loose: soft mineral wool or the cheapest loose foam.

We’ll also clarify this situation. Decorative plaster for interior decoration, most often made on the basis of gypsum. How to properly prepare a porous base in the case when the use of gypsum mixtures is undesirable. With cement-based blocks, no problem.

In any case, the base before decorative plastering should be aligned as if gluing wallpaper. Therefore, the walls should first be leveled with a cement composition, and when it dries, decorative gypsum plaster for interior decoration can also be applied. You will learn more about this in the next chapter.

Internal plastering of aerated concrete

So, in our story, we went directly to the implementation of internal plastering on aerated concrete walls. We will try to highlight the most important nuances of this process, and for clarity, we offer to watch the video in this article.

The nuances of preparation

Porous surfaces are characterized by the highest moisture absorption, which must be reduced by priming. On aerated concrete walls, it is produced more abundantly than, for example, on brickwork. To do this, you need to take not just an adhesive primer, but the composition of deep penetration.

Important! Primers are prepared, but they are concentrated - that is, they are diluted with water in a proportion determined by the manufacturer, which must be observed. You should not think that if you apply undiluted soil, then it will be possible, for example, to reduce the number of passes. The composition should have a normal concentration.

The first layer is applied abundantly, preferably with a spray gun. You can also take for this purpose a conventional garden sprayer, with which trees are sprayed. After the aerated concrete wall dries slightly after processing, another layer is applied, after which the surface should already completely dry.

Double impregnation significantly reduces the absorption of the wall, but does not eliminate it at all. Yes, this is not necessary - otherwise how will the solution stick to the surface? The surface of the gas blocks is very smooth, and for plastering you need to provide good adhesion. It is impossible to make incisions, as on heavy concrete. How to get out of the situation?

How to make the plaster coating as strong as possible

After priming, task number two is to reinforce surfaces. This is necessary not only for the best adhesion of the layers, but also for the prevention of cracking.

This is especially important when the walls are built of gas silicate, in which five times less cement than in gas blocks. The strength of such a foundation is rather weak, and the plaster, even gypsum, will be more durable, and will work on separation.

Your task is to make a strong layer between the base and the plaster overlay, which will provide them with the best adhesion. Therefore, no matter what type of plaster you use, the starting layer must be done with a glue mixture, which is intended for the installation of cellular blocks.

To create a reinforcing layer, ordinary tile adhesive is also suitable. Many masters, due to the lower cost than the masonry mixture, prefer to use it. Why is adhesive needed, and not just plaster?

Note! The fact is that adhesives are always modified with polymer additives, which not only adhere, but tightly adhere surfaces. The glue layer is thin and durable, a fiberglass mesh is also embedded in it. It is not only an excellent basis for plaster, but also reliably fixes blocks, preventing microcracks from appearing and expanding.

A similar approach to preparatory work is especially important when self-made solutions are used for plastering. In them, unlike the factory ones, specially designed for gas blocks, there are no improving modifying additives, as well as fibers that reinforce the plaster in bulk.

No words, factory mixtures solve all problems, but because of the high cost, they are often used for facades. On the internal plaster, which is not exposed to such influences as on the street, you can save money - you just need to do it wisely. If you do not want to have problems in the near future, the adhesive layer must be done anyway.
Installation of the grid, in principle, is not required, and is carried out by masters at the request of the owner of the house. But the customer must know that the creation of the reinforcing layer only improves the quality: both the plaster and the foundation - after all, no one knows what shrinkage processes will occur in the ground.
It’s better to be safe, and spend a little on the net, than to bear the cost of a full repair in the future. We especially advise you not to neglect the grid when the walls are being prepared for painting - after all, any crack on them will be immediately visible. Cracks are invisible under dense wallpaper or tiled lining, but the task is not to hide them, but to prevent them from appearing.

