Plastering walls made of aerated concrete is a justified measure. , like the foam block, despite all its advantages, the material is hygroscopic. This means that it easily absorbs moisture. Therefore, a gas-block house must be protected from the weather. If the gas block gets wet in the rain and then dries, it will not lose its properties. And if it gets wet in winter, then the water accumulated in the pores of aerated concrete will freeze and expand. This is fraught with the appearance of small cracks that spoil the view, as well as the occurrence of more serious damage.
Conclusion: protection of aerated concrete from the outside from freezing, moisture, snow and other precipitation is a necessary measure. During and during winter conservation (if necessary), this function can be performed by a film stretched over the walls. During the operation of the house, it can be any facing material for the exterior of the facade - plaster for cellular concrete. The main thing is to create vapor permeability conditions so that the aerated concrete "breathes".
The exterior finish of aerated concrete houses, in addition to block protection, allows:
One of the most popular ways to exterior finish an aerated concrete house is to apply plaster. Therefore, questions often arise, for example, how and with what to plaster aerated concrete, which we will try to answer as fully as possible. We will conduct a comparative review of the characteristics of the best mixtures for facade decoration, and also describe the wall plastering technology in the form of step-by-step instructions understandable to beginners without construction experience.
Summarizing the experience of builders and owners of aerated concrete houses, we can conclude that three types of finishing materials are used for plastering aerated concrete walls:
No. Regardless of whether the gas blocks were laid on cement or on glue. In general, it is highly undesirable to plaster aerated concrete with cement mortar, because aerated concrete is very smooth and the mortar does not adhere to it, and it also strongly absorbs water from the mortar.
Reasons why it is impossible to plaster an aerated concrete house with cement mortar:
Note. For the same reason, it is undesirable to use rigid heaters (polystyrene and expanded polystyrene) for insulating a house made of aerated concrete.
Remember, the foundation must be periodically moistened and covered with a film to ensure uniform drying. So why should it behave differently on the wall? The primer saves the situation, but not much. The appearance of a cobweb of small cracks on the plastered surface of aerated concrete cannot be avoided.
Note. In order to save money, you can mix a cement-sand mixture and a special mixture for finishing aerated concrete blocks in a ratio of 1 to 1. But is such savings needed, which will significantly reduce the speed of work, and the finished surface will not be 100% of high quality.
You can increase the adhesion index (sticking, adhesion of surfaces) by adding lime to the classic cement mortar recipe (proportion: 8-10 kg of lime per 100 kg of concrete).
Cement-lime plaster can be purchased as a ready-made dry mix. For example, dry building cement-lime mixture CREPS Extra-light (240 rubles / 25 kg), Startvell T-21 (208 rubles / 25 kg), Baumit HandPutz 0.6 (300 rubles / 25 kg).
Also undesirable. Although designed with the specifics of aerated concrete in mind, it is intended for thin layer application and jointing, not for exterior wall applications.
Violation of the vapor permeability of aerated concrete will lead to such problems as cracking of the finishing layer, the appearance of traces of seams (disappear after drying), the appearance of mold.
Advantages of plaster based on gypsum:
Disadvantages of gypsum plaster:
Despite the disadvantages, plastering the walls with gypsum is an acceptable option for finishing aerated concrete. Well proven: gypsum vapor-permeable highly plastic plaster mixture Pobedit Velvet G-567 (previously Pobedit-Egida TM-35 for 320 rubles / 25 kg.), Knauf Rotband (360 rubles / 30 kg) and Bonolit (290 rubles / 30 kg).
The most effective material for plastering exterior and interior walls of aerated concrete. Facade plaster has a number of characteristics, including the vapor permeability index identical to that of aerated concrete (for most types of plasters), good adhesion to the base, beautiful appearance.
When choosing how to plaster aerated concrete, it is best to focus on a high-quality special mixture. In addition, the use of facade plaster simplifies the finishing of an aerated concrete house with your own hands.
There are a variety of ready-made mixtures for plastering aerated concrete walls on the market. To make the right choice, you should pay attention to the characteristics of the plaster:
And only when choosing between two equivalent mixtures, one should be guided by the price, it decides not the last role in this matter, but not the key one either.
According to reviews, plastering of aerated concrete walls outside the premises is popular among users - a dry mix with plasticizers Ceresit CT 24 (380 rubles / 25 kg), leading in terms of price / quality.
The material was prepared for the site www.site
Since aerated concrete easily absorbs moisture, it is better to protect it from getting wet immediately. We repeat, it is not critical if the material gets wet, but you should not allow moisture to freeze in the gas block. This can lead to its weakening and the appearance of unwanted cracks.
