Concrete contact: description, use, technical characteristics

When doing renovations, it is not enough to purchase finishing materials. It is important to use them correctly to ensure maximum adhesion. When performing repairs yourself, problems arise with the finishing coatings lagging behind the treated surfaces of walls and ceilings. Inexperienced builders will witness peeling plaster, peeling tiles, peeling wallpaper. A special primer - concrete contact - will help solve a serious problem, providing an increased degree of adhesion of finishing materials to the surface.

What is concrete contact

Not everyone knows what it is. The popular concrete contact, the use of which ensures increased adhesion of finishing materials to walls and ceilings, is a special mixture for priming the surface being treated.

This primer is intended for surfaces that do not absorb moisture well.

The soil contains the following ingredients:

Portland cement.
Quartz sand.
Polymer filler.
Special additives.

Concrete contact is a polymer-based building mixture that is resistant to alkalis and increases the adhesion of the material to the base.

Briefly about the main thing

Betokontakt is made from acrylic dispersion, fine-grained solid filler, and functional additives.

Almost all manufacturers add pigment additives to the composition to monitor the consistency of the coating.

The main task of the primer is to create good adhesion of solutions with smooth and dense concrete. Additionally, such substrates as ceramic cladding, brickwork, and oil paint are considered. Such surfaces are not always included in the list of acceptable ones for a particular brand of soil.

In the recommendations, you must find out information about the possible use of the material outside and in wet rooms, since not all options are universal.

Why is it needed?

The main purpose is to provide strong adhesion between two materials and strengthen the base. Improving adhesion is necessary not only on the ceiling and walls, but also when installing floor screed. Concrete contact is used both under concrete and cement-sand screeds, and under self-leveling floors. As a result, the finished surface is not scattered layers, but a solid and durable structure.

On concrete wall slabs, which are characterized by a particularly smooth surface and poor moisture absorption, the use of such a solution is mandatory. Without it, it will not be possible to carry out the work of plastering or painting the wall. The finishing materials will not stick or will quickly crack and fall off from such a surface, and the wallpaper simply will not stick.

Concrete contact is a convenient modern replacement for wall banding , which was used in the Soviet and post-Soviet periods. To create this design, the entire surface of the walls was covered with a fabric mesh. For gluing, regular PVA glue was used. This method was not only difficult, but also did not always lead to the desired result.

By using concrete contact it is also possible to save yourself from labor-intensive and expensive work on cleaning the surface of the old coating. This mixture can be applied to oil paint and tiles. In this case, the quality of the final result will be no worse than when applied to a surface cleaned of them. All that remains is to strictly follow the manufacturer’s instructions, follow the technology of use and complete all work within the specified time frame.

In addition to good adhesion to the surface, improved adhesion and versatility, concrete contact has another important feature. After the composition dries, a waterproofing layer is formed on the surface, which will not be superfluous for both internal and external work. But this quality is especially important for preserving plastered surfaces for the winter. Under the concrete contact layer, the plaster coating will remain as smooth and dry as it was before the frost.

USING CONCRETE CONTACT

You can work with the primer in the same way as with conventional strengthening solutions. Any self-respecting manufacturer of concrete contacts describes the use of the solution in short instructions included with the packaging.

Most often, the primer is sold ready-made; in this case, to use it you just need to clean the wall of mechanical impurities and start applying the primer to the surface. Sometimes powder forms of concrete contact are used, especially when working with large volumes of priming. According to the instructions, the finished concrete contact is stored without loss of technical characteristics for a year, dry mixtures are designed for use after a longer storage period.

Concrete contact is always made on a water basis, so during long-term storage some of the water may evaporate. Before use, or even better, upon purchase, experts recommend opening the package and inspecting the surface of the liquid concrete contact. If there are traces of a dried layer with cracks on the walls of the container, it is better to postpone the use of such a solution. It is always necessary to check the suitability of concrete contact for use based on its expiration date.

Purpose

The scope of application of the soil lies in the information about what it is - concrete contact. The acrylic binder has the ability to penetrate deeply. The composition forms a vapor-permeable rough film. Such properties are valued when working with substrates that do not absorb moisture and have a smooth surface. A common option of this type is concrete.

Smooth concrete floor Source yandex.net

The high adhesive ability of the soil ensures a strong connection of materials. To tear off the coating you will need to apply an average force of 100 g/sq.mm. This suggests that the base treated with concrete contact will be able to withstand a large layer of leveling plaster and cladding.

Among other things, due to the filler and the properties of the acrylic component, the dry residue can strengthen the base. The film has a high tensile strength. This is especially true when finishing an old base with microcracks.

As a result, the scope of application of concrete contact extends to the treatment of surfaces of the following nature:

high-density concrete (panel houses, columns);
ceramic tiles for finishing without dismantling the coating (two-layer application of primer is recommended);
dry wooden base to be plastered (other compositions are not suitable);
metal structures for any purpose without pre-treatment with an anti-corrosion compound;
plastic or glass surface with correct calculation of the weight load of subsequent finishing.

