Is it possible to plaster walls with sand concrete – step-by-step technology

Plastering is a popular option for wall finishing because it produces smooth, long-lasting surfaces. However, what if you were thinking of doing this task with sand concrete? Many are unsure about whether it’s a practical option or how to proceed.

A mixture of cement, sand, and water, sand concrete is frequently used in construction for a variety of purposes. It’s not as simple to use for plastering walls as traditional plaster mixes, though. A certain method must be used to guarantee a smooth and sturdy finish.

This tutorial will take you step-by-step through the application of sand concrete for wall plastering. There are useful tips to help you complete the task correctly, whether you’re a do-it-yourself enthusiast or trying to save money on professional services.

Step	Description
1. Surface Preparation	Clean the wall, remove loose materials, and apply a bonding agent.
2. Mixing Sand Concrete	Mix sand concrete with water until it reaches a smooth, workable consistency.
3. Applying the First Coat	Use a trowel to apply a thin layer of the mix to the wall, covering evenly.
4. Leveling the Surface	Use a straight edge to smooth and level the surface before it dries.
5. Applying the Second Coat	Once the first coat is dry, apply a second coat if needed for a smoother finish.
6. Curing	Keep the plastered surface moist for a few days to prevent cracking.
7. Final Finishing	Once dry, sand the surface for a smooth finish or apply paint.

Types of sand concrete

Sand concrete (PC) is categorized as a cement-sand mixture based on its composition. Between cement plaster and concrete, the substance is in the middle.

It is different from the former in that it doesn’t contain a significant filler, like crushed stone, and from the latter in that it has more cement and coarse-grained sand. The original purpose of sand concrete (PC) was to create durable slabs that required extremely high manufactured structure strength, as well as concrete screeds. However, as it turned out, sand concrete exhibits the same benefits as a plaster coating.

Sand concrete can be, for example:

• universal (used both for the construction of screeds and for plastering);
• waterproofing (in the manufacture of structures that require water resistance);
• installation-plane (used as a masonry solution for brick or masonry, when plastering);
• wear-resistant (for the manufacture of floors, foundations, basements).

Two varieties of readiness are produced by manufacturers in PB:

• dry mixes (analogous to plaster SS), marked BSS;
• ready-to-use mortar that can be laid immediately, marked BSG.

A mixture’s characteristics classify it into one of the following categories:

• heavy (BST);
• light (BSL);
• fine-grained (BSM).

• mobile (marked "P");
• rigid (marked "Zh");
• super-rigid (marked "SZh").

In order to interpret the manufacturer’s marking (as per GOST 7473-94), you must be aware of the significance of the following letters:

• F – frost resistance (number of freeze cycles);
• W – water resistance (the higher the indicator, the greater the water pressure the concrete resists without liquid seeping through the pores) from 2 to 20;
• B – strength class (indicated in MPa compressive strength).

Is it possible to plaster walls with sand concrete

There are various uses for plaster finishing.

• protective (for example, waterproofing, X-ray shielding, heat-retaining, noise-reducing, etc.).d.);
• leveling;
• ennobling (decorative).

The "new product" made of sand and concrete was also useful to plasterers. When it’s necessary to level the walls, use sand concrete to plaster to create a long-lasting, wear-resistant facade. This material is appropriate for hallways, stairwells, and damp, unheated rooms.

Large coating weights aren’t permitted everywhere, though. For instance, sand concrete is not used in situations where the strength of the wall materials is less than that of the concrete (e.g., walls composed of gas blocks, gas silicate, etc. d.).

This sand concrete BSM is utilized as plaster, so let’s think about it:

1. B7.5 P2 F200 W4 (previously labeled M100) contains a sand fraction of 0.8-1.2 mm. More often than others, it is used for plastering. It has low compressive strength (98-100 kg / cm²).
2. B10 P2 F200 W4 (previously M150) contains quartz and river sand up to 2.0 mm. Suitable for plastering facades, brickwork. Can be supplied by concrete pumps to a height of up to 52 m.
3. B15 P2 F200 W4 (before M200) can be used for screeds when installing warm floors and plaster.
4. B20 P2 F200 W4 (old labeling – M250) is durable, durable, suitable for filling the floors.
5. B25 P2 F200 W4 (or M300) is universal.

Sand concrete plastering is not only feasible but also a sensible choice if you want a smooth, long-lasting finish. You can ensure that even if you’re doing it yourself, the results will look professional because this step-by-step guide will take you through every step of the process, from prepping the surface to applying the final layer.

