Plaster is an excellent material for decorating and leveling walls, ceilings and other surfaces. But such mixtures have "childhood" diseases. Over time, the coating peels off and cracks. And if cracking depends on the selection of components and the drying process, then the first problem is solved only by preliminary application of primers.
Not knowing the specifics of the finishing work, many do not consider it necessary to use these funds. After all, the mixture for plaster itself has sufficient viscosity. But experts argue that a primer before wall plastering is simply necessary to improve the adhesion of the composition to the base wall material. What is this primer, we will consider further in our article.
Soils before plaster - why are they?
Many are sure that it is not necessary to apply primers - let's consider whether this is so.
I must say that even despite the composition of the plasters, which is very similar to putty, the adhesion of such mixtures is much higher. This allows not only to impose the material with the thinnest layer, but also to grind and then polish. With plasters this will not work. While the mass is wet, its viscosity seems very high. But over time, the coating will peel off, and in large areas.
The reason is the high rate of absorption of moisture from the mixture for plaster by the wall material. As a result, this composition cannot reliably grasp the material. After thorough cleaning of the surface, it is necessary to cover the wall or ceiling with a primer. Before plastering, it provides good protection against moisture. Also, the tool increases the level of surface adhesion. Regardless of the composition, soils stabilize the porosity of the wall. This will then allow the plaster to be applied evenly.
Basic properties
After covering the walls with primers, a special waterproof film is formed on the surface. It reliably protects the wall material from moisture - the plaster will dry as it should. The special chemical composition of primers will also protect against mold and fungal deposits.
The components that make up the stucco preparations increase the glossy gloss of the surface. This makes it possible to hide various defects. Several primer layers in front of the wall plaster will enhance the properties of the plaster.
Applying such a tool is also a saving. So, primed surfaces are more even and have enhanced adhesive properties. Plaster mass will be better and more evenly applied to such a wall. Due to this, you need to use less building material.
The primer of the walls before the plaster makes the wall stronger and stronger. Even after thorough cleaning, dust and other small particles still remain on it. Soils firmly hold together all these elements, completely eliminating the possibility of delamination in the future.
Kinds
These building materials are characterized by different porosity, which means that the moisture absorption rate of these materials is also different. You need to know this when choosing mixtures. Knowing what the primer of the walls in front of the plaster is necessary for, it is possible to easily select the appropriate composition for the wall material. Consider the main types of soils.
Acrylic
Such a drug is considered universal and is the most popular. It is suitable for all surfaces. It can chipboard, concrete, wood, brick wall, drywall. The product is characterized by high penetration. Therefore, the primer of the walls before the plaster is very often made using exactly acrylic compounds. Penetrating deep into the pores of the base, the material increases adhesion several times.
The only thing where it is undesirable to use acrylic primers is on metal surfaces. Over time, rust may appear.
Mineral soil
As a basic component in such compositions, cement is used. These products are the most inexpensive and affordable of all types of primers. Application features - facade parts of buildings made of brick and concrete. But nothing prevents the priming of a brick wall before plastering in residential premises with such material. It will be inexpensive and practical. With the addition of certain additives to the composition, this product turns into a deep penetration soil.
Alkyd
This composition is intended primarily for wood and wooden walls.
After applying the primer, the wood changes its structure to slightly expanded. This enhances adhesion to plaster mixes. Alkyd soil is suitable for indoor use. Drying time is 10-15 hours at room temperature.
Glifthal
The material is used as a primer before plastering walls in dry rooms. The drug showed itself well when applied to metal. For complete drying, this soil needs about a day.
Polyvinyl Acetate Formulations
These are synthetic materials based on a polyvinyl acetate dispersion or on a latex basis.
Primer is applicable before painting, but can also be used before plastering. Drying time is almost instant - 15-30 minutes. These are the most quick-drying formulations among others. However, their cost is an order of magnitude higher than that of analogues. The price of one liter of the composition is about 520 rubles.
Perchlorovinyl
Such primers are widely used for concrete and brick surfaces. The drug dries quickly. Reviews say that the product becomes solid within an hour after application. According to the characteristics, perchlorovinyl compounds are not inferior to their polyvinyl acetate competitors. Its main disadvantage is high toxicity. This makes it inapplicable to residential premises.
Priming concrete walls before plastering in residential buildings is best done using safer products. It can be acrylic and emulsion primers. They are odorless and harmless to humans and animals.
The surface
A beautiful wall can be obtained not only from a tongue-and-groove plate or drywall. Good results can be achieved with plasters. And if it's decorative, then further decoration can be completely abandoned. But not every wall can be plastered. And the primer is not the drug on which you can save. What primer to use before plastering walls of different materials?
For loose or porous surfaces, as well as other unreliable types of surfaces, reinforcing soils are best used. This is brick, concrete. It is better to apply a deeply penetrating primer on a freshly plastered surface. Anticorrosion compounds are applied to metal structures. Wooden walls are best treated with antiseptic impregnations.
Manufacturers and Products
For primers before wall plastering, it is best to use two classes of compositions. These are deep penetration primers, or special plaster compounds for concrete and other smooth surfaces.
The former in appearance resemble ordinary milk, they have a neutral smell. Upon drying, a thin film forms. But due to overheating, such products can produce an unpleasant odor. After drying, it will disappear.
As for the second option, this is concrete contact and other similar products. The composition contains a suspension of solid particles and an adhesive substance. Specifically, concrete contact is pink. It is a reliable and high-quality product that can penetrate very deeply.
Many craftsmen recommend purchasing Feidal products. This is the most expensive, but the best drug. For 20 kg, you will have to pay about 2 thousand rubles. The primer from "Osnovit" will cost 1300 rubles. Feidal is the benchmark among primers. After drying, the surface becomes very rough. Stucco adheres well to such a wall.
If you couldn’t find Feidal, then with which primer should you treat the walls before plastering? The stores always have the usual drugs. These are the soils of deep penetration. Among the manufacturers we can distinguish indisputable leaders - these are Knauf and Bergauf. The consumption of drugs is low, and the price will be about 700 rubles per 10 liters.