How to plaster a wall of aerated concrete. Plastering walls of aerated concrete indoors. Dry plaster technology

Increasingly popular in Russia suburban construction. For this, blocks made of aerated concrete are used. Many Russians are attracted not high 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 provides a higher speed of construction and reduces the complexity 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 allow 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 individual characteristics material.

Aerated concrete was originally used as a heater, and only after some time they began to build outbuildings from it and residential buildings. If there are enough blocks, then additional insulation no need. As for finishing, first of all get off internal walls houses, 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 walls made of aerated concrete, performed in this order, is the most common and rather gross mistake that can lead to delamination 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 finishing methods. 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 falling precipitation there is a rapid wetting of the surface of the walls, 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 finishing

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 is applied for cellular concrete.
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.

Wall plaster 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. Installed plastic corners at 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 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 plots walls 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 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 may appear as small cracks on the finished surface or blistering. On the facade may appear vertical cracks, plaster peeling begins.

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.

Machines not only facilitated the work of plasterers, but also raised new level the quality of the work done. 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 finishes.

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 the rules bigger size. 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 Vacation home you can plaster yourself. 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 floors from aerated concrete material has several advantages. First of all, it is light weight and low coefficient of thermal conductivity. In order to avoid destruction, a wall made of this material must be finished. Due to its porous structure, indoor plastering of aerated concrete walls is carried out with the nuances associated with maintaining the microclimate inside the house. Therefore, not every finishing material can be used.

Material Properties

Before proceeding with the choice of plaster composition for walls made of gas blocks, it is advisable to understand what properties they have and why not every type of finishing material is suitable. Aerated concrete is an energy-efficient material for various types of construction. According to its parameters, it belongs to the group of cellular concrete, since its larger volume is made up of gas bubbles. The advantages of such a building material are:

• thermal insulation properties;
• low specific gravity;
• good sound insulation;
• possessing fire resistance of I and II degrees;
• ease of processing.

Working with aerated concrete is easy and fast. From it you can build a house on your own, without resorting to the services of construction organizations. Approximately a day a person can lay up to three cubic meters gas blocks. The composition of the material includes cement, lime, sand, aluminum paste and water. All substances are mixed in a given proportion, the value of which determines the strength of the resulting block. The reaction between aluminum paste and lime produces hydrogen. It contributes to the appearance of a huge number of pores, reaching maximum size equal to two millimeters.

The mixed mass with the ongoing reaction is sent to the molds, where it solidifies. After the frozen form is cut into standard blocks and polished. Despite all its advantages, aerated concrete blocks are hygroscopic material. And this means that not every finishing mixture is suitable for plastering walls from gas blocks. Due to the high porous structure, the internal plaster of aerated concrete walls is simply necessary to protect it from moisture. environment. Moisture quickly penetrates into the thickness of unprotected gas blocks through the structure of air bubbles, causing their destruction.

Features of use

The construction technology using aerated concrete is not particularly different from the construction of walls from another type block materials. The difference lies only in the binder composition for the blocks. The connecting seams are made with the minimum possible thickness to prevent the formation of cold bridges. Therefore, when building walls, glue is used that allows you to make a seam with a thickness of not more than three millimeters. Thus, the features of the use of aerated concrete are as follows:

​

Mortars used for plastering interior and exterior surfaces differ in their characteristics due to different conditions environmental impact. For outdoor use, they must not only be resistant to moisture, but also not change their parameters with temperature fluctuations.

Solution Requirements

It is necessary to select plaster with great responsibility. The final result will depend on this choice in the end. When choosing how to plaster walls from aerated concrete indoors, first of all, environmental conditions and the requirements for the resulting wall are taken into account. Making a choice building mix for plastering, pay attention to the following parameters:

When choosing a mixture, it is necessary to pay attention to its labeling. It should indicate the main characteristics and the purpose is written - for cellular concrete. Usually the price of such plaster is slightly higher than that of ordinary mixtures.

