Aerated concrete is a popular building material, from which strong, durable, warm and resistant to various negative impacts of the structure are obtained. It has an acceptable cost, and construction with its help can be done by one's own hands, even for beginners. After the construction of the house, it is necessary to decide what materials will be used for finishing work. Initially, the walls are covered with high-quality plaster, so it is important to figure out how to plaster aerated concrete outside and inside the house, as well as how to do this work correctly.
Important! It is not allowed to use the same material for exterior and interior work, since it is important that the resulting coatings are resistant to the existing operating conditions, and they differ significantly on the street and inside the house.
Types of plaster for aerated concrete
Plasters are presented on the market in numerous forms. Not all varieties are suitable for aerated concrete, so the parameters of each material must first be studied, after which the desired option is selected for outdoor use or for interior work.
Important! Plaster for outdoor use must have high thermal insulation parameters, resistance to moisture and temperature changes, and at the same time must provide good sound insulation and have an attractive appearance.
There are several of the most popular plasters used for aerated concrete. Each option has its own characteristics, so it is important to study the parameters of any type before making a specific choice.
cement plaster
This material is considered to be in demand for various types of work, but it is considered unsuitable for aerated concrete. This is due to the fact that smooth walls are obtained from it, on which cement mortar does not adhere well. Also, aerated concrete has a specific feature to absorb moisture from the solution. Cement plaster has a vapor permeability that is lower than that of walls, so if you use it for finishing work, the microclimate that is installed in residential premises can significantly deteriorate.
Also, the cement mortar has a low adhesion to the surface of aerated concrete. Often, to increase this parameter, lime is added to the composition. If, nevertheless, this material is chosen for outdoor work, then a special finishing layer is certainly applied after the plaster has dried, allowing you to get a perfectly smooth surface. 
Important! If the vapor permeability of aerated concrete is impaired, this can cause various cracks, mold or traces of seams.
Adhesive for aerated concrete
A special adhesive mixture is presented on the market, designed for application to walls made of aerated concrete. It has the optimal composition for working with this material, however, its main purpose is the connection of individual blocks, so it is used in joints.
The material is applied in a thin layer, therefore it is not considered suitable for forming the outer layer on the walls of aerated concrete. It will not be possible to make an optimal protective coating out of it, and its cost is considered quite high, so it is not advisable to use it for these purposes.
Gypsum plaster for aerated concrete
This material has many advantages for use on aerated concrete walls. Its pluses include:
- fast drying, so after the layer hardens, you can quickly proceed to subsequent finishing work;
- the coating does not shrink;
- with proper application of plaster on aerated concrete, the formation of a perfectly smooth surface is guaranteed;
- due to the high quality of the material, there is no need to apply a top coat after the layer has dried.
But this material is not without certain significant shortcomings. These include:
- not too good vapor permeability ();
- to obtain a high-quality mixture, a sufficiently large amount of water is required;
- if moisture or snow gets on the coating, which is not protected by any additional layer, it will quickly get wet;
- often ugly and clearly visible spots appear on surfaces, therefore, for an attractive appearance of aerated concrete walls, it is required to use special coloring compositions to eliminate them.
Important! Even with many disadvantages, gypsum mortar is considered relevant for use on aerated concrete walls, but is usually used for interior decoration in rooms with a low humidity index.
Special facade plaster designed for aerated concrete
There is a special material for aerated concrete walls on the market, used for both outdoor and indoor use. The advantages of using it for a house built from aerated concrete include:
- a good indicator of vapor permeability, equal to the vapor permeability of the building material itself;
- excellent appearance of the resulting coating;
- good adhesion to aerated concrete.
It is this material that is most often chosen for finishing a building made of aerated concrete. It provides a high-quality, uniform and durable layer with an interesting look. But this material has a rather high cost, so a lot of money is spent on finishing the whole house. For internal walls, the use of gypsum mortar is considered optimal.
