Plaster of gas silicate blocks. The technology of plastering walls from gas silicate blocks How to plaster blocks from the outside

Aerated concrete blocks are incredibly in demand today - and not only in private construction, but also in the construction of frame-block multi-storey buildings. The products are compact, lightweight, easy to install, which allows a person to build a warm and inexpensive home with their own hands.

However, raising the walls and bringing them under the roof is not all. You need to know exactly how to plaster aerated concrete inside the house, and understand by what principle interior plaster is selected in general. These questions are the subject of this article.

Both aerated concrete and gas silicate concrete belong to the category of cellular concrete. There is an opinion that this is the same thing, but there is still some difference between them.

In both materials, there is a combination of two cement-lime binders. However, their percentage is different, resulting in a material with completely different strength characteristics.

Leveling coatings for aerated concrete

Up to 60% of cement is present in aerated concrete, and the rest is lime and sand. In gas silicate products, cement is only 14%, almost twice as much lime, and many times more sand. It is clear that if there is so little cement, then the strength of the products is no longer the same. In general, gas silicate concrete is no longer a structural material, but a heat-insulating one.

• Perhaps now you have a question: “What does the plaster of the walls have to do with it?”. And despite the fact that it is selected depending on the type of base, and in order not to have problems with the coating later, you need to know exactly what and with what can be combined. The characteristics of the binder are decisive here.

Note! Cement, or rather products and solutions based on it, always has greater strength than lime and gypsum. When creating multi-layer screeds, the following principle must be observed: the base must always be stronger than the coating - otherwise, its delamination will inevitably occur.

• From the foregoing, it is not difficult to conclude: if there is no or almost no cement in the blocks, then the internal plaster of the walls, and even more so the external one, cannot be done, for example, with a cement-sand mortar (see Optimal ratio of cement and sand for plaster ). Applicable to gas blocks, it can be used, since they have a high percentage of cement, and the wall surface has sufficient strength.

• You can even use not special purchased mixtures, one of which we see in the photo, but knead the solution yourself. Just keep in mind that the plaster should not be done as for heavy concrete or clay bricks - in proportions of 1: 3, when a solution of the M150 brand is obtained.

Plastering of internal walls made of aerated concrete is carried out with a solution of half the strength: M75. For its manufacture, cement M400 is taken, and mixed with sand 1: 5.

With an increase in the brand of cement, its amount in the solution should decrease to 1:6, or even to 1:6.7 - this is the arithmetic. Everything is done quite simply, and the lower price of self-mixing plaster will significantly save on finishing work.

How to plaster gas silicate

Now, as for the gas silicate wall, in which there is very little cement. Accordingly, such plaster, as for aerated concrete, is not suitable for it. However, it is impossible to infinitely reduce the amount of a binder in a solution - only part of it can be replaced by another binder that is less weak in strength.

• There is a large percentage of lime in gas silicate blocks, and it is most logical if it is also present in the plaster. That is, the most ideal option for plastering such walls would be lime-cement plaster. It is more difficult to make it yourself, since lime dough must be present in the solution.

• It is much easier if the plaster inside the house is made with a purchased mixture. And by the way, if it is suitable for gas silicate, then it is also suitable for aerated concrete (and not vice versa). Manufacturers often orient plaster mixtures to both materials, which means that, in addition to cement, lime is also present in them.
• Sometimes the instructions on the packaging say that the mixture can be used for all cellular concretes. This means that they can also be applied to foam concrete walls, which contain only cement from binders. Just keep in mind that there are also cementless varieties of foam blocks made on the basis of lime.
• Like gas silicate, this material is also more of a heater than a structural material. Foam blocks, in which there is no cement at all, are used for the construction of interior partitions. They can also be plastered, but only there should be no cement in the solution.

It should be noted that the best option for leveling walls made of gas and gas silicate blocks, lime foam blocks, as well as silicate bricks are silicate plasters. But since they contain liquid glass, and they are very caustic, they are not used for residential premises - only in production workshops and on the facades of buildings.

The feasibility of using gypsum mixtures

The plaster inside the house, which has lime surfaces, can be made with a gypsum or lime-gypsum mixture. In principle, they are suitable for all types of foundations, but there is one thing, and it concerns walls built from cellular concrete.

