Proper plastering of aerated concrete walls. Plaster for aerated concrete: internal and external features. Internal work on plastering walls made of cellular concrete

Aerated concrete is a cellular type of concrete and has a porous structure. Therefore, buildings made of aerated concrete blocks easily absorb moisture. Accordingly, for greater resistance to bad weather, the material requires protection. Among the most common methods is the use of plaster. Let's take a closer look at the features of plastering aerated blocks, where to start, what tools are needed, what finishing technologies exist using this method.

Aerated concrete absorbs moisture very well, so it needs to be protected

When to start finishing aerated concrete walls

The main distinguishing feature of aerated concrete is its increased hygroscopicity. Moreover, when the building gets wet, when the temperature is above zero, negative consequences you can avoid it - it will simply dry out, everything will be fine, but if water gets into the pores of the stone in winter, it freezes, accordingly, it expands, and cracks may appear.

Considering this, it would seem that the sooner the walls are plastered, the better. But this approach is wrong. It is ideal to carry out these activities for the next season, when the surfaces are completely dry after laying. Drying time depends on what mortar was used for laying. For example, a seam made with a concrete-sand mixture will take longer to dry than where the adhesive mixture was used, since it is much thicker.

Plastering is recommended for the next season

Another condition for finishing walls made of aerated concrete, which is recommended to be observed in order to achieve a high-quality result, is the need to do everything in warm weather. Optimal time Experts call March-October when the air temperature is above zero. If this is not possible, you must at least coat the stone with a primer, cover plastic film, thanks to which it will stand without losing its properties until it is completely finished. The primer will most effectively reduce water absorption deep penetration.

But sometimes there is no opportunity to postpone finishing work - it is necessary to carry it out immediately after the completion of the construction of the walls of the building. Here experts recommend paying especially close attention to the composition of the solution. It must have good plasticity and vapor permeability, then moisture can escape freely.

If plastering needs to be done immediately, then you need to carefully select the material

Which side to start finishing a gas block building from?

There are three options for where to start covering aerated concrete block walls. Each has its own characteristics, and only one is considered correct. In particular, you can start:

1. outside;
2. from the inside;
3. simultaneously from both sides.

Start plastering outside experienced builders recommended only when the home is located near bodies of water. The primary task here is to protect aerated concrete from water and wind. Under other circumstances, the method of processing from the outside is not suitable - if you plaster the stone from the outside, all the moisture will go inside the house, which can cause cracks to appear, and the drying process of the joints at the end of the masonry will be significantly delayed. In addition, the stone itself may begin to deteriorate. Plastering aerated concrete walls indoors will help avoid the above problems - this method is considered the most preferable due to its effectiveness. The third method is considered the most unpopular method of finishing aerated concrete walls - despite good properties vapor permeability, having “blocked” moisture on both sides, it will have nowhere to go, which sooner or later will lead to peeling finishing mixture from the block itself, and subsequently even to the destruction of the latter.

Plastering only needs to be done on one side

Sequence of work

Plastering aerated concrete blocks contains three stages. Before plastering aerated concrete, it is necessary to apply a special primer with a brush or roller, intended for building materials that absorb moisture well. The greatest effectiveness is achieved by applying the solution evenly, that is, there should be no dry spots. After graduation this stage The primer must be absorbed and dry.

At the second stage, a special reinforced mesh, resistant to alkaline components. The mesh is fixed at a certain distance from the stone - there should be free space between them.

The final, third stage is the actual plastering of aerated concrete walls. Here it is important to choose materials whose vapor permeability properties are higher than those of aerated concrete itself. You can increase the service life of the surface while maintaining its attractive appearance after a year by covering it with a water repellent.

The material for plaster should be selected with greater vapor permeability than aerated concrete.

How to plaster - requirements, nuances

Plaster on aerated concrete will be of the highest quality; it will not have to be short term carry out a new one if the composition of the mixture meets certain requirements and the packaging contains special markings. Among other things, it should be characterized by:

1. resistance to cracking, drying out, and fading;
2. increased ductility without sacrificing strength;
3. good adhesion to porous types of concrete;
4. water-repellent properties;
5. high level of vapor permeability.

Compliance with such criteria is especially important when used outside the building.

Even considering a large number of various types Only a few modern plaster mortars have these characteristics, so the following are most often used when working on aerated concrete.

Silicone plaster is perfect for finishing aerated concrete outside.

Silicone plaster for aerated concrete has the most advantages. Resistant to adverse weather conditions, has good vapor permeability, water repellency, and is easy to apply. This type has no disadvantages in operation, except for its high cost, which is nevertheless compensated by the long service life of the coating.

The second place belongs to silicate plaster for aerated concrete, characterized by a suitable level of vapor permeability and low water absorption. Main disadvantages: small color palette plus loss of original attractiveness appearance silicate when exposed to dust.