Haste in facing is also useless. After laying aerated concrete, the walls should dry well. That is why the plastering of aerated concrete walls is carried out only in the warm season. In the case of using a concrete-sand mortar as a binding element when laying aerated concrete blocks, the drying time increases, since such a seam is several times thicker than a seam made with a special adhesive mixture.
If it is not possible to finish the house during the warm season, you need to cover the walls with any deep penetration primer. For example, Ceresit ST-17 (549 rubles / 10 l).
The primer will reduce water absorption. It is also desirable to cover the walls with polyethylene left over from packing pallets with aerated concrete.
According to the masters, the most preferable time for finishing work is the period when the night temperature exceeds 0 °C. For central Russia, this time is from late March to early October.
We will conduct a comparative analysis of several popular options for the order of execution of wall decoration.
There is an opinion that the most important thing is to protect the gas block from the street, because. it absorbs moisture. However, this is not so, even after standing without protection (but primed) for a whole winter, the gas block will “give up” the accumulated moisture in the spring. And if it is closed from the outside, where will the vapors be directed? That's right, indoors. This will not only increase the drying process and delay the interior decoration, but is also fraught with the appearance of cracks inside the room.
With this approach, the pores of the aerated concrete block are partially closed in the process of finishing work. And if they are plastered first from the outside, the accumulated water vapor will simply have nowhere to go. Settling inside the block, moisture will contribute to its destruction. Plastering the walls of aerated concrete indoors will avoid this situation.
After the plaster has touched the interior walls and dried well, you can start finishing the exterior walls.
The method is the least preferred. The moisture that the gas block “pulls” at the same time from the outside and from the inside will not have the opportunity for a quick exit at all.
Despite the fact that plaster for aerated concrete has good vapor permeability, the speed of this process is not so high. Which is especially critical in the cold season (at night temperatures below zero). In this case, water vapor will settle in the form of condensate and, as a result, can lead to peeling of the plaster layer from the aerated concrete. In practice, this option will lead to the destruction of the gas block as quickly as possible.
Theoretically, each of the options has the right to be implemented. But the second one is correct.
How to plaster aerated concrete walls with your own hands
We figured out the question of whether it is possible to plaster aerated concrete. Now it is important to understand how to do it correctly, without prejudice to aerated concrete to let in moisture.
Plastering of aerated concrete blocks has no fundamental difference from the performance of work of this kind on other materials. The putty application technology differs only in a few details, which will be emphasized.
The technology of finishing aerated concrete with plaster indoors - the sequence of work:
It begins with the alignment of the walls - the removal of irregularities is done using a planer or grater for aerated concrete. This work is recommended to be done at the stage of building a house, but many people neglect this, saving time. In principle, this stage can be omitted, which will lead to a significant increase in the consumption of the mixture and an increase in the thickness of the coating layer. In turn, this is fraught with flaking of the plaster and cracks.
Often there are recommendations that the primer should be diluted with water 1 to 1. This is fundamentally wrong, because. reduces its ability to increase surface adhesion. There are better ways to save money. For example, remove dust from the surface by applying clean water to it. Water is applied with a brush or roller as if it were a primer. And then, after drying, a primer is applied.
The choice of primer depends on the purpose of the room to be finished. For a corridor or hallway, any universal primer is suitable, for example, Unis (250 rubles / 5l). For the bathroom and kitchen, it is advisable to use a deep penetration primer, for example, Prospectors (450 rubles / 10 l).
Beacons, as the name implies, determine the thickness of the application of the solution. They are set to the width of the rule. The accuracy of the installation is determined by the building level.
This is the name of the method of applying the first layer of plaster. The work is done from the bottom up. Next, you need to base the rule on the beacons and align (extend) the sketched layer along them. If voids appear, they must be repaired immediately. The main thing is that the plaster does not peel off from the base. If this happens, you need to remove the plaster, treat the surface with a primer and apply the solution again.
After the first layer of plaster has dried, it must be slightly moistened (with a spray gun) and leveled. Since the beacons serve as cold bridges, it is advisable to remove them at this stage, and seal the places (recesses after dismantling) with mortar.
A perforated corner with a mesh is used to arrange and reinforce the outer corners.
Grouting (if necessary) and painting of aerated concrete walls is carried out. In the case of wallpapering, finishing is not required.
For paint for aerated concrete, requirements are also put forward regarding vapor permeability. Such properties are possessed by interior paints based on PVA, latex, acrylic emulsions, on organic solvents and cement paints.