Given their high vapor permeability, and the similar property of gypsum, it is not always advisable to use plaster based on it indoors:

• Here it is already necessary to consider the structure of the wall decoration as a whole, and oddly enough, you need to focus on the option of exterior decoration. For example, outside the cellular concrete walls will be monolithically lined with bricks, clinker tiles, or stone, or plastered over polystyrene foam.
• Due to their poor vapor permeability, these materials will lock moisture into the thickness of the walls, preventing it from escaping. In this case, only cement plaster should be used inside, or a decorative coating should be provided that will become a barrier to steam.
• For example: if it is paint, then alkyd; if wallpaper, then vinyl or cork. Yes, the same tile or stone, any sheathing with insulation - all this will not allow porous walls to be saturated with moisture.
• In what case can the internal plastering of walls made of aerated concrete, or other cellular material, be done with a gypsum mixture? There are only two options here. The first is when the outer walls are leveled on the underlying base with plasters with a high degree of vapor permeability: silicate, silicone, special for cellular concrete.
• The second option is a ventilated facade. When there is an unobstructed outlet for steam and condensate on the outside of the wall, the internal plastering of the walls, as well as their finishing, can be done in any way. But note that if the facade is insulated, then the heat-insulating boards should be loose: soft mineral wool or the cheapest loose foam.

• Let's clarify this situation. Decorative plaster for interior decoration, most often made on the basis of gypsum. How to properly prepare a porous base in the case when the use of gypsum mixtures is undesirable. With cement-based blocks, there are no problems.

In any case, the base before decorative plastering should be leveled as for wallpapering. Therefore, the walls should first be leveled with a cement composition, and when it dries, decorative gypsum plaster can also be applied for interior decoration. You will learn more about this in the next chapter.

Internal plastering of aerated concrete

So, in our story, we came directly to the performance of internal plastering work on aerated concrete walls. We will try to highlight the most important nuances of this process, and for clarity, we offer you to watch the video in this article.

Nuances of preparation

Porous surfaces are characterized by the strongest moisture absorption, which must be reduced by priming. On aerated concrete walls, it is produced more abundantly than, for example, on brickwork. To do this, you need to take not just an adhesive primer, but a deep penetration composition.

Important! Primers are ready-made, and they are concentrated - that is, they are diluted with water in a proportion determined by the manufacturer, which must be observed. You should not think that if you apply undiluted primer, it will be possible, for example, to reduce the number of passes. The composition must have a normal concentration.

The first layer is applied liberally, preferably with a spray gun. You can also take an ordinary garden sprayer for this purpose, with which trees are sprayed. After the aerated concrete wall dries slightly after processing, another layer is applied, after which the surface should already dry completely.

Double impregnation significantly reduces the absorbency of the wall, but does not eliminate it completely. Yes, this is not necessary - otherwise how will the solution stick to the surface? The surface of the gas blocks is very smooth, and for plaster it is necessary to ensure good adhesion. It is impossible to make notches, as on heavy concrete. How to get out of the situation?

How to make the plaster coating as durable as possible

After priming, task number two is the reinforcement of surfaces. This is necessary not only for the best adhesion of the layers, but also to prevent the appearance of cracks.

This is especially important when the walls are built from gas silicate, which contains five times less cement than in gas blocks. The strength of such a base is rather weak, and plaster, even gypsum, will be more durable and will work to tear off.

• Your task is to make a strong layer between the base and the plaster, which will provide them with the best adhesion. Therefore, no matter what type of plaster you use, the starting layer must be made with an adhesive mixture, which is intended for the installation of cellular blocks.

• To create a reinforcing layer, ordinary tile adhesive is also suitable. Many craftsmen, due to the lower cost than that of the masonry mixture, prefer to use it. Why do I need an adhesive composition, and not just plaster?

Note! The fact is that the adhesive compositions are always modified with polymeric additives, which not only adhere, but tightly glue the surfaces. The layer of glue is thin and durable, fiberglass mesh is still embedded in it. It is not only an excellent base for plaster, but also securely fixes the blocks, preventing microcracks from appearing and expanding.

• This approach to preparatory work is especially important when home-made solutions are used for plastering. In them, unlike the factory ones, specially designed for gas blocks, there are no improving modifying additives, as well as fibers that reinforce the plaster in bulk.