Competent choice of plaster for walls made of aerated concrete
When choosing a material intended for plastering aerated concrete walls, the basic requirements and criteria that it must meet are taken into account. To get a really high-quality and optimal coating, the plaster must have:
- good indicator of vapor permeability;
- resistance to low and high temperatures;
- resistance to exposure to significant humidity;
- resistance to the appearance of cracks, mold or other negative factors on the created surface;
- the duration of the viability of the solution, and this factor is most important for people who independently perform the process of applying plaster, and at the same time do not have experience with such solutions.
Important! For each buyer, an additional important parameter is the cost of the mortar, and it must correspond to its quality and properties, but it is not recommended to pay attention to the most affordable material, since it will not have optimal properties for use on aerated concrete walls.
When is plaster applied to aerated concrete walls?
Aerated concrete is considered a specific material, characterized by good moisture absorption, therefore, immediately after the construction of the structure, it is recommended to take care of protecting the walls from water. Wetting of the material is not considered critical, but it is impossible for the moisture in the aerated concrete to freeze, as this can cause cracks or weaken the walls.
Important! However, one should not rush, since after building a house from aerated concrete, it is recommended to give the material time to dry thoroughly.
Plaster is applied to aerated concrete only in the warm season. If a cement mixture is used during operation, then its drying time is considered significant, and this is due not only to its parameters, but also to the fact that a layer of sufficient thickness is certainly created.
If it is not possible to apply plaster in the warm season, then the walls will certainly be covered with a special primer, and it is important to choose a means of deep penetration. The resulting layer reduces the water absorption of aerated concrete. It is allowed to cover the entire structure with polyethylene or other similar material.
From what part of the house does the finishing of the aerated concrete building begin?
There are several options that determine the sequence of actions required to repair a house built of aerated concrete. These include:
- First exterior finish, and after internal. Experts assure that, first of all, it is necessary to protect the building from various negative atmospheric factors that can adversely affect the condition of the house made of aerated concrete. It is not permissible for the walls to gain a large amount of moisture. However, on the other hand, water vapor will accumulate in a house closed from the outside, which will negatively affect the duration of its drying, and there may also be difficulties with internal finishing work. This option is considered preferable for houses built on the banks of various rivers or lakes.
- First, interior finishing work is carried out. This option involves the partial closure of the pores in the walls of the structure of aerated concrete. After interior finishing, it is not allowed to immediately carry out exterior work. The fact is that this can lead to the fact that a large amount of water vapor accumulates in aerated concrete blocks, so moisture will settle in the walls of the house, which can cause their destruction. Therefore, the exterior decoration of walls made of aerated concrete is carried out only after the plaster has completely dried inside the house.
- Simultaneous execution of works. This method assumes that both internal and external finishing processes are immediately implemented. This method is considered the least popular, and this is due to the fact that moisture does not have time to leave the aerated concrete blocks.
Important! Although modern high-quality plasters have good vapor permeability, they dry out for a long time, and this is especially important if the finishing of aerated concrete walls is planned for the cold season, so it is advisable to leave the process until the warm season.
Aerated concrete wall finishing technology
The use of plaster for the interior decoration of a house built of aerated concrete is a simple and straightforward process. It is divided into successive steps:
- Foundation preparation. It is important to eliminate significant irregularities on aerated concrete walls. To do this, they are polished with a planer or a special grater. It is allowed to skip this stage, however, in the process of work, a large amount of plaster will be needed, which will significantly increase the cost of finishing.
- A good quality primer is applied. It is not recommended to mix this agent with water, as this action will lead to a deterioration in the quality of the material. Before applying the primer, it is necessary to clean the base from dust, for which the walls are washed with plain water. The primer is applied after the walls of aerated concrete have completely dried. A specific type of primer is selected in accordance with the particular room you have to work in. For standard rooms, which include a bedroom or a hall, you can choose an inexpensive and versatile material, but for a bathroom or kitchen, a blue penetration agent is purchased.
- Installation of beacons. The next stage involves the installation of beacons on the walls of aerated concrete. They are represented by special metal structures that provide a perfectly even coating of plaster. They are usually mounted using a small amount of plaster solution. The distance between them is left in accordance with the width of the rule that will be used to level the solution. In the process of work, a building level must certainly be used, which guarantees the evenness of fixing the beacons.