An example is ESKARO AKZENT (antibacterial paint, 325 rubles / 0.9 kg). At the same time, for rooms with high humidity, special paints should be used, for example, AquaNova Premium (282 rubles / 2.8 kg)
Decorative plastering of the facade of the house may involve the application of plaster for outdoor use in a thick layer (thick-layer finish) or several layers (thin-layer plaster).
Consider a multilayer version of applying thin-layer facade plaster for aerated concrete. Its feature is the creation of three thin (no more than 10 mm) layers.
A metal mesh with small cells can be used as a reinforcing layer, for example, a steel mesh with a wire diameter of 0.1 mm and a cell pitch of 0.16x0.16 mm (average price 950 rubles / sq.m. = 2,850 rubles / roll) or fiberglass mesh (for example, reinforcing fiberglass mesh with a cell pitch of 50x50 mm (approximate price 17.60 rubles / sq.m = 880 rubles / roll).
The mesh is attached with an overlap of 50 mm. At the same stage, the corners of the building are formed using a perforated corner with a grid. The mesh helps prevent cracks in the plaster due to shrinkage of the building. Thus, the plaster of the aerated concrete facade will not be covered with a web of small cracks. The mesh is sunk into the applied solution with a spatula. It is especially important to install the grid in places of high voltage, near windows and doors.
Advice. Mounting the mesh on a dry wall will not give any result, because the mesh will be fixed to the base with self-tapping screws. In the case of its installation on the solution, it forms a monolith with the solution, and will move with it.
Next, you need to wait until the first layer dries completely. Otherwise, it may fall off under the weight of the second layer. Since this method involves a thin-layer application of the solution, it will take 3-4 days to wait. The thicker the layer, the more. You can check if the layer is dry with water. If you spray on the wall and the water is absorbed, then it's time to get to work.
Note. When the plaster dries, it must be protected from the influence of environmental factors (moisture, snow, rain).
For painting aerated concrete, only paints for outdoor use are used. For example, Nova-Facade (590 rubles / 7 kg), Gasbetonbeschichtung from Dufa (2674 rubles / 25 kg), ROLPLAST Gordianus (3700 rubles / 10 kg), Dyotex (concentrate, 5500 rubles / 15 kg).
When deciding how to putty aerated concrete, you need to know that there are three types of finishing materials on the market that are similar in purpose, but differ in their composition. All this, facade plaster for aerated concrete, sold as a ready-made mixture. It is intended for thin-layer finishing of the plastered surface.
Ready-made silicate plaster, for example, Baumit SilikatTop Kratz Repro 3.0 mm (3700 rubles / 25 kg)
Silicone plaster, for example, Baumit SilikonTop (3300 rubles / 25 kg) 
Acrylic plaster, for example, Ceresit CT 77 (3800 rubles / 25 kg) 
Facade "fur coat" Weber.pas akrylat or Weber.pas akrylat Fur coat 615С 1.5mm (1800 rub/25 kg) Consistently performing work on plastering walls made of aerated concrete and using only vapor-permeable materials, it is possible to provide a reliable finish that will decorate the facade of the house for more than one year. And scheduled repairs will be reduced to periodic painting, to restore the color of the paint and eliminate small cracks.
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 itThe main distinguishing feature of aerated concrete is its increased hygroscopicity. Moreover, when the structure gets wet, when the temperature is above zero, negative consequences can 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, respectively, expands, cracks may appear.
Given this, it would seem that the sooner the walls are plastered, the better. But this approach is wrong. It is ideal to carry out these activities for the next season, when the surfaces are completely dry after laying. Drying time depends on which mortar was used during masonry. For example, a joint made with a concrete-sand mixture will take longer to dry than one where the adhesive mixture was used, since it turns out to be much thicker.
Plastering is recommended for the next season Another condition for finishing walls made of aerated concrete, which is recommended to be observed in order to achieve a high-quality result, is the need to do everything in warm weather. Experts call March-October the optimal time, when the air temperature is above zero. If this is not possible, 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 it is completely finished. The most effective water absorption will be reduced by a deep penetration primer.
But sometimes there is no opportunity to postpone finishing work - it is required to carry it out immediately after the completion of the construction of the walls of the building. Here, experts recommend paying especially close attention to the composition of the solution. It must have good plasticity, vapor permeability, then moisture can freely go outside.
