Developers often have a question about how to plaster aerated concrete on the outside. Before starting work, it is recommended to decide on important characteristics and, based on this, select best option finishing.

Aerated concrete plaster must meet the basic requirements - the mixture adheres tightly to the surface and has good adhesion. The finishing layer is durable, frost-resistant and has the required level of vapor permeability and water repellency.

When to do plastering work

External plastering is recommended after completion of finishing work in the building. It is generally accepted that if the surface of aerated concrete blocks is not protected from the street, it will absorb moisture. This is not so, primed walls can stand without a protective layer for a whole winter, and when the climate changes in the spring, the moisture from the surface will evaporate. In the opposite case, when the house is treated from the facade, evaporation vapor will be directed into the room, which will lead to dampness.

Note! An exception is the option of building a house on the seashore or pond. When it is necessary to protect external walls from the influence of humid climates and winds.

Before plastering, walls made of aerated blocks must dry thoroughly. If during the construction process a cement mortar was used, which has the ability to absorb moisture. For this reason, exterior decoration will not be effective during the rainy season. But especially dangerous for walls is cold water, which then turns into ice. During the melting process, the structure of aerated concrete begins to collapse.

Facade insulation

If the building is properly insulated, you can heat the room faster and save money on heating costs. It is recommended to insulate the outside with mineral wool, polystyrene foam, polystyrene foam or other options. For example, the insulation and plaster of the facade of a house can be replaced by building an additional brick wall or treat with liquid polyurethane foam.

Types of plasters

There are several types of plaster that are suitable for treating aerated concrete walls. There are certain requirements for mixture compositions for outdoor work.

1. The material must be permeable and its coefficient must be higher than that of the surface being treated - aerated concrete or sealant.
2. The plaster must be resistant to frost and temperature changes.
3. To prevent cracks, the applied layer must be elastic.
4. The plaster must have strong adhesion properties to aerated concrete.

Mineral

How to plaster aerated concrete walls? Professionals and private builders recommend using plaster compositions for mineral based. They are among the thin-layer compounds specially created for finishing aerated concrete. Such solutions are made with your own hands, they are affordable, good vapor permeability and light weight.

Ready-made formulations include the following components:

• lime;
• white cement;
• marble chips and other fillers.

The color palette of such plaster mixtures is limited. They can be easily painted; the only caveat is the use of vapor-permeable coloring compounds. Painting can protect the coating from moisture, because a damp environment can destroy mineral plasters.

Silicate

The basis of this type construction plaster contains potassium liquid glass, which is the connecting component.

Advantages of silicate mixture:

1. Easy to apply;
2. Resistance to moisture;
3. Vapor permeability;
4. If necessary, it can be painted in any color;
5. Reasonable price;
6. Long service life (up to 25 years);
7. Decorative qualities.

Silicone

Plaster aerated concrete blocks better with façade silicone plaster. It has high technical and performance characteristics and is superior to other plaster mixtures.

The advantages of silicone plasters include:

• properties to repel water;
• the building material is easy to apply with your own hands, without the involvement of specialists;
• plaster has a high degree of resistance to atmospheric phenomena and vapor permeability;
• Long service life;
• Fillers have different textures;
• The material is elastic.

Acrylic

The material has high decorative qualities and durability. The big disadvantage of acrylic plaster for processing aerated concrete and other cellular textures is low level vapor permeability. For this reason, condensation forms in the inner layer of the plastered surface. As a result, such exposure causes surface deformation - peeling and cracking.

Cement-sand

Cement plaster is not suitable for treating external aerated concrete surfaces. For what reasons is this popular building material not suitable:

1. The solution does not adhere to the smooth surface of aerated concrete due to insufficient adhesion properties. The mixture has high density and high weight;
2. When applying cement mortar to the surface, aerated concrete absorbs moisture and the adhesion of the materials weakens. As a result of such rapid drying, the integrity of the layer is destroyed;
3. Low vapor permeability cement mixtures- inconsistency building regulations, and violation of optimal microclimatic parameters in residential premises.

If cement plaster is used for interior work, it will protect aerated concrete walls from steam penetration into them.

Important! Expanded polystyrene and polystyrene foam are not recommended for treating aerated concrete surfaces.

Plaster

The plaster base, which includes gypsum, has the following positive qualities:

• dries quickly;
• the solution does not shrink;
• the mixture goes on smoothly;
• no finishing coat required.

Disadvantages of plastering walls with gypsum:

• average level of vapor permeability;
• a larger amount of water is required compared to special mixtures, approximately 10-15 liters per 1 bag of 25 kg;
• the surface will quickly get wet after rain and snow;
• spots appear on the surface that need to be painted over.

Facade

The mixture is most effective for treating both external and indoor walls; the material is easy to apply with your own hands. Plaster has a number of positive qualities - good adhesion to the base, attractive appearance. Including the material has vapor permeability indicators identical to those of aerated blocks. When choosing plaster for building aerated concrete, it is better to choose a high-quality special mixture, this will simplify the process of finishing the house.

If you have to choose plaster or drywall, which is better for aerated concrete inside the house. The following facts should be taken into account: walls made of aerated blocks are smooth, and they do not require leveling. Accordingly, plaster will cost less, and the solution will form an even and beautiful layer.

Self finishing

We plaster the aerated concrete on the outside with plaster intended for exterior use. There are two options for applying the mixture - a thick layer or several thin layers, which are applied in no more than 3 layers and no more than 1 cm each.

Work order:

• the surface is prepared for plastering - contamination is removed;
• Next, you should hang the surface with your own hands using beacons;
• spray is applied - the first layer of plaster coating;
• the primer is applied and leveled;
• cutting corners;
• finishing of slopes;
• a covering layer is applied;
• the surface is rubbed.

