How to plaster aerated concrete inside a house. How and how to plaster aerated concrete inside a house: we are considering plastering options for various surfaces Plastering on aerated concrete blocks technology
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In Russia it is becoming increasingly popular suburban construction. For this, blocks made of aerated concrete are used. Many Russians are attracted by their low price and good construction characteristics. Externally, aerated concrete blocks resemble porous rock, but have clear shapes with a smooth surface.
They are characterized by poor moisture resistance. To get rid of this serious drawback, aerated concrete walls are covered with a layer of plaster.
Those who have decided to buy a house from this material should know that in order to create a normal microclimate, you need to correctly select the components of the plaster and the thickness of its layer applied to the walls.
Aerated concrete blocks
Such blocks are most suitable for low-rise construction. Walls built from them have a number of significant advantages, for example, small specific gravity which provides more high speed construction and reduces the labor intensity of work.
Thanks to the porous structure of aerated concrete blocks, the microclimate in the building can be compared to the atmosphere wooden house. This is another property that makes aerated concrete popular. The material has excellent sound insulation.
It is believed that aerated concrete walls breathe. They allow oxygen into the house, releasing water vapor and gases formed by natural processes of human activity.
Like any other material, aerated concrete blocks have some disadvantages. The main one is the low bending strength of the material, so when building a house you need to take these features into account. The foundation of the house must be monolithic, so the masonry must be reinforced with reinforcement through an equal number of rows. These works make it stronger and more reliable.
Sequence of finishing work
It should be noted that they have very high vapor permeability. This is how they differ markedly from brick and foam concrete. Plastering walls made of aerated concrete should be carried out taking into account individual characteristics material.
Aerated concrete was initially used as insulation, and only after some time they began to build outbuildings and residential buildings from it. If there are enough blocks, then additional insulation no need. As for finishing, the internal walls of the house are finished first, and then the facade.
Many developers do the opposite. Taking advantage of the good weather, they work on the facade of the house, and then begin to decorate its interior. Plastering walls made of aerated concrete, carried out in this order, is the most common and rather serious mistake, which can lead to peeling of the finish from the aerated concrete and the formation of numerous cracks.
Interior finishing work
Moisture is the enemy of any structure. Aerated concrete walls are no exception. Water falling on them penetrates the porous structure of aerated concrete. It does not get inside the building through the walls and cannot damage the interior decoration, but it reduces the protective characteristics of the house. Water evaporates from the pores of the material very slowly, and if the weather is rainy, then this process simply stops. Moisture accumulated inside aerated concrete walls significantly limits its natural ventilation and thermal insulation parameters. Plastering aerated concrete walls on both sides will help avoid inconvenience. Except protective function, it will also perform decorative work.
There are several methods for finishing aerated concrete walls. The most common and accessible is plastering, which belongs to the technology of finishing vapor-proof materials.
Plastering internal walls is not much different from ordinary ones finishing works. Before they begin, the wall must be well prepared. It is cleaned, leveled, and then a layer of primer is applied, which must dry completely. Only after this can you begin finishing work.
There is also mechanized plastering of walls. When finishing using this method, the mixture lays down in a dense and uniform layer, but it is quite expensive and many Russians cannot afford it.
Mixtures for finishing works
Manufacturers produce a variety of them. Their choice depends on the purpose of the room. To decorate a small living room, use a standard mixture. Walls in rooms with large percentage moisture after finishing work is coated with a special primer that perfectly resists the influence of water.
Beginning home craftsmen need to know that plaster applied to an aerated concrete surface must meet certain requirements. The finishing of aerated concrete walls is influenced by some features of the material itself. The blocks are strong, smooth and fit perfectly together at the joints, which makes it difficult to fix the mortar on the wall surface.
One of the main ones is vapor permeability. Simply put, the material must absorb and release excess or missing moisture.
If the mixture is incorrectly selected, the following defects may occur:
- The appearance of cracks on the internal and outer surface building.
- When the surface of the wall gets wet, a silhouette of the masonry may appear on it, which will disappear after drying.