There is nothing complicated in the installation of the grid, and in the video presented in our article, you will see it. Cloths overlap with freshly applied adhesive solution, and then pressed, combing with a notched trowel. The use of such a tool is very important, because thanks to it, scallops from the squeezed solution remain on the surface of the mesh.
When they dry, you get a beautiful embossed surface on which you can apply any plaster. First, the mesh is pressed into the adhesive layer with random movements, trying to press it as tightly as possible to the base. If normal leveling plastering is to be carried out on the walls, in the end, you need to do horizontal combing.
This is necessary only so that the plaster, which in the next step will be applied to this surface, does not slip from the wall. Well, for decorative plaster - if it will be used for interior wall decoration, the base should be smooth. In this case, the relief is not left, and the solution on the grid, extruded by a notched trowel, is smoothed.

When can you start directly to plastering? We must say right away that doing this right the next day is undesirable.

Even if the surface seems dry, the cement adhesive has not yet gained sufficient strength. It is not scary if the plaster is applied on it in gypsum. If it is a cement mortar, then the adhesive layer must be given at least five days - or rather a week, for a set of strength.

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 gained great popularity, during the production of which special additives are introduced into the composition of the solution, causing excessive 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, a similar structure of aerated concrete brings a number of difficulties in the decoration of the erected walls. A special approach is needed here, both in the sequence of work and in the materials used. In addition, the plastering of walls made of aerated concrete indoors will depend on their planned external finish.

What is the "capriciousness" of aerated concrete in terms of finishing, and in what ways you can solve these problems? These are the issues in this publication.

Features of aerated concrete

But on the materials for the work should go into more detail.

The open porous structure of aerated concrete will not be limited only to the filling of the walls - a thin layer simply can not stay on such a surface. Therefore, even if the wall is laid out with the highest accuracy and does not require special adjustments to its plane - you still can not do without plastering. And on the aerated concrete wall 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 the highly porous structure are affected), if not reinforced with a reinforcing mesh. If on other wall materials the use of reinforcing mesh is desirable, then in the case of aerated concrete, this condition should be considered as mandatory. The mesh is best - fiberglass, resistant to alkaline environment, so that over time it simply does not dissolve in the thickness of the hardened plaster mass.

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

Aerated concrete walls are characterized 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, which causes it to quickly dry out, crack and shed - in the case of gypsum compounds, and the violation of normal hydration of cement if plasters based on it are used. And in that, and in another case, the quality of the coating will be low, and the finish itself will be extremely short-lived.

It is important to find the “moisture balance" correctly, 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 sprayed solution begins to "creep", the layer becomes loose or inhomogeneous, etc.

Which exit?

- you can use special plaster mixes specifically for aerated concrete, designed for interior decoration. Their component composition, when properly mixed with water, in accordance with the instructions, is fully optimized for the features of such a surface and even sometimes does not require preliminary priming of the surface. All this is mandatory indicated by the manufacturer in the instructions for use of the composition.

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

And in that, and in another case, professional masters do not immediately advise giving a thick sketch - it is best to limit yourself to the minimum layer in which the reinforcing fiberglass mesh is embedded. Such a layer does not require a large amount of moisture, it is much easier to “rub” it into the aerated concrete with force, and the reinforcement will create a solid foundation, without cracks. But after drying such a substrate, it will be possible to safely proceed to the main plastering of the lighthouses.

Video: work of a master on plastering aerated concrete wall

As already mentioned, the composition of the stucco mixture directly depends on whether it is necessary to leave its high vapor-permeable properties on the wall, or, on the contrary, to impede the penetration of moisture into the material as much as possible.

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

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

Silicate plasters, based, are very well suited for aerated concrete, especially in terms of vapor permeability. However, such 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.
Especially for aerated concrete or similar surfaces, cement-lime based plasters have been developed. Their composition is optimized specifically for such surfaces that do not even require preliminary priming before plastering. An example is Baumit HandPutz plaster or a mixture from a complete “ensemble” of mortars specially designed for AeroStone aerated concrete.