Plastic technology

1. Before plastering, the wiring is de -energized and the basis is prepared. This is a mandatory first stage of any plastering work.
2. Then prepare a leveling solution (for each leveling layer the solution is prepared separately).
3. The third stage – plastering.
4. Care for the applied solution during its hardening.

Packaging provides a description of the process technology. must meet the requirements for plastering the walls. For instance, the manufacturer lists the air and water temperatures for "winter" mixes. Work is typically done inside at a temperature between +5 and +25 o C.

Sand concrete plastering requires some acclimatization because the mixture, while related to cement-sand plaster, has unique properties. For instance, the heavy mass will slide down under the weight if the solution is applied in a layer deeper than 6-7 mm.

The base is reinforced with a mesh so that it is inside the layer of plaster mass in the event that the layer needs to be thickened and plastering needs to happen faster. In order to prevent it from sagging, the mesh cloth is fastened to the wall.

Preparing walls for plastering

One can conditionally categorize preparatory work into the following categories:

• for cosmetic repairs;
• for major repairs;
• in a new building.

Grease, rust, and mold stains must always be removed from the surface as a result of the preparatory work.

To improve adhesion, a new building with smooth walls has notches all over the base’s surface.

In bricklaying, metal brushes are used to scrape the top of the bricks and the seams are widened to a depth of 1 cm for the same reason. Eliminate superfluous hardware from the walls and, if possible, paint over the ones that remain with oil paint. After cleaning, surfaces are primed and dusted.

Remove delicate finishes (wallpaper, paint, whitewash, and peeling plaster) in the event that repairs are necessary. Fix large cracks and chips. Next, remove any dust, prime, and let it dry.

Preparing the solution

Plastering is leveled layer by layer; each layer’s solution is made separately and has a distinct consistency. As a result, it’s critical to accurately estimate the solution’s volume to ensure that there is just enough to apply a layer and no significant excess.

Powder and water are combined manually (using a mixer) or in a mortar and pestle mixer. The mixture should be uniform in both situations. It takes two minutes to mix in a mortar and pestle. The solution is allowed to infuse for five to ten minutes before use.

How to plaster with sand concrete

The following order is followed when applying sand concrete leveling plaster:

1. The spray layer is made with a solution that has the consistency of kefir. The wall is moistened before application, the dough is thrown on with a trowel, ladle or applied with a float. The layer is not leveled, since its purpose is to create a buffer bonding zone. Thickness – 5-6 mm. The layer is not allowed to dry! As soon as the "kefir" begins to mattify (become matte), proceed to the next stage.
2. The main leveling layer (primer) is made with a thicker solution. This layer is applied by spreading with a float, after moistening the previous one. The surface is leveled with a rule. It may be necessary to make two layers of primer. In any case, the applied mass is not allowed to dry, since cement requires humid conditions to gain strength. After application, to protect moisture, the wall is covered with wet mats or film. When the solution begins to set, remove the beacons, fill the grooves with soil.
3. To create the third layer, it is allowed to use polymer decorative plasters or cement covering to obtain a smooth surface. The third layer can be a solution with fine sifted sand of the consistency of kefir. In the case of finishing tiling, this layer is not needed.

In a day, the layer will fully solidify. In two weeks, additional finishing is possible. In four weeks, the coating will "mature" and reach its maximum strength. It’s important to keep the first day or two from drying out.

Sand concrete consumption per 1 sq.m

Similar to plaster mixtures, the amount of solution used is expressed in kilograms per square meter of screed that is 10 mm thick (typically between 17 and 30 kg / m2). As a result, the computation is performed in a manner consistent with that of the plaster SS consumption calculation. The number of squares with a centimeter thickness can be obtained by multiplying the area (number of squares) by the average coating thickness (in centimeters) for wall leveling.

The manufacturer’s specified consumption is multiplied by the final value to determine the necessary weight of the sand concrete mixture. There is still a 15-20% reserve to be added.

For instance, the wall area is 2 x 4.5 = 9 m2, the leveling layer’s average thickness is 3 cm, and the manufacturer specifies a 22 kg PB consumption. We multiply: 18 bags weighing 40 kg or 9 x 3 x 22 x 1.2 = 713 kg.

Composition of sand concrete and its characteristics

Portland cement, which creates an artificial stone and binds the sand grains of the filler, is the primary ingredient in fine-grained concrete (another name). The mixture’s most expensive ingredient is cement binder.

