Plastering walls made of aerated concrete inside and outside

Plastering aerated concrete walls can differ slightly from plastering other kinds of walls. Because of its low weight and insulating qualities, aerated concrete needs extra care to produce a smooth and long-lasting finish.

Gaining the best results from plastering on aerated concrete requires knowing how to apply it correctly, whether you’re working on the inside or outside. Every stage, from surface preparation to plaster mix selection, is critical to the final result.

We’ll walk you through the steps of plastering aerated concrete walls in this post, emphasizing important methods and pointers to guarantee a professional result. This information will assist you in completing the task correctly, whether you’re beginning a new project or remodeling an existing area.

What is vapor permeability of aerated concrete.

Vapor permeability is the capacity to create systems for supplying and absorbing excess moisture from the outside environment and the interior microclimate of the home. It is impossible to downplay the significance of this parameter. The choice of plaster for aerated concrete must therefore be made carefully when doing exterior and interior decoration projects.

You can look up and apply all the necessary figures in one of the many tables available on the Internet.

Another name for vapor permeability is the "breathing" of walls. When "breathing" is interfered with, the following outcomes occur:

• cracks inside and on the external facade of the building;
• appearance of traces of masonry in rain or fog;
• increase in humidity in the room;
• growth of mold in the corners of rooms.

Aerated concrete and foam concrete are not the same thing. These materials appear similar on the outside, but they are very different from one another in terms of their properties.

Foam concrete has a higher resistance to moisture because of the unconnected air bubbles in its structure. Consequently, there is an increase in frost resistance and thermal conductivity.

As opposed to this, the interconnectedness of the aerated concrete allows moisture to freely flow along the bubbles, producing heat or causing frost to freeze. Consequently, plastering aerated concrete walls both inside the building and on the exterior of the home is crucial.

Primary tasks for priming walls.

We stress once more how aerated concrete is not the same as foam blocks. The presence of pores in aerated concrete complicates both internal and external plastering. The truth is that aerated concrete was intended to be used as an insulating material for walls. It did not receive any additional attributes as a result. The higher degree of wall absorption makes priming aerated concrete before plastering more difficult.

Thus, before plastering, it needs to be primed two or three times. Primer lowers the possibility of fungi by greatly increasing the adherence of plaster to aerated concrete. Today’s primer selection is flawless, with a plethora of options readily available in stores. Therefore, there are numerous implementation options available from various manufacturers in response to the question, "What to prime aerated concrete with before plastering?"

Think about using a primer with three layers. Usually, the package will contain instructions on how to dilute the mixture with water in a ratio of 1:4 before applying for the first time. This is done in an effort to use less of the mixture. The mixture will be absorbed by the aerated concrete’s pores, changing its characteristics during the initial coating.

The cost of the second and third applications will be lower. Once the first has dried, apply the second, which has been diluted in a smaller ratio, in the same manner. The primer’s third and final stage is completed using an undiluted composition.

Aerated concrete walls can be plastered indoors using a method that involves breaking down the plaster with a hammer (creating a lot of recesses on the plane) to improve the bond between the materials.

Does plastering aerated concrete require mesh? Pre-reinforcing a house’s aerated concrete facade plastering with a reinforced mesh is an option. This is frequently merely required. In this instance, no primer is used before applying the plaster over the mesh.

Additional vapor barrier of aerated concrete.

For certain customers, an additional vapor barrier is necessary to mitigate the inferior qualities of aerated concrete. The technique for plastering aerated concrete walls varies slightly in this instance. Placing a polyethylene film in between the blocks is the first technique. Peeling could result from increased condensation if the technique is not followed.

Plastering aerated concrete walls both inside and outside using a cement-sand mixture without the addition of lime or dolomite flour is the second, higher-quality method. Peeling is still possible even with this option, which will tenfold lower the vapor barrier.

Using contemporary vapor barrier solutions is the best approach. They can increase an aerated concrete wall’s quality by a factor of 25. It takes three to four coverings of the blocks to accomplish this.

Vapor permeability will be further decreased if oil paint is applied to the wall after plastering.

Aerated concrete walls require plastering on both the interior and exterior to ensure longevity and improve wall aesthetics. Because it is porous, aerated concrete can be difficult to work with even though it is lightweight and insulating. A smooth, polished appearance is produced, these surfaces are sealed, and they are shielded from moisture and damage by proper plastering. Knowing the proper methods and supplies for plastering aerated concrete is essential for producing a polished and long-lasting finish, whether you’re working on exterior facades or interior walls.

Plastering on aerated concrete for interior work.

The primer primer is the initial step. It needs to be chosen with the completed room in mind. Mixtures for covering the kitchen, living room, or bathroom can be found in stores. For unheated premises, there is a unique primer. can be applied with a straightforward brush or valley. Use a spray gun to apply spraying to expedite and simplify the process.

The beacons’ exposure is the second step. These unique profiles make it simple to level the wall coating. Check out the post on beacons for plaster to learn how to select them. Place them in line with one another along the rule’s width. This is done so that any excess can be removed from the wall’s surface and they can be easily slid over in the future. Putty is used to attach lights.

Note: use a vertical level to ensure that the beacon display is accurate. Even a tiny error here could result in a future wall curvature.

