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At the end of construction, the question arises of how to arrange your home with inside, that is, how to plaster the aerated concrete inside. This material is more often used in small buildings that have 2 floors.

This popularity of aerated concrete has several reasons:

• low weight, which allows you to save on specialized equipment and construction time;
• retains heat well, therefore, even if the house will be built in an area where low temperatures, the owners do not have to worry about the cold at home;
• if we compare this material with ceramic bricks, then the second has a thermal resistance 3 times higher;
• such a house will be reliably protected from street noise;
• air permeability also has high rates, so there will never be stale air in such a building;
• influence environment and weather conditions have absolutely no effect on strength and durability of this material;
• high resistance of aerated concrete to open fire.

But you should know that aerated concrete plaster is selected depending on the density grade.

Due to the porous structure, aerated concrete was assigned the role of insulation. During masonry, ordinary adhesive solutions are used, since the exact geometric shape allows you not to think about the number and size of the joints.

But it is worth noting one negative feature - low bending strength. This, in turn, requires the creation of a monolithic foundation, reinforced masonry, floors and rafter structures.

How to properly finish aerated concrete walls

You should be aware that aerated concrete walls are somewhat different from surfaces created using other materials. Aerated concrete has a porous block structure, since it belongs to the category of lightweight aerated concrete. As noted above, at first this material was used in the role additional insulation, and later became independent.

The porosity of the structure is achieved by adding aluminum powder to the mixture. It reacts with other components to form gas bubbles. And this improves the properties of the vapor barrier. This feature affects how the internal will be done.

The lowest cost and easy way interior wall decoration - plaster. It is used not only for interior walls, but also for the facade of the house, but you should always start plastering from the inside. This is done so that the water is provided with an outlet, otherwise it accumulates in the walls of the house, which leads to the formation of condensation, fungi and mold.

When conducting construction in winter period the fumes will crystallize, which inevitably leads to cracking of the plaster, followed by its peeling. Therefore, plastering must start from the inner surfaces, moving towards the outer walls.

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Aerated concrete plaster: options

An important criterion for the selection of finishing material is not to clog the pores, otherwise the vapor permeability will be impaired. This means that cement-sand mortars are not suitable for such purposes. Otherwise, moisture will be absorbed into the body of the block, and when it begins to dry, cracks will appear. Moreover, neither a primer nor a high-quality putty will save the situation.

It is necessary to select such a material that could emphasize the breathing feature of aerated concrete, otherwise the home microclimate will be disturbed. Modern construction market offers a special plaster that is designed for working with aerated concrete.

In some cases, they adhere to a different direction - to create maximum vapor barrier. This option provides a longer service life for the building. This is due to the fact that aerated concrete is saturated with the required level of moisture due to the lack of steam out into the street.

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Materials for aerated concrete plaster

There are several options for how interior wall decoration is carried out:

1. Plaster and gypsum. If you plaster the walls with a mixture of plaster and plaster putty, then the level of vapor permeability increases. For this work, it is necessary to choose those materials that have high performance for this property. The best option is gypsum and its derivatives, because such mixtures are based on perlite sand and slaked lime. The convenience of this method is that there is no need to prime the walls. This coating does not impede vapor penetration.
2. Plastering can also be done with mixtures made on the basis of chalk, limestone, marble or dolomite. An important point in determining the correct mixture is the size of the fractions that make up such a plaster. It depends on how easily and evenly the composition will be distributed over the aerated concrete, as well as what its color will be after drying and how difficult it is to rub it. The presence of polymer components does not affect the vapor permeability of the material. Treated walls almost immediately become ready for further finishing activities.

It should be remembered that the plaster will last for a long time only if the surface of the aerated concrete is pre-primed.

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Interior finishing of aerated concrete with vapor barrier materials

For walls made of aerated concrete, it is necessary to use a porous plaster mixture with high vapor permeability.

This point is also important when working with purl surfaces. For this purpose, you can simply apply plastic wrap. But if the technology is not followed, condensation may appear, and the plaster itself will swell.

Therefore, it is necessary to plaster the walls with sand-cement mixtures, which do not contain lime or dolomite. This will help to reduce the transfer of water vapor, but the plaster itself will certainly flake off. Therefore, this moment must be taken into account without fail in order to imagine the consequences of the choice.

To reduce the effect of vapor barrier, you can pre-prime the walls with 3-4 layers, and if you paint them additionally oil paint, then the effect will increase.

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How to plaster walls and what is needed for this

To prepare the mixture and then apply it to the walls, you must have the following materials:

• a container for kneading, it can be a bucket or a tank;
• construction mixer or drill with special nozzle for mixing solutions;
• Master OK;
• grater;
• beacons;
• primer.

Typically, plaster is prepared by mixing dry mix and water in the proportions indicated on the package. As soon as the composition has reached the desired consistency, it is applied to the surface using a trowel by means of a throw-over method. It is necessary to distribute the solution as well as possible over the aerated concrete, which will help to create a minimum of drops and seams. So that the surface is evenly processed, beacons are installed.