Types of plaster mixes

In specialized outlets You can find products from different manufacturers. There are several most commonly used types of plaster. Depending on the composition of the mixture, they are: lime-cement, gypsum, silicate and silicone.

Plasters based on cement-sand mortar are not considered very suitable. Although of all other types are the cheapest. Such a solution has a low vapor permeability coefficient and quickly gives up its moisture to aerated concrete. Because of this, it breaks technological process solidification and adhesion of the solution. Therefore, this type of mixture as internal plaster for aerated concrete is almost never used.

In the case of plastering with just such a mixture, lime is added to increase vapor permeability, and after drying, a layer of gypsum finishing putty is applied on top of the plaster. To improve adhesion, a primer is used that provides increased adhesion of materials, which eliminates the difference in price compared to specialized mixtures. It should be borne in mind that a decrease in vapor permeability leads to the formation of mold.

The use of glue used to bond the blocks together is undesirable. The adhesive mixture is developed exclusively for application in a thin layer. It will not be possible to make an even protective coating from it, and the cost of such material is quite high.

Gypsum plaster is considered the most popular for plastering gas silicate blocks. Its advantages include:

• optimal drying time;
• does not shrink;
• with sufficient skill, the applied layer forms a perfectly flat surface;
• the quality of the plaster allows not to apply the finish coat.

In addition, gypsum also has disadvantages: mediocre vapor permeability, the likelihood of various spots on the surface, the process of mixing the solution requires a large number water.

To work with gas silicate blocks it is recommended to use a special facade plaster. It is she who provides the desired indicator of vapor permeability and good adhesion to the base. Due to the low absorption coefficient, there is no need to apply additional layers of plaster. This type of mixture quickly gains strength, it usually already contains fibers for reinforcement. The main downside is the price.

When choosing the type of plaster, financial possibilities are also evaluated. The cheapest way would be to use a lime-cement composition, but at the same time the quality of the finish will be the lowest. Silicate compounds are optimal in terms of price-quality ratio, but require additional puttying. Mixtures based on silicone additives are ideally combined with the characteristics of aerated concrete blocks, but they are also the most expensive.

Finishing technology

Regardless of the mixture chosen, before you start plastering aerated concrete indoors, you will need to prepare both the tools and the surface. At the first stage, the surface of the overlap is inspected for the presence of glue sagging and irregularities in the seams. Defects in the seams are sealed with putty, and the influxes are cleaned off with a spatula, planer or grater.

The next step is to apply a primer. Before applying it, dust is removed from the surface, for example, by wiping with a damp cloth. After drying, the primer is already applied. It is distributed evenly over the entire surface. The easiest way to do this is with a roller or a wide brush. The choice of primer type depends on the type of room and the plaster mixture planned for use. So, suitable for gypsum mortar universal primer, and for sand-cement - deep penetration soil.

With insufficient skill, as well as for the convenience of plastering, beacons are installed. Their height limits the thickness of the applied solution. They are located on the wall vertically to the floor. The distance between them is chosen less than three to four centimeters of the length of the rule, and the evenness of the installation is determined using a level.

Application technique

Once preparatory stage is finished, proceed to the direct application of a layer of plaster. To do this, using the directions of the instructions shown on the bag with the mixture, a solution is prepared. The standard ratio is 1 kg of plaster per 0.5 liters of water. It should be noted that with an excess of water, the solution will spread, and with a shortage, it will crack.

After kneading to a creamy state, the solution is left for five minutes and mixed again. The mixture should be prepared in small portions, even if the surface to be plastered is large. This is due to the "life" of the material, which averages 40-50 minutes, after which its properties deteriorate.

A trowel or spatula is used to spread the solution. Throwing starts from the bottom up in such a way that the layer of plaster overlaps the height of the lighthouses. Then, along the lighthouses, making translational movements, they carry out the rule as if on rails, removing the excess.

As soon as all the work is completed and the plaster hardens, the beacons are removed. The voids formed after their removal are filled with putty. The entire wall is inspected for defects, if necessary, puttied with a spatula.

On the last step performed finishing. To do this, if necessary, grouting and sanding is performed.