If you need to plaster immediately, then you need to carefully select the material There are three options for where to start covering aerated concrete wall blocks. Each has its own characteristics, and only one is considered correct. In particular, you can start:
Experienced builders recommend starting to plaster outside only when the dwelling is located near water bodies. The primary task here is to protect 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 after the masonry is completed will be significantly delayed. In addition, the stone itself may begin to break down. Plastering walls made of 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 to finish walls made of aerated concrete - despite the good properties of vapor permeability, having "blocked" moisture from both sides, it will have nowhere to go, which sooner or later will lead to the detachment of the finishing mixture from the block itself, and subsequently - even destruction of the latter.
Plastering only needs to be done on one side. Plastering aerated concrete blocks contains three stages. Before plastering aerated concrete, it is necessary to apply a special primer with a brush or roller, designed for building materials that absorb moisture well. The greatest efficiency is achieved by applying the solution evenly, that is, there should be no dry spots. After the end of this stage, the primer should be absorbed and dry.
At the second stage, a special reinforced mesh resistant to alkaline components is fixed by means of self-tapping screws. The mesh is fixed at a certain distance from the stone - there must be free space between them.
The final, third, stage is directly plastering walls from aerated concrete. Here it is important to choose materials whose vapor permeability properties are higher than those of aerated concrete itself. It is possible to increase the service life of the surface, while maintaining its attractive appearance, in a year by covering it with a water repellent.
The material for plaster must be chosen with greater vapor permeability than that of aerated concrete Aerated concrete plaster will become of the highest quality, it will not have to be re-made in a short time if the composition of the mixture meets certain requirements, and the packaging contains special markings. Among other things, it must be characterized by:
Compliance with such criteria is especially important when applied outside the building.
Even taking into account the large number of different types of modern plaster mortars, only a few have these characteristics, therefore, the following are most often used when processing aerated concrete.
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. There are no disadvantages of this type in operation, except for its high cost, which is nevertheless compensated by the long service life of the coating.
The second place belongs to silicate plaster for aerated concrete, which has a suitable level of vapor permeability, low water absorption. The main disadvantages are a small color palette plus the loss of the initial attractiveness of the silicate appearance when dust enters.
In third place is plaster based on cement with lime. It also has the necessary qualities to cover this type of structure.
Plastering aerated concrete can be carried out with a mixture based on cement 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 average vapor permeability characteristics, susceptibility to rapid wetting from precipitation, in addition, spots 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 fire resistance, which is why it is used only in certain rooms, 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 waterproofing.
Having studied the characteristics of all the materials presented, everyone can independently choose how to plaster aerated concrete.
Aerated concrete finishing scheme Plastering of aerated concrete walls is carried out by means of tools used in the processing of other surfaces. Beating off the protruding parts of the walls, making them smoother, 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 shears, a puncher, a hacksaw, and other standard tools. Regarding lighthouses, there are several options. 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 improvised means: even blocks of wood, pipe trimmings, and other suitable “details”. Thanks to the beacons, the plane is perfectly flat, the angles are correct. The listed tools will come in handy if the plastering of aerated concrete walls is done manually.
Special equipment can provide faster uniform application. The method is more expensive financially, but this is fully compensated by the quality of the end result: due to the implementation of plastering under pressure, the bonding of the solution to the surface of aerated concrete is quite strong.
Machine plastering is a bit more expensive The technology for finishing walls with plaster for aerated concrete is quite simple - it is performed in four steps:
For reinforcement, a metal or fiberglass mesh is used. Moreover, special attention during its installation must be paid to windows and doors - places where the most significant load.
Having fixed the grid, the plane is covered with a finishing layer of plaster, and when the coating dries, the so-called grout is performed, that is, the surface is relieved of bumps, roughness, and other minor defects.
Before plastering aerated concrete, the wall should be leveled Starting to cover aerated concrete with plaster, 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, fall off over time, and it also contains a lot of water, which has a devastating effect on the walls themselves.
When plastering gas blocks, a prerequisite is the intended purpose of all means specifically for cellular material.
Experts recommend not using cement mixtures for finishing aerated concrete. It is also important to start work on the exterior cladding of the facade, when all the “wet” interior work has already been completed, then condensation can be avoided inside the walls. Moreover, the thickness of the plaster layer inside the building should be twice as large as the outer one, otherwise the water vapor will remain inside the blocks, they will become damp. 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 fastidious and requires special treatment. And in order for it to retain its useful properties to the maximum, a number of measures must be taken. But following the above recommendations, it will prove to be a very reliable material, last a long time, and the home will be cozy and comfortable.