In third place is cement-based plaster with lime. She also has necessary qualities for covering this type of building.

Plastering aerated concrete can be done with a cement-based mixture

Often in such houses a gypsum mixture is also used. Its advantages: it dries quickly, subsidence is excluded, there is no need to apply a finishing layer of plaster, in addition, you can make the surface as smooth as possible. However, the solution has its drawbacks. These include average vapor permeability characteristics, susceptibility to rapid getting wet from precipitation, and, in addition, stains may appear during its operation.

In addition, acrylic solutions are used for processing. Their quite significant advantage is strength, but we must also remember the disadvantages - low fire resistance, which is why they are used only in certain rooms, and a relatively low level of vapor permeability. To prevent condensation from accumulating in the pores of aerated concrete, experts recommend using additional ventilation or internal waterproofing.

Having studied the characteristics of all the materials presented, everyone can independently choose how to plaster aerated concrete.

Aerated concrete finishing scheme

Tools used

Plastering walls made of aerated concrete is carried out using tools used when processing other surfaces. Knocking off protruding parts of the walls, making them more smooth, and installing notches where they are needed is done with a plaster hammer or hatchet. The deep penetration primer is applied with a special brush (mack brush). You will also need a plumb line (it helps to install beacons to cover the desired surface with the solution), building level, square, metal scissors, hammer drill, hacksaw, others standard tools. Regarding beacons, there are several options. The first is to purchase specialized metal beacons at a hardware store; fortunately, the choice of them is now quite wide.

Before you start work, you should prepare everything necessary tools

The second, “old-fashioned” method is to use available means: even blocks of wood, pipe scraps, and other suitable “parts”. Thanks to the beacons, the plane is perfectly flat and the angles are correct. The listed tools will be useful if plastering aerated concrete walls is done manually.

Faster uniform application can provide special equipment. The method is more financially expensive, but this is fully compensated by the quality of the final result: thanks to plastering under pressure, the bonding of the mortar to the surface of aerated concrete is quite strong.

Machine plastering is a little more expensive

Coating technology

The technology for finishing walls with plaster for aerated concrete is quite simple - it is performed in four steps:

1. preparatory stage, where, before plastering the aerated concrete, it is leveled, thus reducing the consumption of the solution;
2. padding;
3. covering aerated concrete walls with a thin layer of plaster, which will then serve as a base when securing the reinforced mesh;
4. mesh reinforcement (prevents cracks).

For reinforcement, metal or fiberglass mesh is used. Moreover, when installing it, special attention must be paid to windows and doors - places where the load is most significant.

Having secured the mesh, the surface is covered with a finishing layer of plaster, and when the coating dries, the so-called grouting is performed, that is, the surface is eliminated from unevenness, roughness, etc. minor defects.

Before plastering aerated concrete, the wall should be leveled

Features of finishing aerated concrete

Starting to cover aerated concrete plaster mortar, the features should be taken into account of this material. First of all, experts recommend avoiding the traditional combination of cement and sand. The corresponding coating can crack and fall off over time, and it also contains a lot of water, which has a destructive effect on the walls themselves.

When plastering aerated blocks, a prerequisite is that all products are intended specifically for the cellular material.

Experts recommend not to use cement mixtures for finishing aerated concrete

It is important to begin work on the external cladding of the facade when all “wet” internal work has already been completed, then the formation of condensation inside the walls can be avoided. Moreover, the thickness of the plaster layer inside the building should be twice as large as the outside one, otherwise water vapor will remain inside the blocks and they will become damp. This is the only difference between carrying out this work inside and outside - the technology itself remains unchanged.

If you take into account the recommendations of experts, aerated concrete will last you a long time

Thus, we see: with all its advantages, the building material is still quite finicky, it requires special treatment. And so that he preserves his beneficial features, a number of measures need to be taken. But by following the above recommendations, he will prove to be very reliable material, will last a long time, and the home will be cozy and comfortable.

Video: Plastering aerated concrete, preparing the base

Video: Putty and plaster of aerated concrete

Plastering walls made of aerated concrete requires special materials And correct process application. If you use unsuitable materials or do not follow the process of applying the plaster, it will not last long and will quickly begin to deteriorate and peel off.

Briefly about aerated concrete

Aerated concrete is building material, which is used to construct the walls of a building. Preferably produced in blocks measuring 400x200x600 mm (dimensions may vary depending on the manufacturer).

Aerated concrete is produced from such components as:

• Cement.
• Quartz sand.
• Lime.
• Water.

By mixing the above components with aluminum powder, hydrogen is released, which increases the crude solution several times. When concrete hardens, a large number of hydrogen bubbles create its porous structure.

Advantages and disadvantages of aerated concrete

Advantages:

• Good thermal and sound insulation.
• The blocks have light weight and is easy to process.
• Environmental friendliness of the material.
• High fire resistance.