External work technology

1. If necessary, insulation is installed for the blocks under the plaster.
2. Preparing walls - leveling the surface to reduce material consumption and application thickness.
3. Before you start plastering the walls, aerated concrete must be treated with a primer. For this purpose, compositions designed for the fine-cell structure of materials are used.
4. Applying a thin layer of plaster mixture for aerated concrete surfaces - up to 5 mm. This base will serve to attach the mesh.

It should be noted right away that plastering aerated concrete blocks from the outside with adhesive solutions is unacceptable. Because glue won't do the job. In order to protect and level surfaces, it is recommended to use specially designed mixtures that meet all operational requirements.

When plastering aerated concrete facade work is carried out, it is recommended to follow some rules, which are described below.

• after the building is erected, a certain period of time must be maintained so that the internal moisture evaporates naturally;
• the brand of plaster must be suitable for outdoor use;
• subsequence repair work– first inside the house, then outside;
• the temperature regime must correspond to +8 to +30 C0 - for exterior finishing;
• Building regulations that must be observed in relation to increasing thermal conductivity coefficients. Each material installed or applied to the gas block should be taken into account.

Reinforcement

To the question whether it is necessary to reinforce the plaster, and whether a mesh is needed. The answer is simple, since the plaster layer of aerated concrete can vary from 5 to 15 mm. If the layer exceeds 10 mm, a metal mesh with a fine cell texture is used as a reinforcing layer. For example, a mesh with a wire diameter of 0.1 mm and a cell size of 0.16 x 0.16 mm, or fiberglass mesh with cells of 5x5 cm, is suitable.

The mesh must be installed with an overlap of 5 cm; for the corners of the house, perforated corners with mesh are used. This method will help prevent the formation of cracks in the plaster after the building shrinks. It is better to install the mesh into the applied solution using a spatula. Especially important point is the installation of the mesh in places with a high level of stress - the area of ​​​​windows and doors.

Advice! If you attach the mesh to a dry surface, the result will be zero. Because the mesh needs to be fixed to the wall using self-tapping screws, and then a layer of mortar must be applied. Otherwise, the unfixed mesh will move along with the putty.

Work order:

1. Level the plaster layer over the mesh using vapor-permeable plaster.
2. It is necessary to wait until the first layer is completely dry. Otherwise, it will fall off under the weight of the next layer. This technique involves thin-layer application of the mixture. You will have to wait three to four days for complete drying. Accordingly, the thicker the layer, the longer it takes to dry. Checking whether the surface is dry is done using water. Having splashed the liquid onto the surface, it was quickly absorbed - this means that it is time to begin further work.
3. A second layer of plaster is applied, which is considered leveling. Therefore, the layer should be even and smooth;
4. A third finishing coat of plaster is applied and will require further grouting if necessary.
5. Painting the surface with materials for exterior work or applying putty.
6. Treatment with a water repellent. Experts recommend applying this solution 12 months after painting and completion of all façade cladding work. A water repellent gives any coating additional water-repellent properties.

Note! When the plaster layer dries, it must be protected from the influence of such undesirable environmental factors as moisture, snow, rain.

Putty

When deciding whether to putty aerated concrete, it is recommended to find out about the types building mixtures. There are 3 types of product varieties on the market that are intended for finishing. By and large, this is a facade plaster intended for thin-layer finishing of an already plastered surface, differing only in composition. Ready-made mixtures are sold in buckets and come in silicate, silicone and acrylic.

Important! When plastering the outside of a house, it is recommended to use only vapor-permeable building materials. This will provide not only a reliable finish, but will serve as a decoration for the building.

Gas silicate-based blocks are widely used as a building material for the construction of buildings. They provide increased thermal insulation of buildings, but due to their porous structure they absorb moisture. Form protective coating walls allow plaster mixture. First, rough plaster for gas silicate blocks is laid on the prepared surface. Then apply thin layer solution and grouting is performed. Covering the wall with aerated concrete, plastered with dry mixtures, helps prevent cracking of the material due to waterlogging.

Properties of gas silicate material and its protection using a plaster layer

Silicate blocks are a modern building material characterized by a cellular structure. They are made from a mixture quartz sand and cement, to which aluminum powder and lime are added. When mixing the ingredients, it occurs chemical reaction, as a result of which the gas silicate solution increases its volume and then hardens in special forms.

Gas silicate based blocks are used as building materials for the construction of buildings.

As a result of the gas formation reaction, the blocks acquire a porous structure, which determines the main performance characteristics material:

• reduced thermal conductivity. Gas silicate walls reduce thermal energy losses and reduce heating costs;
• ability to absorb noise. Cells unevenly distributed inside the blocks prevent extraneous noise from entering the room;
• increased vapor permeability. Air exchange occurs through the pores, improving the microclimate of the living space.

In addition, the blocks have energy-saving properties. They gradually accumulate thermal energy, which is then transferred to the room and increases its temperature.

• reduced weight;
• increased strength characteristics;
• increased volume;
• correct geometry;
• minimum tolerances on dimensions;
• good machinability;
• environmental cleanliness;
• frost resistance;
• fire safety.

In the area low-rise construction silicate blocks have proven themselves positively

The need to plaster the surface of porous blocks is associated with the following properties of the material:

• increased hygroscopicity. Porous gas silicate is prone to absorbing moisture, which causes gradual destruction of the material at negative temperatures, and also contributes to the development of microorganisms. To prevent cracking of the blocks, they are plastered;
• reduced adhesion of the cellular surface of the blocks to finishing materials. Plaster mixtures based on sand and cement, as well as lime-based plasters, do not adhere well to porous gas silicate. Carrying out finishing measures allows you to increase adhesion;
• moisture condensation inside the gas silicate mass. As a result of intensive air exchange occurring under conditions of temperature changes, moisture accumulates inside the blocks. It makes it difficult for air vapor to escape from the room and negatively affects the microclimate.

