Low-rise construction using gas silicate blocks has become widespread in all climatic zones our country. The unique properties of the material, which we will discuss in detail below, allow the construction of aerated concrete structures in hot regions and in places where negative temperatures prevail. However, carrying out the actual construction work is only half the battle. Comfort of further living in the house, its durability and preservation performance characteristics depend on the proper finishing of the façade and inner surface walls One of the main stages is plastering indoor aerated concrete walls. Let's take a closer look at the technology of the finishing process and the nuances that affect the quality of the final result.

Features of plaster on aerated concrete

To figure out what, when and how to plaster aerated concrete correctly, you need to study the properties of the concrete itself. building material. Features of plastering walls are associated specifically with unique characteristics gas silicate blocks.

Initially, aerated concrete was developed as a material that was 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 emerged:

• 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).

During the process of creating blocks, gas bubbles tend to the surface, making their way through the thickness of the mixture. Therefore, the cells in the structure of aerated concrete are not isolated, but represent a unique system of interconnected channels. This is due to main feature material, thanks to which the finishing technology for gas silicate differs significantly 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 inside for a long time.

Based on the foregoing, the fundamental principle for plastering walls made of aerated concrete looks like this: water vapor should be able to be easily removed from the thickness of the walls or should not penetrate inside at all. Failure to comply with this approach is fraught with serious problems during the cold season: negative temperatures the moisture inside the blocks will freeze, and the material will simply “tear”: cracks will appear, shedding will begin, and not only will the appearance, but also thermal insulation characteristics. To prevent this from happening, it is necessary A complex approach to the choice of options for external and interior decoration buildings.

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

• the impact of environmental factors on the porous structure of the material will lead to accelerated erosion;
• the above-mentioned structure, consisting of almost through microchannels, makes the material quite blown air currents, which creates discomfort when living in a house in cold, windy weather;
• insufficient mechanical strength open material makes it vulnerable to accidental impacts and other force impacts;
• a 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 select a material for interior work in accordance with the design option for the external surface of the walls, consider the main characteristics various types aerated concrete. For ease of perception, we will create a summary table of parameters:

From the data presented it is clear that even the most dense and durable brand aerated concrete has a high energy saving rate (the value of the thermal conductivity coefficient of 0.15 is compared with that of natural wood, traditionally considered the standard of warm materials). At the same time, vapor permeability remains at a significant level for all brands of gas silicate.

In the process of human life, interior spaces Moisture is constantly released into the air. In addition to the normal breathing of the inhabitants of the house, there are business processes including washing and drying clothes, washing dishes, and high humidity in sanitary facilities is their integral property. As mentioned above, excess moisture must either be easily removed through gas silicate walls, or not reach the surface of the material at all.

If special vapor-permeable plaster is used for exterior work, then a similar composition must be used inside. As a result, the overall vapor conductivity will remain virtually unchanged compared to the original characteristics of aerated concrete, and the aesthetic appeal and wear resistance of the structure will increase significantly.

Ventilated facades

Alternative option exterior finishing, in which vapor-permeable plaster is also used for interior work, is the creation of ventilated facades. This technique involves installing a ventilation gap between the wall surface and the layer of finishing material. The most common examples of such options are siding or trim. brickwork"into the loose" The creation of ventilated facades provides for the possibility of additional external insulation of walls, however, it is also necessary to use materials with appropriate vapor permeability: mineral wool is quite acceptable, while foam plastic and extruded polystyrene boards are categorically unacceptable.

Other finishing options

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

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

Materials

The given recommendations help solve the problem of choice budget options interior decoration. Which is better: plaster or drywall? The vapor conductivity coefficient of the densest aerated concrete is 0.16, and the same indicator for gypsum sheets = 0.07, which is more than two times less. Therefore, it is recommended to use drywall only in the case of installing blind vapor barriers. external facades, to create a ventilated structure must be used inside the house plaster mixtures For aerated concrete surfaces.

With regard to the kitchen, bathroom and toilet in houses made of gas silicate, the question no less often arises: is it possible to lay tiles? The answer is similar: since vapor conductivity ceramic products is close to zero, such finishing is acceptable with hydrophobic design of the walls on the outside.

How to plaster aerated concrete

Having understood the features of the technology, let’s move on to choosing the finishing material itself. With today's diversity building mixtures It’s not difficult to decide what to plaster with.