The size of the grains distinguishes the filler in sand concrete. River (rounded) sand is sifted through sieves with a mesh size of 3 mm for use in sand concrete. In comparison to cement-sand compositions with angular sand grains, rounded sand grains of varying diameters when laid form a structure with a minimum number and size of pores, forming a denser material. Sand concrete is more resistant to moisture penetration because of its dense packing.

Sand grains that are large serve as finely crushed stone. Concrete mixtures containing quartz sand are also utilized. Quartz has a Mohs hardness of 7, making it a robust and fracture-resistant rock. The composite has a strong resistance to abrasion thanks to this filler.

PB is classified into the following types according to the percentage of filler used:

• fine-fraction – the largest grains up to 1.2 mm;
• medium-fraction – grain size up to 2.5 mm;
• coarse-grained – grains 3-4 mm.

Of course, the strength (bending, compression) of sand concrete material makes it valuable. PB grade M300 is most frequently used for plastering. Sand concrete resists repeated freezing because of its density and water resistance. Finishing facade surfaces is crucial in areas that experience bitterly cold winters.

Manufacturers of sand concrete make an effort to differentiate their mixtures from competitors by adding unique features. As an illustration, the "Stone Flower" mixture exhibits higher frost resistance (100 cycles as opposed to 50).

Through the use of plasticizers, mixtures can become extremely plastic. However, the material’s strength is its greatest asset. Manufacturers control every one of the attributes by adding additives, which are categorized according to their actions.

• anti-frost (allow you to use the mixture at sub-zero temperatures);
• plasticizing (allow you to reduce water consumption during mixing, increase strength and density);
• anti-shrinkage or expanding (their addition allows you to compensate for the shrinkage of the mass during hardening);
• stabilizing (prevent water separation during laying);
• accelerating the hardening of the solution;
• extending the service life (period of mobility);
• increasing strength properties (resistance to external loads, for example, abrasive);
• increasing gas saturation (to obtain porous PB, which retains heat well, but has reduced strength), etc.

Two different kinds of plasticizers are used in PB: the first increases the mixture’s plasticity, and the second increases the finished coating’s resistance to vibration and shrinkage.

Strength is the primary factor used to separate sand concrete. In other words, the artificial stone made from the compositions will have a compressive strength that is not less than what the certificate specifies:

• at M100 – not less than 10 MPa (or 100 kgf/cm2), the mixture is distinguished by a minimum content of cement and the presence of lime;
• M500 and M400 – respectively, not less than 50 MPa and 40 MPa (achieved by an increased content of high-grade cement – ​​up to 70%).

The grades for intermediate compositions are M300, 150, and 200. Plastering inside uses grades up to M150. Sand concrete M300 is used to plaster facades, basements, and foundations.

Additional crucial technical attributes:

• adhesion ~0/4 MPa;
• density (bulk) – 1500 kg/m3;
• stratification – 5%.

Advantages

The benefits of BP include the following in addition to the capacity to produce a solution with guaranteed composition and properties:

• high strength (resistance to compressive and bending loads);
• resistance to vibration;
• homogeneity of mass;
• long service life.

Disadvantages

Among the drawbacks are:

• increased consumption of Portland cement (affects the cost);
• high hardness of the resulting material, its intractability to processing;
• greater susceptibility to shrinkage (compared to polymer plaster solutions).

Storage and transportation

The manufacturer packages PB in multilayer paper bags with a 25 or 40 kg filling. Despite the fact that this container is quite sturdy, precautions should be taken to protect the cargo while it is being transported. Road transportation will be less expensive.

Here, it’s critical to properly pack the bags and shield them from the elements. Additionally, you can order sand concrete with delivery.

Practically speaking, the quality of the mixture degrades with every month of storage, so buying a recently produced mixture before using it for business makes more sense.

Dry warehouses have a six-month (or even a year) shelf life. PB cannot be stored in moist areas even with the impregnated outer paper shell. Pallets are used for storage, keeping the bags off the ground.

Sand concrete plastering is not only feasible but also a useful way to achieve smooth, long-lasting surfaces. Compared to traditional plaster, the process might take a little longer, but the benefits are well worth it.

The technology can be followed step-by-step to guarantee a durable finish and a strong bond. Sand concrete offers a dependable wall plastering solution, whether you’re building a new building or remodeling an old one.

Your walls can provide both practicality and visual appeal for a long time if the proper methods of preparation and application are used. Try it out, and you may discover that sand concrete ends up being the material of choice for all future plastering projects.

Video on the topic

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