To ensure adhesion of the gas silicate surface, the following work is carried out:

• cover the gas silicate with a special solution. The soil penetrating deep into the cellular gas silicate improves adhesive properties;
• strengthen the gas silicate surface of metal, nylon or fiberglass mesh. It allows you to apply an increased layer of plaster;
• Several layers of plaster are applied successively. Layer-by-layer finishing allows you to create a smooth surface with increased adhesive properties.

The cellular structure determines the need to protect the surface of gas silicate blocks

The need to protect the surface of gas silicate blocks and other products made of porous concrete is due to their cellular structure. Finishing gas silicate walls is a must.

Purpose of plastering:

• prevention of destruction of gas silicate walls as a result of temperature fluctuations;
• protection of gas silicate blocks from intense moisture absorption and development of microorganisms;
• improving the appearance of various buildings whose walls are built from gas silicate blocks;
• reducing the volume of heat loss through the unprotected surface of gas silicate walls;
• security comfortable conditions indoors by providing increased sound insulation;
• leveling the surface of the walls after laying the blocks, allowing you to create a flat base for finishing;
• protection of block walls from the formation of cracks, allowing to increase the service life of the building.

Aerated concrete is susceptible to the influence of natural factors - precipitation, ultraviolet rays and weathering. In addition, porous gas silicate is destroyed as a result of mechanical damage. Plastering walls made of gas silicate blocks provides reliable protection throughout the period of operation.

Reliable protection is provided by plastering walls made of gas silicate blocks

We prepare the necessary tools and building materials

Preliminary preparation of building materials and the necessary tool will speed up finishing work and increase their productivity.

To plaster gas silicate walls you should prepare:

• a rule designed to stretch the plaster mixture along the beacons. The length of the rule is selected depending on the distance between the beacons;
• metal guides, called beacons, to ensure flatness. The beacons serve as a guide when working with the rule;
• drill with attachment or mixer. They are used to ensure accelerated and uniform mixing of the plaster mortar;
• trowel and spatulas with extended work surface. The tool is used for throwing and leveling the plaster mixture;
• plumb line, building level, tape measure. They are used in the marking process and are used for control during plastering activities.

You will also need a wide brush or roller to apply the primer composition to the surface of the blocks. To carry out the kneading, you need an appropriate container, and to fix the mesh you will need nails or dowels.

Tool for plastering walls

In addition to tools, you must purchase the following materials:

• adhesive mixture for priming. It provides increased adhesion of plaster to gas silicate blocks;
• mesh for surface reinforcement. Mesh reinforcement makes it difficult for cracks to form and strengthens the finishing layer;
• dry mixture for plastering works. It is easy to purchase a ready-made composition for plaster in specialized stores.

Having prepared everything you need, proceed to work.

Plaster mixture for gas silicate blocks - choosing high-quality plaster

Novice finishers and home craftsmen often ask the question of what to plaster with. gas silicate blocks, as well as what requirements apply to the plaster mixture.

In construction supermarkets it is easy to purchase plaster compositions from well-known manufacturers:

• Knauf companies;
• brand Ceresit;
• EuroMix company;
• brand PROFIT.

Plaster compositions from well-known manufacturers can be easily purchased in construction supermarkets

Along with imported plaster mixtures and primers, finishing mixtures produced by domestic manufacturers are also offered. The expanded range of plaster compositions makes it difficult to accept the right decision novice masters. You can consult with construction department salespeople on how to plaster gas silicate blocks inside. Professionals will offer the best plastering option and also advise how to plaster gas silicate blocks on the outside of the building.

When purchasing ready-made plaster for external and internal finishing work, you should consider a number of factors:

• area of ​​use of plaster;
• adhesion properties of the mixture;
• resistance to negative temperatures;
• vapor permeability of plaster after hardening;
• moisture-proofing characteristics;
• environmental friendliness of the finishing material;
• shelf life of the composition;
• manufacturer's image;
• duration of setting.

If you have the necessary ingredients, it’s easy to make your own plaster mortar. To do this, take cement and lime in equal proportions, mix with three parts of sand and dilute the resulting mixture with water to the desired consistency. Adding chalk will increase plasticity plaster composition and will make it easier to apply.

It’s easy to prepare your own plaster solution if you have the necessary components

Internal plastering of walls made of gas silicate blocks - stages of work

According to the technology, internal work on plastering gas silicate walls includes the following steps:

1. Cleaning walls from dirt.
2. Impregnation gas silicate material special soil.
3. Installation of the mesh to the gas silicate surface.
4. Layer-by-layer application of plaster mortar.
5. Final finishing activities.

Let us dwell on the features of each stage of work.

We prepare the wall surface for treatment with a special primer

Preparing the surface of gas silicate is a critical step that ensures adhesion and affects the quality of plastering work.

The critical stage is preparing the gas silicate surface

Preparatory activities include:

1. Dust removal of gas silicate.
2. Removing old coating and dirt.
3. Degreasing problem areas.
4. Elimination of oily traces.
5. Increasing the depth of gas silicate masonry joints.

It is not always possible to remove oil and grease stains that have penetrated into the gas block mass with a metal brush. In this case, they are cut out with a chisel.