- Increased humidity in the rooms of the house, the appearance of an unpleasant odor.
The most popular plaster is gypsum based. It is easily diluted and after application and drying forms an even matte surface. The disadvantages include poor vapor permeability. Because of this, when precipitation occurs, the surface of the walls quickly gets wet, which takes a long time to dry. Sometimes they may appear yellow spots, traces of which can only be painted over.
The most expensive and most effective is acrylic facade plaster. It is used only in conjunction with fiberglass mesh. It has good adhesion, vapor permeability and excellent appearance. The disadvantages include the fact that only an experienced craftsman can work with this mixture. Only he can create a perfectly smooth building facade.
How much does it cost to plaster walls? The price depends on the cost of the mixtures and ranges from 236 to 550 rubles per 1 m². The manufacturer and container volume play an important role.
The plaster must first be applied to the wall and only after an hour must the leveling begin. Next, the mixture should dry for 24 hours. The second layer, which makes the wall perfectly flat, is applied to the already dry surface slightly moistened with water. After completely dry the wall can be painted with special paint for aerated concrete blocks. Remember that plastering interior walls is responsible work, requiring complete concentration and patience. Only then will you get the expected final result.
Developers need to remember that they should not skimp on construction and finishing materials. Cheap aerated concrete blocks made in a makeshift way, won’t even save much high quality plaster- she simply will not be able to gain a foothold on them.
Facade finishing
The surface must be plastered immediately after the construction of aerated concrete walls in order to protect the walls from all external factors. Otherwise, cracks will form under the influence of temperature changes and precipitation.
Cement plaster walls will not work in this case. Externally, aerated concrete walls are finished in the following sequence:
- The facade is cleaned of dirt and dust.
- A special primer for cellular concrete is applied.
- A reinforced mesh made of fiberglass is attached.
- Porous plaster is applied to the walls.
The reinforcing mesh is attached using self-tapping screws. When choosing it, you must remember that the mesh must be sufficiently resistant to alkaline environments. If this is not observed, then during finishing work the mesh may dissolve under the layer of plaster.
The mesh, made of galvanized steel, must be covered protective layer, because over time it collapses due to corrosion.
Plastering walls gypsum plaster the outside of the building must protect it from the harmful effects of moisture, so the mixture must have water-repellent properties.
The material used to construct the walls is gas permeable, so the plaster used must also comply with this parameter. And given the harsh climate in most regions of Russia, it must be frost-resistant and have good compressive strength. To do this, manufacturers add protective synthetic components to façade plaster, which looks like a dry mixture.
Preparatory work
Plastering walls with gypsum plaster is carried out after certain preparatory work:
- Before plastering, walls are cleaned of dirt and dust.
- Existing defects are filled with special glue.
- Installed plastic corners on corners and slopes.
- Beacons are installed to monitor the evenness of the wall finishing.
- The wall is wetted with water.
Facade and interior plastering of aerated concrete walls must be carried out at a temperature not lower than +10 °C.
Preparation of the solution
The plaster solution is quite simple to make. IN ready mixture a certain amount of water is added. For optimal consistency, you will need 0.2 liters of water per 1 kg of mixture.
The solution is thoroughly mixed. You can do this manually or use an electric drill with a special attachment. After 15 minutes, the prepared solution must be mixed again. If the consistency is not satisfactory, you can add more water or mixture. The prepared solution should be used within an hour, otherwise it will lose all its properties.
Finishing work
The mixture is applied to aerated concrete walls using a trowel or a straight thin board small size. Small areas walls can be leveled with a 30 cm steel trowel. High-quality, control leveling of the plaster is carried out using a ruler 80 cm long. Excess plaster removed from the wall surface can be reused.
If the expected layer of plaster exceeds 7 mm, then the work on finishing the wall is carried out in two stages.