Most branded manufacturers of building materials produce compounds for working on aerated concrete. The most popular plasters include AeroStone, Bonolit, Ceresit or Knauf. Vapor-permeable plasters are somewhat more expensive than conventional plasters, so when deciding which one is better, financial side plays not the least role.

Before purchasing, be sure to read the product description and make sure that the mixture you are purchasing is actually intended for use on aerated concrete.

Preparing the walls

So, is it necessary to plaster - we figured it out, with suitable materials We've decided, let's get to work. Gas silicate blocks have standard size and are laid in perfectly even rows, so preliminary leveling of the surface requires minimal effort and time. This is usually done using grout mesh or sandpaper.

The next step is priming for plaster. This procedure cannot be skipped, because otherwise the finishing material will not adhere well to the walls or will quickly crack during use.

Plastering process

Next we move on to the finishing work itself. The technology for plastering aerated concrete walls indoors is not much different from similar work on any wall base and can be easily done with your own hands:

• vertical beacons are installed along the width of the rule;
• Preliminary puttying of the walls without plaster is carried out to secure the fiberglass mesh.

Is a mesh needed?

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

Despite the additional acquisition costs, the answer to the question of whether a mesh is needed is clearly 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:

• spread a layer of plaster from bottom to top over the area to be treated;
• guided by the beacons, we level the surface;
• dismantle the beacons and seal their attachment points;
• After drying, we finally rub down the walls.

Tools

Scroll necessary tools small:

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

Putty

If you plan to further paint the aerated concrete, after plastering it is recommended to carry out finishing putty. This will improve the adhesion of the paint to the surface and increase its service life. To carry out the operation, use special compounds for puttying aerated concrete, sold in construction supermarkets.

IN Lately using blocks from cellular concrete not only carry out thermal insulation, but also build houses. This material is somewhat “capricious”, so plastering walls made of aerated concrete indoors and outdoors should be carried out taking into account some nuances.

Many craftsmen believe that finishing work on walls made of cellular concrete must be carried out immediately after the construction of the building, but this undertaking is quite risky. It is better to carry out this procedure after a year. The fact is that aerated concrete must have time to dry before the onset of cold weather, which can be hampered by the plaster layer. If moisture remains inside in winter, it will freeze, which will lead to cracking of the material.

The first step should be interior plaster for aerated concrete, after which you can begin finishing external surfaces. You can even delay the time a little by completing interior work in the fall, and exterior late spring. The only exceptions may be buildings on the sea coast. In this case, the first step is to protect external walls from atmospheric influences.

Internal plastering is carried out first, and then external

Important! It is strictly forbidden to plaster a house made of aerated concrete from November to March.

Is it necessary to plaster aerated concrete blocks on the outside?

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

Many craftsmen are against external plastering of aerated concrete walls

Some advise using polystyrene foam for insulation, but this material is practically impenetrable to water vapor. This leads to condensation accumulating at the junction of the insulation and gas blocks. During the cold season, it freezes and leads to cracking of cellular concrete. If, after all, it was decided to use foamed polystyrene, then you need to lay a layer of 80 mm, while the thermal resistance thermal insulation material should not be lower than this indicator of aerated concrete.

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

How to plaster gas blocks

The question of how to plaster aerated concrete outside and inside is not an idle one. It should be immediately noted that plastering on aerated concrete cannot be carried out using cement-sand mortars.

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

Internal work on plastering walls made of cellular concrete

Before plastering aerated concrete, you should pay attention careful preparation grounds. To do this, remove all irregularities using a plane or a special tool for processing cellular concrete blocks. This process is recommended to be performed at the stage of wall construction, but some builders simply forget about it in order to save time. Treatment with a plane does not affect the performance properties of the future coating in any way, but with its help it can be significantly reduced during finishing.

After this, you need to apply a primer. Some craftsmen dilute the primer with water, but this is fundamentally wrong. This way you can save a little on the solution, but at the same time the adhesion of the treated blocks will drop significantly, which may affect the life of the coating. To save primer, it is better to first moisten the roller with water and pass it along the wall, then repeat the procedure, but with a primer. For wet rooms it is better to use impregnation deep penetration, for dry ones - simple.

