Initially, aerated concrete was preparing the fate of a good insulation, and he perfectly set about fulfilling his task. But over time, apparently, the “concrete” nature of this material played its role, and it began to be widely used as the main material in construction, successfully replacing the same brick or stone.

The price of the significance of the material has increased, but the requirements for the products that are used in conjunction with it have also increased, conventional cement mixtures and plaster are no longer suitable. Here we need special ones, with which the construction industry did not fail to immediately saturate the market.

General information

When working with aerated concrete, it is necessary to know the nature of its production.

A little about the essence of the problem

In the manufacture of aerated concrete blocks, the same are used:

• cement,
• quartz sand,
• even ash and slag,
• as well as gypsum and lime.

But, which creates advantages for this material and some problems in the future, when finishing - so-called gas generators are added to the composition, which, reacting with lime, contribute to the release of hydrogen and the formation of pores 1-3 mm inside. It is these pores that provide the unusual properties of the resulting product. Usually, all kinds of aluminum pastes act as a blowing agent.

What do we get as a result

As a result of all physical and molding processes, we get a material with simply outstanding properties:

• it is unusually strong, concrete is all the same;
• it is noticeably lighter than the usual concrete block of the same volume;
• it turned out to be very easy to process, now it’s not even a problem to get any corners and irregularities in any direction - all this is due to the pores inside;

• even nails easily enter this material;
• it is completely non-combustible;
• compared to ordinary concrete, “gas” has less so-called natural radioactivity, because crushed stone and natural mica are not used in its production;
• as practice has shown, and which was another additional and unexpected plus - the material hardens even more over time, increasing the strength of the structures created from it;

• but most importantly, around which all the fuss flares up when finishing aerated concrete - it has excellent heat-insulating properties and
• vapor permeability.

Why be surprised that more than 250 factories for the production of this material have already been set up around the world. Only in Russia there are more than 80 of them, and most of the largest ones were built literally within 2-3 years - from 2009 to 2012.

Omnipresent standards

Such mass production of aerated concrete necessitated the creation of new State standards governing both its production and use.

Here is a list of all documents regulating the use of aerated concrete on the territory of the Russian Federation:

• GOST 25485-89 "Acellular concrete" - classifies all possible types of materials under one common name - cellular concrete;
• GOST 21520-89 “Small cellular concrete wall blocks” - determines the procedure for working with blocks;
• SNiP 277-80 "Instructions for the manufacture of products from cellular concrete" - building codes and rules for working with this material;
• GOST 31359-2007 “Autoclaved cellular concrete. Specifications” - technical conditions for the production and use of one of two types of aerated concrete - autoclave, which is produced at elevated pressure in a steam-saturated environment (the other type - “non-autoclave” - is produced without pressure or with electrical heating);
• GOST 31360-2007 “Wall products, unreinforced from autoclaved cellular concrete” - defines the recommended types of buildings from the described material.

A bit of physics and consequences from it

When it comes to aluminum, hydrogen and a chemical reaction, whether you like it or not, you have to delve into the essence of emerging processes that tell us that:

• yes, we get a very good material in terms of vapor permeability;
• but it also requires an appropriate discipline in its use, which many violate;
• as a result, visible damage to the surface finished with plaster, which is based on aerated concrete;
• the fact is that it is impossible to cover a material with high vapor permeability with a material that does not let steam through at all - this leads to the fact that moisture simply will not find an outlet to the outside and will accumulate inside at the boundary of the layers;
• therefore, it is necessary to follow the “non-decreasing” scheme of the vapor permeability coefficient; in other words, if we assume that this coefficient for aerated concrete is 1.0, then for the next layer it should already be at least 1.0, or even higher, let's say 1.2, then the next one is already higher than 1.2 and so on .

And this is physics, from which there is no escape, as from the law of universal gravitation.

What does disobedience lead to?

Violation of physical laws is always unpleasant, and this is not only an apple that has fallen on your head.

In the case of aerated concrete, this is:

• periodic cracking of the surface, which is periodic, depending on the time of year and ambient humidity;
• in the end, cracks turn into cracks and the finish simply collapses;

• in addition, in the inner layers there is a constant accumulation of moisture, as a result - mold and, again, the destruction of the masonry;
• in any case, even aerated concrete is no longer able to perform its original functions of thermal insulation.

There is an exit

As a matter of fact, all these processes did not come as a surprise to builders and special ones were developed:

• adhesives for joining blocks of aerated concrete when laying them on top of each other;
• primers for exterior finishing of these blocks;

• plasters for both indoor and outdoor use.