Applying a primer to aerated concrete of internal walls and partitions

Treatment of gas silicate with a primer solves the following problems:

• increases the adhesion of blocks with the finishing mixture;
• reliably seals internal cavities;
• gives the gas silicate surface additional roughness.

Primer should be applied in an even layer

Priming of blocks is carried out using various methods:

• manually, using paint brush or wide roller;
• using a spray bottle to cover a larger area.

The primer should be applied in an even layer, paying special attention hard to reach places in the area of ​​corners and openings. Plastering on gas silicate blocks is carried out after the soil has completely dried.

We attach the reinforcing mesh to the gas silicate blocks

Strengthening blocks plaster mesh provides improved adhesion of plaster. The mesh is attached in various ways:

• by attaching a metal mesh to a gas silicate surface with dowels or nails;
• by pressing a fiberglass or nylon mesh into a pre-thrown layer of finishing composition.

Mesh reinforcement in combination with priming will achieve increased adhesion. After installing the mesh, the beacons should be fixed, and the gas silicate surface should be moistened with a spray bottle or brush for better penetration of the finishing composition.

Reinforcement with mesh in combination with priming will allow you to achieve increased adhesion

Plaster for aerated silicate blocks - the process of finishing aerated concrete material

Let's figure out how to properly plaster walls made of gas silicate blocks. Perform plastering in the following order:

1. Using a trowel, spread a layer of plaster mixture onto the gas silicate masonry.
2. Distribute the finishing composition along the guides as a rule.
3. Remove hardened lumps of plaster after it has hardened.

There is no need to try to ensure perfect flatness. You just need to distribute the mixture over the wall area.

Applying the finishing layer after finishing rough work

At the final stage of finishing activities, the following work is performed:

1. Rough plaster is covered with primer.
2. Finishing gas silicate plaster is carried out.
3. Irregularities are removed and finishing putty is applied.

Interior plaster walls made of gas silicate blocks at the finishing stage acquire the necessary flatness during the process of grinding and grouting.

Applying the finishing layer

Plastering external walls with plaster compounds

For façade finishing of buildings, it is used, to which ingredients are added to increase water resistance.

This plastering of gas silicate blocks with cement mortar is carried out according to the following algorithm:

1. The facade of the building is cleaned of dirt.
2. The primer is applied to the surface of the gas silicate.
3. The metal mesh is being installed.
4. Facade plaster for gas silicate blocks is applied.

An improved aesthetic perception of the finish is achieved by coating the surface with paint.

Plastering walls with cement-sand mortar is used for façade finishing of buildings

External and internal plaster of gas silicate walls - useful tips

When performing plastering work yourself, you should follow the advice and recommendations of professional finishers.

They focus on the following nuances:

• performing work at temperatures of 5-30 degrees Celsius. At this ambient temperature, normal drying of the plaster is ensured;
• the need for layer-by-layer application of the finishing mixture. In this case, the finishing layer of plaster is applied only after the main layer has dried;
• feasibility of surface wetting. At elevated temperatures, spraying liquid prevents the formation of cracks;
• ratio of thicknesses of external and internal finishing equal to 2:1. This allows you to shift the dew point and prevent moisture condensation inside the blocks.

Please also note that optimal thickness the internal finishing layer is 8-14 mm. Professionals draw attention to the fact that gas silicate finishing can be done a month after the completion of wall laying.

Conclusion

Do-it-yourself plastering of walls made of gas silicate blocks allows you to save significantly. High-quality plaster will reliably protect gas silicate blocks. Getting started finishing works for the first time, carefully study the technology requirements and take the choice of finishing material seriously. Advice from experienced builders will help you avoid mistakes.

Aerated concrete has recently been used to build houses. Lightweight material, warm and vapor permeable. But there are also several shortcomings, to remove which the base must be covered with a finish. The fastest and most reliable way is plastering.

But since the gas block is whimsical, not all mixtures are suitable for these purposes. This means you need to carefully choose the best way to plaster walls made of aerated concrete in order to get the desired result.

The material is created from natural ingredients. When the components are mixed, a chemical reaction occurs, which results in the formation of a large number of gas bubbles. After the mass hardens, voids remain, and they are the main cause of all positive and negative qualities aerated concrete.

Thanks to this structure, the following features of the material are distinguished:

• high vapor permeability - moisture that is released during human activity does not accumulate in the premises, but goes beyond the boundaries of the house;
• low coefficient of thermal conductivity - walls made of aerated concrete retain heat perfectly in winter, and summer time- coolness. But when choosing a material for construction, you should pay attention to its density. The higher the indicator, the more heat will evaporate;
• soundproofing properties - thanks to the same voids filled with air, aerated concrete does not transmit sounds well in any direction. Therefore, noise on the street will not disturb the residents of the house;
• hygroscopicity is the biggest drawback. The material quickly absorbs moisture from the environment and takes a long time to dry completely. In the hot season, moisture is not harmful to gas concrete, but when the temperature drops to negative levels, the water will freeze in the pores and destroy them;

This material should not be used to build walls in rooms with high humidity, for example, in the kitchen or bathroom.

Since aerated concrete is capable of absorbing moisture, it is simply necessary to protect it from the outside from harmful influences. The most common choice is plaster. Such finishing can both protect the building from all kinds of influences and embellish the facade, especially if a modern textured composition is chosen.

Choosing a method, how, with what mixture and what is the best way to finish?

Aerated concrete is a very demanding material, therefore the technology of applying plaster to aerated concrete walls has its own nuances and subtleties. It is better not to do such work yourself, but to use the services of professionals. Although anyone who has encountered this process can handle it themselves.