Required Tools

When carrying out plastering work without the use of special tools it will not be possible to achieve an acceptable quality finish. For work, you will need to use both manual and electric type tool. But at the same time, there is necessary minimum, which is indispensable. It includes:

• container for kneading;
• putty knife;
• trowel;
• level.

Of course, even with a high level of craftsmanship, it will be impossible to achieve evenness and smoothness of the surface without beacons. Except minimum tool, you will need to have a rule, a trowel, a grater, an angled spatula, a drill with a whisk for kneading.

Aerated concrete is increasingly being used in private construction, competing with traditional brick. Such houses are much warmer, and it takes less time to build. By technical specifications aerated concrete differs markedly from other materials, and these differences must be taken into account when choosing exterior finish for walls. Plastering is considered the most popular option, and in order for the coating to correspond as closely as possible to the base material, you need to choose the right composition.

Let's take a closer look at the types facade plasters for aerated concrete and the correct technology for their application.

Aerated concrete has a cellular structure with open pores, which provides not only thermal insulation properties, but also high vapor permeability. Thanks to this quality, an optimal microclimate is created inside the house, the accumulation of condensate is excluded, and the risk of mold development is minimized.

But there is a downside: open pores increase the hygroscopicity of the material, and the absorbed water destroys the cells when it freezes. For this reason, the exterior finish must be waterproof in order to reliably protect the walls from moisture, and have a vapor permeability not lower than that of aerated concrete, so as not to impede the release of fumes.

Important! According to the standards prescribed in SP 50.13330.2012, in heated houses, the vapor permeability of materials should increase from the inner to the outer layers. Only under these conditions is it possible normal functioning bearing structures. Since for aerated concrete this parameter varies between 0.11-0.23 mg / (m h Pa), the plaster composition must be selected with a vapor permeability of at least 0.12 mg / (m h Pa).

Additionally, facade plaster must have the following qualities:

• high adhesion to the base material;
• frost resistance (at least 35 cycles);
• increased compressive strength;
• weather resistance;
• decorative.

In principle, aerated concrete surfaces can be operated without protective coating, but after a few years, the external attractiveness will disappear: the blocks will darken, peeling will appear, mold may develop. So it is better to immediately perform a facade finish and then only periodically update the coating with painting.

Prices for aluminum stairs

Aluminum ladder

Types of plasters for aerated concrete

The most common and most budgetary plaster for outdoor use is cement-sand. But since its vapor permeability is only 0.09 mg / (m h Pa), it is not at all suitable for aerated concrete structures. Other types have the necessary parameters plaster mixes such as mineral, silicate and silicone. Let's consider the characteristics of each of them in more detail.

Mineral

Mineral-based plaster refers to inexpensive materials and it is easy to do it yourself. The main disadvantage is the limited range of colors, but since this coating lends itself well to dyeing, it is not so great. a big problem. Ready mixes contain lime, white cement, marble chips and other fillers, as well as some additives that improve the quality of plaster. Home-made mixtures are most often made from cement, lime paste and sand, or only from sand and lime. It is worth noting that sand-lime solutions have low water resistance, and direct exposure to precipitation is detrimental to them.

silicate

In silicate plaster, liquid potash glass acts as a binder. Such compositions are more convenient to apply, are not afraid of moisture and perfectly pass evaporation, which allows them to be successfully used for finishing aerated concrete walls as finish coat.

Silicate plaster - photo

The color range is quite limited, but, again, this drawback is easily eliminated by staining. Silicate plaster goes on sale in a ready-to-use form, and at a cost slightly higher than dry mineral mixtures.

Silicone

The basis of silicone plaster are silicon-organic polymers. She possesses the best performance compared to other types of plasters: it does not absorb water, it is easy to apply, it is resistant to weathering, vapor permeable and does not lose its visual appeal for a very long time. In addition, such a coating remains elastic, and does not become cracked during shrinkage of aerated concrete blocks. Silicone plasters are also sold ready-to-use, have many color options. Due to the presence of special fillers, silicone plasters make it possible to create a varied texture of the coating. The only negative is the high price of the material, so not everyone can afford such a finish.