Now you only need to know about the presence of these finishing materials and use only them with aerated concrete.

Helpful advice! Another conclusion from all the arguments about physics is that when finishing these blocks, we strongly advise you to first complete all the work inside, wait for some time, when all the finishes are thoroughly dried, and only after that. And by no means the other way around.

Work progress

If everything is understood correctly, then the work itself will not present significant difficulties.

The scheme we're aiming for

When working, the final result will be such a simple layered structure:

• A - aerated concrete block;
• B - reinforcement, you can’t do without it, despite the increased strength of the blocks;

• C - a special adhesive for aerated concrete, by no means an ordinary cement mortar;
• D - plaster on a possible primer.

We plaster aerated concrete

All work is done as follows:

• first, a thorough cleaning of all seams between blocks to a depth of 1 to 4 mm is carried out; the main thing here is to exclude any insecurities in the masonry;
• then we thoroughly clean everything from dust, including with a damp cloth;
• let the surface dry completely;

• then everyone can choose the finishing algorithm at their discretion;
• for example, a very desirable next stage - a primer - is skipped by many, and there is no big crime in this departure from technology; the area of ​​work, as a rule, is quite solid and unnecessary work that is not super-obligatory is not a sin to exclude;

Helpful advice! If you still decide to carry out a primer and want to do it faster, then we advise you to use an airbrush and spray the primer. This method, of course, is not distinguished by an economical attitude to materials, it does not always give satisfactory uniformity, but you will save a lot of time.

• but the next operation, one way or another, will have to be performed - the fact is that the aerated concrete itself and the plaster used have good adhesion and are able to hold each other without any problems;
• but we advise either to make notches with a chainsaw on the surface of the wall to improve adhesion, or, best of all,
• place a fine metal or polyethylene mesh over the entire surface area, this will contribute to a much greater plaster retention effect;
• and you can fix the mesh with the usual available fasteners, we advise you to choose only those protected from corrosion;

Helpful advice! To prevent the mesh from sagging, it is necessary to accurately select the fastening step of the fasteners. We advise you to choose it within 120-150 mm, as practice shows, this is the most convenient distance.

• the first layer of plaster is applied to the grid, which is also called spatter; this layer will fill the grid cells and create a good basis for future layers, which is why this first layer is not even customary to smooth down;
• as soon as the “spray” has seized, the next layer is applied, not thicker than 5 mm, which is already smoothed out; on this layer, irregularities will be visible that will have to be eliminated by the finishing layer;
• we wait until the rough plaster is completely dry;
• as a final chord, we proceed to the finishing layer based on very small components;
• when the last layer is completely dry, it is polished, first we grind it in the rough with ordinary sandpaper, and then more carefully with a grinding machine.

findings

Aerated concrete is an excellent and very popular building material with remarkable properties that make it one of the most popular. But you have to pay for these outstanding properties with your understanding of all ongoing processes. Hence the use of special plaster, and the need to observe strict discipline when.

Violation of these rules can lead to complete and undeserved disappointment with aerated concrete. Be sure to watch the additional video in this article, it will help you not to relax and remind you of the nuances of the topic.

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Primer for aerated concrete: requirements, examination of samples, application and subsequent finishing

Aerated concrete is one of the most popular building materials in private construction. However, it has a number of features that must be taken into account when decorating the walls externally and internally. Today we have to get acquainted with primers for aerated concrete - their features, application and methods of finishing after priming.

Properties of aerated concrete

Advantages

Thanks to the technology of its production, this material has a number of properties that are extremely useful in construction:

• Ideal geometry that allows you to make the seams between the blocks as thin as possible;

Each seam is a cold bridge and contributes to an increase in heat loss. The thinner it is, the less heat leakage. That is why when building walls, not a cement-sand masonry mortar is used, but a special glue with a finely dispersed filler.

• Low specific gravity (from 300 to 1200 kg/m3);

In most cases, aerated concrete with a density of 400-700 kg/m3 is used as a building material. A lower density material (300 kg/m2) is used as a filling for the walls of frame-monolithic buildings, a larger one (the so-called structural aerated concrete) is used for the construction of load-bearing structures.