Priming a painted surface Source snappygoat.com
See also: Catalog of companies that specialize in finishing materials.

Separately, a primer with sand is considered for suitability for brickwork. Not all manufacturers include such a base in their scope of application. The reason is the heterogeneity of ceramic blocks and grout. The latter refers to porous materials that are rarely permissible to be covered with concrete contact.

Acrylic-based compositions can be diluted with water if necessary (not recommended). After drying, the coating can be painted with dispersion paints. Often the surface is decorated using concrete contact. If the composition is not stirred until smooth, then using a brush you can form a chaotic pattern. This way, you don’t have to align the walls with the ceilings, but you can visually transform it for a long time, and additionally protect it from fungus, mold, and corrosion.

Often in the old foundation, finishers are faced with oil paint and chalk. Such finishing is subject to maximum elimination. Next, you should make notches under the plaster or cladding using an ax or a hammer with a chisel, and sand the surface with a coarse abrasive to create roughness.

Notches on a complex base Source couo.ru

After removing grease stains and dust, priming can be carried out, preferably in two layers with intermediate drying.

Among the recommendations you can find the use of contact concrete under putty. However, this material is intended for thin layer application and finishing. The sand contained in the soil will contribute to the formation of scratches and, in general, the composition will be a waste of time, effort, and money. For final leveling, it is enough to treat the base with a dust-removing agent for plaster, a highly specialized primer for metal, plastic, and glass.

Restrictions on use

Most manufacturers and consultants on trading platforms position concrete contact as a universal material. This applies to any soil regarding the nature of the finish with the base, but not suitability for work indoors and outdoors. Samples applicable in both directions exist, but their number is limited. In fact, some soils cannot be used for treating the facade, roof, or basement.

Primer for interior work Source stpulscen.ru

Some options are only permissible for substrates in dry rooms. It is important to first read the instructions on the labels of the cans or buckets.

Due to the high strength of the film, soil is often used to strengthen a loose foundation, for which concrete contact is unsuitable. The composition will penetrate into pores and microcracks, but only superficially. As a result, the finish may fall off the wall or ceiling in a layer under its own weight. Here you need a special strengthening agent with deep penetration.

In order to enhance adhesion and reduce absorbency, any porous substrates must be treated. Soil with quartz sand is not suitable for this, since the binder component will mostly end up in the pores. As a result, the permeability of the breathable surface will decrease to an insignificant extent, and the bond between the filler grains will be insufficient to withstand the declared mechanical load. The solution here is an impregnating agent, which is applied in 2-4 layers with intermediate drying.

Porous materials Source prom.st

Material Specifications

At the moment, there are four most important technical characteristics of this material that affect the quality of the work performed:

Durability - the technical characteristics of concrete contact indicate that the properties of the composition are maintained for eighty years. For interior decoration of the premises, this period is more than enough, since repair work is usually carried out with much less frequency.
Drying time – after applying the concrete contact, if the instructions are followed, the surface is ready for further finishing within two to three hours.
Resistance to moisture - concrete contact, in fact, creates additional waterproofing, since when applied to the surface this composition forms a waterproof film.
Material consumption is the approximate consumption rate of concrete contact per square meter. a meter is between two hundred and four hundred grams. It should be borne in mind that these indicators are very conditional and vary depending on the technical characteristics of the composition itself, as well as on the characteristics of the surface being treated.

Properties of concrete contact

The mixture is characterized by increased performance characteristics:

fastens the base, which is covered with soil;
contacts with smooth, non-absorbent substrates, forming an adhesive layer;
does not contain harmful ingredients;
does not emit unpleasant odors;
used to cover substrates located indoors and outdoors;

forms a waterproof layer on a primed base, providing reliable waterproofing;

contains a dye that facilitates visual inspection during coating;
applied manually or mechanically;
supplied prepared;
dries quickly, which allows you to continue further work after two to three hours;
can be used for a long period (more than 50 years).

The high performance properties of concrete contact were appreciated by professional builders who use modern primers.

Peculiarities

Betonkontakt cement mixtures are intended for priming surfaces. The composition penetrates deeply into the fibers of the material, creating a rough coating on which finishing work is carried out. Special polymer compounds ensure reliable adhesion of the coating to the base.

The peculiarity of the building mixture is its versatility of use, since the composition is suitable for different types of surfaces (wall panels, ceilings, floors, arches, niches).

When using the material, it is necessary to prepare a clean surface free of dust and oil stains. It must have a temperature above minus. Concrete slabs, wood, metal, tiles, glass and other painted surfaces can be used as a base for the coating.