Acrylic

But acrylic plasters for aerated concrete can only be used under the condition of enhanced waterproofing on the inside of the walls and good ventilation premises. This is due to the low vapor permeability of the material, which is closer to cement-sand compositions. If you do not provide sufficient protection to the internal surfaces, water vapor will begin to accumulate in the thickness of the walls and provoke peeling of the finishing layer.

Popular types of plaster mixtures for aerated concrete blocks

Prices for various types of decorative plaster

Decorative plaster

Technology of plastering aerated concrete facades

Conditions for work

It is possible to plaster the facade of aerated concrete only after all the “wet” processes inside the room are completed and the surfaces are completely dry. This applies not only to plastered and painted walls, but also to screeds on the floor, the moisture from which evaporates very actively. The blocks themselves must also be dry - the maximum allowable humidity is 27%. If you plaster wet walls, the intense release of water vapor will cause peeling of the coating.

It is recommended to perform plastering of external walls at a temperature of +5…+30 °C, while the relative humidity of the air should not exceed 80%. If for some reason it is not possible to complete the exterior finish before the onset of frost, it is necessary to treat the entire area with a deep penetration primer. The best option- primer Ceresit ST-17, applied in 2 layers. Such protection will be enough until spring, when the weather conditions will allow you to start plastering.

Advice. Do not apply plaster compositions in the heat, when strong wind and exposed to the walls of direct sun rays. These factors contribute fast drying solution, and he does not have time to firmly grasp the base. As a result - the appearance of many small cracks and flaking of the plaster.

Deep penetration primer prices

Deep penetration primer

Surface preparation

As a rule, walls made of aerated concrete blocks are quite even and smooth, so they do not need to be specially leveled. If there are deep chips or dents, you need to seal them with the glue that was used when laying the blocks.

To do this, knead a little glue (you can mix it with the dust formed when sawing the blocks), collect it with a narrow spatula and fill the recesses. Remove excess and allow the solution to dry. In the same way, empty seams between the blocks are closed. When the glue dries, the walls need to be rubbed to remove minor flaws. Use a metal flat grater for this. Finally, brush off dust from the entire surface.

Padding

For priming aerated concrete walls under plaster, deep penetration compounds with strengthening properties are used. They create a very strong elastic film that allows water vapor to pass through, but does not allow the material to absorb water. Additionally, such primers increase the adhesion of the base and finishing layer. Popular means: Knauf Grundiermittel, Siltek E-110, Aerated concrete-contact-1.

The primer is applied in 1-3 layers, depending on the climatic conditions of the area. For example, in dry and warm regions, one coat of primer is enough, and in areas with a damp climate, coastal areas, three coats are needed. To apply the composition, use a roller or a wide paint brush. Primed with a continuous layer, evenly distributing the composition over the base. in the corners and hard-to-reach places use a narrow brush so that there are no dry areas left.

Plaster and reinforcement

It is not necessary to reinforce a layer of plaster up to 10 mm thick if the walls are well primed. With a greater thickness, reinforcement is indispensable, and for this, a fiberglass mesh with mesh sizes of 3x3 mm is used. The mesh must be alkali-resistant - this will ensure high durability and strength of the finishing layer. This information is indicated on the packaging, so when buying a mesh, pay attention to this item.

Step 1. Cooking plaster mortar. The proportions of water and dry mixture are in the manufacturer's instructions, so read it carefully before starting work. For kneading, take a clean container, pour the indicated volume of water with a temperature of + 15 ... + 20 ° C. Add dry ingredients and stir construction mixer at a speed of 400-800 rpm. Allow the solution to brew for 5-7 minutes and mix again.

Construction mixer price

construction mixer

Step 2 They take a wide metal spatula, put a solution on the edge and apply it on the wall in an even strip. The spatula must be held at an angle to the surface and not pressed too hard, so the composition will be distributed most evenly. The layer thickness should not exceed 5 mm.