In order for the process to be as productive as possible and bring the result that the home owner wants to see, it is necessary to decide on:

1. Plaster application method.
2. A composition that is most suitable for aerated concrete.
3. Plastering technology.

Each of these points is very important and it is simply impossible to treat them irresponsibly. Otherwise, all pipes will be in vain.

Plastering the outside of the house, and then inside

As mentioned above, aerated concrete is hygroscopic and, according to all the rules, the first step should be to protect its facade, and then proceed to interior decoration. But professionals know for sure that this is not worth doing. Let's find out why.

Plaster is also used for interior work. In this case, moisture will be absorbed from the solution into the building material. When with outside The walls are already covered with plaster, then evaporation takes much longer. Therefore, the applied inner layer may become covered with small cracks or even fall off.

In some cases, moisture can condense at the junction of the external plaster layer and the wall. The consequence of this will be “shooting” of the layer - this is what professionals call flaking. In order for the building to easily endure the winter period, the façade is covered with a water-repellent agent, which will repel precipitation from the walls.

Attention! If the house is built near the sea, river or lake, then this method would be preferable. Wind with an abundance of moisture will quickly destroy the constructed foundation, so the façade should be protected first.

Plastering inside the house and then outside

This finishing method is the most common. The first step is to plaster the walls inside the house. Then the moisture from the solution, which has been absorbed into the base, can freely come out without being trapped in the thickness of the wall.

It is important not only to start with the rooms, but also to wait for the treated surfaces to dry completely. If this is not done, there is a high probability of cracks or peeling areas.

Simultaneous

But it’s better not to use this method at all. The reasons are as follows:

• moisture is absorbed both from the facade and from the interior;
• there are no ways to remove moisture from aerated concrete;
• V winter time water will freeze in the voids building material which will lead to slow destruction.

Someone will say that they will use plaster with high vapor permeability. This means that moisture will still come out.

And this statement will be correct, but the drying time of both layers will increase several times. Then the whole finishing process will also be delayed. In addition, here there is a high probability of a web of cracks appearing.

Types of plasters

Once the correct method has been chosen, it is worth asking the question: what is the best way to plaster walls made of aerated concrete? Not all known species plasters are suitable for these purposes. Therefore, when choosing a mixture, check out the characteristics.

If something confuses you, then ask for help from a consultant in the store or go shopping with a master who will do the finishing. Pay attention to the following:

1. Vapor permeability coefficient. It must match the indicators of aerated concrete.
2. The amount of water required to prepare the mixture.
3. Adhesive properties.
4. Maximum and minimum thickness layer.
5. Resistance to temperatures below zero is also important for the façade.

Now let's take a closer look different types plasters.

Gypsum plaster

This option is more preferable for interior work. What does it matter if the room is different? high humidity, then it is better to choose another option. This is due to the fact that gypsum quickly and abundantly absorbs moisture from the environment.

In addition, the gypsum solution also requires a lot of moisture to seal, and this is not very good for the mixtures that will cover aerated concrete walls. But despite this, gypsum plasters have several positive aspects:

Cement-sand plaster

Ordinary cement-sand mortar It is absolutely not suitable for finishing walls made of aerated concrete both outside and inside the house. If other bases work perfectly with concrete, then in this version it’s the other way around:

1. The mixture is poorly distributed because it has low adhesion rates to cellular structures.
2. High water content in solution. The hygroscopic aerated block quickly absorbs moisture, and this leads to a deterioration in the quality of the applied layer. In order for the cement-sand mixture to become a good, even layer without imperfections, uniform and slow drying is necessary. In this case it is impossible.
3. The frozen layer has low vapor permeability. For buildings made of aerated concrete this characteristic very important.

If you really want to use cement mortar, then it is advisable to add lime to it. This action is insignificant, but will improve the quality of both the solution and the frozen layer. Some craftsmen mix cement-sand mortar with a special one for cellular surfaces and treat the base with this composition. But such an event will not make the mixture of the highest quality.

Facade mixtures

Range of mixtures for plastering different surfaces presented in options that are specially designed for aerated concrete and foam block foundations. Therefore, experts in their field recommend choosing this option. Manufacturers have selected components that, when mixed, result in a composition that fully meets the characteristics:

• the same vapor permeability indicator;
• excellent adhesion to the base;
• resistance to external influences;
• aesthetic appearance.

The cost of such compositions is a little higher, but the result is worth it. All components are already mixed in the required proportions, which means the work will progress much faster.

Application technology, is a mesh needed?

If you decide to do plastering yourself, be sure to familiarize yourself with the technology of applying mortar to aerated concrete walls. To do this, you will have to look for special literature or articles on the Internet. Even if the work is carried out by professionals, it will not be superfluous to monitor the process.

Preparing the base

To reduce the layer of applied mortar and reduce the likelihood of cracks, be sure to carefully prepare the base. These events include:

1. Removing stains, if any, on the surface of aerated concrete.
2. Removing excess mortar that may have remained in the seam area. To do this, choose a special grater. By the way, it is much easier to remove excess mortar during the construction stage, but many people ignore such actions.
3. Dust removal of the base. To remove dust, use a damp brush, rag or roller. We use the tool as if we were applying a primer.

Applying primer

This treatment is needed not only to increase adhesion, but also to protect the base from high humidity. Choose formulations with antiseptic, antifungal and hydrophobizing effects. Such soil can protect the base from fungus and mold.

This is especially important for rooms with high humidity, as well as for the facade. Apply the primer with a roller or brush in a dense layer. It is prohibited to dilute the composition with water, since such a solution no longer has all the necessary properties.

Some people wonder whether a mesh is needed when plastering aerated concrete? There is no clear answer to this question. But if we consider the advantages of its use, we highlight the following:

• increasing the adhesion of the solution and the base, especially if you plan to apply a thick layer;
• reducing the risk of cracks.