- Plaster preparation. In the process of creating a solution, you must strictly follow the instructions that are attached to the material by the manufacturer. In this case, obtaining the optimal mixture with the desired consistency and uniformity is guaranteed.
- Applying plaster by spraying. It is this method that is used to form the first layer of plaster. The procedure is performed from the bottom up, and the mixture is thrown over the entire surface of the base. Next, the resulting layer is extruded using the rule. When voids form, they must be filled with mortar. It is important that the material does not peel off, because if this happens, the plaster is removed and then re-applied.
- Processing the resulting layer. It is performed only after the mixture has dried. Further, the coating is slightly moistened, for which it is recommended to use a spray gun. Then it is carefully leveled and beacons are removed. The resulting empty spaces are filled with plaster.
- High-quality and even corners are created. To obtain the perfect result, special perforated metal corners are used, equipped with mesh on the sides.
- Finishing walls made of aerated concrete. After the final drying of the layer of plaster, finishing begins. To do this, the walls are covered with paints or other finishing materials.
Thus, the process of plastering aerated concrete walls is a fairly simple process that is easily performed by every home owner.
Important! You can get the perfect result of work only if you strictly follow the basic rules and follow the correct sequence of actions.
How to plaster aerated concrete walls outside?
Exterior finishing work for a house made of aerated concrete involves the creation of a sufficiently thick layer. Therefore, several layers are usually applied at once, and reinforcement is also performed. The whole process is divided into stages:
- aerated concrete walls are being prepared, and this process involves the elimination of large transitions and irregularities, which will positively affect the cost of purchasing finishing materials;
- coating the surface with a primer;
- applying plaster, and the thickness of the first layer should not exceed 5 mm;
- reinforcement is made of a pre-purchased metal mesh equipped with small cells;
- a layer of plaster is leveled along a fixed grid;
- a second layer of material is applied after the first one dries, and it is important to pay much attention to proper leveling and obtaining a smooth and smooth surface of aerated concrete walls;
- a third layer is applied, which, if necessary, is wiped after drying;
- the resulting coating is painted or covered with textured plaster;
- it is treated with a water repellent, and it is usually applied a year after finishing, and the main purpose of this tool is to protect the walls of aerated concrete from moisture.
Video: aerated concrete plaster
Thus, applying plaster on walls made of aerated concrete is a simple process. It is easy to perform both inside and outside the house. To obtain a high-quality result, it is important to carefully study the instructions, as well as clearly follow the sequential steps. Another important point in creating the perfect coating for aerated concrete walls is the correct choice of the plaster itself, which must correspond to the operating conditions that are available on the street or inside the house. The article - "" may also be useful.
Repairs inside or outside the premises will not do without plastering walls and other surfaces. At the design stage it is necessary to familiarize yourself with the features of plaster, which are divided into types, they differ in characteristics and price. The right type of finishing material is half the battle, because Mixture characteristics can vary significantly., and what is ideal for one type of room may be completely unacceptable for another.
Some features of plaster
Plaster is a mixture that is used for surface treatment as a rough finish. What are the functions of the material? With the help of plaster, you can level the walls, repair cracks and other defects. Herself the structure of this solution is a coarse mixture, so after drying the surface will have rough surface. These effects can be easily eliminated in the future.
You can plaster walls of almost any type, concrete and wooden structures will be protected from the harmful effects of environmental factors. Various techniques and materials are used for plastering walls made of aerated concrete. Trends in the field of construction are developing in such a way that such building material as aerated concrete is becoming increasingly popular. It has a lot of advantages in comparison with concrete and brick construction.
The building, erected from aerated concrete, has increased energy-saving properties. This material is much lighter than traditional analogues, due to this fact, it is possible to reduce the cost of arranging the foundation and the construction time is significantly reduced. What kind of plaster is better to plaster the walls of aerated concrete blocks?
How to plaster aerated concrete walls?
One of the ways to finish walls made of aerated concrete is plastering. For plastering walls from blocks of cement-sand type - this is the best option. As for the process of applying the finishing layer, if desired, you can apply it directly to the wall. The same can be done with brick walls. However, some difficulties may arise in doing so.