Step 3 A grid is laid on top of the solution, straightened, and then gently deepened into the plaster, rubbing with a spatula over the surface with effort. If necessary, add the solution in small portions and again rub well. After fixing the grid, apply the solution to the next section and repeat all over again. The mesh must be overlapped by 40-50 mm to avoid cracks at the border of adjacent sections.

Step 4 In the corners, special perforated profiles are attached with a mesh fixed at the edges. To do this, apply the solution to the very corner, level it with a spatula in height, apply corner profile and press gently. Then, like a mesh, they deepen into the plaster and level the surface with a spatula. They are placed not only on the outer and inside corners but also around the perimeter of window and door openings.

Corners and mesh should never protrude above the plane of the wall. The surface must be flat, smooth, without visible defects. Now you need to let the solution dry well. Drying time depends on the composition of the mixture and weather conditions, on average it ranges from 3 to 7 days.

Finishing layer

Knead the solution for the finishing layer and apply it with a wide spatula to the surface. The thickness of this layer varies between 4-10 mm. Special care is required here, since all defects will remain in sight. When plastering adjacent squares, the formation of stripes along the edges should be avoided, all excess should be immediately removed with a spatula.

When the plaster has sufficiently set, but not yet completely hardened, proceed to the grouting of the walls. For this, it is most convenient to use a polyurethane grater, but a metal grater is also suitable. The grater must be applied flat to the surface, pressed, and smooth the plaster layer in a circular motion. You should not press too hard, so as not to leave scratches and dents.

After grouting, it is necessary to wait for the plaster to dry completely, and only then proceed to the final stage - painting. You can also apply decorative structural plaster, applying it in a thin layer on the prepared base.

Video - Facade plaster for aerated concrete

Initially, fate was prepared for aerated concrete good insulation and he did his job well. 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 aerated concrete necessitated the creation of new State standards governing both its release 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 the two types of aerated concrete - autoclaved, the production of which takes place during high blood pressure in a steam-saturated environment (another 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 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.

Useful 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 spend thorough cleaning all seams between blocks to a depth of 1 to 4 mm; 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;

Useful 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;

Useful 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.

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 polish it in a rough standard sandpaper, and then more carefully - with a grinding machine.

conclusions

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 special plaster, and the need for strict discipline when .

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

Aerated concrete plaster, internal and external, must have optimal parameters, protecting the walls of the structure from destruction and cracks under the influence of external influences. There are several basic options for finishing mixes that will improve and maintain the quality of the base. The right technology application 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 preserve the quality of the material, preventing the accumulation of condensate and the occurrence of mold, will help correct finish aerated concrete.

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 a house made of aerated concrete blocks. Primarily because the standard sand solutions different high density, 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.

The plaster must maintain an optimal microclimate inside the building, protecting the walls from moisture. Therefore, mixtures with a vapor-permeable base should be chosen. Otherwise, steam escaping from the house will get stuck inside the walls, as the plaster will simply block it from escaping. Thus, moisture will begin to accumulate in the walls, which will eventually lead to their destruction. Of course, nothing will happen to the house in a few years, but in six or eight years, an 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 a plaster for aerated concrete, one should not ignore any of the items listed above.

Applying plaster to a house made of aerated concrete blocks

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

Types of plasters suitable for aerated concrete blocks

The choice of plaster mixture for aerated concrete primarily depends on whether you are going 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 understand, exterior plaster is intended for facade decoration. Since it performs protective functions here, its strength, moisture resistance and thermal insulation indicators 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 wall cladding in the bathroom. Due to the lack of resistance to moisture, internal mixtures are much cheaper than external ones.