After the solution is completely dry, it is treated with a grater. Next, you need to prime the walls. The number of layers depends on the quality and grade of the plaster used.

To detect possible defects, a rail is required with a length equal to the height of the ceilings. It is tightly applied to the surface and see if there are any differences. If they do not exceed 0.5 cm, then they are left; otherwise, such irregularities must be eliminated.

Aerated concrete is a cellular type of concrete, has a porous structure. Therefore, buildings made of aerated concrete blocks easily absorb moisture. Accordingly, for their greater resistance to bad weather, the material requires protection. Among the most common methods is the use of plaster. Let us consider in more detail the features of plastering gas blocks, where to start, what tools will be required, what finishing technologies exist in this way.

Aerated concrete absorbs moisture very well, so you need to protect it

When to start decorating aerated concrete walls

Basic hallmark aerated concrete is its increased hygroscopicity. Moreover, when the structure is wet, when the temperature is above zero, negative consequences it will be avoided - it will simply dry out, everything will be fine, but when water gets into the pores of the stone in winter, it freezes, accordingly, it expands, cracks may appear.

Given this, it would seem that the earlier the walls are plastered, the better. But this approach is wrong. Ideally, these activities should be carried out for the next season, when the surfaces are completely dry after laying. Drying time depends on the type of mortar used for laying. For example, a seam made concrete-sand mixture, will dry longer than where it was used adhesive mixture because it turns out to be much thicker.

Plastering is recommended for the next season.

Another condition for decorating walls made of aerated concrete, recommended for compliance in order to achieve a high-quality result, is the need to do everything in warm weather. Experts call the optimal time March-October, when the air temperature is above zero. If it is not possible to do so, it is necessary at least to cover the stone with a primer, cover it with plastic wrap, so that it will stand without losing its properties until the moment of complete finishing. The most effective water absorption will be reduced by the primer deep penetration.

But the opportunity to postpone finishing work is sometimes not available - it is required to carry out them immediately after the completion of the construction of the walls of the building. Here, experts recommend paying particular attention to the composition of the solution. It must have good plasticity, vapor permeability, then moisture can freely go out.

If you need to plaster immediately, then you need to carefully select the material

Which side to start finishing the gas-block building

There are three options for where to start covering aerated concrete wall blocks. Each has its own characteristics, and only one is considered correct. Specifically, you can start:

1. outside;
2. from the inside;
3. simultaneously from both sides.

Start plastering outside experienced builders recommended only when the dwelling is located near water bodies. The primary task here is to protect the aerated concrete from water and wind. Under other circumstances, the method of processing from the outside is not suitable - if you plaster the stone from the outside, all moisture will go inside the house, which may cause cracks, and the drying process of the joints at the end of the masonry will be significantly delayed. In addition, the stone itself may begin to deteriorate. Plastering walls from aerated concrete indoors will help to avoid the above problems - this method is considered the most preferable due to its effectiveness. The third method is considered the most unpopular way of decorating aerated concrete walls - despite the good vapor permeability properties, having "blocked" moisture from both sides, it will have nowhere to go, which sooner or later will lead to the separation of the finishing mixture from the block itself, and later even the destruction of the latter.

Plastering only needs to be done on one side

Sequence of work

Plastering of aerated concrete blocks contains three stages. Before plastering aerated concrete, apply a special primer designed for building materials that absorb moisture well with a brush or roller. The greatest efficiency is achieved by applying the solution evenly, that is, there should be no dry places. After completing this stage, the primer should be absorbed and dry.

At the second stage, a special reinforced mesh resistant to alkaline components. The mesh is fixed at a certain distance from the stone - there should be free space between them.

The final, third, stage is directly plastering the walls from aerated concrete. Here it is important to choose materials whose vapor permeability properties are higher than those of the aerated concrete itself. Extend the life of the surface while keeping it attractive appearance, you can, in a year, covering it with a water repellent.

The material for plaster should be chosen with a higher vapor permeability than that of aerated concrete

How to plaster - requirements, nuances

Aerated concrete plaster will become of the highest quality, it will not have to be done through short term perform on a new basis if the composition of the mixture meets certain requirements, and the packaging contains special markings. Among other things, it must be characterized by:

1. resistance to cracking, drying out, fading;
2. increased plasticity without sacrificing strength;
3. good adhesion to porous concrete types;
4. water-repellent properties;
5. high level of vapor permeability.

It is especially important to meet these criteria when used outside the building.

Even considering a large number of different types modern plaster solutions, the specified characteristics are possessed by units, therefore, most often when working on the processing of aerated concrete, the following are used.

Silicone plaster is perfect for finishing aerated concrete outside.

Silicone plaster for aerated concrete has the most advantages. Resistant to adverse weather conditions, has good vapor permeability, water repellency, and is easy to apply. This type has no disadvantages in operation, except for its high cost, which is still compensated by the long service life of the coating.