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

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

Installation of plaster beacons will allow you to apply the plaster perfectly evenly

When the preparatory work is completed, they begin plastering the aerated block walls. It is carried out using the following technology:

• First of all, apply using the casting method. It is called spray, and its thickness is no more than 3 mm.
• After the spray has set, you can take on the base layer. It is called primer, and all indicators of the finished coating depend on the quality of application of this layer. The material is picked up on a spatula and transferred to the wall, and the entire area between the two beacons is treated in this way.
• Then you need to take the rule, press it against the beacons at the bottom of the wall and lift it up, while making zigzag movements from side to side. The solution will remain on the blade of the rule; it should be thrown up the wall. The procedure must be repeated until the blade remains clean after lifting.
• After the material has set, the beacons are removed from it, and the resulting grooves are filled with solution. Next, the corners are processed and hard to reach places, after which the entire wall is left to dry.
• After the main layer has dried, the last one is applied - the covering. It is considered decorative, so its thickness is 1-3 mm. It is carefully leveled, and when it dries, it is rubbed with sandpaper.
• You need to wait for the material to gain strength (the time is indicated by the manufacturer on the packaging), and you can begin finishing.

The plastered surface is covered with wallpaper or painted. It is better to use materials based on acrylic, latex, cement or organic solvents as paint.

Plastering external walls made of aerated concrete

Plastering aerated concrete on the outside can be carried out using two methods: applying one layer or several. The single-layer option is somewhat inferior, so it is recommended to opt for the second method. Before plastering a concrete wall, you need to carry out the same manipulations with it as with the internal wall. After this, it is necessary to install a reinforcing mesh.

Exterior plaster aerated concrete walls made using reinforcing mesh

For these purposes they use hardware with a wire with a diameter of 1 mm and a side of 16 mm or a fiberglass mesh with a cell of 5 cm. This product is cut into fragments of such an area that it is convenient to work with them. After this, a plaster solution is applied to the surface in a layer of no more than 5 mm, while it is fresh, a mesh is pressed onto it and recessed.

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

In turn, with an interval of 3-4 days, two more layers of material of 10 mm each are applied. After drying, the plastered surface is rubbed down in the same way as internal ones.

The last stage wall decoration is grouting plaster

On a note! Before plastering concrete walls, it is important to immediately decide on the type finishing. Under different types paints require different types of plaster.

Blocks made of cellular concrete rarely require any finishing other than decorative, but if such a need arises, then, first of all, you need to choose the right material for plastering aerated concrete, and also follow the above rules and technologies.

Aerated concrete plaster is important stage during interior finishing work. The main objectives of plaster are to perfectly level the wall plane, as well as a solid base for finishing, for example, tiles, wallpaper or decorative putty.

In this article we will analyze the types of plaster compositions, as well as their properties that need to be taken into account for the interior decoration of residential premises and rooms with high humidity.

Let's start with the fact that plaster comes in two main varieties:

• Gypsum based plaster.
• Cement based plaster.

Which plaster to choose for wet rooms?

For wet rooms, such as bathrooms, saunas, kitchens, it is recommended to choose cement plasters, and there are several reasons for this.

Firstly, cement compositions They are not afraid of moisture, but on the contrary, they gain good strength from water.

Secondly, heavy cement plasters have low vapor permeability, which prevents excess moisture from entering the thickness of the aerated concrete from inside the room. Excess moisture should be removed by a ventilation system, preferably forced exhaust.

Gypsum will last significantly less in damp rooms, and moisture will gradually reduce its strength, unlike cement.

For plastering bathrooms, you can use both ready-made cement plasters and self-mixed ones made from cement, sand and lime. But it is worth noting that ready-made plasters for aerated concrete contain special additives that have better adhesive properties, as well as strength, due to microfiber.

But ready-made plasters are much more expensive, and in order to save money, you can make self-mixing ones, with high-quality preliminary priming of the surface and reinforcement with fiberglass mesh with a density of 120 or more.

Which aerated block plaster should I choose for living rooms?

Gypsum plasters are usually used for living rooms, and here are the reasons.

Firstly, gypsum plaster, like aerated concrete, is vapor-permeable, which does not interfere with the movement of vapors from inside the room to the outside, that is, it is supported natural humidity in room.

If there is normal ventilation, the meaning of vapor permeability for aerated concrete is not particularly important. The so-called “breathing walls” are some kind of marketing ploy. Yes, walls made of aerated concrete are capable of drawing in and removing steam, but ventilation will cope with this task without problems.

The second reason why it is better to use gypsum plasters for residential premises is the saving of material and ease of operation. Since aerated concrete has an almost ideal geometry, the walls turn out to be very smooth, that is, not littered and without humps and holes.