The brick is small, so seams between bricks serve as a connecting element when applying plaster. In the case of aerated concrete, the situation is somewhat different, because the aerated concrete itself is large. This problem can be solved in several ways. Consider the main ones that are often used in practice.
Walls can be plastered both inside and outside the room. Both types of finishes have some features. When choosing a plaster, it is best to choose the one with the highest adhesion coefficient. This is to ensure the quality of adhesion of materials.
Preparatory work
Before applying a layer of plaster, the walls of aerated concrete are preliminarily prepared, this is necessary in order to ensure adhesion of materials. How is it done and what does this stage of surface finishing include?
First, you need pay attention to the seams between aerated concrete, they need to be well sealed, approximately 4 - 5 mm. The wall is leveled, and all defects that may occur, dust and other trace elements that reduce the quality of adhesion of materials, are cleaned. To clean the surface, you can use sandpaper, which will help to more thoroughly sand the blocks.
How to use the grid when plastering walls?
If you decide to use the third method of surface finishing, then you need to know what is used in this case. galvanized mesh. It is more durable, reliable and does not rust. As for the size of the grid cells, you should pay attention to the one in which the cells are small. After carrying out the preparatory work, it will be necessary to attach the grid directly to the wall. This must be done with ordinary nails. They are driven into the wall first by one third, after which the nail is bent, fixing the mesh.
Particular attention should be paid to the edges of such a section, they usually stick out, before applying the plaster, all edges should be bent, then they will not stick out from under the plaster.
When the mesh is fixed, it is necessary to start applying the first layer of plaster. This is done in a way known as "spray", it is mainly used to fill grid cells with mortar. After it, several more layers of plaster will follow. This will necessarily be a primer layer, which must be kneaded by adding slag sand to the solution. The final layer will be the final layer, to prepare the solution for it, you must use fine sand.
All layers of plaster can be apply when the previous layer is not completely dry. This will reduce the time without reducing the strength and quality of the finishing layer.
Wall plastering mortar can be purchased ready-made, it is sold in a dry state. To prepare the mixture, you just need to add water. But, you can also prepare a cement-sand mortar yourself. In this case do not save on the quality of the cement itself, since the water-repellent ability of the plaster will suffer as a result. When plastering walls, a lot of tasks and requirements are solved, such as thermal insulation characteristics of the surface, water resistance, sound insulation, and so on.
Gas silicate blocks are a cellular building material for the construction of buildings. The product is in high demand in private housing construction due to its affordable cost. A significant drawback of such blocks is vapor permeability. Plastering will help solve this problem. The material is used outside and inside the building. The main thing is to know how to plaster gas silicate blocks.
Plastering walls from gas silicate blocks should not be deaf. It is also impossible to make the finish completely waterproof. These are mandatory recommendations. Their violation of the rules leads to the rupture of the walls in severe frost. At the same time, the building base needs to be protected from moisture, as this guarantees the creation of a comfortable microclimate inside the building. Properly selected plaster for gas silicate blocks will help to solve this problem.
Finishing is recommended to start not from the facade, but from the inside of the building. Thanks to this sequence, the gas silicate blocks will dry out, which guarantees a long operational repair period without the formation of mold and fungus under the materials.
Types of plaster for gas silicate blocks
How to plaster gas silicate blocks is a question that can baffle an amateur. Professionals for finishing are recommended to use special mixtures designed for this material. On the packaging, the manufacturer makes a note: "Plaster mixes for gas silicate blocks."
It is important to know not only how to plaster gas silicate blocks, but also how they cannot be finished. So for this material it is not recommended to use a cement-sand mixture for the following reasons:
- Bad adhesion. The cellular material will quickly absorb moisture from the cement-sand mortar. Loss of moisture leads to the formation of defects on the surface. Then pieces of plaster will fall off along with the finish.
- Poor vapor permeability. Cellular materials also have poor vapor permeability, which, in combination with a cement-sand agent, leads to a deterioration in the microclimate inside the building, since the air in the wall stops circulating.
