Wall finishing – plastering of expanded clay concrete blocks

Expanded clay concrete blocks must be plastered in order to complete walls for both practical and decorative reasons. Because of their superior lightweight and thermal insulation, expanded clay concrete blocks require careful surface preparation for a smooth, long-lasting finish.

Plastering these blocks adds an extra layer of protection against environmental wear and moisture while also improving the walls’ aesthetic appeal. Using the proper plastering technique can greatly extend the life and functionality of your walls.

The best methods for plastering expanded clay concrete blocks will be covered in this guide. You will discover all the information you require to attain a polished finish, from choosing the right supplies to detailed application techniques.

Knowing the subtleties of plastering these blocks will help you produce a smooth and durable wall surface, regardless of your experience level as a builder or your level of do-it-yourself enthusiasm. To make sure your wall finishing project is a success, let’s get into the specifics.

Step	Description
1. Surface Preparation	Clean the blocks, removing any dust or debris. Ensure the surface is dry and free of any loose material.
2. Apply Primer	Use a primer suitable for expanded clay concrete to improve adhesion of the plaster.
3. Mix Plaster	Prepare the plaster mix according to the manufacturer"s instructions. Ensure it has a consistent texture.
4. Apply First Coat	Spread the plaster evenly over the surface using a trowel, starting from the bottom and working upwards.
5. Level the Surface	Use a straightedge to level the plaster, ensuring a smooth and even finish.
6. Apply Second Coat	Once the first coat has dried, apply a second, thinner coat to enhance the surface quality.
7. Final Smoothing	After the second coat dries, smooth the surface with a float or sandpaper to achieve the desired finish.
8. Curing	Allow the plaster to cure properly, avoiding rapid drying to prevent cracks.

Plastering expanded clay concrete blocks to finish the walls is a crucial step in building that improves the structure’s aesthetics and functionality. The rough surface of the blocks is smoothed over with a protective layer of plaster during this process, which not only enhances their appearance but also adds strength and insulation. A seamless, long-lasting finish that raises the value and comfort of any building can be achieved by homeowners and builders by carefully preparing the surface and selecting the appropriate plastering techniques.

Basic requirements for plaster on expanded clay concrete blocks

Plastering walls composed of expanded clay blocks is the most straightforward and affordable finishing solution. Finishing the walls independently can include plastering the walls.

Further finishing with ornamental stone or tiles is also advised. Plaster composition application is required to get the wall base ready for painting or wallpapering. Decorative plaster finishing is an option.

The following are the primary needs for plastering supplies for the concerned blocks:

• High strength of the resulting coating.
• Creation of moisture-resistant protection.
• Good adhesion to expanded clay concrete.
• Sufficient plasticity of the material.

Lightweight concrete products are less resistant to front surface mechanical damage. Water is readily absorbed by the material’s porous structure, and when it builds up inside the pores, the material eventually breaks down. As a result, expanded clay blocks need to have their surface well shielded from moisture and impact.

Strong material adhesion is necessary for the plaster layer to be fixed to the wall in a reliable manner. Adequate plasticity of the materials is necessary to prevent plaster cracking caused by wall masonry shrinkage.

Types of plaster on expanded clay concrete blocks

The following kinds of plaster compositions with a base can be utilized for finishing, taking into consideration all the requirements:

• Mineral;
• Acrylic;
• Silicate;
• Silicone.

Each of these plasters has benefits and drawbacks of its own. Any composition’s drawbacks can occasionally be addressed by adding different additives, such as plasticizers and hydrophobic fillers.

Finishing walls with mineral-based mixtures

Using mineral-based compositions is the most straightforward and affordable method of plastering.

They fall into one of two categories based on the primary binder component:

• Cement-sand;
• Gypsum mixtures.

The benefits of cement-sand plaster are numerous.

• High adhesion strength to the surface of expanded clay concrete;
• Resistance to water;
• Durability of the coating;
• Affordable price of materials.

The compositional identity of the blocks and plaster helps explain their high adhesion. It effectively repairs and reinforces the wall structure.

Plaster with a cement base can be used for finishing on the inside and outside. Mixtures of cement and sand are resistant to moisture. They are utilized in all kinds of settings, including highly humid ones.

Using a cement-based plastering solution, expanded clay concrete walls can have all of their pores securely closed, cracks hidden, and masonry joints leveled. It produces a dependable layer of defense that is resilient to variations in humidity and temperature.

Finishing materials are relatively inexpensive, and obtaining them presents no special challenges. This is the plaster finishing price range that is the most reasonable.

The primary drawback of plaster made of cement and sand is its weight. It increases the load on the building’s foundation, which needs to be considered in the design calculations. Furthermore, handling this material is physically more taxing than handling lighter gypsum mixtures.