In other words, a minimum layer of gypsum plaster for leveling is needed, usually from 1 to 5 mm.

Cement compositions cannot be used for such a thickness, since it is too thin layer will peel or crack. For cement plasters, a thickness of 10 to 20 mm is recommended. Now calculate, if for gypsum plaster the average thickness is about 3-5 mm, then for cement plaster it is 15 mm, which is at least three times more.

This means that for gypsum plaster it is necessary to purchase and carry three times fewer bags, and if you take into account that when water is added, gypsum also swells, then the savings can increase by another percentage.

Moreover, gypsum plaster can be smoothed with a sponge and spatula to a glossy state, which completely eliminates the need for putty, and this is another plus in favor of savings.

It is worth noting that if you want to leave the aerated concrete walls in some rooms completely vapor-permeable, then as a final finish you need to choose vapor-permeable materials, for example, paper, textile or non-woven wallpaper. Heavy vinyl wallpaper is completely vapor-proof.

For more information about choosing wallpaper for aerated concrete, read our article here.

Also, the vapor permeability factor must also be taken into account when choosing insulation, if one is planned.

Option of insulated vapor-permeable aerated concrete walls

Mineral wool + aerated concrete + gypsum plaster + paper wallpaper.

External plaster on mineral wool should be a special thin-layer plaster with high vapor permeability. You can also use brick cladding with a ventilation gap between the brick and the insulation. All layers are completely vapor permeable.

Thickness mineral wool you can choose any, but a thickness of 100 mm or more will be economically feasible.

Option for vapor-tight insulated walls

Foam plastic from 100 mm + aerated concrete + any plaster + vinyl wallpaper.

This option can only be used when the aerated concrete is as dry as possible. It turns out that because of the foam plastic, steam cannot escape from the wall, but because vinyl wallpaper he can't hit the wall. And the foam thickness of 100 mm shifts the dew point outward and freezing occurs exclusively in the insulation, which makes this design eternal. For this option you need good system ventilation in the house.

Priming is a mandatory step, which will significantly extend the life of the interior finishing. The primer removes dust from the surface, increases the adhesion of the plaster to aerated concrete, and also reduces the absorption of aerated concrete.

Aerated concrete absorbs water very quickly, and if you apply plaster without priming, the aerated block will absorb all the water too quickly, which is why the plaster will not have time to gain strength normally and will crack or peel off.

Therefore, it is necessary to prime with high quality, and twice, especially for cement plaster, because cement takes a long time to gain strength, and it constantly needs moisture for strength.

Plaster reinforcement

Reinforcement is also an important process that eliminates the occurrence of shrinkage cracks. The reinforcement works in tension, thereby strengthening the plaster and preventing cracks from appearing during the drying process.

The physical process of shrinkage itself is that when drying, the materials change slightly in volume, and at the border different materials Different degrees of shrinkage are created, and excess stress occurs, which can turn into cracks or peeling of the plaster. High-quality reinforcement solves this problem.

Typically, fiberglass mesh with a density of 120-150 g/m2 is used for reinforcement; fiberglass is used less frequently.

After constructing the box of the house, which includes the walls and roof, you need to wait at least half a year before finishing the interior. The thing is that it's fresh from the factory autoclaved aerated concrete very humid, the proportion of water in it can be 30%.

To begin finishing work, aerated concrete must shrink and dry enough so that most of the moisture has time to disappear.

External finishing and insulation are recommended to be done after interior and exterior work. heating season. But if this is a system with a ventilated facade, then in principle it does not matter when to do it, since ventilation gap between the aerated concrete and the cladding will not prevent the release of water vapor from the thickness of the aerated concrete.

Always remember the rule: the vapor permeability of the outer layers should be higher than the inner ones, so the aerated concrete wall will always be dry.

Preparing aerated concrete for plaster, video

Treating walls with plaster: advantages and disadvantages compared to other types of finishing work
Construction and repair technologies are changing, new materials are appearing, but plaster remains a popular method of wall finishing that has stood the test of time. Reliability, thoroughness and durability of the result obtained are strong arguments in favor of plastering.

Drywall, which gained popularity due to its ease of installation and became an excellent option for perfectly leveling walls, could not completely displace its “fundamental” competitor. Although communications are conveniently hidden under sheets of plasterboard and a thermal insulation layer can be placed - these are undoubted advantages, but they do not withstand loads, reduce the area of ​​the room and require finishing - these are disadvantages.