The products are used for interior and exterior finishing works. Without the mixture, it will not be possible to create the required degree of adhesion between different covering building materials. The primer allows decorative coatings to remain in place at sub-zero temperatures in the autumn-winter period.

Scope of application of concrete contact

Concrete contact primer is used on any surfaces that are unable to absorb moisture normally. Since the concrete surface absorbs moisture quite poorly, any construction mixture has poor adhesion to the surface. Treatment of the ceiling surface in this case involves the use of only a primer.
Until recently, qualified specialists, in order to prevent premature falling off of the plaster, applied a special product - a fabric mesh of the required size was glued to the surface using PVA, after which they continued to apply a layer of plaster.
This whole procedure took a certain period of time and required special skills. The use of concrete contact primer greatly facilitates the work of craftsmen. In addition to the speed of application, this product is also distinguished by its durability and reliability.
It is also worth noting that the above-mentioned primer can be used both indoors and outdoors. As a rule, it must be applied before starting surface finishing work - applying decorative plaster, installing tiles or decorative stone.

The unique properties of the primer composition allow it to be applied to surfaces of any configuration and complexity. The processed surface acquires a peculiar texture, which provides high adhesion.

Prohibitions on the use of Betonkontakt

It is not advisable to use a primer for:

Impregnation of crumbling, loose, fragile base.
Before laying a self-leveling floor or cement screed on a rough base.
On a wall whitewashed with chalk or lime.
On the base on which the tiles will be glued. Adhesion glue adheres to surfaces better. When Concrete Contact is also added, the tiles’ adhesion to the wall will be much worse.

We pre-treat a weakly absorbent smooth surface with an abrasive material to make it rough.

Is concrete contact necessary over oil paint?

Finishers also use Betonkontakt over oil paint. Most people advise removing the paint anyway, because both with and without concrete contact, the plaster under its own weight can separate from the paint. If the composition is firmly ingrained and cannot be removed by any means, you must:

Be sure to thoroughly degrease the surface.
Remove smoothness using abrasive treatment - coarse sandpaper or a wire brush. It doesn’t matter what, as long as it works.
Make notches using a chisel or axe.
Please note that some manufacturers position their Betokontakt only for interior work
Remove dust. You can wash it, you can vacuum it. The main thing is to be thorough.
Apply the first layer of concrete contact.
Dry.
Apply a second layer of concrete contact.
Dry.
You can putty, plaster, lay tiles.

In this case, it is also clear why Concrete Contact is needed and how it works. But it is quite possible to stop before the first application of Concrete Contact. If there are notches of sufficient area, both the plaster and the tile will stick. Use a suitable primer to fill any “chips” in the wall and, once dry, apply the next material.

Olimp has designated its Contact-Grunt as a product for decorative plasters and ceramic tiles

Many people assume that the sticky surface that Betokontakt leaves will hold better. In general, it works, but only if you do everything as written. And yes. Drying is complete and final. The expiration date is indicated on the can and differs depending on the manufacturer. The shortest drying period is 3-4 hours for Betonkontakt Fedal, the longest is about 24 hours for some cheap ones.

Scope of material use

Why do you need concrete contact
? Concrete contact is a special type of soil composition that is not capable of absorbing water. If this type of base is coated with a primer, it will crumble when it dries, since there will be nothing for the plaster layer to cling to on a smooth surface. To prevent the layer of plaster from slipping, concrete contact is usually used.

On what principle does concrete contact work?

The material is not cheap, so you need to buy it only in special cases. In order not to throw money away, you should first find out exactly the properties and scope of application of the composition. Each jar contains instructions for use, but finishing specialists give their own recommendations. Who to believe? To answer this question, let’s figure out how this material works.

After applying concrete contact, a sticky layer with inclusions of abrasive particles is formed on the surface, to which the plaster (putty) adheres well. Crystals or granules in the composition provide additional support to the finishing layer. In other words, the main task of concrete contact is to increase the adhesion of plaster to a smooth surface. But this method is not always suitable.

I repeat once again that concrete contact should be used for foundations that do not allow water to pass through, namely:

Smooth non-porous concrete. Typically, such walls are found in panel houses or in modern monolithic buildings. For concrete with a loose and porous structure, a different soil composition will be needed.
Ceramic tile. To install new tiles, it is not necessary to knock down the old ones. Of course, if possible, it is better to remove the old layer. But if this cannot be done, two layers of concrete contact are applied to the surface of the tile, and then a new tile is laid.
Wooden surface. Coating wood with concrete contact is the only way to plaster wood. But only if the tree is dry.
Metal. This material is guaranteed not to absorb water, and in order for the plaster to adhere to it, a layer of concrete contact is required.

INTERESTING: Chipboard: sizes, types and characteristics

So we have listed all the cases for which concrete contact is necessary. In all other options: under putty, under decorative plaster - this is a waste of money. There is no need to use this material so as not to worsen the situation. Putty and other finishing compounds will adhere perfectly to fresh plaster.