Flaws:

• Exterior finishing is required.
• Fragility of the material.
• High price.

The use of aerated concrete in construction can significantly reduce time and financial costs, since its laying does not require special skills, and thermal insulation properties allow you to save on insulation.

Preparing the walls

Since walls made of aerated concrete have smooth surface, the plaster does not stick well to them. Regardless of whether external or internal plastering of aerated concrete walls requires preparation before finishing. It is also worth knowing that aerated concrete has a high vapor permeability; this fact must be taken into account when plastering walls made of this material.

Preparing aerated concrete walls for plastering is carried out as follows:

After the walls are prepared and reinforced, you can begin plastering work. It is worth considering that after reinforcing the walls with glue, you must wait several days, since the glue has poor water absorption when drying and the plaster may sag.

Technology

The technology for plastering walls made of aerated concrete consists of the following stages:

1. Preparing the walls.
2. Priming the walls. It is recommended to use a primer based on acrylate siloxane.
3. Wall reinforcement. To reinforce the walls I use fiberglass mesh that is resistant to stretching and has high tensile strength.
4. Installation of beacons. Beacons are installed at a distance of no more than 120 cm from each other. The use of beacons allows you to plaster the walls perfectly evenly. If the walls are smooth, beacons can not be used.
5. Applying the first layer of plaster. The first layer of plaster is applied using a methodical ladle or trowel, after which it is leveled with a wide spatula or wooden slats at least 1 meter.
6. Applying a second layer of plaster. For the second layer you need to use finishing plaster it has fine sand, which allows you to hide the flaws of the first layer. The second layer is applied in the same way as the first, only leveled more thoroughly.
7. Grouting joints. A few days after applying the plaster you can grouting. The joints are grouted with a wooden float, after lightly moistening the wall with water. Grind the seams, lightly pressing the grater against the wall in a circular motion.

After grouting the joints, the walls are ready and you can apply decorative plaster or wallpaper. Finishing work on plastered walls should be done only after they have completely dried.

Selection of cladding for aerated concrete

Plaster mixtures for aerated concrete walls must have the following properties:

• Good strength.
• Weather resistance.
• Good waterproofing properties.
• High vapor permeability.
• Elasticity.
• Good adhesion to walls.

These are some of the main criteria for plastering aerated concrete walls for interior and exterior finishing.

Wall cladding made of aerated concrete can be made with the following materials:

It is important to use plaster designed for aerated concrete walls. Using other types of plasters in the future may lead to their peeling.

Conditions for working with facing material

For high-quality and durable plastering of walls, it is necessary to adhere to the following conditions:

1. Maintaining consistency plastering first external then internal.
2. Plaster walls can be carried out after all wet screeding, puttying, etc. work has been completed. The walls must be thoroughly dry after previous work.
3. Plastering walls can be produced at a temperature of +5 +30 degrees. Under no circumstances should work be carried out sub-zero temperature, as the plaster will fall off.

You should also know that for buildings made of foam concrete, polystyrene foam cannot be used for exterior finishing, since it does not have vapor permeability properties, and accumulated moisture between the wall and the insulation will contribute to its delamination.

Interior and exterior decoration

The process of plastering external and internal walls consists of the following stages.

Interior plaster:

• Initially, the walls of the building must be carefully prepared. Clean them from any remaining solution, paint, bitumen stains, dust and dirt. If necessary, the walls can be washed with water and soapy water. It is also necessary to seal all seams and joints of the blocks with special putty.
• After the putty has dried, you can prime the walls. The primer must be compatible with the plaster used. The primer is applied evenly with a roller or brush, in two layers, without missing a single section of the wall. After approximately three hours, the primer will dry and the process of plastering the walls can begin.
• Initially, it is necessary to apply a starting layer of solution, made according to the manufacturer's instructions, which are indicated on the packaging. The solution is evenly applied to the wall surface with a metal float or spatula.
• After the first layer dries You can apply the finish in the same way. After a day, the dried plaster is rubbed with a wooden float, after wetting the wall with water.
• At the final stage a plastered wall can be painted with emulsion paint with vapor-permeable properties.

External plaster:

• Exterior wall finishing must be made strictly with materials that have vapor permeability properties. Just like for interior plaster, you need to clean the walls and remove all cracks, chips, etc. This can be done using tile adhesive. Temperature environment at the time of plastering work it should be from +10 to +25 degrees.
• After preparing the walls, it is necessary to strengthen the fiberglass reinforcing mesh. You can strengthen the mesh with glue or wood screws. The mesh prevents the solution from draining and holds it well on the wall, and also helps avoid cracks due to shrinkage of the plaster.
• The next step is applying plaster. Plaster is applied in the same way as for interior decoration. You should know that it is necessary for the vapor permeability of plaster to be higher than that of aerated concrete. If necessary, you can install beacons to align the walls.

  You should also know that the thickness of the outer layer of plaster should be half that of the inner one.