The second place belongs to silicate plaster for aerated concrete, characterized by a suitable level of vapor permeability, low water absorption. The main disadvantages are small color palette plus the loss of the original attractiveness of the appearance of silicate when dust gets in.

In third place is cement-lime plaster. She also has the necessary qualities to cover this type of building.

Aerated concrete plaster can be carried out with a cement-based mixture

Often, gypsum mixture is also used in such houses. Its advantages: it dries quickly, subsidence is excluded, there is no need to apply a finishing layer of plaster, in addition, you can make the surface as smooth as possible. However, the solution has its drawbacks. This includes the average characteristics of vapor permeability, susceptibility to rapid soaking from precipitation, in addition, stains may appear during its operation.

In addition, acrylic solutions are used for processing. Their rather significant advantage is strength, but one must also remember about the disadvantages - low refractoriness, which is why it is used only in certain rooms, with a relatively low level of vapor permeability. To prevent condensation from accumulating in the pores of aerated concrete, experts recommend using additional ventilation or internal water protection.

After examining the characteristics of all the materials presented, everyone can independently choose how to plaster aerated concrete.

Aerated concrete finishing scheme

Used tools

Plastering of aerated concrete walls is carried out using tools used in the treatment of other surfaces. Beating off the protruding parts of the walls, making them more smooth, installing notches where they are needed, is done with a plaster hammer or hatchet. The deep penetration primer is applied with a special brush (brush). You will also need a plumb line (it helps to install beacons to cover the desired surface with a solution), a building level, a square, metal scissors, a puncher, a hacksaw, and other standard tools. There are several options for lighthouses. The first is to purchase specialized metal beacons in a hardware store, fortunately, their choice is now quite wide.

Before starting work, you should prepare all the necessary tools

The second, "old-fashioned", method is to use the means at hand: even pieces of wood, pipe cuttings, and other suitable "details". Thanks to the beacons, the plane is perfectly flat, the corners are correct. The listed tools will come in handy if the plastering of aerated concrete walls is done manually.

Faster, more uniform application can provide special equipment... The method is more costly financially, but this is fully compensated for by the quality of the final result: thanks to the implementation of plastering under pressure, the bonding of the solution to the surface of aerated concrete is quite strong.

Machine plastering is slightly more expensive

Coating technology

The technology of wall decoration with plaster for aerated concrete is quite simple - it is performed in four steps:

1. the preparatory stage, where, before plastering aerated concrete, it is leveled, thus reducing the consumption of the solution;
2. padding;
3. covering the walls with a thin layer of plaster made of aerated concrete, which will further act as a base when fixing the reinforced mesh;
4. mesh reinforcement (prevents cracking).

For reinforcement, a metal or fiberglass mesh is used. Moreover, when installing it, special attention should be paid to windows and doors - places where the most significant load.

Having fixed the mesh, the plane is covered with a finishing layer of plaster, and when the coating dries up, the so-called grout is performed, that is, the surface is eliminated from irregularities, roughness, and other minor defects.

Before plastering aerated concrete, level the wall

Features of finishing aerated concrete

Starting to cover aerated concrete with plaster mortar, you should take into account the features of this material. First of all, experts recommend avoiding the traditional combination of cement and sand. The corresponding coating can crack over time, fall off, and it also contains a lot of water, which has a destructive effect on the walls themselves.

When plastering gas blocks, a prerequisite is the intended purpose of all funds specifically for cellular material.

Experts recommend not to use cement mixtures for finishing aerated concrete

It is important to start work on exterior cladding facade, when all the "wet" internal work has already been completed, then it is possible to avoid the formation of condensation inside the walls. Moreover, the thickness of the plaster layer inside the building must be twice as large as the outside, otherwise water vapor will remain inside the blocks, they will dampen. This is the only difference between carrying out these works inside and outside - the technology itself remains unchanged.

If you take into account the recommendations of experts, aerated concrete will serve you for a long time.

Thus, we see: with all its advantages, the building material is still quite picky, requires a special attitude. And in order for it to retain its beneficial properties to the maximum, a number of measures must be taken. But observing the above recommendations, it will prove itself as a very reliable material, it will last a long time, and the home will be cozy and comfortable.

Video: Plastering aerated concrete, preparation of the base

Video: Aerated concrete putty and plaster

Aerated concrete is increasingly used in private construction, competing with traditional bricks. Such houses are much warmer, and less time is required for construction. By technical specifications aerated concrete is noticeably different from other materials, and these differences must be taken into account when choosing an exterior finish for walls. Plastering is considered the most popular option, and in order for the coating to match the base material as much as possible, you need to choose the right composition.

Let's consider in more detail the types of facade plasters for aerated concrete and the right technology 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 condensation 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 necessarily be waterproof in order to reliably protect the walls from moisture, and have a vapor permeability no lower than that of aerated concrete, so as not to impede the escape of vapors.