• Low thermal conductivity, which is provided by the porous structure of the material;
• High vapor permeability. It is due to the fact that a significant part of the cells in the structure of aerated concrete are open. Vapor permeability allows you to maintain a comfortable microclimate inside the house, getting rid of excess moisture.

disadvantages

As is customary, the shortcomings of the material are a continuation of its advantages:

• Aerated concrete has a huge, by the standards of building materials, water absorption - up to 30-35% of its own weight;

• When moisture is absorbed, the heat-insulating properties of the walls fall sharply: the water that fills the cells is much more thermally conductive than air;
• Freezing of water inside the cells leads to the destruction of the walls at an accelerated pace. Remember: during the transition to a solid state of aggregation, water increases in volume; during crystallization, it breaks the cells, giving rise to cracks inside the blocks;
• Not only that: consistently high humidity leads to the appearance of a fungus, which, feeding on minerals, additionally accelerates the destruction of walls.

Where can water get into the thickness of the walls?

There are actually only two sources:

1. Precipitation. With oblique rain, insufficiently wide roof overhangs leave the facade without protection from moisture;

1. Condensation of water vapor filtered from the interior. It becomes possible with an incorrectly chosen finish structure.

About vapor permeability

So what should be the structure of the outer wall in order to completely exclude water condensation inside the aerated concrete blocks?

One of the main building rules says: the vapor permeability of enclosing structures should increase from the inside to the outside. Interior decoration should pass less water vapor than the material of the main wall; external - the same or more.

What happens if you break this rule?

It is obvious! The interior finish will allow a sufficiently large amount of moisture to pass through, which will linger in the thickness of the wall. We have already studied the further development of the scenario: an increase in thermal conductivity and crystallization of water in the pores during the very first frosts with the accompanying destruction of the wall material.

findings

• External wall decoration should be carried out with materials with the highest possible vapor permeability.. The primer for aerated concrete blocks is no exception: it should not create a barrier to water vapor;

At the same time, it is highly desirable that the soil has water-repellent properties, making the open cells of aerated concrete closed. In this case, the moisture absorption of the walls during precipitation will decrease, and at the same time the paint consumption during fine finishing.

• For interior work, a normal deep penetration primer or an adhesive primer with quartz sand can be used. The latter, as the name implies, will significantly improve the adhesion of walls to plaster or putty.

Priming purposes

Is it necessary to prime aerated concrete walls for plastering or painting?

So to speak: highly desirable. On the one hand, the oldest residential building made of this material in the post-Soviet space was built in 1939 and has been standing for almost 80 years without external finishing in general and without applying water-repellent compositions to the facade in particular.

On the other hand… let me just list the results of applying the primer:

• Improves adhesion between wall blocks and the next layer of finish (plaster or decorative putty);
• The surface is strengthened: the primer binds the outer layers of the wall, increasing their tensile and bending strength;
• Reduced paint consumption when plastering, the walls absorb less cement milk, which means that the plaster retains greater strength;
• Moisture of the walls and all the negative consequences associated with it are excluded.

Sample study

And now let's take a closer look at several products from the market sector of interest to us.

For outdoor decoration

So, how to prime aerated concrete before plastering the facade?

Eskaro Aquastop Facade

Polyplast PGS-116

Polimin Super-primer AC-5

For interior decoration

Knauf Betokontakt

Application

How to prime aerated concrete walls with your own hands?

By the time work begins, the wall must be cleaned of dust, dirt and streaks of masonry mortar or glue. If there are oil stains on it, aerated concrete is degreased with any organic solvent. .

The primer is carried out at an air and base temperature not lower than + 5C, otherwise the water base of the soil will freeze. Adhesive primers are applied either with a wide brush in one layer.

When priming, tinted primers (for example, pink Betokontakt from Knauf) are very convenient: they allow you to visually control the condition of the surface.

In order to reduce their consumption, penetrating vapor-permeable soils are usually applied in three stages with a gradual increase in the concentration of the aqueous solution. Here is a step by step guide:

1. When priming in the first pass, the soil is diluted with water in a ratio of 1:4;
2. In the second pass, the concentration increases to 1:2;

1. The third time the wall is treated with an undiluted primer.

Finishing

What is the external finishing of aerated concrete walls after priming?

Cement plaster mixtures of increased vapor permeability. They have sufficient mechanical strength and moisture resistance, while at the same time not interfering with the filtration of water vapor from residential premises to the street.

If you prefer to paint the facade over a primer without prior plastering, use waterproof acrylic, latex or silicone-based facades. All of them have sufficient vapor permeability for our purposes.

The “rubber” water-dispersion paint based on acrylic latex made the most favorable impression on me. It is absolutely impervious to water, which will help protect the facade from precipitation.

What materials can be used for interior finishing of aerated concrete walls? Here the set is quite standard:

• Gypsum plasters and putties;

In the photo - finishing gypsum putty.