Recommendation from professionals: coarse-grained concrete contact is better suited for plaster, and fine-grained concrete for putty.

As for surfaces made of wood and metal, betocontact is used if it is necessary to plaster small fragments. For example, protruding sections of structures or beams. It is not advisable to use BC for processing large areas; there are special technologies for this. We are talking only about small areas.

Costs of concrete contacts of different brands - is there a difference?

The consumption of concrete contact from a wide variety of manufacturers depends, firstly, on such qualities of the treated surface as:

porosity;
absorbency.

In Table 1 you can see the consumption rates of concrete contact for surfaces of different structures.

Table 1

It can be seen that any primer per 1 m2 is consumed approximately the same.

There is a way to slightly reduce the consumption of concrete contact for porous surfaces - preliminary impregnation with a deep penetration primer and an antiseptic. Secondly, you need to keep in mind the influence of the size of the sand, expanded clay or marble chips included in the composition:

concrete contact with fine-grained (0.3 mm) filler is applied in a thin layer;
compositions with coarse-grained particles (0.5-0.6 mm) - thicker, about 1.5 - 2 times larger.

Thirdly, the consumption is influenced by the characteristics of the recipe of each specific manufacturer. You can compare the average consumption values depending on the brand of concrete contacts in Table 2.

table 2

As you can see, there is a difference, although not very big.

To accurately determine the consumption rate, the probe method is used:

a certain amount of concrete contact soil and the tool with which it will be applied is weighed;
a square meter of surface is marked out (with chalk or adhesive tape) and covered with soil to the required quality;
the remaining solution and tools are weighed;
find the difference in the scale readings - how much is the consumption rate;
the resulting value is simply multiplied by the total area to be processed.

Compound

Any variation of Concrete Contact, regardless of the manufacturer, contains the following:

Acrylic dispersion or copolymers. Responsible for adhesion - stickiness. Leaves a sticky viscous layer after drying. The quality of the polymers included in the composition affects the durability of the primer.
Fillers. Mostly quartz sand, but there are others. They are used to create roughness, which improves adhesion when applying the next layer.
Additives and additives that give Betonokontakt additional properties: water repellency, frost resistance, antibacterial properties.
Dyes. To control the application process without bald spots. When such a component is not in the composition, you can add it yourself.
The acidity level of Betonokontakt is neutral, which allows the primer to be used under both gypsum and cement putties and plasters.

How to buy concrete contact and not go broke on construction

Not a single professional will advise saving on priming surfaces with concrete contact. In order for the plaster, glue or topcoat to last long and firmly, the layer of such primer must be applied evenly, without gaps and have sufficient thickness. The greater the thickness of the concrete contact layer, the better its adhesive properties are manifested. There is no point in saving here - you can lose much more by spoiling, for example, not cheap drywall, tiles and other materials that have fallen off.

The sufficiency of the thickness of the covering concrete contact is determined simply: you need to run any spatula over the dried surface, and if the sand particles crumble, you need to apply another layer.

The cost of concrete contacts on the Russian market varies greatly, so the average price will not make much sense.

You can buy high-quality concrete contacts much cheaper from domestic manufacturers, especially since high cost does not always mean better quality. Often the price of concrete contact per 1 m2 is no more than 10 - 20 rubles (one-time coating).

Attention! Due to the fact that there are often counterfeits of the product or failure to comply with storage standards, an important question is: where to buy concrete contact? The answer is only from reliable suppliers, in specialized stores with stable temperatures, or through the manufacturer’s website.

Based on the consumption rates, it turns out that a 10-liter can of concrete contact is enough to cover 20 - 50 square meters. meters of surface.

If you also take into account the service life of the coating, it turns out that it is not that expensive.

FEATURES OF APPLYING PRIMER

Before use, it is recommended to mix the finished mixture thoroughly until smooth. During storage, the solution may separate, and this does not mean it is defective or unsuitable for use. The mixture contains substances of different densities; heavier cement and quartz filler can settle to the bottom. When applying unmixed soil, a pattern of uneven saturation is formed on the wall; accordingly, the adhesion strength to cement will also be different.

During preparation, the wall should be checked with a spatula for the presence of peeling, dirt, oil stains and deep cracks. Small cracks are not particularly dangerous for the use of concrete contact; thanks to the adhesive base, the primer thoroughly strengthens the surface layer.

The best option for applying concrete contact is to use a foam paint roller or a wide brush; in both cases, the soil is applied evenly and is well controlled due to the specific tinting. Most often it is white, although Krauf products use more expressive pink shades that cannot be confused with other primers.