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 such conditions is the normal functioning of the supporting structures possible. Since for aerated concrete this parameter varies within the range of 0.11-0.23 mg / (m · h · Pa), then the plaster composition must be selected with a vapor permeability of at least 0.12 mg / (m · h · Pa).

Additionally, facade plaster should have the following qualities:

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

In principle, aerated concrete surfaces can be operated without protective coating, but after a few years, the visual appeal will disappear: the blocks will darken, delamination will appear, and mold may develop. So it's better to immediately execute facade decoration and then only periodically renew the coating by painting.

Prices for aluminum stairs

Aluminum ladder

Types of plasters for aerated concrete

The most common and most affordable 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 of plaster mixes, such as mineral, silicate and silicone, have the required parameters. Let's consider the characteristics of each of them in more detail.

Mineral

Mineral-based plaster is an inexpensive material and is easy to do with your own hands. The main disadvantage is the limited color gamut, but since this cover it lends itself well to staining, this is not such a big problem. The composition of ready-made mixtures contains lime, white cement, marble chips and other fillers, as well as some additives that improve the quality of the plaster. Homemade mixes are most often made from cement, lime paste and sand, or only from sand and lime. It is worth noting that sand-lime mortars have low water resistance, and direct impact precipitation is destructive for them.

Silicate

In silicate plaster, liquid potassium glass acts as a binder. Such compositions are more convenient to apply, they are not afraid of moisture and are perfectly permeable to fumes, which allows them to be successfully used for finishing gas concrete walls as a topcoat.

Silicate plaster - photo

The color gamut is rather limited, but, again, this drawback can be easily eliminated by coloring. Silicate plaster goes on sale in a ready-to-use form, and the cost is slightly higher than dry mineral mixtures.

Silicone

Silicone plaster is based on organic silicon polymers. She possesses best performance in comparison with other types of plasters: does not absorb water, is easy to apply, resistant to atmospheric influences, vapor permeable and does not lose its visual appeal for a very long time. In addition, such a coating remains elastic, and when the aerated concrete blocks shrink, it does not crack. Silicone plasters are also sold ready-to-use and come in many color options. Thanks to the presence of special fillers, silicone plasters make it possible to create a variety of coating textures. 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 be used only under the condition of enhanced waterproofing on the inside of the walls and high-quality ventilation of the premises. This is due to the low vapor transmission capacity 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 the peeling of the finishing layer.

Popular types of plaster mixes for aerated concrete blocks

Name	Specifications
	Dry mix on a mineral basis. Differs in plasticity and ease of application. The ready-made solution must be used within an hour. Application thickness - from 3 to 30 mm. After drying, the coating can withstand temperatures from -50 to + 70 ° C, and at least 100 freezing cycles. Consumption of dry mix per m2 is about 14 kg when applied 10 mm thick. You can paint the coating 7 days after application.
	Cement-lime dry mix. It has good resistance to shrinkage, firmly adheres to the base, and is not afraid of moisture. It is applied with a thickness of 5 to 30 cm, consumption - 14 kg with a layer thickness of 10 mm. The ready-made solution must be used within 3 hours. Frost resistance of the coating is equal to 50 cycles, can be operated in the temperature range from -50 ° С to + 65 ° С
	Ready mix based on silicone resins. Very flexible, firmly adheres to the base, forms a strong coating with dirt and water repellency. The palette includes about 200 colors and shades. Consumption is 2.5-3.9 kg / m2, depending on the thickness of the application
	Ready-to-use silicone-based plastering compound. It has various grain sizes - from 1.5 to 3 mm, can be tinted in more than 200 colors and shades. The coating is resistant to moisture. Pollution, exposure to ultraviolet radiation and temperature extremes. Consumption is 2.4-4.7 kg / m2
	Ready-to-use silicate plaster. Has a grain size of 1.5 to 3 mm and 200 tinting options. Forms a dense coating with high vapor permeability and moisture resistance. Approximate consumption 2.5-4.2 kg / m2
	Acrylic compound with mineral filler. It can be used for exterior finishing of aerated concrete blocks in the presence of internal waterproofing and ventilation of premises. Forms a thin but durable coating that is resistant to negative impact... Possesses frost resistance up to 100 cycles, consumption is 4.5-5.2 kg / m2

Prices for various types of decorative plaster

Decorative plaster

Plastering technology for aerated concrete facades

Conditions for work

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

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 any reason, execute exterior decoration before the onset of frost does not work, you need 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 weather conditions will allow you to start plastering.

Advice. Do not apply plastering compounds in the heat, when strong wind and under the influence on the walls of straight lines sun rays... These factors contribute to the rapid drying of the solution, and it does not have time to firmly adhere to the base. The result is the appearance of many small cracks and plaster flaking.

Deep penetration primer prices

Deep penetration primer

Surface preparation

As a rule, walls made of aerated concrete blocks are quite even and smooth, therefore, they do not need to be specially aligned. 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 blocks), pick it up with a narrow spatula and fill the grooves. Remove excess and allow the solution to dry. In the same way, the empty seams between the blocks are closed. When the glue dries, the walls need to be rubbed to remove minor flaws. Use a flat metal grater for this. In conclusion, dust is swept away from the entire surface with a brush.