Requirements for plaster
Plaster on gas silicate blocks must meet the following requirements:
- water resistance to protect the building base from precipitation that destroys the material;
- frost resistance for use of a product in severe climatic conditions;
- vapor permeability so that there is no rupture of the walls at low air temperatures;
- resistance to mechanical damage;
- heat resistance - this property allows you to protect the building base in case of exposure to the material with an open flame, which increases the fire safety of the object;
- good adhesion so that the product adheres securely to the surface;
- elasticity - this property prevents the occurrence of defects on the material during changes in air temperature.
Price
Plastering gas silicate blocks will be cheaper if you do the finishing yourself. In this case, the costs are only for the purchase of materials and tools. If you use a domestic cement mixture, then the price of such a product will be approximately 180 rubles per bag weighing 25 kg. You will also need a primer, reinforcing mesh and other tools. The total cost depends on the manufacturer and type of products.
Gas silicate plaster, which is made by craftsmen, will cost more. In this case, the customer pays for the services of professionals and compensates for the cost of materials. The final price depends on the area of the building, the manufacturer of the compositions and the pricing policy of the craftsmen. The average cost is 500 rubles per square meter of surface. This includes priming, reinforcement and plastering. The cost of materials is paid separately.
Necessary materials and tools
For finishing you will need:
- plaster for gas silicate;
- primer;
- reinforcing mesh;
- metal profiles;
- rule for leveling the composition;
- trowel, which remove excess material;
- industrial grater for cleaning the surface;
- a plumb line to check the quality of the finish;
- a special bucket for throwing the solution onto the surface;
- self-tapping screws;
- industrial mixer or drill with a mixer attachment for mixing the product;
- container for dosing primer;
- brush, roller or spray gun for applying the primer;
- bucket for mixing the solution.
Surface priming
- Plastering walls from gas silicate blocks begins with surface preparation. The building base is swept to remove all dust and other contaminants. At this stage, the surface is coated with a primer. For gas silicate blocks, it is recommended to use a primer that is designed for a building base with properties to quickly absorb liquid.
- The primer is poured into a clean container and applied with a brush or roller. If the master uses an airbrush, then the primer is poured into the tool and sprayed onto the surface.
- The primer is applied in two layers. Each treatment is followed by a break to dry the material. The surface is treated carefully, avoiding gaps.
Reinforcement
Gas silicate wall plaster, finishing video below, is applied to the reinforced surface. It is recommended to use fiberglass mesh, which is resistant to the alkaline environment of the product. If this condition is not met, then after some time the reinforcing material will dissolve under the layer of plaster. This will cause the entire finish to move away from the wall.
The material is fixed to the surface with self-tapping screws. The mesh is pulled so that there is no sagging, as shown in the photo below.
Solution preparation
Before plastering gas silicate blocks, it is necessary to prepare a solution. The agent is kneaded using an industrial mixer or a drill with a mixer nozzle. The solution is prepared in strict accordance with the instructions indicated on the package.
- Pour water into the bucket and pour the dry mixture. It is important to observe the proportions of the material and liquid. Too thick composition is poorly attached to the building base, and the slurry drains.
- The solution is kneaded until it acquires the consistency of thick sour cream.
- After that, the mixture is kept for 10 minutes and stirred again.
Surface plastering
Plastering a house from gas silicate blocks is carried out as follows:
- Fix the guides on the walls. First install beacons on the sides, then along the perimeter at a distance less than the length of the rule.
- Throw the solution on the wall with a ladle. Layer thickness - 1.5 cm.
- Level the material with the rule. Remove excess solution with a trowel.
- Take a break to dry the material. Clean the surface with an industrial float so that there are no streaks, bumps or other defects on the base.
- The instruction says that the decoration is performed two days after the surface is plastered. For the finish coat, paint, decorative plaster and other material are used.
In the video in this article, the master clearly shows how to apply plaster on gas silicate blocks.
It is recommended to treat the plastering of gas silicate blocks with all responsibility. Mistakes in finishing can lead to sad consequences, up to breaking the wall.
But it differs from them in the composition of air bubbles inside.
Aerated concrete blocks are made of cement with a mass fraction of at least 50%.