The consistency of concrete contact is similar in viscosity to liquid sour cream or thickly grated paint; the soil is easily held on a brush or foam roller surface. When applying concrete contact, the best method is the sequential use of short vertical and horizontal strips. The optimal temperature for concrete contact is from +5 to +30°C. The instructions do not recommend using soil at higher or lower values due to the violation of the drying regime. In cold weather, concrete contact turns into a viscous mass that is completely impossible to work with.

The drying time of the layer is from 2 to 4 hours, but for a more complete use of all the benefits of the primer, experts advise not to wait and start plastering work after 2.5 hours.

The minimum recommended time is at least 2 hours; during this period, the use of any equipment in the room that generates dust or mist should be avoided.

Means of protection

Concrete contacts are chemically safe solutions, completely non-toxic. Nevertheless, it is recommended to use protective equipment when working with them - drops that get on the skin are not easy to wash off.

Windows and installed doors should be protected - they should be covered with cloth or covered with paper for the same purpose to prevent drops of acrylic and sand from settling. It is difficult to remove them due to the high adhesion of concrete contact with any surfaces. In addition, drops of soil can scratch the glass when removed.

Kinds

The main difference between the types of concrete contact is the size of the quartz sand particles, which determines the choice of surface for treatment with this mixture. In addition, there are primers that are intended only for indoor use, and a combined primer for external and internal use. The packaging of the primer composition always contains instructions describing the materials suitable for processing. It is worth trying to take into account the manufacturer’s recommendations, this will reduce primer consumption and obtain the desired result.

The following components must be present in the concrete contact:

Cement or Portland cement;
Fine quartz filler;
Polymer, most often acrylic, component;
Special technological additives.

The technical characteristics of the composition do not depend on the manufacturer or type of mixture and are always the same:

Environmentally friendly. The composition does not have an unpleasant odor or harmful fumes. To work with it, personal protective equipment for hands and respiratory tract is not required.
Resistant to alkalis and aggressive environments.
Waterproofing properties.

It allows gases to pass through, which creates proper air circulation in the room and prevents the formation of mold.
Resistance to parasites, mold and fungi.
Drying speed at room temperature and moderate humidity is only 2-3 hours.
The service life declared by the manufacturers is 80 years. After this period of time, the concrete contact layer begins to collapse.
Air temperature for work is 5-35°C, recommended humidity is 60-80%.

To make it easy to control the thickness of the layer and the uniformity of the coating, manufacturers add white or pink dye to the mixture, which is clearly visible on the surface being treated. Without dye, contact concrete is a clear liquid.

The solution can be applied to any surface either manually or mechanically using a compressor or spray gun. There are options for using mechanical devices; this must be indicated in the instructions. In addition, specialized stores have a selection of mixtures in aerosol cans.

Any type of concrete contact must comply with GOST 28196: according to its characteristics, it refers to water-dispersed compositions with acrylic copolymer. If the GOST number indicated on the packaging is different, it is better to refuse such a purchase.

The consumption of the mixture per 1 m² depends not only on the size of the sand particles, but also on the porosity of the treated surface:

for a smooth and slightly porous surface, such as a painted wall, metal and glass bases, ceramic tiles, the mixture consumption will be about 150 g/m².
for a medium-porous surface made of concrete slabs or finishing bricks, the consumption will range from 300-350 g/m².
for a highly porous surface, such as concrete or building brick, the consumption can be 500 g/m² or more; To reduce the consumption of concrete contact, the surface is coated with a deep penetration primer.

Concrete contact is sold ready-made in containers of 3, 5, 20 and 50 liters. To get started, you just need to open the lid and mix the composition so that the quartz filler is evenly distributed throughout the mixture. Stirring must also be repeated periodically during operation.

Before starting to apply the mixture, the surface to be treated is carefully prepared:

a coating that does not adhere well to the base must be beaten off or scraped off;
remove grease stains, glue and bitumen drips;
Clean the surface from dust and wait for it to dry completely.

Please note that the base must be treated with concrete contact immediately after it has dried. If a new layer of dust settles, cleaning will have to be repeated again. Concrete contact does not adhere only to dusty and greasy surfaces.

You need very few tools to apply the mixture:

wide brush, roller or spray gun;
stick for mixing the composition;
container with concrete contact.

You can apply concrete contact with a roller, but it is better to replace it with a wide brush. This way you can achieve a more even coating and better penetration of the composition into all the cracks and pores in the base. The mixture can be diluted with water, but only in cases where mechanical methods are allowed for application: this possibility is indicated in the manufacturer’s instructions.

On the contrary, it is better to prime a painted wall or drywall with a roller. With other methods, you can get a layer that is too thin and weak. The brush and stained surfaces should be thoroughly washed immediately after completing all actions. Uncured concrete contact can be washed very easily, but the hardened composition cannot be removed.

3-4 hours after applying the primer, it would be a good idea to check the quality of the resulting coating. It is easy to determine from the dried layer whether there are gaps or places where the primer has been completely absorbed. If such defects are found, the surface must be coated again with the same composition. You also need to check the strength of the layer, which needs to be scraped with a knife or spatula. High-quality applied material will not fall off or deform.