The process of plastering aerated concrete inside a house, like any other room, is labor-intensive, it takes more money and time, you have to go through a rather “dirty” period, but as a result the walls acquire high-quality coating, capable of serving for several decades. Of course, it also requires decorative finishing, but unlike a plasterboard base, its strength will withstand almost any load - shelves and canopies can be mounted on these walls and any design and renovation experiments can be implemented.

Plaster can be applied to any surface, except very uneven walls, which require a thick layer to level concrete mixture. In this case, it is easier and more profitable to use plasterboard finishing.

Selection of material for plastering aerated concrete walls

Aerated concrete ( gas silicate blocks) is a relatively new building material, but it has gained incredible popularity and the title of “revolutionary” on the market. Thanks to its cellular structure, it provides good thermal insulation combined with excellent air and moisture conductivity.
Its excellent air and vapor conductivity characteristics place special demands on the technology, quality of finishing and materials used.

Firstly, the finishing material should not drown out these valuable qualities, completely blocking the pores and depriving the house of the ability to “breathe”.

Secondly, porous aerated concrete, while providing good air exchange, can quickly “dry out” a plastered wall and cause cracks to appear on it.

Therefore, the choice of material for plastering aerated concrete surfaces is approached with special care. It is necessary to use specially formulated plaster mixtures marked “For aerated concrete”. They have added components that bring the properties of the plaster as close as possible to the properties of cellular concrete and improve its adhesion, adhesive and vapor-permeable characteristics.
In addition, the solution prepared from these mixtures acquires elasticity and durability and can be applied to the walls in a thin layer.

Sequence of work

For the same reasons, the sequence of work has its own specifics: first they plaster the internal walls, wait for them completely dry, and only then can you begin exterior finishing work. The moisture must completely escape from the inside to the outside, and not vice versa.

The plastering process consists of three stages:

• preparation of the base;
• applying the base layer;
• applying the finishing coat.

Preparing the base. Gas silicate walls They have a smooth, uniform surface with very thin seams, since glue, rather than concrete, is used for laying. A smooth surface necessarily requires the application of a primer layer, which strengthens the adhesion of the plaster and the wall and reduces the moisture-absorbing properties of aerated concrete so that drying occurs evenly.

Applying the base layer. After the primer has dried, the dry mixture is diluted with water in accordance with the manufacturer’s instructions and a base reinforcing layer of plaster is applied to the wall using a notched comb trowel. It is reinforced with alkali-resistant fiberglass mesh: it is simply pressed with a trowel into the upper third of the layer and smoothed. The mesh sheets are embedded in the plaster with a one-on-one overlap of 8-10 mm. They prevent the occurrence of deformations, shrinkage and cracks.

Sufficient thickness of the base layer is about 4 mm - special additives in the mixture for aerated concrete make it possible to obtain a durable coating with minimum thickness. The plaster takes a long time to dry - you have to put up with this. As a rule, 1 mm is given 1 day to dry, i.e. The entire layer will dry for about 4 days.

Applying the finishing coat. It is recommended to prime the base reinforcing layer before applying the topcoat. The decorative layer is applied with a metal float. Its thickness depends on the size of the fractions in the mixture - solid particles that give the plaster a relief pattern. For example, if the size of the fractions is 2 mm, then the thickness of the decorative layer should not be more than 2 mm.

Having leveled the plaster and waited a little until it “sets”, they “texture” it with a plastic trowel - giving it relief. Some finishing coatings do not require further painting, because already contain color pigments.

It would be useful to know that finishing work in a house made of gas sand-lime brick It is not recommended to start immediately after erecting the frame. The humidity of a “fresh” aerated concrete block from the factory is high - about 30%, it is advisable to wait about six months for it to dry to 15%. Aerated concrete walls do not require special insulation, so the house can be used at first without finishing.

Finishing begins with plastering the aerated concrete inside the house, i.e. With interior walls, but finish with the outside, and in no case vice versa. Drying should take place through the outer wall.

Work is carried out in compliance with temperature regime within the range from +8 to +30 C. Optimally – at 15-20 C.

If you follow the recommendations, the right technology works and selection of appropriate materials, plastered aerated concrete walls will last for decades, providing comfortable air exchange, absence of dampness and cracks on the surface.