Applying the final 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-cement mortars quite durable and at the same time vapor-permeable, because their main component is lime, which replaces sand. Eliminate poor water resistance, elasticity and limited selection color palette material can be using various additives. Modern ready-made mixtures contain special fillers that improve the properties of the coating.

acrylic it is advisable to finish the building from aerated concrete only if there is a high-quality internal insulation walls. Such plaster cannot boast of good vapor permeability, but as decorative finishes, it is strong and reliable.

silicate plaster for aerated concrete is made on the basis of liquid potassium glass. The covering differs in good moisture resistance, vapor permeability and durability. The silicate type solution is easy to apply. The finishing layer is resistant to dirt and abrasion, providing a long-term decorative finish (more than 25 years). The problem of silicates is a small choice of colors.

Alignment of walls with silicate plaster

Silicone compounds contain resins, organosilicon polymers. The quality characteristics of the material are optimally suited for creating durable coating. Plaster silicone look retains elasticity after application, which ensures the absence of cracks on the surface even when the blocks shrink. It is important to note the special decorative finish, thanks to special fillers and color variations you can give an original look to the facade.

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

On our website you can find contacts construction companies, which offer the service of designing houses from aerated concrete. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

The most popular manufacturers

Market building materials saturated with a huge amount of plaster mixtures of various brands for finishing aerated concrete surfaces. Popular formulations have optimal performance for work.

Applying plaster on the interior walls of a house made of gas blocks

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

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

Founding 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

See the video comparison of facade plasters for aerated concrete:

Baumit Silicon Top. A high level of adhesion and plasticity is achieved due to the basis of the mixture - silicone resins. The coating retains its decorative effect for a long time, thanks to its dirt-repellent properties. Wide selection material color palettes (up to two hundred shades).

Weber.pas silicone. Mixture based on silicone emulsion. There is a possibility to choose the appropriate grit size. Optimum material resistance to moisture, temperature, dirt.

Baumit Silikat Top. Silicate type of plaster. The covering differs in durability, good vapor permeability. The composition has a different grain size and up to two hundred variations of tinting.

Surface priming before plastering

Internal plaster walls made of aerated concrete

Internal work on plastering walls from gas blocks is carried out gypsum mortars with various additives. Composites in the form of perlite, marble chips will increase the decorative effect of the finish. There is the possibility of coloring the composition with various colors.

Gypsum mixtures without additives are different necessary level vapor permeability, which allows the plaster to be used as a base for wallpapering. Standard work sequence:

• elimination of irregularities, chips on the surface of the walls;
• removal of dust and application of the first layer of solution;
• installation of reinforcing mesh;
• applying the 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 subject to the preliminary application of a waterproofing composition, priming.

Internal plaster walls

External plastering of aerated concrete walls

Plaster for aerated concrete front view can be applied using various technologies: thick-layer or thin-layer finishing. The sequence of work includes:

• mandatory preparation of wall surfaces, leveling;
• priming (compositions based on acrylate siloxane);
• applying a thin layer of mortar - the basis for attaching the mesh;
• reinforcement (protection against cracks);
• leveling the finishing layer;
• the second layer of coating (formation of a smooth, even surface);
• finishing layer of plaster, grout.

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

Features of plastering walls from gas blocks

Proper execution of work must take into account the characteristics 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 finishing.

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

Video description

Watch the video of the process of applying plaster to a house made of 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 interior coating.

It is strongly not recommended to carry out work on plastering surfaces from gas blocks earlier than 6 months after the walls have been erected. The structure must dry completely, getting rid of excess moisture accumulated during the laying of the material.

Plastering on reinforcing mesh

Optimal conditions for applying plaster

External plaster aerated concrete must be produced under certain conditions. It is important to complete interior work advanced level humidity. The supporting structures of walls made of gas blocks must be completely dry, not exceeding 27%. Otherwise high humidity 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 should correspond to + 5- + 30 ° С, with air humidity not more than 80%. If it is necessary to perform finishing at low temperature indicators, it is recommended to use a special deep-penetrating primer before acceptable weather conditions.

Proper work will help to avoid peeling, cracks and defects. It is forbidden to apply the coating in hot weather, in direct sunlight and in windy weather.

Plastered facade of aerated concrete house

Conclusion

Choosing a quality solution for plastering aerated concrete structures will help improve performance characteristics material, will create a strong and durable surface protection.