• Gypsum board with gypsum adhesive. "Perlfix" or "Volma Montage" perfectly adhere to the surface of aerated concrete blocks after their treatment with the notorious Betocontact or any other adhesive primer.

Conclusion

From the article, you learned about the properties and features of the use of aerated concrete primers used in wall decoration from the inside and outside. In the video in this article, as usual, you can find additional thematic materials. I look forward to your comments and additions. Good luck, comrades!

December 19, 2016

If you want to express gratitude, add a clarification or objection, ask the author something - add a comment or say thanks!

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

Some features of plaster

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

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

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

How to plaster aerated concrete walls?

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

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

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

Preparatory work

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

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

How to use the grid when plastering walls?

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

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

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

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

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

In Russia, suburban construction is gaining more and more popularity. For this, blocks made of aerated concrete are used. Many Russians are attracted by their low price and good construction characteristics. Outwardly, aerated concrete blocks resemble porous rock, but have clear shapes with a smooth surface.

They are characterized by poor moisture resistance. To get rid of this serious drawback, aerated concrete walls are covered with a layer of plaster.

Those who decide to acquire a house from this material should know that in order to create a normal microclimate, it is necessary to choose the right components of the plaster and the thickness of its layer applied to the walls.

Aerated concrete blocks

Such blocks are most suitable for low-rise construction. The walls erected from them have a number of significant advantages, for example, a small specific gravity, which ensures a higher construction speed and reduces the labor intensity of work.

Due to the porous structure of aerated concrete blocks, the microclimate in the building can be compared to the atmosphere of a wooden house. This is another property that makes aerated concrete popular. The material has excellent sound insulation.

It is believed that aerated concrete walls breathe. They let oxygen into the house, releasing water vapor and gases from it, formed by the natural processes of human life.

Like any other material, aerated concrete blocks have some disadvantages. The main one is the low parameters of the bending strength of the material, therefore, when building a house, these features must be taken into account. The foundation of the house must be monolithic, so the masonry must be reinforced with reinforcement through an equal number of rows. These works make it durable and more reliable.

The sequence of finishing works

It should be noted that they have a very high vapor permeability. In this they differ markedly from brick and foam concrete. Plastering of aerated concrete walls should be carried out taking into account the individual characteristics of the material.

Aerated concrete was originally used as a heater, and only after some time they began to build outbuildings and residential buildings from it. If the blocks are sufficient, then additional insulation is not needed. As for finishing, the interior walls of the house are finished first, and then the facade.

Many builders do the opposite. Taking advantage of the good weather, they perform on the facade of the house, and then proceed to its interior decoration. Plastering aerated concrete walls in this order is the most common and rather gross mistake that can lead to peeling of the finish from aerated concrete and the formation of numerous cracks.

Internal finishing works

Moisture is the enemy for any design. Aerated concrete walls are no exception. Water falling on them penetrates the porous structure of aerated concrete. Through the walls, it does not get inside the building and cannot damage the interior decoration, but reduces the protective characteristics of the house. Water from the pores of the material evaporates very slowly, and if the weather is rainy, then this process simply stops. Moisture accumulated inside the walls of aerated concrete significantly limits its natural ventilation and thermal insulation parameters. Plastering aerated concrete walls on both sides will help to avoid inconvenience. In addition to the protective function, it will also perform a decorative one.

There are several methods for finishing aerated concrete walls. The most common and affordable is plastering, which belongs to the technology of finishing vapor-proof materials.

The plastering of internal walls is not much different from ordinary finishing works. Before they begin, the wall must be well prepared. It is cleaned, leveled, and then a primer layer is applied, which must dry completely. Only after that you can start finishing work.

There is also mechanized wall plastering. When finishing in this way, the mixture lays down in a dense and even layer, but it is quite expensive and many Russians cannot afford it.

Finishing mixes

Manufacturers produce various ones. Their choice depends on the purpose of the room. For finishing a small living room, a standard mixture is used. Walls in rooms with a high percentage of moisture after finishing work are covered with a special primer, which perfectly resists the influence of water.

Novice home craftsmen need to know that the plaster applied to the aerated concrete surface must meet certain requirements. Some features of the material itself affect the finishing of aerated concrete walls. The blocks are strong, smooth and fit perfectly to each other at the joints, and this complicates the fixing of the mortar on the wall surface.

One of the main ones is vapor permeability. Simply put, the material must take and give away excess or missing moisture.