According to this scenario, work is carried out to apply plaster to aerated concrete walls. The work should not pose unsolvable questions to the home craftsman. The most important thing is to take into account the recommendations experienced craftsmen and follow their instructions, then the developer will be able to protect his home from adverse consequences. Pay attention to the picture on the left - this is plaster walls. The photo shows one of the moments of the work.
Problems caused by improper finishing
If during the work the rules were violated or the mixture was incorrectly selected, after some time various defects will appear on the surface of the wall.
They may appear as small cracks on the finished surface or swelling. Vertical cracks may appear on the facade and peeling of the plaster may begin.
Defects must be corrected immediately. This will increase final cost plastering walls and will once again prove that using high-quality construction and finishing material needed initially.
Mechanical plastering of walls
Mechanized wall plastering is the process of making and applying a mixture using special equipment. These machines greatly simplify heavy physical work. With their advent, there was no longer a need to perform finishing work manually.
The machines not only made the work of plasterers easier, but also raised the new level quality of work performed. Even an experienced master cannot always prepare a solution of a mixture of uniform consistency and then distribute it over the entire surface. The work takes place in stages: the solution is mixed, placed on the wall, and leveled. As a result, part of the wall has already dried, another has begun to dry out, and the third is still being applied with plaster. This does not guarantee the end high quality finishing.
When mechanizing the work, the plaster is applied evenly and quickly. The time spent on work is noticeably reduced. The machine applies the prepared mixture faster, which allows you to use the rules bigger size. A wall made of aerated concrete is more even.
Mechanized plastering of walls allows you to reduce work time and save the amount of mixture.
The advantage of mechanized plastering of walls and facades:
- Reducing the time required for plastering work.
- Saving on material costs.
- Material loss is reduced by 5 times.
- High quality.
- The service life is increased.
Mechanical plastering of walls, the price of which depends on the volume of work, ranges from 300 to 580 rubles per 1 m². It guarantees a high quality finish. It all depends on the developer and his financial capabilities.
Bottom line
Aerated concrete Vacation home You can plaster it yourself. You should correctly use the advice of experienced craftsmen, choose the right mixture, perform all finishing work, adhering to the sequence described in this article. The end result will be a beautifully plastered house.
Aerated concrete is a popular building material used in house construction.
The blocks have enough big size, but light weight.
With their help you can short time build a comfortable and safe building.
Plastering walls made of aerated concrete indoors differs from finishing work on walls made of brick or concrete. And this process makes the work a little more complicated, so you need to approach it responsibly and carefully study all the nuances.
Features of aerated concrete and its advantages
Aerated concrete is made from cement mixture and aluminum powder, which foams concrete.
This technology involves the formation of open cells, which raise questions about finishing work. The cells increase the vapor permeability and water permeability of aerated concrete.
The construction of walls and finishing work is best done in the warm season. First of all, you need to plaster the inside of the house, and then move on to the facade, this way everything will be preserved positive sides this material.
If you don't follow this order, then it will gather in blocks excess moisture, which will lead to the formation of condensation on the internal walls of the house. Over time, mold, cracks, or peeling of the plaster layer may form on the walls.
The material is used for construction residential buildings, dachas, garages, bathhouses, cellars. Aerated concrete blocks have many advantages over other materials:
- Low cost (building a house will cost several times less than, for example, made of brick);
- Convenience, simplicity and reliability of installation;
- Good thermal insulation;
- Fire safety.
Selection of plaster for finishing work
For aerated concrete, using a mixture of cement and sand is not recommended.
The material quickly absorbs water, which is part of conventional mixtures. The moisture remains in the cells and after drying, small microcracks form on the plaster. Regular solution reduces the level of vapor permeability of aerated concrete.
For high-quality finishing interior spaces plaster with a high moisture resistance is used. The second layer of finishing material is used with the addition of slag or blast furnace sand. This composition increases the thermal insulation of the room.
For interior decoration premises, you can use a ready-made special mixture for aerated concrete blocks. This construction product is produced by domestic and foreign manufacturers.
You can use plaster that is designed specifically for foam blocks. The mixture is resistant to low temperatures, vapor tightness, impact resistance.