Aerated concrete walls need exterior and interior finishing due to porosity and high levels of moisture absorption.
Features of aerated concrete
This building material has a cellular structure, which gives it special properties:
- good thermal insulation - in terms of characteristics, aerated concrete is comparable to wood;
- low mechanical stability, which leads to the appearance of cracks and chips over time;
- porous material is blown by air currents, which is why houses made of it without finishing are considered rather cold;
- unaesthetic appearance;
- high absorbency leads to corrosion of the material in winter, during frosts.
The special structure of aerated concrete blocks requires careful processing with finishing materials to improve its quality characteristics. External plastering is carried out using special solutions that are selected for certain environmental conditions. Proper plastering of aerated concrete walls provides reliable protection of the base and its durability, and also allows you to give a more aesthetic appearance to the room.
How and with what to plaster aerated concrete indoors?
Regardless of the choice of type of plaster, finishing work must begin indoors. Changing the order and plastering the facade of the building will lead to excess humidity in the room. The fact is that when steam leaves the room, especially in winter, condensate accumulates between the blocks and the finish, creating places with excess moisture. This is the main cause of cracks on the surface and shedding of the plaster. To avoid such troubles, you should first deal with the plastering of walls from gas blocks indoors. Experienced craftsmen distinguish two types of technology for plastering aerated concrete walls in a house:
- with full vapor barrier;
- maintaining and increasing the vapor permeability of the material.
The main element of plastering aerated concrete using the first technology is a polyethylene film. It is fixed between the layers of the solution, and the vapor permeability of the walls is reduced several times. Also, for vapor barrier, oil paints are used, which are applied as a finish, and priming the base with special compounds.
The dependence of plastering technology from the inside on the outside
To accurately determine the approach to internal work, you need to decide on external plastering. The plastering of aerated concrete walls outside the room affects the method and sequence of actions for finishing the room:
- When the outer wall already has some kind of coating or is insulated with dense and vapor-tight materials, then moisture will accumulate in the walls. In this situation, interior decoration is carried out using materials with low vapor permeability. You also need to take care of a reliable ventilation system so that moisture does not accumulate in the corners of the room and on the windows.
- When the aerated concrete facade is not covered with anything, or treated with porous heaters, such as mineral wool, then its vapor permeability is not impaired. In this case, it is necessary to first carry out work on the interior decoration of the room, and then move on to the outside.
Foundation preparation
The technology of plastering walls made of aerated concrete is practically no different from working with any other surface. First of all, you need to make sure that the walls are even, and if this is not the case, grind them with a planer or grater for aerated concrete. Many craftsmen skip this stage, but as a result, the cost of plaster increases, which is also used to level defects. Before applying the primer, aerated concrete walls are wetted with water. For drier rooms, it is recommended to choose a universal composition, and for the kitchen and bathroom - a deep penetration primer. \
Building beacons are mounted on a dried surface, which will serve as a guide for successful plastering of the room. After installing the beacons, the internal plaster of the aerated concrete walls will lie flat, and the work will move faster.
The technology of finishing the facade of the building is somewhat different standards. First, the walls are cleaned of dust and leveled. Slots and cracks are filled with special glue for aerated concrete. After drying, it is necessary to apply a layer of primer for cellular materials. An important stage in the preparatory work for plastering the facades of buildings made of aerated concrete is the reinforcement of the surface with a mesh. When choosing the type of reinforcing mesh, it is necessary to pay attention to the fact that under the influence of an alkaline environment, the material from which it is made can dissolve. Experts recommend choosing fiberglass types.
Aerated concrete plaster (video)
How to plaster aerated concrete surfaces
In order for the repair of an aerated concrete house to serve for many years, it is necessary to competently approach the choice of material for finishing the walls inside and out. Masters distinguish as many as four options for processing walls made of cellular material:
- Gypsum plaster.
- Cement-sand mortar.
- Facade mixtures.
- Drywall.
The last option is the so-called dry plaster. What is better drywall or plaster on aerated concrete walls is a moot point. Surface plastering is a costly and time-consuming process. Working with GKL takes less time and, as a result, smooth walls are obtained. Procedure:
- vapor barrier of surfaces using a polyethylene film, membrane or glassine;
- installation of the crate for fastening the plasterboard;
- fastening drywall to the frame;
- puttying joints between sheets using sickle tape.