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. In addition, these primers increase the adhesion of the substrate and the finishing layer. Popular media: Knauf Grundiermittel, Siltek E-110, Aerated concrete-contact-1.

The primer is applied in 1-3 layers, depending on climatic conditions terrain. For example, in dry and warm regions, one layer of primer is enough, and in areas with a damp climate, coastal areas, three layers are needed. To apply the composition, use a roller or a wide paint brush. They are 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 no dry areas remain.

Plaster and reinforcement

It is not necessary to reinforce a layer of plaster up to 10 mm thick if the walls are properly primed. With a greater thickness, reinforcement is indispensable, and for this, a fiberglass mesh with a mesh size 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 point.

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

Construction mixer price

Construction mixer

Step 2. Take a wide metal spatula, apply a solution to 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 is distributed most evenly. The layer thickness should not exceed 5 mm.

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

Step 4. In the corners, special perforated profiles with a mesh fixed at the edges. To do this, apply the solution to the very corner, level it with a spatula, apply an angle profile and gently press it. Then, like the mesh, it is deepened into the plaster and the surface is leveled with a spatula. They are placed not only in the outer and inner corners, but also along the perimeter of window and door openings.

Corners and mesh should not protrude above the plane of the wall anywhere. 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 is from 3 to 7 days.

Finishing layer

Mix the finishing layer solution 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 plain sight. When plastering adjacent squares, the formation of stripes along the edges should be avoided, all excess must be immediately removed with a spatula.

When the plaster has set enough, but has not yet completely hardened, they begin to grout the walls. For this, it is most convenient to use a polyurethane float, but a metal float is also suitable. The grater must be applied to the surface flat, press down, and smooth the plaster layer in a circular motion. Do not press too hard so as not to leave scratches and dents.

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

Video - Facade plaster for aerated concrete

Lightweight, practical, reliable, inexpensive aerated concrete has created competition for traditional building materials. But at the same time we have to look for new finishing technologies, and special attention here plastering of walls from aerated concrete is required inside and outside. Many factors have to be taken into account: the unpresentable type of aerated concrete, and the non-moisture resistance of foam blocks, and shrinkage, and poor adhesion, therefore, special requirements are put forward for the plaster.

Next, we will analyze in detail how the technology of plastering walls made of aerated concrete and other cellular surfaces differs from finishing materials of high density, we will give step-by-step instructions, we will tell you what types of mixtures for blocks exist, how to prepare a solution with your own hands. We also picked up several videos on how to plaster walls from aerated concrete with our own hands, video tips will help you avoid major mistakes when performing work.

Types of plasters for concrete, aerated concrete, foam blocks, expanded clay concrete, gas silicate blocks

Plaster is the most rational way to protect, level and finish surfaces made of foam concrete and aerated concrete blocks, only it will help to properly optimize the performance properties of a porous material:

• improve heat and sound insulation;
• protect from harmful chemical, biological and atmospheric influences;
• prevent the saturation of foam and aerated concrete with dust and hydrocarbon compounds, thereby preventing shrinkage, cracking;
• provide good vapor barrier, oxygen exchange is a good prophylaxis against the formation of fungi and mold;
• improve hygroscopic characteristics;
• protect against large temperature deltas;
• prevent wear and tear of concrete blocks.

Good to know: On the recommendation of professionals, aerated concrete wall plaster inside the room should be twice as thick as the outer layer, it is better if there is a layer thickness of 40-50 mm in the room, and 20-30 mm on the street. If the balance is disturbed, cracks will go.

See how the internal aerated concrete plaster is made, a video on the preparation of the base.

Block to block - strife

At the moment, there are two types of aerated concrete blocks, they differ in manufacturing technology:

• Cast aerated concrete blocks - the solution is poured into a special shaping template-cassette, where it solidifies until complete hardening. This production method has significant disadvantages: when hardened on outdoors irregularities, bumps are formed, and when pulling out their forms, the edges and corners are often chipped. To facilitate the removal, the stripping is impregnated with special oil compounds, which are eaten into the foam concrete, not contributing to the adhesion characteristics when plastering.
• Sawing foam blocks are distinguished by good geometry, as they are made with a large solid plate, which, after hardening, is sawn into segments. The edges are smooth, the surface is rough. Walls made of such blocks are much easier to plaster. Aerated concrete blocks are made in the same way by sawing, but during the production process they are subjected to vibrations in order to compact the material, accelerate the reactions inside the solution and hardening. After unevenness and bubbles are carefully cut from the surface with a string and concrete block placed in an autoclave for heat treatment. Aerated concrete plaster for interior work and exterior decoration it is much easier compared to other aerated concrete blocks.