Advice! If the house is new and the walls are shrinking, then reinforcing mesh is a mandatory attribute.

Installation of beacons

If you plan to apply a solution with a thickness that exceeds 5–7 mm, then it is necessary. They will help make the layer more even. There will still be some disadvantages, but they will be minor. They can be easily corrected by applying a layer of putty.

Often the distance between the beacons is 60–70 cm, but it should not exceed the size of the rule that will be used to level the applied solution. The beacons are fixed with the same solution as the walls are plastered. Then the layer is very small, then you can do without beacons.

Throwing on a “fur coat”

To throw the solution, use a ladle or trowel. Fill the space between the beacons starting from the bottom of the wall. They adhere to the following plan:

1. Portions of the solution are placed as close to each other as possible.
2. After treating an area one meter high, it is necessary to level the mixture.
3. The rule is carried out in the direction from bottom to top, making oscillatory movements from side to side.
4. The tool is pressed tightly against the beacons.
5. If there are areas that are not filled with solution, they are filled again.
6. Once again you need to go through the rule.

The same plan applies to the entire surface. And wait until the layer
will dry out.

Processing the first layer

At this stage it is necessary to remove the beacons. Although some are inclined to believe that it is not necessary to remove beacons, since this will require additional time. After removing the beacon, there will be a recess that needs to be re-filled with mortar, the surface leveled and again wait until it dries completely.

If left, they will become cold bridges, and as a result, frosty air will penetrate into the premises. When the layer is dry, it is moistened with water using a spray bottle. Next, remove the unevenness using a grater.

Forming corners

Such events will not only allow you to quickly create beautiful and straight corners, but also protect the area from chipping. After all, in a given place the load is always high (impacts, friction when moving furniture or other heavy objects).

For this purpose, special perforated profiles with reinforcing fiberglass mesh are used. The devices are attached to the mortar and covered with putty. By the way, a layer of putty is laid not only on the corners, but also over the entire surface to be treated.

Finishing

Depending on the type of decorative finish, finishing is carried out in several ways:

• coloring. In this case, the finishing layer is rubbed with a special grater so that the surface is perfectly smooth. Then the paint will apply without problems, leaving no bald spots;
• decorative plaster. In this case, without waiting for the solution to dry, they create interesting and original patterns on the facade, which will help distinguish the building from the overall picture. Decorative compositions also available in tinted colors;
• use of tiles or other material for a curtain wall. In this case, carry out finishing, is not necessary at all, since the walls made of aerated concrete will be covered with decorative material.

If you have already built a house from aerated concrete, then do not do the finishing yourself. Select a team of craftsmen who will definitely do everything right. In addition, adhere to these rules:

1. Plaster the house, both outside and inside, only in the warm season, when at night the temperature does not drop below +5 degrees Celsius.
2. For the winter, cover the outside walls with a water-repellent agent, and cover the door and window openings with film if the equipment has not yet been installed.
3. To ensure that the plaster does not crack, use a reinforcing mesh and give the aerated concrete masonry time to settle.

Internal and external aerated concrete plaster must have optimal parameters, protecting the walls of the structure from destruction and cracks under the influence of external influences. There are several basic options for finishing mixtures that will improve and maintain the quality of the base. The right technology application will ensure a long service life and decorative effect of the coating.

Aerated concrete has good thermal insulation properties and a high degree of vapor permeability due to its porous structure. It will help preserve the quality of the material by preventing the accumulation of condensation and the occurrence of mold. correct finishing aerated concrete.

In this article we will answer the main question, how to plaster aerated concrete outside and inside the house.

Aerated concrete blocks

Basic requirements for plaster

It is worth noting right away that it is not recommended to apply ordinary plaster to a house made of aerated concrete blocks. Primarily because standard sand solutions are high-density, this leads to poor adhesion when applied to aerated concrete blocks and the rapid appearance of cracks.

Adhesion(from Latin adhaesio - adhesion) in physics - adhesion of the surfaces of dissimilar solid and/or liquid bodies.

The plaster should maintain an optimal microclimate inside the building, protecting the walls from moisture. Therefore, you should choose mixtures with a vapor-permeable base. Otherwise, the steam coming out of the house will get stuck inside the walls, since the plaster will simply block its exit to the outside. Thus, moisture will begin to accumulate in the walls, which will ultimately lead to their destruction. Of course, nothing will happen to the house in a few years, but in six to eight years it will almost begin irreversible process destruction.

Plaster for aerated concrete should be:

• resistant to external weather influences;
• have good adhesion (adhesion to aerated concrete);
• resistant to sudden temperature changes;
• high degree of compressive strength (protection against cracking);
• vapor permeable;
• moderately dense;
• improving the thermal insulation of walls;
• have a decorative appearance.

When choosing plaster for aerated concrete, you should not ignore any of the points listed above.

Applying plaster to a house made of aerated concrete blocks

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

Types of plasters suitable for aerated concrete blocks

The choice of plaster mixture for aerated concrete primarily depends on whether you are going to cladding the walls from the outside or from the inside. Based on the type of application, plasters are divided into external and internal.

As you yourself understand, external plaster is intended for finishing facades. Since here it performs protective functions, its strength, moisture resistance and thermal insulation indicators should be higher.

Internal mixtures are intended for finishing indoor walls, so the presence of moisture resistance in the characteristics of these plasters can be ignored, with the exception of cases of wall cladding in the bathroom. Due to the lack of resistance to moisture, internal mixtures are much cheaper than external ones.