  Leveling the plaster is done with a wooden lath.

• When the plaster has dried, it is necessary to grout the seams and defects. After 48 hours, the plaster will dry and the final stage can be performed. finishing works.

Therefore, we can summarize that finishing a building from aerated concrete is not a cheap pleasure, but saving on materials will lead to much detrimental consequences and large financial costs.

Plastering aerated concrete walls with cement-sand mortar

To save money, aerated concrete walls can be plastered with cement-sand mortar, this is done as follows:

• First you need to prepare the walls: To do this, you need to remove dust, dirt and glue residues from them, and then prime them.
• The next step will be to reinforce the walls using fiberglass mesh and the cheapest common tile adhesive. Using a spatula or metal float, glue is applied to the primed surface of the wall, after which the mesh is applied. After that, the attached mesh must be smoothed horizontally with a notched trowel. When the glue dries, the resulting surface will have grooves that will promote good adhesion. cement-sand plaster.

  Thus, in addition to reinforcing the wall, the seams of the blocks are smoothed out and small irregularities in the wall are removed, and the glue grooves will prevent the plaster from slipping when it is applied. A fiberglass mesh will prevent cracks from appearing when the plaster shrinks.

• After the glue has completely dried, you can begin to plaster the wall. To do this, you need to mix the cement-sand mortar in a ratio of 1:3 and throw it onto the wall with a ladle. After that, use a long lath to distribute the mortar evenly over the wall using light movements from left to right; this procedure must be repeated until the wall becomes level.
• When the walls are completely plastered and dry, you can begin grouting the joints, after which the walls will be ready for further finishing, wallpapering or applying decorative plaster.

Plastering bare walls made of aerated concrete with cement-sand mortar is unacceptable, since it does not have enough good adhesion and will slip, and cracks will appear when it dries.

Plastering aerated concrete surfaces- a measure necessary due to the fact that the porous structure of the material allows moisture to pass through well, and this is unacceptable for the durability of any residential building. Aerated concrete bricks have high hygroscopicity. Therefore, facade plaster for aerated concrete must be applied, preferably in two layers, and with preliminary protection of the walls with a primer and antiseptics.

Any precipitation is a risk of dampening the walls made of aerated blocks, which, after drying, can begin to collapse, becoming covered with microcracks inside and outside the house. And this risk increases markedly in winter time, because water in aerated concrete, when frozen, will expand and expand the building material, breaking its monolithic structure.

Before plastering the facade and side walls of the house, especially in winter, the outer surface must be protected from moisture with a polyethylene film. After mandatory plastering, any decorative material can be attached to the surface finished with mortar. external cladding facade.

Purpose of exterior finishing:

1. Increasing the heat and noise insulation of buildings and premises;
2. Minimizing the likelihood of walls being wetted by precipitation;
3. Protection of external surfaces from contrasting street temperatures;
4. Decorative function.

Applying plaster is the most common method of finishing facades and walls made of aerated concrete due to its relative cheapness and ease of execution. But even such a simple process requires study, so a short review of the characteristics of plaster compositions used in construction for exterior work and methods for plastering aerated concrete surfaces will be useful.

Three types of practical and cheap building materials for wall finishing are common, therefore, how to plaster aerated concrete should be decided after studying all the options:

Cement-sand mortar

1. This is the most common internal plaster mixture among builders, but it is not recommended to use it for plastering aerated bricks on the outside, since aerated bricks do not hold cement well. And, if on the walls inside the house you can use a primer or fiberglass mesh to hold the plaster cement-sand mortar, then these methods are not suitable for working outside due to the constant exposure to temperatures and precipitation. It is not advisable to protect aerated blocks with a cement-sand mortar, since aerated blocks immediately absorb moisture from the mixture. The reasons for the ban are as follows:
   1. The cement-sand mixture has a lower vapor permeability coefficient than aerated concrete. And the most important rule for a plasterer is to use a material whose vapor permeability coefficient is the same as this indicator or greater than that of aerated concrete;
   2. It is not recommended to insulate a house with expanded polystyrene or foam for the same reason.
2. Cement plaster applied over aerated concrete contains a lot of water, since it is mixed with it. Aerated concrete is initially produced with a high coefficient of moisture absorption, so moisture from the solution will quickly get inside the wall, leveling the adhesion, layer quality and strength of aerated concrete blocks, because the main condition for the strength of concrete is slow setting and hardening;
3. Cement-sand mortar has low adhesion, that is, adhesion. Therefore, to plaster internal walls, lime can be added to the solution in proportions of 1:10 (lime - cement);
4. The cement mortar must be covered with a finishing layer of plaster, since the starting layer will be rough.