To improve the physical and mechanical characteristics of the blocks, expanded polystyrene is added to the working solution, at the output it has an improved expanded polystyrene block

Good to know: V foam concrete blocks air bubbles are closed, isolated (each individually), in aerated concrete products they are open, which worsens the resistance to heat transfer, lowers moisture resistance and frost resistance.

Properties of plaster for foam and aerated blocks

Plaster for exterior and interior decoration of aerated and aerated concrete blocks should not interfere with the natural characteristics of the porous material. And above all, vapor permeability should be taken into account. If this property is missed, condensation will accumulate between the wall and the plaster, and as a result, fungus and mold will develop. Therefore, plaster for gas and foam blocks must conduct air flows and water vapor well. And of course the plaster must have high adhesion, otherwise it will simply peel off even from a high-quality prepared gas or foam concrete surface.

Important: Interior decoration in houses made of gas and foam concrete should be carried out first of all, and only the next season can you start facade works... It is advisable to start all work only six months after the completion of construction, this period is enough for the structure to shrink and the blocks to dry out.

Plastering walls made of gas silicate blocks and aerated concrete must fulfill two mutually exclusive requirements: to be sufficiently vapor-tight to keep the microclimate in the room comfortable for life, and at the same time, to conduct air and moisture pores well to protect the walls from microorganisms and fungal attack. In addition, if condensate accumulates between the layer of plaster and the wall of foam, aerated concrete, then after several cycles of freezing and thawing Basic structure will begin to crumble.

Types of aerated concrete used in modern construction

What plaster for foam and aerated concrete blocks is better to choose

According to experts, for plastering walls from foam and aerated concrete blocks, it is better to use ready-made dry mixes sold in bags of 25-30 kg. They contain additives and plasticizers that improve physicochemical characteristics solution, adhesive and vapor permeable properties.

Table of plaster mixes for aerated concrete walls

Watch a lesson on how to make thin plaster of walls from foam blocks with your own hands, the video will help you understand everything technological nuances process.

Special plaster for gas silicate blocks and aerated concrete, developed by manufacturers taking into account all material characteristics:

• Ш-36 is a dry mixture based on cement, it contains synthetic reinforcing fiber.
• PROFIT CONTACT MN - cement-sand mortar with special additives, plaster for mechanized application.
• Dali is a universal plaster for foam and aerated concrete walls.
• Mask mik - dry cement-quartzite plaster, improved with polymer additives.
• ATLAS KB-TYNK is a lightweight wall mix for aerated concrete.

Aerated concrete wall plastering technology

The difference in the characteristics of gas and foam concrete blocks also implies differences in the technology of plastering walls. One general rule - preference should be given to ready-made thin-layer, lightweight plaster mixes.

Preparation

In order for the facade and internal plaster of walls made of aerated concrete and ponoblocks to adhere well and not flake off, the surfaces must be well cleaned of greasy and bituminous spots. Casting blocks should be treated with a coarse abrasive, while sawing blocks are rougher, therefore, sanding can be dispensed with only on slopes and corners.

The next step is priming:

• gas silicate walls it is better to impregnate with compositions with hydrophobizing additives, a primer for aerated concrete under plaster on a silicone base and alcohols as solvents;
• It is recommended to impregnate foam concrete with emulsions from a mixture of polymers, deep penetration, which reduce the absorption characteristics of surfaces.

The soil must contain additives that prevent the formation and development of fungi and mold.

The mesh can be reinforced with a quick-drying solution or with a mushroom dub

After processing the walls, we strengthen the reinforcing frame, it is rational to use polymer nets that are resistant to an alkaline environment, the cell size depends on the thickness of the solution layer. We expose beacons, we reinforce the corners with a special profile.

For your information: If the plaster layer is up to 15 mm, then it can be applied in one step, but if it is thicker, then the process should be divided into 2 or more stages, 1 layer of mortar with a thickness of no more than 10 mm should be applied at once, followed by 20 mm each.

Spraying will increase the adhesion properties of the walls

Facade plaster for foam blocks

The optimal external plaster layer for foam concrete is 15-20 mm. We moisten the walls well with water from a pultilizer. We dilute the mixture as indicated in the instructions on the package. For the first layer, you will need a solution of the consistency of liquid sour cream. We spray it, a layer of 5-10 mm, let it stand for a while, this will provide better adhesion.

The second layer is applied with a thick solution, it should not drain from the trowel. Throw in required thickness and draw out the solution with the rule. After 20-30 minutes, rub over small irregularities with a spatula.

Plaster for foam blocks inside

For better adhesion, the inside of the foam block wall should be treated with an additional layer of soil. Remember that the inner plaster layer should be 2 times thicker than the outer one, this is the only way to bypass the dew point at the plaster / block interface.

Apply from bottom to top base layer solution, we correct the rule for beacons. Apply a thinner finishing layer when the main one has dried. It should not be thicker than 10 mm, the surface is leveled with floats, in a circular motion, with effort.