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

If the owners of the house plan to achieve minimal vapor permeability of the walls from the inside, then usually resort to the use of cement-sand plasters without inclusions of lime or dolomite chips (flour). Naturally, the composition usually includes special plasticizing additives, suffocating the adhesion of the created coating with 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 of the walls will result in a fair amount. But this is only a preliminary alignment, excluding the finish! Is it possible to do simpler, apply more affordable mixtures or generally ordinary home-made plaster mortars, for example, based on cement and sand?

It is possible, but only an experienced craftsman can do such a high-quality finish, and his long-term practice allows him to determine the state of the wall, the need for moisture or priming, and the exact composition of the plaster by eye. And without the experience of such work, to make a mistake on an aerated concrete surface is as simple as simple, and all the work will be done in vain.

However, one very interesting method of preliminary preparation of a gas-silicate wall for the future can be recommended. If everything is done in accordance with the recommendations, it will be possible to apply almost any plaster composition without fear for the appearance of cracks, sliding of the mortar, its quick drying out or, conversely, excessive waterlogging of the wall.

How can a high-quality prepare an internal aerated concrete wall for plastering

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

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

It takes into account the conditions for priming the surface in two layers, moreover, with the dilution of the primer with water at the initial application, and the creation of a preparatory reinforced adhesive layer with a thickness of 5 mm. The calculations will show the result with the reserve “just in case” accepted by builders and finishers 15%.

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

Aerated concrete plasters internal and external should have optimal parameters, protecting the walls of the structure from destruction and cracks under the influence of external influences. There are several main options for finishing mixtures that will improve and maintain the quality of the base. The correct application technology will ensure a long service life and decorative coating.

Aerated concrete has good thermal insulation properties and a high degree of vapor permeability, due to the porous structure. To maintain the quality of the material, preventing the accumulation of condensate and the occurrence of mold, the correct finish of aerated concrete will help.

In this article we will answer the main question, so how to plaster aerated concrete outside the house and inside.

Aerated concrete blocks

Basic requirements for plaster

It should be noted right away that it is not recommended to apply ordinary plaster to the house from aerated concrete blocks. First of all, because standard sand solutions are highly dense, this leads to poor adhesion when applied to the gas block and the rapid appearance of cracks.

Adhesion(from lat. adhaesio - sticking) in physics - the adhesion of surfaces of dissimilar solid and / or liquid bodies.

Plaster should maintain an optimal microclimate inside the building, protecting the walls from moisture. Therefore, you should choose a mixture with a vapor-permeable base. Otherwise, the steam leaving the house will get stuck inside the walls, as the plaster will simply block its exit. Thus, moisture will accumulate in the walls, which will ultimately lead to their destruction. Of course, nothing will happen to the house in a few years, but in six or eight years the almost irreversible process of destruction will begin.

Plaster for aerated concrete should be:

resistant to external atmospheric influences;
have good adhesion (adhesion to aerated concrete);
resistant to sudden changes in temperature;
high degree of compressive strength (protection against cracking);
vapor permeable;
moderately dense;
improving the thermal insulation of walls;
have a decorative look.

When choosing plaster for aerated concrete, you need not to ignore any item listed above.

Plastering a house from aerated concrete blocks

The lack of facade decoration of structures made of aerated concrete will lead to darkening, deformation, peeling of the surfaces of the blocks.

Types of plasters suitable for aerated concrete blocks

The choice of stucco mixture for aerated concrete primarily depends on whether you intend to clad the walls from the outside or from the inside. Plasters according to the type of application are divided into external and internal.

As you yourself understand, the external plaster is intended for the decoration of facades. Since it performs protective functions here, its indicators of strength, moisture resistance and thermal insulation should be higher.

Internal mixtures are intended for wall decoration in rooms, therefore, the presence of moisture resistance in the characteristics of these plasters can be ignored, with the exception of cases of wall cladding in the bathroom. Due to the lack of resistance to moisture, internal mixtures are much cheaper than external ones.

Putting a finishing layer of plaster on aerated concrete

Popular plasters for aerated concrete

Mixtures for finishing facades from gas blocks are divided according to the type of composition into:

lime-cement;
acrylic;
silicate;
silicone.