Applying a finishing layer of plaster to aerated concrete

Popular plasters for aerated concrete

Mixtures for finishing facades made of aerated blocks are divided according to the type of composition into:

• lime-cement;
• acrylic;
• silicate;
• silicone.

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

Acrylic It is advisable to finish a building made of aerated concrete only if there is high-quality internal insulation of the walls. This plaster cannot boast of good vapor permeability, but as a decorative finish, it is durable and reliable.

Silicate plaster for aerated concrete is produced on the basis of liquid potassium glass. The coating has good moisture resistance, vapor permeability and durability. The silicate solution is easy to apply. The finishing layer is resistant to dirt and abrasion, providing decorative effect finishing coating for a long period (more than 25 years). The problem with silicates is the limited choice of colors.

Leveling walls with silicate plaster

Silicone mixtures contain resins and organosilicon polymers. The quality characteristics of the material are optimal for creating a durable coating. Silicone-type plaster retains elasticity after application, which ensures the absence of cracks on the surface even when the blocks shrink. It is important to note the special decorative quality of the finish; thanks to special fillers and color variations, you can create original look façade.

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

On our website you can find contacts of construction companies that offer the service of designing houses made of aerated concrete. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.

Most popular manufacturers

The building materials market is saturated with a huge number of plaster mixtures various brands for finishing aerated concrete surfaces. Popular compositions have optimal characteristics for the job.

Applying plaster to the interior walls of a gas block house

Ceresit CT 24. The mineral composition of the mixture gives the solution plasticity. The material is easy to apply. The coating can withstand up to 100 cycles of low temperature influences. It is recommended to paint after complete drying (after seven days).

CERESIT ST 77. The acrylic type of the mixture is used for facade finishing, ensuring the strength of the coating with a fairly thin layer of application. The material is frost-resistant and resistant to external influences. Used when there is waterproofing and ventilation inside the house.

Founded by Startwell T-21. Cement-lime plaster is frost-resistant and has a sufficient level of adhesion. The resulting coating is resistant to shrinkage and moisture.

Video description

Watch the video comparison of facade plasters for aerated concrete:

Baumit Silicone Top. High level adhesion and plasticity are achieved thanks to the base of the mixture - silicone resins. The coating remains decorative for a long time due to its dirt-repellent properties. Wide choice of material color palette (up to two hundred shades).

Weber.pas silicone. Mixture based on silicone emulsion. It is possible to select the appropriate grain size. Optimal resistance of the material to moisture, temperature, and dirt.

Baumit Silikat Top. Silicate type of plaster. The coating is durable and has good vapor permeability. The composition has different grain sizes and up to two hundred tinting variations.

Priming the surface before plastering

Internal plaster of aerated concrete walls

Internal work on plastering walls made of aerated blocks is carried out with gypsum solutions with various additives. Composites in the form of perlite and marble chips will increase the decorative effect of the finish. There is the possibility of painting the composition in various colors.

Gypsum mixtures without additives have the required level of vapor permeability, which allows the plaster to be used as a base for wallpapering. Standard sequence carrying out work:

• elimination of irregularities and chips on the surface of the walls;
• removing dust and applying the first layer of solution;
• installation of reinforcing mesh;
• applying the second layer.

After complete drying, you can glue wallpaper, paint the walls, or apply a third, decorative layer of plaster.

Interior work is carried out only subject to the preliminary application of a waterproofing composition and priming.

Interior wall plaster

External plastering of aerated concrete walls

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

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

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

Features of plastering walls made of aerated blocks

Proper execution of the work must take into account the characteristics of the construction material. Aerated concrete blocks may have differences in structure. Sawn options have an open, pronounced cellular structure and do not require special preparation for finishing.

The formed blocks are covered with a hydrophobic layer with a closed pore structure and require additional processing. Grinding the surfaces with a wire brush will help improve the adhesive properties of the material.

Video description

Watch the video of the process of applying plaster to a house made of aerated concrete:

It is also important to remember the rule of increasing the degree of vapor permeability from the inner layer to the outer surface. The façade finish should be twice as thin as the interior coating.

It is strictly not recommended to carry out plastering work on aerated block surfaces earlier than 6 months after the construction of the walls. The structure must dry completely, getting rid of excess moisture accumulated during laying of the material

Plastering on reinforcing mesh

Optimal conditions for applying plaster

Exterior plaster aerated concrete must be produced under certain conditions. It is important to first complete interior work with high humidity levels. Load-bearing structures walls made of aerated blocks must be completely dry, not exceeding 27%. Otherwise high humidity will provoke adhesion failure and lead to peeling of the finishing layer of the facade.

The optimal time for finishing the interior of the house is spring, the façade of the building is the end of summer.

External temperature conditions for work must correspond to +5-+30°C, with air humidity not exceeding 80%. If it is necessary to perform finishing at low temperatures, it is recommended to use a special primer composition deep penetration before the onset of acceptable weather conditions.

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

Plastered facade of aerated concrete house

Conclusion

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

Recently, aerated concrete has been used in the construction of private houses. The material has earned wide recognition due to its positive qualities. This material is produced in fairly voluminous blocks of light weight, so construction is carried out at a rapid pace.

Peculiarities

Foam material retains heat perfectly, 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 water dries out without consequences, then in cold weather moisture absorbed into the building material will inevitably lead to the formation of cracks.

Plastering aerated concrete will prevent water from penetrating into the block and maintaining its integrity.

To perform the work efficiently, it is necessary to take into account the peculiarities of the material being processed. Not all aerated concrete blocks are the same - their structure may differ. For example, the outer surface varies.