If the mixture is not properly selected, the following defects may occur:

1. The appearance of cracks on the internal and external surface of the building.
2. When the surface of the wall gets wet, a masonry silhouette may appear on it, which will disappear after drying.
3. Increased humidity in the rooms of the house, the appearance of an unpleasant odor.

The most popular plaster based on gypsum. It is easily diluted and after application and drying forms a smooth matte surface. The disadvantages include poor vapor permeability. Because of this, when precipitation occurs, the surface of the walls quickly gets wet, which dry for a long time. Sometimes yellow spots may appear, traces of which can only be painted over.

The most expensive and most effective is acrylic facade plaster. It is only used in conjunction with fiberglass. It has good adhesion, vapor permeability and excellent appearance. The disadvantages include the fact that only an experienced craftsman can work with this mixture. Only he can create a perfectly flat facade of the building.

How much does wall plastering cost? The price depends on the cost of mixtures and ranges from 236 to 550 rubles per 1 m². An important role is played by the manufacturer and the volume of containers.

The plaster must first be applied to the wall and only after an hour to start leveling. Next, the mixture should dry out during the day. The second layer, which makes the wall perfectly even, is applied to the already dried surface slightly moistened with water. After complete drying, the wall can be painted with a special paint for aerated concrete blocks. Remember that plastering interior walls is a demanding job that requires full concentration and patience. Only then will you get the expected final result.

Developers need to remember that you should not save on building and finishing materials. Cheap aerated concrete blocks made in a handicraft way will not be saved even by very high-quality plaster - it simply will not be able to gain a foothold on them.

Facade decoration

It is necessary to plaster the surface immediately after the construction of aerated concrete walls in order to protect the walls from all external factors. Otherwise, under the influence of temperature differences and precipitation, cracks form.

Cement plaster walls in this case will not work. Outside, aerated concrete walls are finished in the following sequence:

1. The facade is cleaned of dirt and dust.
2. A special primer for cellular concrete is applied.
3. An armored mesh made of fiberglass is attached.
4. Porous plaster is applied to the walls.

The reinforcing mesh is attached with self-tapping screws. When choosing it, it must be remembered that the mesh must have sufficient resistance to the effects of an alkaline environment. If this is not observed, then during the finishing work, the mesh may dissolve under a layer of plaster.

The mesh made of galvanized steel must be covered with a protective layer, because after a while it collapses under the influence of corrosion.

Plastering walls with gypsum plaster outside the building should protect it from the harmful effects of moisture, so the mixture must have water-repellent properties.

The material used for the construction of walls is gas permeable, so the plaster used must also comply with this parameter. And taking into account the harsh climate in most regions of Russia, it must be frost-resistant and have good compressive strength. To do this, manufacturers add protective synthetic components to the facade plaster, which looks like a dry mix.

Preparatory work

Plastering of walls with gypsum plaster is carried out after certain preparatory work:

1. Walls under plaster are cleared of dirt and dust.
2. Existing defects are filled with special glue.
3. Plastic corners are installed on corners and slopes.
4. Beacons are installed, which control the evenness of the walls.
5. The wall is wetted with water.

Facade and internal plastering of aerated concrete walls must be carried out at a temperature not lower than +10 °C.

Solution preparation

Plaster mortar is quite easy to make. A certain amount of water is added to the finished mixture. For optimal consistency, 0.2 liters of water per 1 kg of the mixture will be required.

The solution is thoroughly mixed. You can do this manually or use an electric drill with a special nozzle. After 15 minutes, the prepared solution must be mixed again. If the consistency does not suit you, then you can add more water or a mixture. The prepared solution should be used within an hour, otherwise it will lose all its properties.

Finishing work

The mixture is applied to aerated concrete walls with a trowel or a small straight thin board. Small sections of the wall can be leveled with a 30 cm steel trowel. High-quality, control leveling of the plaster is carried out with a ruler 80 cm long. Excess plaster removed from the wall surface can be reused.

If the estimated layer of plaster exceeds 7 mm, then the work on finishing the wall is carried out in two stages.

According to this scenario, work is underway to apply plaster on aerated concrete walls. Works should not pose unsolvable questions to the home master. The most important thing is to take into account the recommendations of experienced craftsmen and follow their instructions, then the developer will be able to protect his home from adverse consequences. Pay attention to the picture on the left - this is the plaster of the walls. The photo shows one of the moments of work.

Problems Caused by Improper Finishing

If during the work the rules were violated or the mixture was incorrectly selected, after some time various defects will appear on the surface of the wall.