It is recommended to begin applying gypsum plaster or tiling to the surface no later than 12 hours after the surface has dried. Dust quickly settles on the finished rough layer and impairs its penetrating properties. If two or more days have passed after drying, the surface must be additionally treated with a deep penetration primer.

List of the most popular primers

Almost every building materials manufacturer produces a primer with concrete contact characteristics. If you are satisfied with the products of this brand, it makes sense to buy betocontact from the same company. We bring to your attention a list compiled based on reviews of those who worked with this material.

Knauf (Knauf). The composition is high quality, but not waterproof. It is important here to properly dilute the building mixture. If you overdo it with water, you can ruin everything.
Eskaro (Eskaro). It has a strong ammonia smell, so use only in well-ventilated areas. However, it fits well and is comfortable to work with.
Ceresit. The composition has added pink pigment, which makes application easier. But there is a high risk of running into a fake.
Pufas. It sticks less than others, but not by much.
FEIDAL (Feidal). Optimal price-quality ratio. Worth the money.
The German-made Shtock composition uses crushed marble instead of filler and is water-resistant.
Plitonite. After mixing, solid impurities settle slowly, which is also a plus. The composition is not bad.
Prospectors. Coarse-grained composition, dries quickly - 2-4 hours.
Olympus. Budget price and excellent results.
Bolars. The composition is too thick, it is difficult to spread, the time for complete drying is a day.
Found. The solution will have to be constantly stirred; it will take 2-3 hours to dry. Compatible only with gypsum plaster.

This list includes companies from different price categories. Typically, more expensive compounds are lighter and easier to apply. Cheap mixtures are harder to distribute. Due to the uneven consistency, they have to be stirred more often.

It is important to remember that when applying primer to the walls, you should not leave bare areas. If any are detected already at the drying stage, you will have to apply an additional layer and wait for the full hardening time. Otherwise, in the future you will have to replace the peeled fragment.

Many finishers are interested in: how to replace concrete contact, if the need arises? The only option in this case is Ceresit ct-16 primer. The result is the same, but the price will be more expensive.

Manufacturers

In today's market conditions, many manufacturing companies offer their own version of concrete contact. There are both very cheap and very expensive offers. The final decision on which composition to use always remains with the consumer. But still, it is better to understand the main suppliers of such goods in advance.

to , Axton concrete contacts also contain marble chips. Used for application indoors and for outdoor use. The composition is in good standing among consumers. The only drawback is complaints about high mixture consumption. The average price is 300 rubles per 6 kg.

Betonokontakt is designed for work on old tiles, on durable layers of alkyd or oil paint. It is used for both external and internal work. Mixture consumption is 200-300 ml/m². The average price is 500 rubles per 6 kg.

Concrete contact production is also suitable for work both inside and outside the building. Suitable for both concrete and smooth tiled surfaces. Available in fractions of 0.3-0.6 mm and 0.6 mm. The price for a 5 kg package is within 300-350 rubles.

Concrete contact "Bitumast" is not much different from its counterparts. Produced by KhimTorgProekt in St. Petersburg. Suitable for outdoor and indoor use. The average price is 700 rubles per 7 kg.

The concrete contact has a quartz sand fraction of 0.4 mm. Mixture consumption from 170 g/m². Suitable for both indoor and outdoor use. The average price is 400 rubles per 4 kg.

Bettokont from is also suitable for any work, but differs in increased mixture consumption. The manufacturing company indicates a consumption of 450-500 g/m². At the same time, the cost of 6 kg of the composition will not exceed 450 rubles.

The most important thing when purchasing a mixture is to shop only in specialized stores and choose products from well-known manufacturing companies. To be more confident, it is recommended to read reviews on the Internet.

Instead of output

Before purchasing a primer, read the instructions carefully. After all, each composition has its own purpose, and this must be taken into account before purchasing. Some primers are suitable only for a gypsum layer, others - for gypsum and cement. There are mixtures for external use, and some only for interior use. Universal options are also sold.

On store shelves you can find compositions that are suitable for application to painted walls or ceramic tiles. The main thing is that before you pay for your purchase, carefully study the manufacturer’s recommendations regarding the use of their products.

Reviews

As you would expect, reviews of concrete contact are in most cases positive. There have still been no disputes about which mixture manufacturer is better. But occasionally there are negative reviews, but they are more likely about sellers, not about manufacturers.

On one of the forums, a man told a terrible story that after applying concrete contact to the ceiling and then whitewashing it, the result was not satisfactory. At first, pinkish reflections could be seen under the layer of white. And after a week, the whitewash began to chip off along with the primer.

Professional builders in this case explain that either the composition was purchased with an expired expiration date or after repeated freezing, or a fake was purchased.