It is advisable to carry out finishing work at a temperature of at least +5 °C and at low humidity levels.
On every package construction mixture, the method of using the solution is indicated. It is important to read the instructions and pay attention to the expiration date.
When mixing the mixture, it is important to follow a certain sequence: immediately pour the dry mixture into the container, and then gradually add warm water.
As a rule, in dry plaster mixtures water is added in proportion - 200 ml per 1 kg of mixture warm water. Then mix everything thoroughly using a concrete mixer or construction mixer.
Necessary tools and work steps
To carry out the work, you will need a special container in which the solution will be mixed. This can be a bucket (plastic or iron) or a tank.
To effectively mix the solution, you will need a drill with a mixing attachment. It will not be possible to prepare a solution of the required consistency by hand; there will be clots or lumps in it.
Plaster is applied to the blocks using a plaster ladle or trowel.
Leveling is done using a spatula or a fork. It is advisable to purchase plaster beacons; with their help it will be easier to make the surface perfectly flat.
You can rub the surface with a plaster float or fine sandpaper. To simplify the application of plaster, it is recommended to use fiberglass mesh.
Plastering aerated concrete walls indoors is a labor-intensive and scrupulous task. Finishing work must be approached responsibly and the execution sequence must be strictly followed.
It is necessary to prepare the walls for applying the solution. Carefully remove dust, glue residues or any dirt from the surface. If there are oil stains, they must be removed with gasoline or alcohol.
If the stain cannot be cleaned, it must be hollowed out from the block. Then carefully cover the hole with the solution. You also need to sand all the seams and only then proceed to the next step.
Cover the walls generously with primer for aerated concrete walls. Such solutions are vapor-tight. The primer must be applied in several layers to dry walls. Each layer should be allowed to dry before applying the next.
The adhesion of plaster to aerated concrete is low, so you need to use reinforced mesh made from alkali-resistant fiber. This mesh is quite strong.
You need to attach the mesh to the walls using nails (12 cm) or dowels with a wide head. The mesh must be firmly secured so that it does not sag.
It is necessary to apply a rough coat. The mixture is thrown onto the surface using a trowel and then leveled with a rule.
Applying a primer to the rough layer of plaster. Slag sand must be added to the primer. The finishing layer of putty is applied using a trowel.
After drying, you need to rub down the walls. Give time for the walls to dry (2 days) and then you can start decorative design surfaces.
Master class on the process of processing aerated concrete surfaces:
Making aerated concrete blocks indoors is not an easy task, but right choice building materials and compliance with basic rules will give the desired result.
Construction of floors from aerated concrete material has a number of advantages. First of all, it is light weight and low thermal conductivity. In order to avoid destruction, a wall made of this material must be subjected to finishing. Due to its porous structure, plastering of aerated concrete walls indoors is carried out with nuances related to maintaining the microclimate inside the house. Therefore, not every finishing material can be used.
Material properties
Before you start choosing the composition of plaster for walls made of aerated blocks, it is advisable to understand what properties they have and why not every type of finishing material is suitable. Aerated concrete is an energy-efficient material for various types of construction. According to its parameters, it belongs to the group of cellular concrete, since most of its volume is made up of gas bubbles. The advantages of such building material are:
- thermal insulation properties;
- low specific gravity;
- good sound insulation;
- fire resistance of I and II degrees;
- ease of processing.
Working with aerated concrete is easy and quick. You can build a house from it yourself, without resorting to services construction organizations. In about a day a person can fit up to three cubic meters gas blocks. The material contains cement, lime, sand, aluminum paste and water. All substances are mixed in a given proportion, the value of which determines the strength of the resulting block. The reaction between aluminum paste and lime produces hydrogen. It contributes to the appearance of a huge number of pores, reaching maximum size equal to two millimeters.