Construction adhesive mixture

1. Construction adhesive is a very expensive solution, and applying it in a large layer instead of plaster is impractical and uneconomical;
2. When plastering aerated concrete blocks with construction adhesive solution The vapor permeability of aerated concrete will decrease, since the glue does not allow air to pass through well. As a result of clogging of the pores in the blocks, the material may begin to crack, mold may appear in poorly dried areas, and local peeling of the adhesive plaster is possible.

Gypsum for aerated concrete

Positive aspects of plastering with gypsum mortar:

1. The gypsum plaster mixture quickly sets and dries;
2. Gypsum mortar does not shrink;
3. Even a thin plaster surface will be smooth;
4. This type of plaster does not require a finishing decorative layer.

Flaws:

1. The vapor permeability coefficient leaves much to be desired;
2. High water consumption;
3. Any precipitation moistens the gypsum plaster to the entire depth of the layer;
4. Due to too good adhesion, colored spots may appear on the surface from the penetration of mineral dyes in the composition of aerated concrete into the gypsum layer.

Gypsum or alabaster is considered the most effective composition for plastering aerated concrete surfaces outside and inside the house. This mixture is for finishing facade works has a vapor permeability coefficient identical to that of aerated concrete, excellent adhesion, and attractive appearance.

What plaster is best for plastering aerated concrete walls?

There are special mixtures for working on aerated concrete. It is preferable to use mixtures with the following properties:

1. High or medium vapor permeability;
2. No more than 200 ml of water per 1 kg of mixture for mixing;
3. Minimum and maximum thickness layer of plaster (the greater the difference, the better);
4. Adhesion index to the main surface – ≥ 0.5 MPa;
5. Low temperature resistance;
6. Resistance to cracking;
7. Long lifetime of the working solution.

Conditions for plastering aerated concrete surfaces

Carrying out plastering work in the warm season presupposes the rainy season, but getting wet aerated concrete blocks is not as critical as freezing the moisture inside them. Therefore, it is better to protect a home made of aerated concrete with moisture-proof films at any time of the year, since the walls may simply not have time to dry in the fall before frosts.

The newly erected walls of the house must dry before they are plastered, therefore both construction and plastering of aerated concrete should be carried out in the summer. Due to the fact that the first row of gas bricks is usually laid on a cement-sand mortar, the drying time of the walls increases, and this circumstance must be taken into account when calculating technological processes.

Applying two or three layers of primer to aerated concrete will significantly reduce its water absorption. The practice of constructing private housing has shown that best time for the construction aerated concrete walls buildings – the season when the temperature at night does not fall below 0 °C.

There are three options for finishing aerated concrete surfaces, taking into account the order of finishing work:

1. The exterior finishing is carried out first. Private developers mistakenly think that first of all it is necessary to protect the outside of the house so that the walls do not get wet from rain and snow. But even when wet in the fall, but primed, aerated concrete will dry quickly in the spring at positive temperatures. If the walls are covered with plaster, moisture in winter will evaporate only inside the home, which will not only extend the drying time of the walls, but will also affect the occurrence of cracks on the walls. interior walls Houses;
2. The first is the interior finishing. With this organization of the process, the moisture accumulated in aerated concrete has an outlet only to the outside, and the possibility of cracks appearing will be minimal. Therefore, this finishing option is considered the most correct;
3. External and internal finishing is carried out simultaneously. This option is the worst of all three. Moisture in gas blocks becomes clogged, and its slow evaporation will lead to the appearance of cracks, mold, and peeling of the plaster layer.

Internal plastering technology

Before plastering the walls, they must be leveled with a special plane, grinder or aerated concrete float. Leveling will help save on the thickness of the plaster layer - if you apply too thick a layer, the plaster may begin to crack or even peel off.

Sanded walls should be primed, but it is not recommended to dilute the primer with water. Then metal beacons are attached to the walls - 2-3 meter perforated ribbed corners, which determine the thickness of the plaster layer. The corners are attached to plaster or alabaster, the distance between them is determined by the width of the rule or the widest spatula. The verticality of the fastening is checked by level.

On walls for aerated concrete, plaster is applied from bottom to top and leveled according to the rule. Voids and irregularities are filled with mortar using a smaller spatula. After an hour and a half, when the first layer of the solution has set a little, it is moistened with a spray bottle and leveled with a wide spatula (rubbed). It is advisable to remove the beacons before this operation, since they can serve as a point of occurrence of “cold bridges”. Internal corners are leveled and reinforced by the same beacons, external corners are reinforced with metal perforated corner without fins, and fiberglass mesh. After completely dry The last layer of the wall needs to be rubbed down.

If indoor walls are to be painted, it is recommended to use paint with good vapor permeability, for example, acrylic, water-based or PVA-based paints, as well as those based on organic solvents.

How to plaster aerated concrete inside a house updated: January 23, 2017 by: Artyom

What kind of plaster for aerated concrete fits better everything, and how to apply it correctly - these are questions that owners of buildings made of aerated concrete blocks often face. In order to efficiently plaster walls, you need to understand all the nuances of not only building mixtures, but also the material itself.