They can appear as small cracks in the finished surface or swelling. Vertical cracks may appear on the facade, peeling of the plaster may begin.

Defects must be repaired immediately. This will increase the final cost of wall plastering and prove once again that it is necessary to use high-quality building and finishing materials from the very beginning.

Mechanical plaster walls

Mechanized wall plastering is the process of making and applying a mixture using special equipment. These machines greatly simplify heavy physical work. With their appearance, there was no need to perform finishing work manually.

The machines not only facilitated the work of plasterers, but also raised the quality of the work performed to a new level. Even an experienced craftsman cannot always prepare a solution of a mixture of a homogeneous consistency, and then distribute it over the entire surface. The work takes place in stages: the solution is mixed, placed on the wall, leveled. As a result, part of the wall has already dried up, another has begun to dry out, and plaster is still being applied to the third. This does not guarantee the final high quality finish.

When mechanizing work, the plaster is applied evenly and quickly. The time spent on work is noticeably reduced. The machine applies the prepared mixture faster, which allows you to use larger rules. Aerated concrete wall is more even.

Mechanized wall plastering allows you to reduce the time to complete the work and save the amount of the mixture.

The advantage of mechanized plastering of walls and facades:

1. Reduced plastering time.
2. Savings on material cost.
3. Loss of material is reduced by 5 times.
4. High quality.
5. The service life is increased.

Mechanical plastering of walls, the price of which depends on the amount of work, ranges from 300 to 580 rubles per 1 m². It guarantees a high quality finish. It all depends on the developer and his financial capabilities.

Outcome

Aerated concrete country house can be plastered independently. You should correctly use the advice of experienced craftsmen, choose the mixture correctly, perform all the finishing work, adhering to the sequence described in this article. The result is a beautifully plastered nice house.

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 gained great popularity, 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. A special approach is needed here, both in terms of the sequence of work and the materials used. In addition, the plastering of aerated concrete walls inside the room will also depend on their planned exterior finish.

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

Features of aerated concrete

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

• The open porous structure of aerated concrete will not allow you to limit yourself to only puttying the walls - a thin layer simply will not hold on to 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 prone to cracking and shedding (the adhesive features of the highly porous structure affect), if it is 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 - 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 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 one, which causes it to dry out quickly, crack and shed - in the case of gypsum compositions, and disrupt the normal hydration of cement, if plasters based on it are used. In both cases, 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 saturation of aerated concrete with water is also fraught with negative consequences. Yes, and such a wall is very difficult - the thrown mortar begins to "creep", the layer becomes loose or inhomogeneous, etc.

Which exit?

- you can use special plaster mixtures specifically for aerated concrete, intended for interior finishing work. Their component composition, when properly mixed with water, in accordance with the instructions, is fully optimized for the characteristics 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.

— application 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.

In both cases, professional masters do not advise immediately to give a thick sketch - it is best to limit yourself to a minimum layer in which a reinforcing fiberglass mesh is embedded. Such a layer does not require a large amount of moisture, it is much easier to “wipe” it into aerated concrete with an effort, and 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 along the lighthouses.

Video: the work of an aerated concrete wall plastering master

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

Manufacturers claim that the application of such compounds does not even require a reinforcing mesh. But in the case of aerated concrete, this point is better not to be ignored.

• Silicate plasters, based on, 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 finish coating, 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 set of a whole "ensemble" of mortars specially designed for AeroStone aerated concrete.

The composition of such plasters includes cement, building lime, special light aggregates and plasticizing additives, fine-grained purified 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 a minimum vapor permeability of the walls from the inside, then they 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 that suffocate the adhesion of the coating being created 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 walls will result in a fair amount. But this is only a preliminary alignment, without finishing! Is it possible to do it easier, 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 master can perform such a finish with high quality, to whom his many years of practice allows him to "by eye" determine the condition of the wall, and the need for moisturizing or priming it, 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 in vain.

However, we can recommend one very interesting way to pre-prepare the gas silicate wall for the future. 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, slipping of the solution, its rapid drying, or, conversely, excessive waterlogging of the wall.

How can I qualitatively prepare an internal aerated concrete wall for plastering

To work, you will need the usual, most inexpensive of all presented in the store, ceramic tile adhesive, fiberglass mesh, deep penetration primer (normal, such as 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 quite suitable, even in a ratio of 1: 5.

It is rather 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 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 during the initial application, and the creation of a preparatory reinforced adhesive layer 5 mm thick. Calculations will show the result with the 15% margin "just in case" accepted by builders-finishers.

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