The mixed mass with the ongoing reaction is sent into molds, where it hardens. Afterwards, the frozen form is cut into standard blocks and polished. Despite all their advantages, aerated concrete blocks are a hygroscopic material. This means that not every finishing mixture Suitable for plastering walls made of aerated blocks. Due to the highly porous structure, internal plaster of aerated concrete walls is simply necessary to protect it from moisture. environment. Moisture quickly penetrates into the thickness of unprotected gas blocks through the structure of air bubbles, causing their destruction.
Features of use
Construction technology using aerated concrete is not particularly different from the construction of walls from other types of block materials. The only difference is in the binder composition for the blocks. Connecting seams are made with minimal possible thickness to prevent the formation of cold bridges. Therefore, when building walls, glue is used, which allows you to make a seam with a thickness of no more than three millimeters. Thus, the features of using aerated concrete are as follows:
Solutions used for plastering internal and external surfaces differ in their characteristics due to different conditions environmental influences. For outdoor use, they must not only be resistant to moisture, but also not change their parameters with temperature fluctuations.
Requirements for the solution
Selecting plaster must be done with great responsibility. The final result will ultimately depend on this choice. When choosing what to plaster aerated concrete walls indoors, first of all, environmental conditions and the requirements for the resulting wall are taken into account. When choosing a building mixture for plastering, pay attention to the following parameters:
When choosing a mixture, you need to pay attention to its labeling. It should indicate the main characteristics and write the purpose - for cellular concrete. Usually the price of such plaster is slightly higher than that of ordinary mixtures.
Types of plaster mixtures
You can find products in specialized retail outlets various manufacturers. There are several commonly used types of plaster. Depending on the composition of the mixture, they are: lime-cement, gypsum, silicate and silicone.
Plasters based on cement-sand mortar, are considered not very suitable. Although of all other types they are the cheapest. This solution has a low coefficient of vapor permeability and quickly transfers its moisture to aerated concrete. Because of this, it is disrupted technological process solidification and adhesion of the solution. Therefore, this type of mixture as internal plaster is almost never used for aerated concrete.
In the case of plastering with just such a mixture, lime is added to increase vapor permeability, and after drying, a layer of gypsum is applied on top of the plaster. finishing putty. To improve adhesion, a primer is used, which provides increased adhesion of materials, which eliminates the difference in price compared to specialized mixtures. It should be taken into account that a decrease in vapor permeability leads to the formation of mold.
The use of glue used to adhere the blocks to each other is undesirable. The adhesive mixture is developed exclusively for application thin layer. It won't work smoothly. protective covering, and the cost of such material is quite high.
Gypsum plaster is considered the most popular for plastering gas silicate blocks. Its advantages include:
- optimal drying time;
- does not shrink;
- with sufficient skill, the applied layer forms a perfectly flat surface;
- The quality of the plaster allows you not to apply a finishing coat.
In addition, gypsum also has disadvantages: mediocre vapor permeability, the likelihood of various spots on the surface, the process of mixing the solution requires large quantity water.
To work with gas silicate blocks, it is recommended to use special facade plaster. It is she who provides required indicator vapor permeability and good adhesion with base. Low absorption coefficient eliminates the need for application additional layers plaster. This type of mixture quickly gains strength and usually already contains fibers for reinforcement. Significant disadvantage is the price.
When choosing the type of plaster, financial possibilities are also assessed. The cheapest way would be to use a lime-cement composition, but the quality of the finish will be the lowest. Silicate compositions are optimal in terms of price-quality ratio, but require additional putty. Mixtures based on silicone additives are ideally combined with the characteristics of aerated concrete blocks, but they are also the most expensive.
Finishing technology
Regardless of the mixture chosen, before you start plastering aerated concrete indoors, you will need to prepare both the tools and the surface. At the first stage, the surface of the ceiling is inspected for the presence of glue deposits and unevenness in the seams. Defects in the seams are sealed with putty, and sagging is cleaned off with a spatula, plane or grater.