Lime and cement mortars rather strong and at the same time vapor-permeable, because their main component is lime, which replaces sand. It is possible to eliminate a low level of water resistance, elasticity and a limited choice of the color palette of the material with the help of various additives. Modern finished mixtures contain special fillers that improve the properties of the coating.

Acrylicit is advisable to finish the structure of aerated concrete only with high-quality internal insulation of the walls. Such plaster can not boast of good vapor permeability, but as a decorative finish, it is durable and reliable.

Silicate Plaster for aerated concrete is based on liquid potassium glass. The coating is characterized by good moisture resistance, vapor permeability and strength. The silicate solution is easy to apply. The finishing layer is resistant to dirt and abrasion, providing a decorative finish coat for a long period (more than 25 years). The problem of silicates is a small selection of color schemes.

Aligning the walls with silicate plaster

Silicone mixtures contain resins, organosilicon polymers. Qualitative characteristics of the material are optimally suited to create a durable coating. Silicone-based plaster retains elasticity after application, which ensures that there are no cracks on the surface even when the blocks shrink. It is important to note the special decorativeness of the finish, thanks to special fillers and color variations, you can give the facade an original look.

Silicone plaster can undoubtedly be called a leader among others, it has all the advantages of silicate compositions, moreover, it is durable and looks great. But the price of silicone mixtures is much higher than others.

On our site you can find contacts of construction companies that offer the design service of houses made of aerated concrete. You can talk directly with representatives by visiting the Low-Rise Country exhibition of houses.

Most popular manufacturers

The market of building materials is saturated with a huge number of plaster mixes of various grades for finishing aerated concrete surfaces. Popular compositions have optimal characteristics for work.

Plastering on the interior walls of the house from gas blocks

Ceresit CT 24. The mineral composition of the mixture gives the solution plasticity. The material is easy to apply. The coating is able to withstand up to 100 cycles of low temperature effects. Staining is recommended after complete drying (after seven days).

CERESIT ST 77. The acrylic type of the mixture is used for facade decoration, providing coating strength with a fairly thin coating layer. The material is frost-resistant, resistant to external influences. It is used in the presence of water protection and ventilation inside the house.

Founces Startwell T-21. Cement-lime plaster is characterized by frost resistance, a sufficient level of adhesion. The resulting coating is resistant to shrinkage and moisture.

Video description

Look at the video comparison of facade plasters for aerated concrete:

Baumit SilikonTop. A high level of adhesion and plasticity is achieved due to the basis of the mixture - silicone resins. The coating for a long time retains decorativeness due to dirt-repellent properties. A wide selection of material colors palette (up to two hundred shades).

Weber.pas silikon. A mixture based on silicone emulsion. There is the possibility of choosing a suitable grain size. Optimum resistance of the material to moisture, temperature, pollution.

Baumit SilikatTop. Silicate type of plaster. The coating is durable, good vapor permeability. The composition has a different grain size and up to two hundred variations of tinting.

Primer before plastering

Internal wall plaster of aerated concrete

Internal work on plastering walls from gas blocks is performed by gypsum mortars with various additives. Composites in the form of perlite, marble chips will enhance the decorative finish. There is the possibility of staining the composition with various colors.

Gypsum mixtures without additives differ in the required level of vapor permeability, which allows the use of plaster as a basis for wallpapering. Standard sequence of work:

elimination of bumps, chips on the surface of the walls;
dust removal and application of the first layer of solution;
installation of reinforcing mesh;
applying a second layer.

After complete drying, you can glue the wallpaper, paint the walls or apply a third, decorative layer of plaster.

Internal work is carried out only with the preliminary application of a waterproofing composition, priming.

Internal wall plaster

Exterior wall plaster of aerated concrete

Plaster for aerated concrete facade type can be applied using various technologies: thick-layer, or thin-layer finish. The sequence of work includes:

mandatory preparation of wall surfaces, leveling;
priming (compositions based on acrylatesiloxane);
applying a thin layer of mortar - the basis for fixing the mesh;
reinforcement (crack protection);
alignment of the finishing layer;
second coating layer (formation of a smooth, even surface);
finishing layer of plaster, grout.