Properly plastered walls are the key to quality home construction. Many people want to know how the internal plastering of aerated concrete walls should be carried out. The article will tell you all the nuances and sequence of decorative wall plastering.
Aerated concrete blocks are most often used in the construction of low-rise buildings.
Their main characteristics are presented in the table:
In the manufacture of aerated concrete blocks, aluminum powder is added to the solution, which acts as a blowing agent. This creates an open cell structure, which increases the vapor permeability of the blocks. Such characteristics must be taken into account when plastering aerated concrete inside or outside the house.
Plastering of aerated concrete should begin from the inside of the building, and then its facade. This is due to the fact that the water used in "wet work" will go outside through the blocks and the existing ventilation.
Water vapor at a negative ambient temperature will begin to condense inside the walls of the house and at the border of blocks with exterior finish (see Exterior finish of aerated concrete house is a responsible matter). When freezing, moisture will lead to inevitable cracking of the plaster layer, and then peeling it off.
Tip: It is necessary to perform plastering of aerated concrete walls first inside the building.
Internal decorative plaster for aerated concrete walls can be:
The mixture has a minimum weight, sufficiently high adhesive properties, good strength of the hardened coating layer.
The best option than plastering the gas block inside is the usual inexpensive gypsum mixture used in conjunction with a vapor barrier primer.
Tip: To reduce the vapor permeability of a 10 mm thick plaster layer, the walls should be primed at least three times.
The service life of the coating itself depends on the quality of the preparatory work. For this, first of all, the necessary tool is purchased (see Tool for plastering walls: what you need for work). Its main types are shown in the photo.
To plaster the walls with your own hands you will need:
In order for the interior decoration of plastered walls to be of better quality, you will also need such basic tools for applying plaster, such as:
In addition to these basic hand tools, machine plaster is used to plaster large areas. In this case, the entire process from the preparation of the mixture to its spraying is carried out by a machine under high pressure. All other work on leveling the plaster is done manually.
The advantage of this method when applying the plaster composition is that the coating is driven into the wall under pressure, ensuring its strong bonding to the wall.
To get high-quality plaster walls inside the house, you need to perform some preparatory operations:
Textured decorative interior plaster can be:
Advice. You can not start work immediately on a very large area. It is worth experimenting on a small area, otherwise the plaster will dry out and the result will not be satisfactory.
Applying such a coating yourself is quite difficult. You should first watch the video in this article.
The application of a layer of plaster is carried out in the following sequence:
This is how Venetian plaster is applied in a dry room.
Internal plaster with cement and sand differs from the Venetian one in a simpler application. It is enough to prepare the necessary tool, follow a few rules on the technology of applying the solution to the surface. And after finishing work, rinse all tools, leaving no traces of the solution on it. Decorative plaster on the walls of aerated concrete blocks creates an original and beautiful coating.
Before plastering aerated concrete inside the house, let's deal with the properties of this material for building walls. Aerated concrete blocks have a number of advantages, low specific gravity (2 times lighter than silicate brick). But their plastering is done according to the rules.
The construction of houses using aerated concrete blocks is carried out quickly, because due to the light weight of the material, the laboriousness of installing walls is reduced. Aerated concrete has a low thermal conductivity, so the coefficient of thermal resistance of the material is 2-3 times less than that of ceramic bricks.
The cellular structure of aerated concrete and wood creates the same microclimate in the house. An increase in the density of aerated concrete blocks during their production causes a deterioration in the heat-saving properties of the material. This requires appropriate wall decoration. The porous structure of this material provides excellent sound insulation in rooms. The walls both "breathe" and pass water vapor with carbon dioxide.
Aerated concrete is a good thermal insulation, since it has an open porous structure and high strength, and it is also a fireproof material. Adhesive compositions are used for laying blocks, this helps to maintain the exact geometric dimensions of the building. The process of building walls does not require professionalism.
Another advantage of the blocks is their reduced sensitivity to the negative effects of the external environment. The disadvantage of aerated concrete is considered to be low bending strength. Given this characteristic of the material, the construction of a house from it is carried out on the basis of a number of measures.
These include:
Before finishing walls made of aerated concrete, it is taken into account that they differ greatly from brick in their properties. Cellular lightweight concrete has always played the role of insulation. After the insulation of the aerated concrete house from the outside began to be carried out with the help of special heat insulators, the use of blocks was associated only with the construction of the building structure.
Since aluminum powder is mixed into the raw material for aerated concrete, the structure of the blocks becomes cellular, which increases their vapor permeability. This is taken into account in the process of finishing the walls of a building made of aerated concrete blocks.