The next step is to apply the primer. Before applying it, remove dust from the surface, for example, by wiping with a damp cloth. After drying, the primer is already applied. It is distributed evenly over the entire surface. The easiest way to do this is with a roller or wide brush. The choice of primer type depends on the type of room and the plaster mixture planned for use. So, for a gypsum mortar, a universal primer is suitable, and for a sand-cement mortar, a deep penetration primer is suitable.
In case of insufficient skill, as well as for the convenience of plastering, beacons are installed. Their height limits the thickness of the applied solution. They are located on the wall vertically to the floor. The distance between them is chosen to be three to four centimeters less than the length of the rule, and the evenness of the installation is determined using a level.
Application technique
As soon as preparatory stage will be completed, proceed to the direct application of a layer of plaster. To do this, using the instructions shown on the bag with the mixture, prepare a solution. The standard ratio is 1 kg of plaster per 0.5 liters of water. It should be noted that if there is too much water, the solution will spread, and if there is too little, it will crack.
After kneading until creamy, the solution is left for five minutes and mixed again. The mixture should be prepared in small portions, even if the surface requiring plastering is large. This is due to the “lifetime” of the material, which averages 40-50 minutes, after which its properties deteriorate.
A trowel or spatula is used to spread the solution. Throwing begins from the bottom up so that the layer of plaster covers the height of the beacons. Then along the lighthouses, making forward movements, carry out the rule as if on rails, removing excess.
As soon as all the work is completed and the plaster has hardened, the beacons are removed. The voids formed after their removal are filled with putty. The entire wall is inspected for defects and, if necessary, puttyed using a spatula.
On last stage finishing is being done. To do this, grouting and sanding are performed if necessary.
Required Tools
When carrying out plastering work without using special tools it will not be possible to achieve an acceptable quality of finish. To work you will need to use both manual and electric type tool. But at the same time there is minimum required, which you can’t do without. This includes:
- mixing container;
- putty knife;
- trowel;
- level.
Of course, even with high level mastery, it will be impossible to achieve evenness and smoothness of the surface without beacons. Except minimal tool, you will need to have a rule, a grater, a grater, an angle spatula, and a drill with a whisk for kneading.
Treating walls with plaster: advantages and disadvantages compared to other types of finishing work
Construction and repair technologies are changing, new materials are appearing, but plaster remains a popular method of wall finishing that has stood the test of time. Reliability, thoroughness and durability of the result obtained are strong arguments in favor of plastering.
Drywall, which gained popularity due to its ease of installation and became excellent option perfect alignment walls, was unable to completely displace its “fundamental” competitor. Although communications are conveniently hidden under sheets of plasterboard and a thermal insulation layer can be placed - these are undoubted advantages, but they do not withstand loads, reduce the area of the room and require finishing- these are the disadvantages.
The process of plastering aerated concrete inside a house, like any other room, is labor-intensive, it takes more money and time, you have to go through a rather “dirty” period, but as a result the walls acquire high-quality coating, capable of serving for several decades. Of course, it also requires decorative finishing, but unlike a plasterboard base, its strength will withstand almost any load - shelves and canopies can be mounted on these walls and any design and renovation experiments can be implemented.
Plaster can be applied to any surface, except very uneven walls, for alignment of which you will need thick layer concrete mixture. In this case, it is easier and more profitable to use plasterboard finishing.
Selection of material for plastering aerated concrete walls
Aerated concrete ( gas silicate blocks) – relatively new construction material, but received incredible popularity and the title of “revolutionary” in the market. Thanks to its cellular structure, it provides good thermal insulation combined with excellent air and moisture conductivity.
His excellent characteristics air and steam conductivity impose special requirements on technology, quality of finishing and materials used.
Firstly, the finishing material should not drown out these valuable qualities, completely blocking the pores and depriving the house of the ability to “breathe”.
Secondly, porous aerated concrete, while providing good air exchange, can quickly “dry out” a plastered wall and cause cracks to appear on it.
Therefore, the choice of material for plastering aerated concrete surfaces is approached with special care. It is necessary to use specially formulated plaster mixtures marked “For aerated concrete”. They have added components that bring the properties of the plaster as close as possible to the properties of cellular concrete and improve its adhesion, adhesive and vapor-permeable characteristics.