• There are no words, factory mixtures solve all problems, but due to the high cost, they are more often used for facades. On internal plaster, which is not exposed to such influences as on the street, you can save money - you just need to do it wisely. If you do not want to have problems in the near future, the adhesive layer must be done anyway.
• Installation of the grid, in principle, is not necessary, and is carried out by craftsmen at the request of the owner of the house. But the customer must know that the creation of a reinforcing layer only improves the quality: both of the plaster and the base - after all, no one knows what shrinkage processes will occur in the soil.
• It’s better to be safe and spend a little on the grid than to incur the cost of a complete repair in the future. We especially advise you not to neglect the mesh when the walls are being prepared for painting - after all, any crack on them will be immediately visible. Under thick wallpaper, or tiled lining, cracks are invisible, but the task is not to hide them, but to prevent them from appearing.

• There is nothing complicated in mounting the grid, and you will see this in the video presented in our article. The canvases are overlapped on the freshly applied adhesive solution, and then pressed in, combing with a notched trowel. The use of such a tool is very important, because thanks to it, scallops from the extruded solution remain on the surface of the grid.
• When they dry, you get a beautiful relief surface on which you can apply any plaster. First, the mesh is pressed into the adhesive layer with chaotic movements, trying to press it as tightly as possible to the base. If the usual leveling plastering will be performed on the walls, in the end, you need to make a horizontal comb.
• This is necessary only so that the plaster, which at the next stage will be applied to this surface, does not slip off the wall. Well, under decorative plaster - if it is it that will be used for interior wall decoration, the base must be smooth. In this case, the relief is not left, and the solution on the grid, squeezed out with a notched trowel, is smoothed out.

When can I start plastering directly? Let's just say that doing it right the next day is undesirable.

Even if the surface seems dry, the cement adhesive layer has not yet gained sufficient strength. It is not scary if gypsum plaster is applied to it. If it is a cement mortar, then the adhesive layer must be given at least five days - and preferably a week, for strength gain.

The plastering process is the most common outdoor finishing option. With the help of it, the walls of the interior are aligned. However, how different is the material application technology if it is necessary to plaster aerated concrete or brick walls? Or maybe you are a happy owner of a frame house or a structure made of foam blocks. Today I will talk about the basic principles of applying plaster on the walls with my own hands, and we will also look at how the foundation of the house is plastered.

The need for plaster for a brick house

It doesn’t matter if an old brick building is being renovated or the walls of a new building are being designed, plaster is a necessary element for high-quality work. Using modern plaster, you can carry out high-quality protection of walls from negative atmospheric influences.

Important! Using a traditional do-it-yourself mixture, it is better to process fairly large surfaces. Modern materials contain components that increase the useful properties of plaster.

The material to be used for exterior surfaces must meet important requirements:

• The material must be moisture resistant and vapor permeable. If the plaster does not remove the accumulated condensate, the walls will begin to collapse very quickly and the house itself will not stand idle for a long time.
• Must be weather resistant - that is, if an outdoor mixture is used, it must withstand sudden changes in temperature and frost
• Mechanical resistance is an important criterion, as the surface of the walls is often exposed to unintentional impacts and weather disasters.

Brick walls are plastered during reconstruction work, as cracks, chips appear on the walls of the house over time, or simply because of uneven masonry during the construction of the house. You can plaster a brick house with your own hands and for this it is enough to adhere to the following sequence:

1. Before starting the workflow, the surface should be cleaned of dirt and dust. Then spray it with a solution of cement and lime. In some cases, only a cement mixture can be used
2. On the next this primer is carried out
3. Applying a cover layer
4. For high-quality work, do-it-yourself beacons are installed, a plaster solution is applied between them Try to apply the material as evenly as possible
5. Using a trowel, the surface is leveled and checked by level
6. Beacons are dismantled, and the remaining voids are sealed with mortar
7. Before completion, the surface of the walls is sprayed. The resulting finish is sprayed with water for three days. If possible, the base is hidden from direct sunlight, which can speed up the setting process and thereby reduce the performance of the material.

A brick house often requires additional thermal insulation, which can occur with the help of well-known foam. In this case, subsequent plastering is a necessary measure.