After a year after the completion of the facing work, it is recommended to apply a water-repellent solution. Thanks to the treatment of the facade with this composition, the moisture-proof and water-repellent properties of the coating are increased.

Features of plastering walls of gas blocks

The correct execution of work should take into account the features of the material of construction. Aerated concrete blocks may have differences in structure. Sawn options have an open, pronounced cellular structure and do not require special preparation for decoration.

The formed blocks are coated with a hydrophobic layer with a buried pore structure and require additional processing. Polishing surfaces with a metal brush will help to increase the adhesive properties of the material.

Video description

Look at the video the process of applying plaster on a house from aerated concrete:

It is also important to remember the rule of increasing the degree of vapor permeability from the inner layer to the outer surface. Facade finish should be two times thinner than the inner coating.

It is categorically not recommended to carry out plastering of surfaces from gas blocks earlier than after 6 months after the erection of the walls. The design must completely dry, getting rid of excess moisture accumulated during masonry

Reinforcing mesh plastering

Optimal conditions for applying plaster

Exterior aerated concrete plastering must be done under certain conditions. It is important to pre-complete the internal work of a high level of humidity. The load-bearing wall structures from gas blocks must be completely dry, not exceeding the figure of 27%. Otherwise, increased humidity will provoke a violation of adhesion and lead to peeling of the finishing layer of the facade.

The optimal time for finishing inside the house is spring, the facade of the building is the end of summer.

External temperature conditions for work must correspond to + 5- + 30 ° С, with air humidity not more than 80%. If it is necessary to finish at low temperatures, it is recommended to use a special deep penetration primer before acceptable weather conditions occur.

Correct work will help to avoid peeling, cracks and defects. It is forbidden to apply the coating in the heat, under the influence of direct sunlight and in windy weather.

Plaster facade of aerated concrete house

Conclusion

The choice of a high-quality mortar for plastering structures made of aerated concrete will help to improve the operational characteristics of the material, and will create strong and durable surface protection.

Recently, with the help of blocks made of aerated concrete, they not only conduct thermal insulation, but also build houses. This material is somewhat "capricious", so the plastering of walls made of aerated concrete indoors and outdoors should be carried out taking into account some nuances.

Many masters believe that finishing work on walls made of cellular concrete should be carried out immediately after the construction of the building, but this venture is quite risky. This procedure is best done in a year. The fact is that aerated concrete must have time to dry before the onset of cold weather, which may be prevented by the plaster layer. If moisture remains inside in the winter, then it will freeze, which will lead to cracking of the material.

First of all, the internal plaster for aerated concrete should be carried out, after which you can begin to finish the external surfaces. You can even take a little time by completing internal work in the fall and outdoor work in late spring. An exception may be only buildings on the coast. In this case, the first thing is to protect the external walls from atmospheric influences.

First, the internal plaster is applied, and then the external

Important! It is strictly forbidden to plaster a house from aerated concrete during the period from November to March.

Is it obligatory to plaster gas blocks outside

External plaster for aerated concrete is completely optional. On the contrary, many masters recommend immediately ordering walls of such a thickness that would be enough to ensure a comfortable temperature inside the house without using plaster outside. Incorrectly selected composition or violation of the application technology can lead to the destruction of the entire structure.

Many craftsmen oppose the external plastering of walls made of aerated concrete

Some advise using expanded polystyrene for insulation, but this material is practically impervious to water vapor. This leads to the fact that condensation accumulates at the junction of the insulation and gas blocks. In the cold season, it freezes and leads to cracking of cellular concrete. If it was finally decided to use expanded polystyrene, then you need to lay a layer of 80 mm, while the thermal resistance of the heat-insulating material should not be lower than this parameter of aerated concrete.

On a note! To get rid of the need for additional procedures, it is enough to order a wall 10 cm thick in warm regions, 30 cm in cold regions, and 20 cm is suitable for baths.