In addition, the solution prepared from these mixtures acquires elasticity and durability and can be applied to the walls in a thin layer.
Sequence of work
For the same reasons, the sequence of work has its own specifics: first, the interior walls are plastered, they wait until they are completely dry, and only then can the exterior finishing work begin. The moisture must completely escape from the inside to the outside, and not vice versa.
The plastering process consists of three stages:
- preparation of the base;
- applying the base layer;
- applying the finishing coat.
Preparing the base. Gas silicate walls They have a smooth, uniform surface with very thin seams, since glue, rather than concrete, is used for laying. Smooth surface necessarily requires the application of a primer layer, which strengthens the adhesion of the plaster and the wall and reduces the moisture-absorbing properties of aerated concrete so that drying occurs evenly.
Applying the base layer. After the primer has dried, the dry mixture is diluted with water in accordance with the manufacturer’s instructions and a base reinforcing layer of plaster is applied to the wall using a notched comb trowel. It is reinforced with alkali-resistant fiberglass mesh: it is simply pressed with a trowel into the upper third of the layer and smoothed. The mesh sheets are embedded in the plaster with a one-on-one overlap of 8-10 mm. They prevent the occurrence of deformations, shrinkage and cracks.
Sufficient thickness of the base layer is about 4 mm - special additives in the mixture for aerated concrete make it possible to obtain durable coating With minimum thickness. The plaster takes a long time to dry - you have to put up with this. As a rule, 1 mm is given 1 day to dry, i.e. The entire layer will dry for about 4 days.
Applying the finishing coat. It is recommended to prime the base reinforcing layer before applying the topcoat. Decorative layer applied with a metal float. Its thickness depends on the size of the fractions in the mixture - solid particles that give the plaster a relief pattern. For example, if the size of the fractions is 2 mm, then the thickness of the decorative layer should not be more than 2 mm.
Having leveled the plaster and waited a little until it “sets”, they “texture” it with a plastic trowel - giving it relief. Some finishing coatings do not require further painting, because already contain color pigments.
It would be useful to know that finishing work in a house made of aerated silicate brick is not recommended to begin immediately after the construction of the frame. The humidity of a “fresh” aerated concrete block from the factory is high - about 30%, it is advisable to wait about six months for it to dry to 15%. Aerated concrete walls do not require special insulation, so the house can be used at first without finishing.
Finishing begins with plastering the aerated concrete inside the house, i.e. from the internal walls, and finish with the external ones, and in no case vice versa. Drying should take place through the outer wall.
Work is carried out in compliance with temperature regime within the range from +8 to +30 C. Optimally – at 15-20 C.
If you follow the recommendations, the right technology works and selection of appropriate materials, plastered aerated concrete walls will last for decades, providing comfortable air exchange, absence of dampness and cracks on the surface.
Aerated concrete is a modern building material that resembles foam concrete in structure, but is distinguished by air bubbles located inside. The hollow structure of aerated concrete absorbs moisture well, which requires exterior finishing material. The best way to plaster walls made of aerated concrete is discussed in this article.
For the manufacture of the material the following are used:
- quartz sand is the basis of the mixture;
- lime;
- cement;
- water;
- aluminum powder is added during the manufacturing process of the material. Acts as the main gas generator and gives the material a specific structure.
Advice: When purchasing aerated concrete, you must take into account that the pores of the blocks, unlike foam concrete, are open. This determines the features of its application and finishing.
Comparative characteristics of foam concrete and aerated concrete are presented in the table:
| Foam concrete | Aerated concrete |
| In its structure, air bubbles are not connected to each other, which increases the material’s resistance to getting wet. | The air bubbles are interconnected, allowing moisture to move freely through them. |
| Good qualities of frost resistance and thermal conductivity. | Gives off heat and freezes from frost. |
| The inner layer of the plaster layer should be twice as thick as the outer one | The walls should be plastered indoors and then on the façade of the building. |
| To improve adhesion, the walls need to be cleaned, then thoroughly sanded to remove the top hydrophobic layer. Due to poor moisture absorption, to increase adhesion, the solution is sprayed, and then the base layer is applied. | Higher adhesion rates |
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.