Foundation protection

The foundation of the house is the most important place of the entire structure, which is most exposed to negative impacts. Protection of the foundation with plaster should be carried out at the highest level and most often you should contact specialists for this. But if you want to plaster the foundation with your own hands, then follow this plan:

1. All contaminants must be removed and notched. It is performed for a foundation that has stood uncoated for more than a year.
2. Elimination of defects - all weak points are beaten off to the state of a solid foundation
3. A layer of primer is applied to the surface of the foundation
4. Defects and potholes, together with the seams, are filled with cement mortar
5. Mount the chain-link mesh with dowels
6. Install beacons
7. Plastering is done in 2 layers - the first is the primer, and the second is the finish
8. The first layer should dry well, only after that the second one is applied - usually the drying time reaches 5-7 days. At the same time, the surface is periodically sprayed with water.
9. The decorative layer is applied on a damp foundation with a thickness of about 5 mm. It is important that this time the mixture be thicker and more plastic.

As a finishing layer for the foundation, you can use various types of decorative plaster. For the foundation, a mortar with a “travertine” texture, terrazite plaster and a fur coat is suitable. It is important that the finish of the foundation coincides with the overall design of the facade.

Plastering foam concrete

Being a fairly light and durable material, foam concrete is in great demand for building a house. The advantages of the foam block have long been justified; for a long service life, the surface of the foam blocks must be plastered both outside the house and inside.

The technology of plastering walls from foam blocks is different from the processes for other types of surfaces. However, to achieve maximum effect, you should use some tips:

• Like any base, the surface of the foam block must be primed. To do this, it is best to choose a deep penetration primer and apply it in two layers. Thus, the adhesion of the foam block and plaster will be maximum
• Before plastering the walls of the house from the foam block, a reinforcing mesh should be installed. Watch her condition - there should be no gaps
• When choosing foam blocks in a hardware store, you should pay attention to the color of the material. Foam block products should be gray, the advantage of yellow will indicate a large amount of sand. Because of this, the material will be very fragile.
• If the base of the walls is made of cast foam block, then use not a construction mesh, but fiberglass

Doing the work with your own hands, you should give preference only to high-quality materials that will allow you to complete the finishing process as quickly, efficiently and for a long time as possible.

Facing a frame house

For a frame house, plaster is used as often as panel siding. Before performing work outside the house, you should choose a plastering method:

1. With cement particle boards
2. With the help of multi-layer reinforced plaster using a metal mesh

If the finishing of the frame house will be carried out every 5-7 years, then you may well choose the first option. It is easier to do it yourself. However, having spent more time and effort on the second method, you will get a facade of a frame structure that will last at least 13-15 years.

If the use of decorative plaster is also planned for a frame house, then one layer of the mixture can be applied along the building mesh. In the case of a single-layer application, clinker, as well as ceramic tiles or stone, can be used for the frame structure.

Important! A water repellent is used for plasters as an enhancement of the water-repellent properties of a frame house. With their help, the gas permeability remains the same, but the absorption of moisture is significantly reduced.

For a frame house and covering it with plaster, all bases must be processed. However, in some cases it is allowed to cover only those surfaces that are most affected by moisture.

Self-facing aerated concrete

Finishing aerated concrete with plaster

Aerated concrete is a popular building material that is used in low-rise construction. This material gained popularity due to its light weight and the speed of building houses with it. However, with such positive qualities, aerated concrete has a low coefficient of thermal conductivity and therefore requires high-quality finishing.

Important! The microclimate created inside a house made of aerated concrete is comparable to the microclimate of wooden buildings. Therefore, the plastering of aerated concrete walls is necessary in the same way as the plastering of a wooden house outside.

Aerated concrete inside the house must be plastered using certain solutions. The use of a cement-sand mixture is unacceptable, since the material has the property of absorbing moisture. Aerated concrete is best finished with gypsum putty or gypsum-based solutions. Inside the house, you can apply solutions with fillers such as chalk, marble or dolomite.

Important! On the modern construction market, there is a special plaster with which cellular material can be finished without deteriorating the vapor barrier properties.

To maintain a vapor barrier, aerated concrete can be finished with plastic wrap. However, if all work is carried out with errors, then condensation may appear on the surface of the walls, and the plaster will swell over time. That is why many people decide to plaster aerated concrete with a sand-cement mortar, but even in this case, the coating will definitely begin to peel off. Before you start finishing aerated concrete, you should study in detail all the pros and cons of these methods and only after that carry out the design of the walls inside and outside the house. Aerated concrete has different grades of density and it must be remembered that the plaster is selected based on these data. External plastering of the house can be done independently, all processes must take place in the warm and dry season.