Facade plaster for aerated concrete

Here, a vapor-permeable plaster for aerated concrete is suitable, a special ready-made mixture with a high content of gypsum, which also contains fine-grained perlite sand and lime dough. Mixes are universal, suitable for outdoor and indoor use.

Remember, it is not recommended to make the outer plaster layer more than 20 mm. To decorate the walls with our own hands, we throw a layer of mortar, level it with the rule of lighthouses. When the solution sets, apply a thin layer up to 5 mm, and carefully smooth the surface for painting.

Aerated concrete plaster for outdoor use must be protected from getting wet, in regions with a humid microclimate this is especially important. To extend the service life of the decoration and the house as a whole, external aerated concrete wall plaster is treated with a protective layer of a water repellent agent.

Plastering of aerated concrete walls indoors

Internal aerated concrete plaster is made with non-moisture resistant mixtures. In saunas, bathrooms, swimming pools - surfaces are treated with waterproofing materials, and only then the walls are plastered with moisture-resistant cement-based compounds.

Rough finish - apply the mixture to the prepared wall, leave it for an hour, smooth it gently. Then you can proceed to fine finish, on a well-prepared base layer, you can safely apply decorative plaster, glue the tiles, putty under the wallpaper.

The recipe for a plaster mix for aerated concrete from homemade

With large volumes of work, it can be expensive to buy a ready-made mixture, a solution made with your own hands will cost much less. We offer a recipe for plaster for aerated concrete walls:

• 1 hour of cement, not lower than M400;
• 3 hours perforated sandstone, fraction up to 3 mm (some craftsmen recommend using perlite sand);
• 1/3 lime dough.

Mix dry components thoroughly, add water and lime, bring the solution to a pasty state. Liquid soap can be added to the solution as a plasticizer.

We offer you to watch the final stage of plastering concrete walls with your own hands, the video demonstrates the pre-finishing finish.

Low-rise construction using gas silicate blocks is widespread in all climatic zones our country. The unique properties of the material, which we will discuss in detail below, make it possible to erect aerated concrete structures in hot regions and in places where freezing temperatures prevail. However, directly carrying out construction work is only half the battle. The comfort of further living in the house, its durability and the preservation of operational characteristics depend on the competent execution of the finishing from the side of the facade and the inner surface of the walls. One of the main stages is indoor plastering of aerated concrete walls. Let's consider in more detail the technology of the finishing process and the nuances that affect the quality of the final result.

Features of aerated concrete plaster

To figure out what, when and how to properly plaster aerated concrete, it is necessary to study the properties of the building material itself. Features of plastering walls are associated precisely with unique characteristics gas silicate blocks.

Initially, aerated concrete was developed as a material that is used to insulate buildings. Therefore, research was carried out in the direction of creating a porous structure, which, as is known, provides maximum thermal insulation.

As a result, two varieties appeared:

• foam concrete, the porosity of which is achieved by forced mechanical foaming;
• aerated concrete, in which gas bubbles are formed by adding aluminum chips that react with the main composition (hence the name of the material).

In the process of creating blocks, gas bubbles tend to the surface, punching their way through the thickness of the mixture. Therefore, the cells in the structure of aerated concrete are not isolated, but represent a kind of system of interconnected channels. This is due to main feature material, due to which the technology of finishing gas silicate significantly differs from other building materials. This difference is vapor permeability. Aerated concrete perfectly conducts saturated water vapor through its structure. At the same time, it has increased hygroscopicity, that is, it is able to quickly absorb moisture and retain it for a long time inside.

Based on the foregoing, the fundamental principle of carrying out plaster for walls made of aerated concrete looks like this: water vapor should be able to freely remove from the thickness of the walls or should not penetrate inside at all. Failure to comply with this approach is fraught with the appearance of serious problems in the cold season: negative temperatures the moisture inside the blocks will freeze, and the material will simply "break": cracks will appear, shedding will begin, not only the appearance, but also the thermal insulation characteristics will deteriorate sharply. To prevent this from happening, an integrated approach to the choice of options for external and internal finishing of the building is required.

We immediately answer the question: is it necessary to carry out outdoor work? Definitely yes, because:

• impact of factors external environment on the porous structure of the material will lead to accelerated erosion;
• the above-mentioned structure, consisting of practically end-to-end microchannels, makes the material sufficiently blown by air currents, which creates discomfort when living in a house in cold windy weather;
• insufficient mechanical strength open material makes it vulnerable to accidental blows and other forceful influences;
• finished wall definitely has aesthetic advantages over untreated masonry.

Dependence of internal plaster on facade finishing

To clearly demonstrate the reasons for the need to choose a material for interior work in accordance with the design option outer surface walls, consider the main characteristics of various types of aerated concrete. For ease of perception, we will form a summary table of parameters:

From the above data, it can be seen that even the densest and most durable brand of aerated concrete has a high energy saving rate (the value of the heat conduction coefficient is 0.15 compared with a similar indicator natural wood traditionally considered the standard warm materials). At the same time, vapor permeability remains at a significant level for all brands of gas silicate.