Such cases, unfortunately, do occur. Therefore, if the purchase of concrete contact occurs not in a specialized store, but in the market, then it is better to open the container and check the homogeneity of the mixture. If the solution is not homogeneous, the purchase should be abandoned.

Recommendations

Concrete contact cannot be applied before plastering with a cement mixture. The peel-off strength of the film after such a primer is 0.1 MPa less than that required for cement-based mortars. Therefore, plastering with cement compositions should be carried out only on concrete.

When purchasing a primer, you need to pay attention to the production date and storage conditions. It is recommended to use only formulations that have been manufactured less than a year. If the concrete contact was stored incorrectly and was subject to freezing, there is no point in using it. After defrosting, this mixture loses its adhesive properties.

To reduce the consumption of concrete contact, the surface is pre-coated with a deep penetration primer. If the base is too dry and porous, after the first layer has dried, you need to apply the primer again. Treatment with concrete contact is possible only after the soil has completely dried.

What is concrete contact, see below.

general information

Let's find out why Concrete contact is needed. When it is necessary to roughen non-absorbent, dense, smooth substrates to improve adhesion (adhesion, stickiness), the Betonokontakt primer is successfully used. This makes it easier to subsequently lay plaster and gypsum putty. The material design varies, designed for different operating conditions and requirements for the basic rough surface.

The primer was invented by the German company FEIDAL. In the original it is called Betokontakt. In Russia, it is most often called Betonokontakt, since initially the ready-made mixture was always applied to concrete.

There are various other names for soil that are given by manufacturers to distinguish their product from competitors. The original composition remains with the company-inventor.

For others it may differ slightly.

Concrete contact has the following positive qualities:

environmental friendliness;
vapor permeability;
high drying speed;
long service life;
durability.

Where you should absolutely not use the composition

It is important to know not only why Concrete Contact is needed, but also where it is not needed and even harmful. For example, you should not listen to advice to saturate loose or loose substrates with the composition. This requires other deep penetration primers. And Betonokontakt sticks to a smooth surface without particularly trying to penetrate it. It makes no sense to cover whitewash, ordinary fiberboard with a loose structure, gas and foam concrete, plaster, etc.

Betokontakt is often purchased for priming a wall or floor before laying tiles. If the surface absorbs water, you should not do this. And that's why. Look at the characteristics of tile adhesive and BC. The glue has an adhesion of 0.8-0.9 MPa, and BC has an adhesion of 0.4-0.5 MPa. That is, by adding a layer of concrete contact to a normally absorbent base, you are worsening the situation at your own expense, and considerable money at that. Although some manufacturers write in the instructions that the composition can also be used for laying tiles. But the situation with adhesion is similar...

For external and internal work it can be used over old paint (written in the description)

If you want to ensure that the tiles do not fall off, take good glue. Yes, it is more expensive, but a pair of BC + cheap glue costs no less, and the result is unpredictable. If in doubt (not a very reliable base), it is better to use a deep penetration primer and/or a better adhesive. It is usually positioned “for difficult surfaces” and holds tightly, as it penetrates deeply into the base.

The use of Betokontakt will do more harm than good when applied under self-leveling floors. Cement ones will have worse adhesion than they could have, and gypsum ones will simply have to be “pulled.” They practically do not spread on the sticky base. The result is cracks, swelling and other very unpleasant moments. These are not the surfaces and cases for which Concrete Contact is needed.

Important rules and conditions for performing external and internal work Adhere to the following recommendations:

Primer, incl. intended for outdoor use, applied at a temperature of +5…+35C. In the cold the material thickens and in the heat it loses its working properties. Skin, hair and eyes are protected with protective clothing, gloves and goggles. The composition is sticky and can be removed with great difficulty when dried. Hair has to be cut. When treating the ceiling and walls from above, it is recommended to fasten a brush or roller to a 1 m long stick. This will allow the master to be at a safe distance, where drops of primer will not fall on him. It is recommended to lubricate exposed skin with a rich cream or oil so that the concrete contact is washed off more easily. Using a roller or brush, they are periodically cleaned of sand on the edge of the container. Without this, the pile will quickly clog and become unsuitable for work. During the application process, the primer is periodically stirred to lift the settled sand. If these rules are followed, the coating will be strong and durable.

Video description

From the video you can get acquainted with the features of various primers:
There are points for which concrete contact is needed, but with limitations. This applies to metal, wood, plastic and glass. The expected result will be obtained only on a mineral surface with the listed inclusions. For a solid base, the option of subsequent finishing with light weight using paints and varnishes would be relevant.

Experts note deviations from the expected when concrete contact is used under self-leveling floors. If you have to work with cement mortar, the adhesion is good, but gypsum does not spread. As a result, cracks and peeling of the coating appear.