Stucco color

Plastering aerated concrete walls inside the house

The use of decorative plaster is in demand due to the possibility of choosing the desired color of the material. Due to the fact that there are a huge number of plasters that have color, creating a specific design and its shades becomes a fairly simple action. In addition to using ready-made mixtures, you can add pigment when making the solution yourself. However, by giving a certain color in one batch, there is no guarantee that the color of subsequent batches will completely match. Even when using the same proportions, there may be a slight change in color that will be noticeable on the walls inside or outside the house.

In specialized stores, you can choose the color of plaster you need thanks to the palettes of certain manufacturers, as well as determine the shade along with catalogs of already finished houses using these materials. Remember, the richer the tone of the plaster, the longer the color will last. At the same time, a rich dark color can very quickly lose its appearance.

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:

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 plaster for aerated concrete is used, which passes water vapor well, does not get wet, with good adhesion to the surface of the blocks and high frost resistance.

Lime-cement plaster

All the necessary properties are inherent in light thin-layer plasters, specially created for finishing aerated concrete surfaces. 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:

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.

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 grid.

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.

The article popularly talks about widely used building materials, lightweight concrete, the main characteristics and methods of finishing using traditional technologies, plastering house elements.

Aerated concrete wall plastering

Plastering of internal and external structures made of lightweight concrete is the most widely used method of protection from the effects of external climatic conditions and giving the house an original respectable appearance, as well as internal comfort.

The prevalence of technology is due to the ability to inexpensively and on their own to carry out a set of works on the preparation and finishing of structures and achieve the desired results.

Special characteristics of aerated concrete blocks

Aerated concrete refers to cellular concrete, consists of quicklime, cement, sand and aluminum powder that forms gas. When mixing components and water, a reaction occurs with the release of gas, forming voids, the number of which determines the weight, density, thermal conductivity of concrete and areas of use:

• Concrete with a density of 300-400 (kg/m3) is used for thermal insulation.
• Density 500-900 (kg / m3) allows you to use for the construction of partitions and walls.
• With a density of 1000-1200 kg / m3, concrete is used to make load-bearing walls.

Concrete has gained popularity in housing construction due to its properties:

1. Low thermal conductivity allows it to be used as a heat-insulating substance.
2. Frost resistance can reach 150 cycles, among lightweight concretes only expanded clay concrete has greater durability.
3. High fire resistance.

Of the negative qualities for construction, hygroscopicity can be noted, which means that aerated concrete needs to be coated.

The hygroscopicity of aerated concrete requires isolation from moisture.

Preparation of gas silicate blocks indoors for plastering

In aerated concrete, the amount of cement is up to 60 percent, in gas silicate no more than 14, lime is twice as much, the rest is sand. The percentage matters, because the more cement, the higher the strength, and the base must be stronger than the coating, otherwise it will peel off. That is, the decoration of the house must be done with a lime-cement composition.

When finishing, you need to remember that the base must be stronger than the coating.

The main function of plastering surfaces from gas silicate blocks is the formation of a vapor-tight barrier and limiting the absorption of moisture. To improve the adhesion of the coating to the base, the structural elements are coated with a deep penetration primer, the first layer is applied generously, preferably with an airbrush, after drying it is necessary to paint over again.

After priming, given that the gas silicate composition of the base is weak, it is necessary to carry out reinforcement to prevent the appearance of cracks.

The rough reinforcement layer is made from the glue on which the blocks were laid; experienced craftsmen use tile glue for this, as a cheaper composition.

The use of glue instead of a conventional solution is associated with polymer additives in the composition, which provide strong bonding with a thin layer of the mixture.

After applying a thin layer of glue, 2-7 millimeters thick, a fiberglass mesh is embedded in it, which fixes the blocks and serves as a reliable base for the coating. The grid is superimposed on the applied glue with an overlap and is pressed with a spatula with teeth.

It is desirable to start applying the solution after 5-7 days, when the reinforced layer gains strength.

Plastering of gas silicate blocks inside the building: technologies used

Protection of gas silicate structures occurs in three stages:

1. Plastering with lime-cement mortar.

2. Priming.

3. Putty.

A lime-cement or lime-gypsum mortar with a thickness of not more than one centimeter is applied to the reinforced surface.