In the process of human activity during indoor areas moisture is constantly released into the air. In addition to the usual breathing of the inhabitants of the house, there are household processes that include washing and drying clothes, washing dishes, and high humidity in plumbing rooms is their integral property. As mentioned above, excess moisture should either be removed freely through the gas silicate walls, or not reach the surface of the material at all.

If a special vapor-permeable plaster is used for outdoor work, then a similar composition must be used inside. As a result, the total steam conductivity will practically not change in comparison with the initial characteristics of aerated concrete, and the aesthetic appeal and wear resistance of the structure will increase significantly.

Ventilated facades

An alternative option for exterior decoration, in which vapor-permeable plaster is also used for interior work, is the creation of ventilated facades. This technique involves equipping a ventilation gap between the wall surface and the layer of finishing material. The most common examples of such options are siding or jointed brickwork. The creation of ventilated facades provides for the possibility of additional external wall insulation, but here it is also necessary to use materials with appropriate vapor permeability: mineral wool perfectly acceptable, while foam and extruded polystyrene boards are categorically unacceptable.

Other finishes

Other materials for the decoration of facades (traditional plasters, adhesive bases for decorative stone, porcelain stoneware, etc.) violate the vapor permeability of aerated concrete, therefore, internal work should also provide maximum vapor barrier. In such cases, it is advisable to use special hydrophobic primers and finishing materials based on sand with cement, and the thickness of the plaster should be much greater than for compositions used while maintaining the ability of the walls to pass water vapor.

With this method of decoration, the room must have a well-thought-out ventilation system. Otherwise, constant humidity will lead to multiple manifestations of mold and mildew.

Materials (edit)

The given recommendations help to solve the problem of choice budget options interior decoration. Which is better: plaster or drywall? The coefficient of steam conductivity of the densest aerated concrete is 0.16, and the same indicator of gypsum sheets = 0.07, which is more than two times less. Therefore, it is recommended to use drywall only in the case of equipping deaf vapor-insulating external facades; to create a ventilated structure, it is necessary to use plaster mixes for aerated concrete surfaces inside the house.

Regarding the kitchen, bathroom and toilet in gas silicate houses, the question no less often arises: is it possible to lay tiles? The answer is the same: since the vapor permeability of ceramic products is close to zero, such a finish is acceptable when the walls are hydrophobic from the outside.

Than aerated concrete is plastered

Having dealt with the features of the technology, let's move on to choosing the finishing material directly. With today's diversity building mixtures it is not difficult to decide what to plaster.

Most branded manufacturers of building materials produce compositions for working on aerated concrete. Among the most popular are AeroStone, Bonolit, Ceresit or Knauf plasters. Breathable plasters are somewhat more expensive than conventional plasters, so when deciding which is better, the financial side plays an important role.

Before buying, be sure to read the description of the product and make sure that the purchased mixture is really intended for work on aerated concrete.

Preparing the walls

So, whether it is necessary to plaster - we figured it out, we decided on the right materials, let's get to work. Gas silicate blocks have standard size and are laid in ideally even rows, so preliminary leveling of the surface requires minimal effort and time. It is usually done with grout nets or sandpaper.

The next step is a primer for plastering. This procedure must not be skipped, otherwise finishing material will not adhere well to walls or quickly crack during use.

Plastering process

Next, we go to ourselves finishing works... The technology of how to plaster walls of aerated concrete indoors is not much different from similar work on any wall base and is easily done by hand:

• vertical beacons are installed along the width of the rule;
• the walls are pre-plastered without plaster to secure the fiberglass mesh.

Do I need a mesh

We will devote a separate section to this aspect. Plaster is a rather fragile coating. Therefore, at the slightest shrinkage of the foundation, cracks may appear on the surface, despite the monolithic reinforcing belts and other strengthening of the structure. Avoiding such phenomena will allow the laying of a special mesh made of materials resistant to an alkaline environment. Strong fibers reinforce the surface and prevent cracking.

Despite the additional purchase costs, the answer to the question - do you need a mesh - is unequivocally affirmative.

If you want the finish to last for a long time, do not start work immediately after construction is completed. The house needs to stand for at least 6 months, and preferably 1 - 1.5 years. This will allow the aerated concrete to achieve optimal moisture levels, and the foundation to undergo final shrinkage.

We continue the plastering process:

• we throw a layer of plaster from the bottom up over the treated area;
• focusing on the lighthouses, level the surface;
• dismantle the lighthouses and close up the places of their attachment;
• after drying, we finally rub the walls.

Instruments

The list of required tools is small:

• sandpaper and grouting nets;
• long profiles for beacons;
• brush or roller for applying the primer;
• container for diluting the plaster mixture;
• spatula for application;
• rule for leveling the surface

Putty

If planned further painting aerated concrete, after plastering it is recommended to carry out the finishing puttying. This will improve the adhesion of the paint to the surface and extend its service life. For the operation, use special compositions for aerated concrete putty sold in building supermarkets.