Building material such as aerated concrete blocks, according to experts, is most suitable for low-rise construction. The construction of walls from such blocks has a number of advantages. Aerated concrete blocks have low specific gravity. For example, it is two times lighter than sand-lime brick. This property reduces labor intensity construction work and increasing the speed of construction. This building material has a low thermal conductivity coefficient. Walls built from it have a thermal resistance almost 3 times less than if they were made from ceramic bricks. However, it should be noted that as the density of the blocks increases, their heat-saving qualities deteriorate, so you need to know what the finish of aerated concrete should be.

Aerated concrete blocks have a porous structure, due to which the microclimate in a house made of aerated concrete can be compared with the microclimate of a wooden house.

Having a porous structure, the gas block has excellent sound insulation. Its surface seems to “quench” sound waves. We can assume that walls built from aerated concrete blocks “breathe.”

They freely allow carbon dioxide and water vapor to pass out, while allowing oxygen in. The microclimate in such a house can only be compared with the microclimate of a wooden house.

Aerated concrete has a cellular open structure, so it was originally used as insulation.

Aerated concrete blocks are fireproof and durable. When performing masonry, having high accuracy geometric dimensions, aerated concrete blocks allow the use adhesive compositions. And the work of erecting the walls of a house does not require highly qualified builders. Another advantage of aerated concrete blocks is their low sensitivity to negative impact environment.

The main disadvantage of this building material is the relatively low bending strength characteristics. Given this feature, when building a house, a number of activities should be carried out, which include: construction monolithic foundation, reinforcement of masonry, floors and truss structures.

Features of wall decoration

When finishing surfaces, do not forget that walls built from aerated concrete blocks differ significantly from brick walls and walls built from other materials. Aerated concrete belongs to the category of cellular lightweight concrete. Initially, the blocks were created as insulation and only later began to be used as a structural material.

The cellular open structure of aerated concrete, which provides increased vapor permeability, is the result of the addition of aluminum powder to the material composition.

During its production, aluminum powder is added to the composition, which acts as a gas former. Thanks to its content, aerated concrete blocks have a cellular open structure, which in turn leads to an increase in their vapor permeability. When finishing the walls of a house made of this material, it is necessary to take this characteristic into account.

Plaster can be considered the most common method of both interior and exterior decoration. It is necessary to start plastering aerated concrete with inside, and then move to the facade of the building. A very serious mistake is made by those builders who, during the construction season, build a house, plaster the outside of its facade, and then... winter period start interior decoration. Most of the water used in wet work will escape through the blocks and vents. Moreover, water vapor at sub-zero temperature environment will condense inside the walls and on the section of blocks and exterior finishing. Freezing, moisture will lead to inevitable cracking of the plaster and its peeling.

Thus, plastering should be done inside and not outside the room.

Plaster options

In order not to interfere with the vapor permeability of the walls, aerated concrete is not used when plastering cement-sand mortar.

When plastering walls inside, you can use two mutually exclusive methods. The first is based on finishing, which, using unique properties This material promotes vapor permeability of walls.

For such interior finishing, cement-sand mortar should not be used. The blocks, due to their structure, will quickly absorb moisture from it, and the walls, when dry, will be covered with a network of cracks. In this case, even high-quality deep primer and surface putty.

Another reason why you should not use cement-sand plaster indoors is the reduction in vapor permeability of the walls. After building a brick house, this property of the plaster is not so important. But if there are walls made of aerated concrete blocks that have such a unique ability, then it must be preserved and not worsen the microclimate inside the house due to the use of the wrong plaster composition. Best purchased from hardware store or there are special mixtures on the market for plastering cellular concrete blocks.

Some builders, when finishing internal surfaces of aerated concrete blocks, use a different principle - their maximum vapor barrier. In this case, the indoor microclimate will be no different from the usual one existing in reinforced concrete buildings. But on the outside, the plaster coating will be more durable. This is due to the fact that after some time required to purchase aerated concrete wall equilibrium humidity, the flow of steam into the external environment is significantly reduced and, consequently, the detachment of plaster from the surface of the facade is practically “reduced to nothing”.

Materials for vapor-permeable cladding

To increase the vapor permeability of aerated concrete, plaster mixtures with gypsum and gypsum putty are used.

This option is most often chosen by builders and customers. To implement it, materials with high vapor permeability are selected. Plaster mixtures based on the use of gypsum and gypsum putty. As a rule, such materials contain light perlite sand and slaked lime. Their use does not require priming the surface of the walls. Water vapor easily penetrates through the finished plaster layer.