The technology of manual plastering is common, if the wall is large and uneven, beacons are installed and the applied layer is equalized with a wide rule.

The solution is kneaded in a bucket, small tank or trough, water is poured into the poured mixture and stirred to the required consistency, you need to cook a little, gypsum sets in 20 minutes, cement needs a little more time, so the amount should be sufficient to produce during this time. You can level immediately after throwing, the last step is grouting.

After finishing with a long rail, the evenness of the surface is checked, irregularities within 5-7 millimeters will be invisible.

Is it necessary to plaster the gas block from the outside

The need to protect the facade of aerated concrete is due to its properties:

1. Hygroscopicity will lead to the saturation of gas blocks with water, which in case of frost will cause the destruction of the structure.
2. Mechanical impact will cause chips, dents, cracks.
3. The material has a porous structure with open pores through which the circulating air carries away heat.
4. An unfinished aerated concrete house looks unpresentable.

For aerated concrete structures, the danger is the accumulation of moisture inside the blocks, which freezes during temperature changes and destroys the block from the inside. Therefore, the protection of external surfaces is mandatory, the method of protection by plastering is widely used for various reasons, one of which is the low cost of this technology.

Applicable materials for outdoor work

For the application of protective equipment from the outside, substances are required that have the following qualities:

• permeable to water vapor;
• not wet;
• with good grip;
• frost resistant.

The main types of mixtures for finishing aerated concrete outside:

• Acrylic for aerated concrete, strengthen loaded structures, plinth.
• Silicate, include liquid glass;
• Silicone, based on silicon-organic polymers, well suited for facades, but high price;
• Gypsum mixture;
• Lime-cement composition.

Do-it-yourself internal plastering of a gas block: a feature of the work

Due to the high hygroscopicity of the material, plastering inside the house has its own characteristics.

Plastering of surfaces must necessarily include the process of reinforcement. It is recommended to use a fiberglass mesh that does not collapse in an alkaline environment.

The surface should be painted over with a deep penetration primer twice.

Apply a thin layer of plaster with a thickness of about 5 millimeters and drown the mesh in it. After drying, apply the main layer using beacons.

What is the best plaster

If vapor permeability is required for kitchen, bathroom or sauna rooms, mixtures of gypsum with perlite sand are used. Silicate is also suitable, however, it should be noted that such mixtures are incompatible with acrylic, silicone, latex materials.

For use on aerated concrete, cement-lime mixtures can be used, which do not require a primer on the walls.

Set of tools

Finishing aerated concrete surfaces requires the following tools:

1. Spatulas.
2. Scraper to remove dirt and debris.
3. Metal brushes.
4. Hammer, for knocking down irregularities, protruding mortar.
5. Sandpaper.
6. Brushes, rollers for priming.
7. Master OK.
8. Tank for mixing solution.
9. Mixer for preparing the solution.
10. Falcon, a shield where the mixture is applied.
11. Grater for grouting.
12. Poluterok.
13. The rule is to align the corners.

How to plaster: work progress

Ready-made mixtures are great for finishing, but have a high cost, therefore, for do-it-yourself work, a wall preparation technology is offered, after which you can safely use any composition.

For preparation, you will need tile adhesive, fiberglass mesh, deep penetration primer. It is necessary to level all the chips and cracks with a composition for laying aerated concrete blocks, then remove dust and debris from the wall with a cheek and paint over with a deep penetration primer twice.

The tile adhesive is diluted and applied to the surface with a thickness of 5 millimeters, the mesh is pressed on top with a notched trowel. When the layer is completely dry, plaster is applied in the usual way, any solution can be used.

The cost of this technology will be less by an order of magnitude than when using ready-made plasters.

How long can you move on to the next stages of wall decoration

After the end, the beacons are removed, the resulting dents are subsequently sealed with putty.

To move on to the following types of finishes, you must wait for the walls to dry completely at a constant temperature. Drying will take about a month in the warm season so that temperature changes do not lead to cracking or peeling. It is undesirable to speed up the process; if necessary, a heater is used.

The interior and exterior decoration of the house is an important stage of construction work, the quality of which depends on the durability, comfort of living and the aesthetic appearance of the house. There are many modern materials and technologies for finishing work, but traditional methods do not lose popularity and are still relevant today. These methods allow you to achieve the desired results at low cost and labor intensity.

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