Plastering is the most common method used for interior and exterior vertical surfaces. Before insulating a house made of aerated concrete, you will need to plaster the surface of the walls. They begin this work from the inside of the building, after that they move on to finishing and begin warming the facade of the house. It will be a mistake to prioritize plastering the building from the outside and performing interior decoration work for the cold season.
Most of the water that is used for finishing work on interior walls escapes through both the walls and the ventilation ducts. Minus temperatures lead to the formation of condensate from the vapor particles of water inside the walls, as well as on the exterior finish. After the water freezes, the plaster cracks and flakes off. This is proof that it is necessary to plaster aerated concrete walls from the inside of the house, and not on the facade.
A layer of plaster on the wall should not interfere with its vapor permeability, so a solution of a mixture of cement and sand is not used for plastering walls. When performing work, one of the methods of interior wall decoration is used. The first of them is based on the fact that the material has a special property that ensures the vapor permeability of the walls.
If a cement-sand mortar is used when plastering aerated concrete blocks, they will quickly absorb moisture due to their structure. As a result, the surface of the walls will dry out and become covered with cracks. It will not be possible to correct the situation even after using a deep primer or putty.
Another reason why a cement-sand mortar is not used for interior plastering of a room is the low vapor permeability of the walls. When the brick house has already been built, then this quality of the plaster is no longer important. If aerated concrete was used during the construction process, and not brick, then improper plastering of the walls will cause a deterioration in the microclimate inside the building.
Special mixtures are sold in construction stores or on the market, with the help of which high-quality plastering of aerated concrete blocks is performed. Finishing is carried out according to the principle of maximum vapor barrier of blocks. The microclimate conditions inside a house made of aerated concrete will not differ from reinforced concrete buildings.
The outer layer of plaster will be durable. This is explained by the fact that after the time it takes for the moisture balance to be established in the aerated concrete wall, there is a reduction in the flow of steam into the external environment. As a result, the plaster will not flake off the surface of the facade.
The use of plaster compositions based on gypsum and gypsum putty increases the vapor permeability of aerated concrete walls. This figure should be high, since customers and builders choose cellular concrete. Finishing materials based on gypsum are produced with the content of slaked lime and light perlite sand. After plastering with these compounds, it is not required to prime the surface of the walls. Finished plaster is able to easily conduct water vapor.
Plastering the walls inside the house using ready-made mixtures with fillers creates a high-quality cladding layer. It includes the following types of fillers:
It is necessary to choose the right fillers and pay attention to the size of their constituent parts. All fractions must be combined in a single cladding solution. Manufacturers producing such mixtures have achieved ease of use. The compositions are easy to overwrite, they differ in the maximum degree of whiteness.
Polymer additives with a high vapor permeability coefficient provide a better coating than exterior plaster. Aerated concrete has a porous structure, so it makes no sense to immediately apply putty, otherwise a lot of primer will be required. It will no longer be possible to save on it, since this will lead to the fact that the putty will begin to crack and fall off.
Often, polyethylene is used for vapor barrier when finishing the interior surface of a room. This is the easiest method. But often after the work is completed, there is an accumulation of water particles and swelling of the plaster.
During the construction and decoration of walls made of aerated concrete blocks, a good vapor barrier is required. Here, sand and cement plaster is used without special additives - dolomite flour or lime. This type of internal plaster allows to significantly reduce the conductivity of water particles. In this case, the plaster will peel off, but the choice of this technology remains with the developer.
Before performing work on plastering surfaces, the blocks are primed with a special solution. It is applied 3-4 times. Remember that the use of modern compositions for finishing blocks leads to a decrease in the level of vapor barrier by 25 times. High-quality adhesives, which are widely used in construction, are capable of eliminating the transmission of water particles. Putty does not make sense.
It is necessary to carry out finishing work on aerated concrete walls with the same tools that are used for conventional plastering. To prepare the solution, a suitable plastic container is used, in which it is convenient to dilute the plaster. You will need a construction mixer with a stirring nozzle.
The dry mixture after adding water is brought to uniformity and the required density. The proportions of the components of the composition are indicated in the instructions for the mixtures. The plaster is applied to aerated concrete using a trowel using the throwing method. You can use a ladle plasterer. In some cases, a trowel is used.
The plastered surface is rubbed with a grater. To remove excess mixture from a wall with a large area, use a trowel. Level the wall using beacons. The plaster is pulled together between the guides.