Widely used for plastering interior surfaces ready-made mixtures having fillers - chalk, limestone, dolomite, marble and others. But it is important not only to choose the right filler. Attention should also be paid to the size of the fractions of its components. Some manufacturers have achieved a composition that is easy to use, rubs well and has almost one hundred percent whiteness. Despite the content polymer additives, the vapor permeability of such materials is even higher than that of external plaster. The finished coating is of high quality, quite durable and almost ready for further finishing.

Aerated concrete has a porous structure, so it doesn’t make sense to putty it right away, as it will require a large number of primers. If you skimp on the latter, the putty will crack and fall off.

Vapor barrier finish

Polyethylene film is used as a vapor barrier material for interior wall decoration.

It is much easier to perform vapor barrier interior wall finishing. The most simple method is the use of polyethylene film under one of the finishing layers. However, this can result in condensation accumulation and swelling of the plaster. If the customer insists on a good vapor barrier on the surface of the block walls, then sand-cement plaster should be used, but without additives such as dolomite flour or lime. Such interior finishing reduces the transfer of water vapor tens of times, but in most cases leads to peeling of the plaster. However, the choice of finishing the internal surface remains with the consumer and must be absolutely conscious of it.

Modern Decoration Materials, used for vapor barrier finishing of blocks, make it possible to reduce this by almost 25 times, almost stopping this process. Before plastering, it is recommended to prime the blocks several times with a special compound. Usually 3-4 times is enough. Wall covering oil paint will lead to an even greater effect.

Special adhesives exist and are currently widely used, the use of which before carrying out plastering works leads to a decrease in the vapor permeability of aerated concrete. In this case, putty is not needed.

Tools used

To perform plastering work on aerated concrete, the same tools are used as for conventional plastering. The solution is prepared in a special container. For this purpose, you can use a regular plastic bucket or tank. Its dimensions should be convenient for mixing the composition.

Water is added to the dry mixture, which is mixed with a construction mixer or drill with a special attachment to the required consistency. The proportions of water and mixture can be read on the packaging.

The plaster is applied to the aerated concrete by “throwing” it using a trowel or plasterer’s ladle. Sometimes you can use a trowel for this. A grater is used to rub the surface. Excess plaster mortar can be removed from a large surface with a polisher. To level the surface of the wall, beacons are used. Plaster mortar pulled together between the guides using a rule.

At the end of the work, its quality is checked using a strip length from the ceiling to the floor. It is applied to the wall in different places vertically and horizontally and allows you to detect various defects. Errors within 6-7 mm are considered acceptable.

Technology of plastering aerated concrete

Interior finishing of aerated concrete walls can be done different ways. The most common is still a vapor-permeable finish - plaster.

The process of plastering aerated concrete indoors is practically no different from conventional finishing work. The first step is preparatory work. The blocks are cleaned of dust and dirt and leveled. Next, a layer of primer is applied, which should take into account the further use of vapor-permeable materials that absorb moisture. Depending on the type of primer chosen, the wall needs a certain amount of drying time. As a rule, it does not exceed 3 hours. After final drying, the blocks are covered with a layer of plaster.

The plaster mixture should be selected taking into account the use of the room. In a living room, you can use ordinary standard plaster designed for cellular concrete. Gypsum plaster fixed on the wall mechanically. It can only be used in dry rooms. It is not recommended for use in damp environments or with strong surface vibrations. Gypsum plaster is excellent for finishing. In this case, the blocks don’t even need to be puttied.

If aerated concrete blocks are constantly in contact with moisture, for example, in a bathroom, then they must be treated and special drugs resistant to moisture. An hour after applying the plaster to the wall, it must be leveled, then wait until it dries completely and smooth the surface.

The effect is absolutely flat surface This is achieved by smoothing it a day after drying. Before smoothing, the blocks are moistened with a small amount of water. After finishing the work, the surface can be coated with paint specially designed for aerated concrete.

For vapor-permeable finishing, you can use plasterboard panels. It should be remembered that in accordance with the rules technological process Internal finishing cannot be done with vapor-permeable materials, and external finishing cannot be done with vapor-tight materials.

The service life of interior decoration depends on the quality of the materials used - construction and finishing. After all, even the most good plaster will not be able to adhere to the surface if the aerated concrete used is of poor quality.