Gypsum plaster’s principal characteristics are:

• Strength;
• Light weight;
• High quality of the finished surface;
• Excellent thermal insulation;
• Good vapor permeability;
• Ease of working with the material;

Plasters made of gypsum are nearly as durable as mortars made of cement and sand. They result in a very smooth surface when used.

This final choice is perfect for additional wall painting. Compared to cement, gypsum compositions have substantially better thermal insulation qualities.

Gypsum plaster’s high vapor permeability makes it possible to keep the interior of your space at the ideal microclimate. It is a very practical material for finishing work because of its plasticity.

Along with all of the benefits, gypsum plaster mixes have some significant drawbacks.

• Low moisture resistance of the material;
• Small degree of adhesion to the material.

Gypsum is primarily used for interior decoration because it is extremely sensitive to high humidity. Their surface needs to be specially treated in order to increase adhesion.

Acrylic plaster mixes

Polyvinyl or acrylic are used to make this kind of plaster. There are other plasticizers in the composition.

Characteristics of acrylic plasters:

• High plasticity;
• Good adhesion to the wall material;
• Moisture resistance and resistance to temperature changes;
• Vapor permeability;
• Strength and durability;
• Excellent aesthetics;
• Ecologically friendly material.

Acrylic-based plaster mixtures have good plasticity, so they don’t need to wait for the building to shrink before being used after wall structures are constructed. They are also simple to work with for the same rationale.

They create a strong covering that is impervious to a variety of negative effects because they fit precisely on the surface of the blocks. Additionally, this material can give the space the best possible air and steam exchange.

Because acrylic plaster has a deep tint, it can be applied to blocks right away as a decorative coating. Acrylic paints can also be used to finish the surface.

Acrylic plaster compositions come in a range of colors and textures that let you design unique room interiors and different kinds of building facades. This kind of plaster has a 25-year service life.

The following can be listed as some of these plasters’ drawbacks:

• Low resistance to ultraviolet radiation;
• Insufficient vapor permeability;
• Combustibility of the material.

The color of decorative plaster quickly fades and burns when exposed to prolonged sunlight. Steam passes through a dense, moisture-resistant coating made of acrylic compounds very poorly. The overall fire hazard of the premises is increased by low fire resistance of the material.

Acrylic plasters fall into two categories:

This kind of plaster is most frequently used for decorating walls, ceilings, and facades because it can create nearly any texture, comes in a large variety of colors, and is reasonably priced.

Silicate plasters

Mineral additives, colorful pigments, and liquid glass are components of silicate plaster solutions.

• Very durable finishing material.
• Service life up to 30 years.
• High resistance to all external influences.

Products that have been finished with silicate plaster are shielded from a variety of harmful elements for an extended period of time.

The following are some of the option’s significant drawbacks:

• For good adhesion to the surface of the base material, mandatory treatment of the surface of the blocks with a special silicate primer is required.
• Difficulty in working due to the rapid drying of the solution.
• Difficulty in tinting compositions.

The cost of finishing goes up significantly when a primer pre-treatment is required. Silicate plaster is very tricky to work with; expert knowledge is needed.

Without prior experience working with such materials, you won’t be able to complete it on your own. Furthermore, silicate paints are the only ones that can be used to paint on plaster surfaces because the color range of silicate decorative mixtures is extremely limited.

Silicone-based plastering compounds

Silicone resins are the primary ingredient used in the creation of this kind of plaster.

They endow the content with attributes like:

• Strength;
• Plasticity;
• Moisture resistance;
• Resistance to various damages.

The best material to plaster walls with is silicone plaster.

Drawbacks of the content:

• High cost of the material itself.
• The need to use a special primer, which further increases the overall cost of work.

The cost of silicone plasters is frequently the deciding factor in people’s decisions not to use them as a finish.

Plastering expanded clay concrete block walls has both practical and aesthetic advantages. In addition to adding another layer of insulation and moisture resistance, it improves the walls’ appearance by making them seem polished and smooth. Plaster that has been applied correctly can greatly increase the longevity and toughness of your walls.

It’s important to properly prepare the surface before plastering expanded clay concrete blocks. This guarantees that the plaster sticks firmly and stays put over time. Plaster applied in layers with the appropriate type of material produces a better finish and reduces peeling or cracking.

Furthermore, the final result can differ noticeably from the initial plastering job if best practices and techniques are followed. From properly preparing the plaster to using the right tools to apply it, every step counts toward producing a polished and long-lasting finish. You can build a gorgeously finished wall that endures with meticulous attention to detail.

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