How to plaster gas blocks

The question of how to plaster aerated concrete outside and indoors is not at all idle. It should be noted immediately that stucco on aerated concrete cannot be carried out using cement-sand mortars.

To properly plaster walls from aerated concrete outside or inside the house, you must use the following compounds:

Interior work on plastering walls made of aerated concrete

Before plastering aerated concrete, attention should be paid to the thorough preparation of the foundation. To do this, remove all irregularities by means of a planer or a special tool for processing blocks of cellular concrete. This process is recommended to be performed at the stage of wall construction, but some builders simply forget about it in order to save time. The processing of the planer does not affect the operational properties of the future coating, but with its help it can be significantly reduced during decoration.

After this, a primer must be applied. Some masters dilute the primer with water, but this is fundamentally wrong. So you can save a little on the solution, but at the same time the adhesion of the treated blocks will drop significantly, which may affect the duration of the coating. To save the primer, it is better to moisten the roller with water first and pass it along the wall, after which repeat the procedure, but with the primer. For wet rooms it is better to use deep penetration impregnation, for dry rooms - simple.

For better adhesion of the plaster to the blocks, it is necessary to pre-treat the walls with a primer

Then proceed with the installation of plaster beacons. This is one of the simplest operations, since the blocks processed by the plane do not have large differences. Using the construction level, you need to find the maximum protruding point, add the profile height to the value, and according to the obtained value, set the beacons over the entire cultivated area with an interval of 130-160 cm.

Installation of plaster beacons will allow to put plaster perfectly evenly

When the preparatory work is over, proceed to plastering the walls from the gas block. It is carried out according to the following technology:

The first thing to do is spray. It is called a spray, and its thickness is not more than 3 mm.
After setting the spray, you can take on the main layer. It is called soil, it is all the indicators of the finished coating that depend on the quality of applying this layer. The material is collected on a spatula and transferred to the wall, so the entire area between the two beacons is treated.
Then you need to take the rule, push it to the lighthouses at the bottom of the wall and lift it up, making zigzag movements from side to side. The solution will remain on the blade of the rule, it should be thrown up the wall. The procedure must be repeated until the blade remains clean after lifting.
After setting the material, beacons are removed from it, and the resulting strobes are filled with a solution. Further, corners and hard-to-reach spots are processed, after which they leave the entire wall to dry.
After the base layer has dried, the last one is applied - a coating. It is considered decorative, so its thickness is 1-3 mm. It is carefully leveled, and when it dries, it is rubbed with sandpaper.
You need to wait for the set of strength of the material (the time is indicated by the manufacturer on the packaging), and you can begin to finish the finish.

The plastered coating is papered or painted. As a paint, it is better to use materials based on acrylic, latex, cement or organic solvents.

Plastering exterior walls of aerated concrete

Aerated concrete plastering from the outside can be carried out by two methods: applying in one layer or in several. The single-layer version loses a little, therefore it is recommended to stop the choice on the second method. Before plastering a concrete wall, it is necessary to carry out the same manipulations with it as with the internal wall. After this, it is necessary to install a reinforcing mesh.

Exterior plastering of aerated concrete walls using reinforcing mesh

For these purposes, use metal products with a wire with a diameter of 1 mm and a side of 16 mm or a fiberglass mesh with a cell of 5 cm. This product is cut into fragments of such an area that it is convenient to work with them. After that, a plaster mortar is applied on the surface with a layer of no more than 5 mm, while it is freshly pressed onto it and the net is sunk.

Then you need to pause and wait for the solution to dry. This is easy to check: you need to spray a little water on the coating, if the liquid is quickly absorbed, you can continue to work.

In turn, with an interval of 3-4 days, two more layers of 10 mm material are applied. After drying, the plastered surface is wiped as well as the internal ones.

The final step in wall decoration is to grout the plaster

On a note! Before plastering concrete walls, it is important to immediately determine the type of finish. Different types of paint require different types of plaster.

Aerated concrete blocks rarely require any decoration other than decorative, but if such a need arose, then, first of all, you need to choose the right material for aerated concrete plastering, and also follow the above rules and technologies.