A vapor-permeable finish is also performed using plasterboard panels. Be sure to follow the process technology:
After completing the finishing work, the quality is checked using a rail, the length of which corresponds to the height of the ceilings. It is applied to the wall surface in different places horizontally and vertically. This way all inaccuracies are revealed. A deviation in the range of 6-7 mm is considered acceptable.
To carry out the finishing of the interior of the walls of aerated concrete, various methods are used. The simplest of them is the application of a vapor-permeable finish, that is, plaster. Before its application, a number of preliminary works are carried out. The very technology of finishing walls made of aerated concrete indoors resembles plastering walls.
Blocks before starting work are cleaned of contaminants, and also leveled. After that, proceed to applying a layer of primer. It must be taken into account that materials that absorb moisture will then be used. The drying time of the primer depends on its type. Usually it does not exceed 3 hours. When the applied composition dries, proceed to the wall cladding.
The choice of gypsum mixture for plastering is carried out taking into account the purpose of the room. If this is a living room, plaster is used for wall cladding, which is designed for cellular concrete. Gypsum composition for plastering is fixed on the wall mechanically.
Gypsum plaster is used only for finishing dry rooms. It is not recommended to use it in an environment with high humidity, as well as on strongly vibrating surfaces. Gypsum plaster is used to finish the premises, after which aerated concrete blocks can not be puttyed.
If the aerated concrete surface of the walls is constantly in contact with moisture (in the bathroom), then it is treated with special preparations that resist the effects of a humid environment. 1 hour after application, the composition on the wall is leveled and the final drying and smoothing of the surface are awaited.
There are several ways to plaster walls made of aerated concrete. If you understand the properties of this material, then you will decide on the choice of mixtures and you can get a good result yourself.
Recently, aerated concrete has been used in the construction of private houses. The material has earned wide recognition due to its positive qualities. Such material is produced in rather voluminous blocks of light weight, so construction is carried out at a fast pace.
The foam material perfectly retains heat, therefore, you can significantly save on insulation.
The abundance of pores allows the blocks to "breathe". The bad thing is that they absorb moisture. If in the warm season the water dries up without consequences, then in frost the moisture absorbed into the building material will inevitably lead to the formation of cracks.
Plastering aerated concrete will prevent the penetration of water into the block, maintain its integrity.
For high-quality performance of work, it is necessary to take into account the features inherent in the material being processed. Not all aerated concrete blocks are the same - their structure may differ. For example, the outer surface is different.
Sawn aerated concrete can be plastered without pre-treatment. The molded block has a smooth hydrophobic layer on the outside. It is problematic to apply plaster on such a surface - to increase adhesion, it is necessary to grind the treated side with a metal brush.
We must not forget that the degree of vapor permeability increases in the direction from the inner surface to the outer, so the facade decoration should be done twice as thin as the inner coating.
Before plastering aerated concrete walls after construction, at least six months must pass. During this time, the walls will dry completely, excess moisture that gets into the blocks during the construction of the building will disappear from them.
The outer surfaces of the walls can be plastered with decorative materials, compositions for subsequent painting can also be used. External decoration sometimes serves as additional insulation. In regions with a cold climate, plastering plays a significant role in keeping the heat inside the premises.
For aerated concrete, plaster with optimal parameters should be chosen. Finishing material must protect the walls from destruction on both sides.
Due to the porosity, aerated concrete has received such characteristics as thermal insulation and vapor permeability.
Proper Finishing:
It is impossible to finish aerated concrete walls with ordinary cement mortar. Standard solutions have too much density, so they do not set well with blocks. Due to poor adhesion, after a short time, cracks appear on the walls, which leads to peeling of the plaster layer and exposing the walls.
Special "breathable" mixtures with a so-called vapor-permeable base:
The following requirements are imposed on plasters for finishing aerated concrete:
Good plaster meets all of these requirements. It is easy to apply, looks great and stays on the walls for a long time.
If the facade is not processed, then the aerated concrete will first darken, then it will begin to deform, and its outer part will peel off.
Exterior plasters are different from those used for interior finishing of aerated concrete blocks. The former are more expensive, the latter are cheaper. The main difference lies in the ability of the hardened mixture to resist moisture. If for external walls this indicator is essential, then for interior decoration you can do without it. The exception is plaster for rooms with high humidity. such as bathrooms.
By composition, facade plasters are divided into the following types:
None of the species can be considered ideal - each variety has its own strengths and weaknesses. For example, the vapor permeability of acrylic-based plaster is low, but it has excellent decorative properties. The finish is thin, but very durable. The layer retains an impeccable structure for a long time.