- Changes in technical specifications.
- Increased indoor humidity.
- Mold appears in the corners of rooms.
Special facade plasters are used to finish external surfaces. Particular danger for aerated concrete slabs– temperature changes and severe frosts.
During operation, a certain amount of liquid begins to accumulate inside the structures, which will expand when freezing and can greatly damage the structures of the structure. Plastering aerated concrete bases can only be done 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.
Advice: Owners of buildings made of aerated concrete blocks should take into account that external wall finishing is carried out only after all internal facing works. Otherwise, when carrying out “wet” interior finishing work, the walls will absorb a significant amount of moisture, which will subsequently begin to evaporate.
If external facade will be finished before application interior plaster, with its intense evaporation, peeling of the outer plaster layer from the surface of aerated concrete will occur. After finishing the interior of the room, you can cladding the walls of the house outside special compounds with the highest vapor permeability.
Advice: You cannot plaster facades using standard cement-sand mixtures because they are not enough high properties vapor permeability.
Plaster for gas concrete
To decorate the walls, vapor-permeable plaster for aerated concrete is used, which is highly permeable to water vapor, does not get wet, has good adhesion to the surface of the blocks and high frost resistance.
| Type of plaster | Features of the material |
|
Disadvantages of the material:
|
|
Disadvantages: small selection color range, a loss appearance, due to the settling of dust and dirt on the surfaces of the walls. |
|
Disadvantage: high cost, but over time, it will most likely pay for itself. In this case, it is appropriate to remember that the miser pays twice. |
| Advantages of the composition:
Disadvantages of gypsum plaster:
|
Lime-cement plaster
All necessary properties inherent in the lungs thin-layer plasters, specially created for finishing aerated concrete surfaces. An example of such plaster would be Baumit HandPutz for DIY wall finishing, produced in bags weighing 25 kilograms.
Basics of it physical properties are given in the table:
| Indicator name | Its meaning |
| Grit size, mm | 1 |
| Strength of material in bending, tensile, N/mm2 | ≥0,5 |
| Compressive strength of the composition, N/mm² | ≥3,5 |
| Vapor permeation resistance coefficient μ, | 15 |
| Thermal conductivity coefficient λ, W/mK | 0,8 |
| Density of the mixture in dry form, kg/m³ | 1600 |
| Liquid consumption, liter/bag | 6-7 |
| Mixture consumption (with applied layer thickness 1 cm), kg/m² | 15 |
| Minimum plaster layer, mm | 5 |
| Maximum layer of plaster, mm | 20 |
Tip: Before plastering aerated concrete with this plaster, you need to spray the previously cleaned wall surface with Baumit Vorspritze solution.
Material selection
To choose which plaster is best for plastering aerated concrete walls, you need to purchase a plaster composition that satisfies the following characteristics:
- good vapor permeability;
- the optimal volume of liquid for mixing the mixture: per kilogram of mixture - no more than 0.2 liters of water;
- certain values of the minimum and maximum thickness of plaster application;
- good adhesion with a base of at least 0.5 MPa;
- resistance to negative temperatures;
- high resistance to cracking;
- long viability of the mixture, the larger it is, the easier it is to work with the solution, especially for beginners.
Procedure for plastering aerated concrete walls
Before starting work, it is better to familiarize yourself with the video in this article.
Advice: Building blocks made of cellular concrete are quite smooth with almost invisible seams. There is no need to use plaster mortars to level surfaces. It is enough to apply only a thin layer of the mixture.
The instructions for plastering walls suggest the following 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 attach a plaster mesh to a wall).
- The walls are finished with a thin layer of plaster.
Correctly selected plaster mixtures for aerated concrete blocks allow you to make your home not only beautiful, but also warm, retaining all its positive characteristics for a long time.