Any kind of decorative finish can be applied to a gas-concrete wall leveled in this way. What kind of plaster is better to plaster aerated concrete walls? To answer this question, it is necessary to know the specifics of the solutions and their interaction with the base material.
Disadvantages of different types of plasters
| Name | disadvantages |
|---|---|
|
Cement |
Low level of adhesion in relation to the gas block |
| High moisture content | |
| The vapor permeability index is lower than that of the gas block, therefore, the cement mortar can only be used when vapor-tight materials (polyethylene film, etc.) are used for interior decoration. | |
|
Gypsum |
Picks up moisture during snow and rain |
| The appearance of spots on the plaster | |
| Vapor permeability at a low level | |
| facade | The only drawback of this type of plaster is their high cost. |
Gypsum plaster
The main advantages of gypsum mortar for the treatment of aerated concrete walls include:
- fast drying;
- high level of adhesion;
- no need to apply an additional smooth layer;
- the possibility of leveling the plaster for finishing.
Among the masters, Knauf Rotband, Bonolit and Pobedit Velvet are popular.
Cement-sand plaster
If this option was nevertheless chosen for finishing aerated concrete walls, then there are several ways to improve the composition for better interaction with the base. You can increase the adhesion if you add more cement mortar to the standard mix recipe (8-10 kg of lime will be needed per 100 kg of concrete). The second option, which is acceptable, but still not recommended by craftsmen, is the addition of a mixture for processing aerated concrete (proportion 1: 1) to the cement-sand plaster. Among the leaders in sales of mixtures of this type are Baumit brand solutions and domestic Craps Extra-light.
Facade solutions
This type of mixture, in the case of aerated concrete, is suitable for both indoor and outdoor use. The main positive aspects in working with special plasters for aerated concrete:
- high adhesion rate;
- resistance to deformation and cracking;
- vapor permeability is equal to that of aerated concrete;
- pleasant view;
- does not require additional finishing work.
Do-it-yourself plastering of walls on aerated concrete is shown in the video below. With a competent approach to work and the study of materials, even a novice master can handle plastering a house from aerated concrete blocks.
Aerated concrete is a modern building material that resembles foam concrete in structure, but differs in air bubbles located inside. The hollow structure of aerated concrete absorbs moisture well, which requires external finishing of the material. The better to plaster aerated concrete walls is discussed in the proposed article.
For the manufacture of material are used:
- quartz sand - the basis of the mixture;
- lime;
- cement;
- water;
- aluminum powder is added during the manufacturing process of the material. Acts as the main blowing agent and gives the material a specific structure.
Tip: When purchasing aerated concrete, it must be borne in mind that the pores of the blocks, unlike foam concrete, are open. This determines the features of its application and finish.
Comparative characteristics of foam concrete and aerated concrete are presented in the table:
| foam concrete | aerated concrete |
| In its structure, air bubbles do not connect with each other, which increases the resistance of the material to wetting. | Air bubbles are interconnected, which allows moisture to move freely through them. |
| Good qualities of frost resistance and thermal conductivity. | Gives off heat and hardens from frost. |
| The inner layer of the plaster layer should be twice as thick as the outer one. | The walls must be plastered inside the room, and then on the facade of the building. |
| To improve adhesion, the walls must be cleaned, then carefully sanded to remove the upper hydrophobized layer. Due to poor absorption of moisture, a solution is sprayed to increase adhesion, and then the main layer is applied. | Adhesion indicators are higher |
When plastering external surfaces of aerated concrete, its high hygroscopicity must be taken into account.
This requires the use of non-standard plasters, which over time will not lead to:
- Cracking of the internal and external surfaces of the building, as in the photo.
- The appearance of traces of masonry after fog or rain, which worsens the visual parameters of the walls.
- Change of technical characteristics.
- An increase in indoor humidity.
- The appearance of mold in the corners of the rooms.