The third step involves solving the problem manually or by using a mechanized station, which greatly speeds up the procedure. 4–8 mm is the average thickness. If there are any irregularities, the layer might be a little bit bigger in some places. Applying a lot of the composition at once is not advised as this could cause collapse.

Aerated concrete is internally plastered sequentially, from bottom to top, usually with excess plaster removed. Avoid letting the material peel off and quickly fill in gaps. The composition should be up to two or three millimeters compacted.

Using a spatula to level the dried surface is the fourth step. The tool’s flat side is used to accomplish this in a circular motion. After achieving this level surface, the beacons are taken out. The spaces that remain after them are concealed. They use the same beacons to advance to the next section after finishing the previous one. The beacons can be left until the other wall is level if the room’s corner has been leveled. The wall’s angular joints have undergone particularly thorough alignment because the irregularity is more obvious from a visual standpoint.

Plastering the facade of a house made of aerated concrete.

Priming the outer wall is the first step. Acrylate siloxane-containing strengthening water-repellent composition is employed. For an extended period, the walls can be shielded from excessive moisture by such a coating. The exterior and interior walls are cleared of any imperfections and glue and mortar leak residue that holds the blocks together. The joints are pre-sealed. Ten to twenty degrees above freezing is the working temperature.

Installing a fiberglass mesh for reinforcement is the second step. Alkaline meshes are advised because of their high PH. which enables them to stay in the wall without dissolving for an extended period of time. Taking this precaution now will shield you from cracks later on. These nets do come at a higher cost, but that cost is offset by the fact that they will ultimately save a lot more money. The external wall is fastened to the mesh with basic self-tapping screws.

Note: The procedure is different if you need insulation and plastering on the exterior of a home built with aerated concrete. Plastering must be completed prior to the initial application of insulation. Before plastering, we advise you to read the insulation article.

Facade plaster for aerated concrete is applied in the third step and should have a thickness of 7 to 9 millimeters. Plaster needs to be plastic, easily applied, low-consumption, and highly adhesive. When fully dried, it ought to be impervious to moisture. What prevents frost and maintains the house’s warmth? The application procedure is comparable to that of internal coating. Applying it with mechanical equipment will be far more convenient. Furthermore, there’s an abundance of space outside. Once the coating has been leveled and allowed to fully dry, you can move on to the last step, which is decorating the facade.

The addition of beauty and decoration is the fourth step. You can use decorative plasters or specialty paints for decoration. Fortunately, a vast quantity of them are available in the market. The best plaster for plastering aerated concrete walls is up to you. Pebble, textured with a fur coat and bark beetle effects, or any other material, can be used. This is only going to help external plaster on aerated concrete walls.

Types of coatings for facade finishing.

Naturally, the first thing to do when plastering aerated concrete walls outside of a building is:

• vapor-permeable;
• frost-resistant;
• crack-resistant;
• with good adhesion.

A lime-sand mixture with a low cement content (less than 6% of the total mass) is the best choice. For these purposes, prefabricated lightweight plaster compositions are also available.

1. Acrylic plaster – used both inside and outside the house. It is used to strengthen elements with increased loads, for example, the base. It is used as a decorative type of application. It maintains its color range and unchanged texture for a long time. It has good adhesion, but vapor permeability is not very high. Therefore, if the choice fell on it, it is necessary to initially carry out waterproofing.
2. Silicate – based on liquid glass. It differs from the previous option in excellent vapor permeability. In addition, its price is very interesting. There are many different textures with scratches, roughness or pits to choose from. It is used in plastering work on aerated concrete of external and internal walls. Disadvantages, strong settling of dust and dirt on the surface and limited color range. It is applied both to the aerated concrete itself and to the insulating elements.
3. Silicone plaster is truly a solution to all problems. Exterior decoration of a house made of aerated concrete with this type of plaster has many advantages, but it will only be attractive to smart and calculating. Its cost is much higher, but it will certainly pay off over time. As you know, a miser pays twice. It is based on organic silicon. It has high vapor permeability, is not easily soiled and has a wide range of colors.

Application tips.

Experts advise keeping in mind the characteristics that make application easier and extend the coating’s service life:

• Rough blocks hold the solution more firmly; they are cut before applying. • The proper ratio of layers on the inside and outside should be maintained; • Facade plaster for aerated concrete lays on them much better. The outer layer shouldn’t hold onto moisture; open air circulation is crucial. If condensation builds up there, the liquid will freeze and expand when the temperature changes, which will unavoidably cause cracking; • a thin mist should be used for the initial coating and only then should the main layer be applied. Adhesion is far better in this manner.

Aerated concrete walls require careful plastering to ensure a long-lasting and efficient finish. The first step in any process, whether it’s indoors or outdoors, is surface preparation. Plaster must adhere well to clean, dry surfaces in order to avoid problems like peeling or cracking.

It’s crucial to use the proper mix and methods when plastering aerated concrete. It is usually best to apply a base coat first, then a finishing coat to interior walls. This enhances adhesion and contributes to a polished, seamless finish. Weather-resistant plasters are advised for external walls in order to withstand environmental factors.

Make sure to give each coat enough time to cure. This lowers the possibility of damage and aids in the proper setting of the plaster. In order to ensure a high-quality outcome, routine inspections can help identify any problems early in the process.

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