Aerated concrete - what is it and what is it used for?

Blocks are made from cement, lime, water, quartz sand and aluminum powder. All components are mixed and entered into the autoclave under pressure. There, foaming of the mixture occurs due to the reaction of alkali with aluminum, and a porous material is formed, which is becoming more and more popular every year in low-rise construction. The material is light, but at the same time quite durable. It is easy to use because a regular saw is used to cut it.

Besides, aerated concrete blocks are not susceptible to the growth of mold and mildew, being environmentally friendly pure material. Aerated concrete has poor thermal conductivity, so a building built using this technology will always be cool in summer and warm in winter. Although aerated concrete blocks are a popular material in construction, they are still a little capricious. The fact is that they quickly absorb moisture, which must be taken into account when carrying out finishing work. Plastering aerated concrete always starts from the inside of the building. This is due to the fact that the moisture contained in construction mixture, must have time to evaporate before the exterior finishing of the building is completed.

Lime, acrylic or silicate – what to choose

The main advantage of aerated concrete blocks is their ability to “breathe”. For this reason, plaster for aerated concrete should not clog the pores of the material. In addition, as already noted, the material strongly absorbs moisture, which can lead to cracking. Consequently, it is prohibited to use in the process, which in most cases are used for rough finishing work.

Choose mixtures that can preserve the microclimate of the room; pay attention to compositions specifically designed for cellular concrete. Some experts suggest using mixtures that create a vapor barrier when finishing aerated concrete. In this case, the service life of the building increases due to the fact that the blocks are saturated with moisture as much as possible.

IN modern practice use the following types materials:

• Lime (cement-lime) compositions. The most popular mixtures offered on the market. They have not only excellent vapor permeability, but also good adhesion and are resistant to impact low temperatures. The most popular manufacturers are Knauf, Prospectors, Founder And Volma.
• Acrylic plasters. An expensive type of finishing, which necessarily requires good waterproofing before application. Judging by the reviews and recommendations of experts, preference should be given to brands such as Ceresit, Baumit, Bolix.
• Silicone mixtures. Perhaps the ideal material for finishing interior spaces. They are crack-resistant, but quite expensive. Prominent representatives – Ceresit And Baumit.
• Silicate plasters. As a rule, they are used more for exterior decoration. Produced on the basis of potassium liquid glass, and the most famous brands are such as Caparol, Baumit, Ceresit.
• Gypsum mixtures. With their help it is easy to create a perfectly flat surface, but their only drawback is that they do not tolerate high humidity, therefore, they are categorically not suitable for bathrooms and require mandatory. Good mixtures offer campaigns such as Knauf, Velvet, Bonolit.

Surface preparation is the key to a quality finish

Plastering walls made of gas silicate blocks must be carried out in compliance with the technology, otherwise in the future you may get a surprise - cracking of the plastered surface. At the very beginning, inspect the surface for large chips and residues of the glue used for laying. A planer is suitable for you, which will comb out all these sagging. After cleaning the surface, treat it with a primer. To save money, we do not recommend diluting the prepared solution with water; it is better to wet the wall with a wet roller, then treat the surface with a primer. In dry rooms a simple primer is used, but in wet rooms it is replaced with a deep penetration compound.

To create a reliable and durable surface, internal plastering of aerated concrete blocks should be done on a reinforcing mesh. For these purposes, you can use a galvanized or fiberglass version. Attach it to the surface using nails or dowels. We install beacons on top of the grid, which will be used to carry out plastering work. Beacons are installed strictly according to level at a distance of 130-160 cm from each other. This length is considered optimal for work, but some craftsmen may choose it depending on personal preferences and experience. Ready options You can find beacons made of galvanized steel in the store, or you can make them yourself from a plaster mixture.

When choosing a reinforcing mesh, you should give preference to a material with small cells.

Applying the solution to the wall - how to accurately follow the technology

After completing all preparatory work start lining the gas silicate. The first step is spraying - this is a method of applying a rough layer of plaster. A small amount of the mixture is poured onto the surface in a layer of no more than three millimeters. Next, we stop work until the solution sets. At the next stage, apply the base layer. This process is called primer and consists of applying a plaster mixture to the surface using a spatula or other tool. This fills all the space between the beacons. After that, make a rule. It is applied strictly horizontally to the beacons at the very bottom, and then gradually, making zigzag movements, you need to lift it up.

During leveling, mortar will remain on the tool, which must be removed and thrown onto the wall over the main mass or in those places where depressions have formed. The alignment process is repeated until the rule is clean. After the solution has set, you need to remove the beacons from it (if they were not made of plaster). The cavities remaining after this are covered with plaster mortar flush with the entire surface. The surface is then given time to dry before applying the final layer, called a topcoat. Its essence is to create the most even surface possible, so its thickness does not exceed 1-3 mm.