To finish the exterior surfaces, special facade plasters are used. A particular danger for aerated concrete slabs is temperature extremes and severe frosts.
During operation, a certain amount of liquid begins to accumulate inside the structures, which will expand when it freezes and can greatly damage the structures of the structure. It is possible to plaster aerated concrete bases only with mixtures that have good water-repellent properties that do not prevent moisture from evaporating from the walls.
For exterior finishing of aerated concrete, the plaster must have:
- Good adhesion parameters.
- High compressive strength.
- Frost resistance.
Tip: Owners of buildings made of aerated concrete blocks should take into account that the exterior wall decoration is carried out only after all internal facing work has been completed. Otherwise, when carrying out “wet” interior finishing work, the walls will absorb a significant amount of moisture, which will subsequently begin to evaporate.
If the outer facade is finished before applying the inner plaster, with its intensive evaporation, the outer plaster layer will peel off from the surface of the aerated concrete. After the interior decoration of the room, it is possible to clad the walls of the house from the outside with special compositions with the highest vapor permeability.
Advice: It is impossible to plaster facades using standard cement-sand mixtures due to their insufficiently high vapor permeability properties.
Plaster for gas concrete
For wall finishing, a vapor-permeable aerated concrete plaster is used, which is well permeable to water vapor, does not get wet, with good adhesion to the surface of the blocks and high frost resistance.
| Type of plaster | Material Features |
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Material disadvantages:
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Disadvantages: a small selection of colors, loss of appearance, due to the deposition of dust and dirt on the surfaces of the walls. |
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Disadvantage: High cost, but over time, it will likely pay off. In this case, it is appropriate to remember that the miser pays twice. |
| The advantages of the composition:
Disadvantages of gypsum plaster:
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Lime-cement plaster
All the necessary properties are inherent in light thin-layer plasters, specially created for finishing surfaces made of aerated concrete. An example of such plaster can be - Baumit HandPutz for do-it-yourself wall decoration, produced in bags weighing 25 kilograms.
Its main physical properties are given in the table:
| Name of indicator | Its meaning |
| Grain size, mm | 1 |
| Ultimate strength of the material in bending, tensile, N/mm2 | ≥0,5 |
| Compressive strength of the composition, N/mm² | ≥3,5 |
| Vapor permeability coefficient μ, | 15 |
| Thermal conductivity coefficient λ, W/mK | 0,8 |
| Dry mix density, kg/m³ | 1600 |
| Liquid consumption, liter/bag | 6-7 |
| Consumption of the mixture (with a thickness of the applied layer of 1 cm), kg / m² | 15 |
| Minimum layer of plaster, mm | 5 |
| Maximum layer of plaster, mm | 20 |
Tip: Before plastering aerated concrete with this plaster, it is necessary to spray the previously cleaned wall surface with Baumit Vorspritze mortar.
Material selection
To choose which plaster is better to plaster aerated concrete walls, you need to purchase a plaster composition that meets the characteristics:
- good vapor permeability;
- the optimal volume of liquid for mixing the mixture: for one kilogram of the mixture - no more than 0.2 liters of water;
- certain values of the minimum and maximum thickness of the plaster;
- good adhesion with a base of at least 0.5 MPa;
- resistance to negative temperatures;
- high resistance to cracking;
- long pot life of the mixture, the larger it is, the easier it is to work with the solution, especially for beginners.
The procedure for plastering walls made of aerated concrete
Before starting work, it is better to get acquainted with the video in this article.
Tip: Aerated concrete building blocks are quite even with almost imperceptible seams. It is not necessary to use plaster solutions for leveling surfaces. It is enough to apply only a thin layer of the mixture.
The wall plastering instruction suggests the following work procedure:
- Surface primer. A composition specially designed for aerated concrete, the surface of which actively absorbs moisture, is applied with a brush or roller.
- A reinforcing mesh is mounted, which is attached to the surface with self-tapping screws (see How to fix a plaster mesh to a wall).
- The walls are finished with a thin layer of plaster.
Properly selected plaster mixes for aerated concrete blocks allow you to make your home not only beautiful, but also warm, preserving all its positive characteristics for a long time.