It is advisable to use acrylic plaster when applying good insulation to interior walls.
The basis of silicate plaster intended for aerated concrete is liquid potash glass. The vapor-permeable covering is resistant to moisture, perfectly resists attrition and pollution. Durability is a quarter of a century. The disadvantages include a limited range of colors.
The composition of silicone mixtures includes organosilicon polymers and resins. The cover is very durable. Unlike other types of silicone plaster, it remains elastic after curing. Cracks do not appear on the finishing layer even after shrinkage of the blocks. Due to the fillers, the plaster is given various colors and shades.
The advantages have a significant impact on the cost - silicone mixtures are the most expensive.
Lime-cement mortars are characterized by vapor permeability and strength. They lack elasticity and water resistance. The problem is solved by introducing special additives into the mixture, and experimenting with fillers, you can get different colors.
Ready mixtures are equipped with everything you need - they can be used without prior preparation and the introduction of improving components.
For internal work, completely different compositions are used. Gypsum is present in the basis of plaster for processing aerated concrete indoors.
Before starting work, the blocks should be primed.
The plaster is applied to a leveled surface, free from build-up, dirt and dust.
The work is carried out in several stages:
Wallpaper can be glued onto the treated wall after the material has completely dried.. Optionally, you can perform a decorative finish. The decor appears when fillers in the form of marble chips or perlite are introduced into the gypsum mixture. A wall covered with gypsum mortar can be painted.
It is very important that the aerated concrete walls are prepared for the application of the finishing layer.
Despite the fact that the outer and inner parts of the wall are operated under different conditions, there are general requirements for their pre-treatment:
In order for the plaster to fit well on the gas blocks, the latter should be evenly moistened. For this, ordinary tap water and a simple sprayer are suitable.
If there are chips or cracks, then you will have to pick up a trowel and use the solution to eliminate the flaws. Cement mortar will be an excellent restoration material if the recesses are first treated with a primer.
With the help of beacons, the surface of the walls of the room is displayed in one plane, after which you can begin to perform the main work.
First, finishing is done inside the premises and only then outside - otherwise excessive moisture will form inside the house.
The appearance of the treated walls and the durability of the decorative layer depend on the correct implementation of the technology.
Below is the sequence of processing the outer surfaces of aerated concrete walls.
First you need to inspect the blocks: eliminate all irregularities, clean the cracks, expand and putty with a regular mortar.
In the same way, they act when detecting chips and potholes in each gas block. The listed preparatory work can be done with your own hands - it's not difficult at all.
Those who dare to do the basic work with their own hands without the appropriate skills need:
In order for the plaster to lay down well and not lag behind, gas blocks are primed after cleaning with a metal brush.
A special primer is required - it must contain acrylate siloxane. This ingredient protects the wall from moisture and increases adhesion. At the same time, the composition does not prevent the gas block from "breathing".
The priming operation in accordance with the technology should be carried out in dry weather and an ambient temperature of about +15 degrees. It is advisable to process the walls from the side where there is no direct sunlight.
The next stage - mesh tension - is started after the final absorption of the primer.
For gas blocks, a mesh made of alkali-resistant material is suitable. Any other material will simply dissolve over time, which will negatively affect the service life of the finishing layer. On the wall, the fiberglass reinforcing mesh is fixed with self-tapping screws so that there is a small space between it and the wall.
Plastic plaster, specially designed for aerated concrete, is applied to the prepared wall in dry, warm weather. Mixtures for foam building material are quite expensive, but they repel moisture and allow air to pass through. The plaster is applied to the blocks with a wide spatula.. The result should be an even thin layer, the thickness of which is approximately 8 mm.
This is not the end of the processing. A water repellent is applied to the plaster. After it is absorbed, it's time for the final finishing. The choice can be decorative plaster or paint. In both cases, the compositions are distinguished by "breathing" abilities, which guarantee the unhindered passage of vapors from inside the room to the outside.
The processing of aerated concrete walls inside the house begins in the same way as outside. In the same way, an inspection is carried out, and significant shortcomings are annulled. Before puttying surfaces, the leveled wall is primed.
Interior decoration is carried out with special plaster, which includes gypsum and perlite sand.
After the work is completed, the walls become homogeneous, smooth, without the slightest visible defects. The consumption of plaster is small, because the layer is superimposed very thin. This eliminates the need for long alignment, which is also important.
Interior walls should be painted with paints specially designed for aerated concrete. They can be applied to both ordinary plaster and decorative. Painted surfaces look great - decorative finishes retain their original appearance for a long time.