After all these steps, smooth the surface with a grater. Having previously moistened the wall with water, leave it until completely dry, after which you can begin. Special attention When plastering on aerated concrete, you need to pay attention to forming the corners. To do this, use metal or, which are attached to the surface and then plastered. If it is not possible to purchase them, then take a small spatula and apply the solution to the surface on one side. After the mixture has hardened, remove the excess with a knife and carry out the same procedure on the other side of the corner. If necessary, clean the surface.

As you can see, the interior is made of aerated concrete - not such a big deal. All that remains is to decide how to plaster the aerated concrete inside the house. Usage quality materials This will allow you not to worry about the reliability of the finish; only from time to time you will need cosmetic repairs.

Aerated concrete is one of the most common materials in the construction of houses. It is durable and has many other advantages. One of the few drawbacks in it is its low resistance to moisture. And if it doesn't happen in the warm season big problem, then in winter the moisture that gets inside such a wall after freezing and thawing will begin to gradually destroy the wall. Small cracks will be obvious at first, which will then lead to the problem getting worse.

Why else do you need plaster finishing?

Plastering aerated concrete is a mandatory task when building a house from this material. In this case, it is worth considering the common compositions applicable for this work, possible algorithm and a common method of finishing a wall with plaster. In addition to moisture protection, outer layer for an aerated concrete wall it is also required for other reasons:

• plaster allows you to retain heat inside the house;
• it has good sound insulation;
• This excellent protection housing from temperature changes;
• a layer of decorative plaster will become good decoration facade.

In order for the material to perform its functions fully, it must be properly prepared and applied. Moreover, not only an experienced craftsman, but also a beginner can do this work with his own hands.

General requirements for choosing a composition for plastering walls

When choosing the type of plaster for a house made of aerated concrete, you should pay attention to the features offered in construction stores compositions. The method of preparation, use and quality of coating will depend on the selected material. Regardless of whether aerated concrete wall plaster is used indoors or for external finishing, there are a number of general requirements for the mortar used:

• vapor permeability must be higher than that of aerated concrete so that the wall can breathe;
• minimum amount of water required for cooking;
• It is important to pay attention to the minimum and maximum possible thickness applying a layer;
• the adhesion index should not be lower than 0.5 MPa;
• resistance to cold and sudden temperature changes;
• it is important that the solidified solution does not crack under unfavorable conditions;
• for a novice master, it will be more convenient to use a solution that can be used for a long time without fear that it will quickly harden.

Choosing internal or external plaster for aerated concrete, it is important to pay attention to these parameters. Don't risk quality for the sake of favorable price, since the cheapest plaster can reduce all the effort expended to zero.

Cement plaster for aerated concrete

Common plaster mixtures are divided into 3 main types: cement-sand, gypsum and facade. The question is whether it is possible to plaster aerated concrete with any of these solutions.

According to experienced craftsmen, plastering aerated concrete with cement mortar is highly undesirable, although it is a very common material. There are a number of reasons for this. Firstly, the vapor permeability of such a coating will be lower than that of the wall, so the applied layer of plaster on the gas block will not provide sufficient thermal insulation inside the room.

Secondly, aerated block walls are smooth, so the adhesion of the cement-sand mortar will be weak. Even if you add glue to the mixture before starting work, this will have little effect on the result.

Thirdly, plastering of walls made of aerated concrete blocks is carried out to protect against moisture penetration, but for mixing cement composition you need a lot of water. And even a layer of primer will not protect the solution from loss of liquid during contact with the wall, and improperly dried plaster begins to fall off the wall due to its own weight and the presence of large fillers in the composition.

Some craftsmen use the following method to solve the problem: they mix dry ingredients with water in a 1:1 ratio to reduce the percentage of liquid in the solution.

This option is not very convenient, because it is necessary to plaster the walls quickly with the composition diluted in this way, before the hardening process begins, and this is not possible for everyone who carries out repairs with their own hands.

Features of gypsum and facade plaster

When plastering aerated concrete walls, the use of gypsum compounds is considered acceptable for several reasons. This solution dries faster than a mixture of cement and sand. It does not shrink. Since the base layer already makes it possible to obtain flat surface, gypsum plaster does not require finishing coat.

The disadvantages of this composition include the large amount of water required for preparation (up to 15 liters per bag). The vapor permeability of the coating is better than cement plaster, but this indicator cannot be called ideal. If you use the composition for exterior use, it may become wet during rain or snow, and during the drying process there is a risk of stains appearing on the surface, which will have to be corrected to maintain a decent appearance of the house.

According to the observation of specialists, facade plaster for aerated concrete this is the most the best choice for the master. High rates of vapor permeability and adhesion, combined with pleasant external parameters, give this material an advantage over other solutions.