You can plaster sawn aerated concrete without pre-treatment. The molded block has a smooth hydrophobic layer on the outside. Applying plaster to such a surface is problematic - to increase adhesion, you need to grind the treated side with a wire brush.

We must not forget that the degree of vapor permeability increases in the direction from inner surface to the outside, so the façade finishing should be made twice as thin as the internal coating.

Before plastering aerated concrete walls after construction, at least six months must pass. During this time, the walls will be completely dry and the excess moisture, falling into blocks during the construction of a building.

The outer surfaces of the walls can be plastered with decorative materials, and compositions for subsequent painting can also be used. Exterior finishing sometimes serves as additional insulation. In regions with cold climates, plastering plays a significant role in retaining heat indoors.

For aerated concrete, you should choose plaster with optimal parameters. Finishing material obliged to protect the walls from destruction on both sides.

Due to its porosity, aerated concrete has such characteristics as thermal insulation and vapor permeability.

Proper finishing:

• helps preserve useful qualities blocks;
• does not allow condensation to accumulate inside the pores;
• Prevents mold and unwanted damage.

Types and compositions

Aerated concrete walls cannot be finished with ordinary cement mortar. Standard solutions have too much density, so they do not adhere well to the blocks. Due to poor-quality 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:

• allow steam to pass through unhindered;
• create a positive indoor microclimate;
• protect walls from the accumulation of moisture inside them.

The following requirements apply to plasters for finishing aerated concrete:

• resistance to precipitation and ultraviolet radiation, to rapid and frequent changes in outdoor temperature;
• sufficient density;
• possessing high adhesion;
• presence of vapor permeability;
• compressive strength;
• good thermal insulation;
• decorative appearance.

Good plaster meets all of the above requirements. It is easy to apply, looks great and lasts a long time on the walls.

If the facade is not treated, the aerated concrete will first darken, then begin to deform, and its outer part will begin to peel off.

Plasters for external use differ from those used for interior finishing of aerated concrete blocks. The first ones are more expensive, the second ones are cheaper. The main difference is the ability of the hardened mixture to resist moisture. If this indicator is significant for external walls, 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:

• acrylic;
• silicone;
• silicate;
• lime-cement.

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-layered, but very durable. The layer retains its impeccable structure for a long time.

It is advisable to use acrylic plaster when applying good insulation to internal walls.

The basis of silicate plaster intended for aerated concrete is liquid potassium glass. The vapor-permeable coating is resistant to moisture and perfectly resists abrasion and contamination. Durability is a quarter of a century. Disadvantages include the limited color range.

Silicone mixtures include organosilicon polymers and resins. The coating is very durable. Unlike other types, silicone plaster retains its elasticity after curing. No cracks appear on the finishing layer even after the blocks shrink. Fillers give plaster different 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 by experimenting with fillers, you can get different colors.

Ready-made mixtures are supplied with everything necessary - they can be used without preliminary preparation and introduction of improving components.

For interior work, completely different compositions are used. Plaster used for processing aerated concrete indoors contains gypsum..

Before starting work, the blocks should be primed.

The plaster is applied to a leveled surface, free of build-up, dirt and dust.

The work is carried out in several stages:

• padding;
• applying the first layer of plaster;
• installation of reinforcing mesh;
• applying a second layer of plaster.

Wallpaper can be glued to the treated wall after the material has completely dried.. Decorative finishing can be done if desired. The decor appears when entering gypsum mixture fillers in the form of marble chips or perlite. A wall covered with gypsum mortar can be painted.

Preparation

It is very important that 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 used under different conditions, there are general requirements according to their pre-processing:

• both inside and outside the walls must be smooth;
• for both sides, the plaster should be selected with maximum adhesion ability;
• applying the solution to the mesh is desirable on both sides;
• The craftsman will need a container for the solution, a trowel, a plaster ladle, and a grater.

In order for the plaster to adhere well to 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, you will have to pick up a trowel and use a solution to remove the flaws. Cement mortar will become 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 carry out the main work.

First, finishing is done inside the premises and only then outside - otherwise excessive moisture will form inside the house.

Application technology

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 external surfaces of aerated concrete walls.

First you need to inspect the blocks: eliminate all irregularities, clean the cracks, widen them and fill them with regular mortar.

The same is done when identifying chips and potholes in each gas block. Listed preparatory work You can do it yourself - it's not difficult at all.

Those who dare to carry out basic work with their own hands without the appropriate skills need:

• acquire tools;
• follow the technology for performing plastering work;
• do not be afraid of heights (part of the time will have to be spent on scaffolding at a decent height);
• have free time;
• have physical strength.

In order for the plaster to adhere well and not lag behind, the 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 treat the walls on the side where there is no direct sunlight.

The next stage - tensioning the mesh - begins after the primer has completely absorbed.

A mesh made of alkali-resistant material is suitable for aerated blocks.. 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 secured 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 materials 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.

The processing doesn't end there. A water repellent is applied to the plaster. Once it's absorbed, it's time to perform. final finishing. You can choose from decorative plaster or paint. In both cases, the compositions are distinguished by their “breathing” abilities, guaranteeing the unhindered passage of vapors from inside the room to the outside.

The treatment 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 deficiencies are canceled. Before puttingtying the surfaces, the leveled wall is primed.

Interior finishing is done with special plaster, which contains gypsum and perlite sand.

After the work is completed, the walls become uniform, smooth, without the slightest visible defects. The consumption of plaster is small, because the layer is applied very thin. This eliminates the need for lengthy leveling, which is also important.

Painting interior walls should be done with paints specially designed for aerated concrete. They can be applied to both regular plaster and decorative plaster. Painted surfaces look great - decorative finishing retains its original appearance for a long time.