How to choose the right time to start work

Before plastering aerated concrete, the wall must dry thoroughly. If during the process of laying blocks you used cement mortar, the waiting time will be longer than with an adhesive bonding element.

It is worth remembering that such wall material absorbs water, so it external finishing will not be effective during the rainy season. But it will be especially dangerous for walls, cold water turning into ice. When melting this hard material begins to expand, destroying the structure of aerated concrete.

Therefore, construction must be planned in such a way that it is possible to plaster the aerated block walls between the end of March and September. The main criterion will be the air temperature, which should not be below 0 0 at night.

Algorithm options

Having decided on the best time to plaster the walls, it is important to choose the best sequence of work. It is well known that plastering aerated concrete walls outside is no less important than inside. Therefore, the master has 3 options:

1. If the weather outside is expected to be wet for a long time, or the house is located near a lake or river, it makes sense to plaster the outside of the wall first. So, the structure will be protected from moisture from the outside. But, since with one-sided finishing, vapors from the walls go inside the premises, threatening to spoil the repair and destroy the structure, you should not hesitate with the interior finishing.
2. Most often, craftsmen begin finishing the walls indoors, since in this case air vapor will not penetrate into the building, and after complete hardening interior decoration You can start working on the outside of the house.
3. Finishing both sides at the same time is the worst option for plastering walls. Since the composition absorbs water from the solution, the wall will still be wet. Only if the moisture does not find a way out, it begins to destroy the wall from the inside.

Although the technology for plastering aerated concrete walls can be chosen at the discretion of the master and depending on the situation, best result will be when using the second option.

Internal plaster of aerated concrete walls

Before plastering aerated concrete inside the house, it is necessary to rough the wall. It is necessary to remove all existing irregularities, since the thickness of the applied layer depends on this.

Before applying the primer, it is important to wipe the wall from dust with a roller dipped in water. This simple process will prevent an increase in the amount of water when diluting the mortar for interior work, while a properly prepared mortar will ensure good adhesion to the wall.

The choice of primer depends on the purpose and degree of humidity of the room. So, for bathrooms and kitchens it is better to take a deep penetration composition, while for a corridor or toilet you can get by with a cheap primer.

To ensure that the plaster for facade or selected type of aerated concrete lies in an even layer, beacons are installed. Their vertical evenness is checked using a level, and the installation frequency is determined by a rule.

Since it is necessary to plaster walls made of aerated concrete in several layers, you need to be especially careful with the initial one. It is important that the solution does not deform and does not move away from the wall. If this happens, you need to remove the mixture from the wall and re-prime it.

The first layer of plaster is done by throwing or spraying. The work is carried out from the bottom up. This way the composition is attached to the wall without deforming under its own weight. Additional material is placed in all places where voids have formed.

After the plaster has dried, the layer needs to be slightly moistened. At this stage, you need to remove the beacons, as they will good guides cold into the house. Finally it is used finishing in the form of leveling and painting walls. This step is optional. If you plan to use wallpaper, finishing is not required.

Features of plaster for exterior finishing

In general, the method of exterior finishing is similar to working inside, but there are some differences in this activity. So, the answer to the question whether a mesh is needed when plastering aerated concrete will be positive. Reinforcement requires material with small cells and a wire diameter of 0.1 mm.

Reinforcement prevents the destruction of the plaster layer during the shrinkage of the building when installed on outside Houses. And it is especially necessary in the area of ​​windows and doors, where such damage is more often observed.

But how to plaster an external wall correctly? After completing the surface leveling and primer, it is necessary to apply the first thin layer solution into which the prepared mesh should be immersed. This design will be of higher quality than mounting on a dry wall, because it will ensure the greatest fusion of the reinforcement with the mortar. And over the mesh it is necessary to apply the first layer of plaster.

To proceed to the next stage, you must wait until the first layer has completely dried. The time period can be 3-4 days or more depending on the thickness of the layer. To protect from rain, you can cover the walls with polyethylene or other waterproof material. The degree of readiness is checked using water: the dried wall will absorb the liquid.

When applying the second layer, the main emphasis should be on leveling the surface. The third layer is already the finishing layer, followed by grouting or painting the house itself, if necessary.

You can clearly see the process by watching the following video:

The question: is it necessary to plaster aerated concrete blocks becomes resolved for those who know the features and weak sides this material. It's about about the low resistance of such walls to moisture, which is the main reason for the use of protective equipment.

When deciding how to plaster aerated concrete outside and inside, it is worth considering a number of factors: vapor permeability, amount of liquid in the composition and resistance to negative impacts. An important factor is which side you need to start finishing the house from.

A common method allows you to do the work yourself. Knowing correct sequence, you can perform work on any surface, whether internal or outer wall. The main thing is to observe the proportions when preparing the solution, give each layer enough time to dry and not continue working if the composition begins to move away from the wall. By following the recommendations of experienced professionals, you can be sure that everything will work out.