What not to do

If you wish, you can find reviews or videos that say that the plaster/tiles have fallen off from Betonkontakt. To prevent this from happening, apply primer only to recommended substrates. In addition, you should not do the following things:

Dilute the plaster or putty composition with more water than indicated on the package. Yes, it’s easier to work with, but as a result, the putty may collapse.
Do not apply the composition to frozen ground.
Do not apply Betonokontakt to an unprepared surface (remove all detachable parts, degrease, remove dust).
Do not apply BC on a damp base. Dry only.
Eskaro produces a primer for non-absorbent rigid substrates with increased water resistance
When working, do not forget to periodically mix the contents, as sand particles (granules from some manufacturers) fall down.
You cannot continue work until the primer layer has completely dried (indicated in the instructions).
Do not work at temperatures below +5°C. This does not mean that it cannot be used for outdoor work. It is possible, but it must be applied at positive temperatures.
Do not allow dust to enter. It sticks very well to the adhesive surface, but then falls off along with the plaster. If the surface is dusty, another treatment is necessary.
Do not use a composition that has expired or has been frozen. The exception is frost-resistant compounds (there are such). Before use, they must be defrosted, wait until the temperature rises above +5°C, then you can work. By the way, the inscription “frost-resistant” does not mean that it can be applied at sub-zero temperatures. It can only withstand several defrost/freeze cycles before application without loss of properties.
The German company Bergauf also has an acrylic primer Beton Kontakt
Do not add water, even if it seems that the composition is too thick. Unless the manufacturer described this possibility in the instructions. But so far we haven’t seen any of them.

And for Betonokontakt to work, it must be “real”. There are a lot of fakes, so you have to be careful. And to be sure, you can check. Pre-treat a small piece of wall with BC according to the instructions. Apply the planned layer of plaster/putty. Wait until it dries and try to tear it off. If everything is done correctly, nothing will work out for you. They say that high-quality Betokontakt allows you to apply plaster even on glass. By the way, you can try it.

Errors at work

Due to inexperience or ignorance, building materials for intermediate installation are often used, making mistakes. The consequences of this can be unpredictable, and it is almost impossible to track the processes of destruction under finishing in a timely manner. This also applies to concrete contact.

Consequences of violating plastering technology Source kontrolstroy.ru

In reviews, there is often a remark about adhesives and leveling mixtures that they have poor adhesion to soil with quartz. This is only possible if the solution contains an excess amount of water. This drawback leads to the separation of mixtures due to a disrupted moisture transfer process and a low concentration of the binder component.

Deviations from the declared soil parameters may occur for the following reasons:

applying the composition at temperatures below +7 – +10°C or above +25°C, at a relative air humidity above 65%;
processing frozen or wet bases;
finishing of an unprepared surface (dust, grease stains, affected areas, weak spots);
inadequate drying of the coating (how long the concrete contact dries depends on the recipe, the original takes only 3-4 hours);
wind or draft accelerates the process of water loss and the formation of dry residue, but disrupts its quality;
adding water reduces the concentration of the binder and deteriorates the quality of the adhesive film;
use of cheap analogues of Betokontakt for “heavy” finishing.

“Heavy” wall cladding with porcelain stoneware Source otdelkino.ru
Dust can be invisible, but it actively sticks to the primed surface. The plaster and glue will peel off from such a base. You will have to do the pre-treatment again.

The solid filler is heavier than the other components in concrete contact. It settles relatively quickly to the bottom of any working container. Therefore, it is important to stir the composition periodically.

The original soil is stored in an airtight container for only 2 years, analogues from six months. Mostly natural ingredients will most likely not cause any harm to health after the expiration date. But quality indicators will noticeably decrease. After sub-zero temperatures during storage, it will be possible to work only with frost-resistant soil. But in any case, it is applied at temperatures above +7 – +10°C to +25°C. This applies to the material, the base and the air.

What to apply

You need to not only know why Concrete Contact is needed, but also how and with what to apply it. It just seems like there is nothing complicated about it, but try it first. The composition is often thick, approximately like kefir, and sometimes thicker. Moreover, it contains grains of sand and crystals, which it is very desirable to distribute evenly over the entire surface, and not collect in one place. In general, it's not that simple. There are some tips:

It is best to work in protective clothing, and it is advisable to cover everything. It is washed off from the skin with great problems; it is removed from the hair only along with the hair. To make it easier to wash off unprotected areas of the skin, cover it with a thick cream or some kind of oil. When treating the ceiling, it is advisable to protect your face, even if you have applied cream/oil to your skin. At the very least, glasses are a must.
Applying Betonokontakt primer is not so easy
When treating a large area, it is easier to apply with a roller. It is more convenient to take it in a size that fits into a bucket. It is better to work with a fleecy one - with a pile of 12-18 mm. Yes, some amount of the composition is absorbed, but it is really more convenient to work this way than with foam rubber, which very quickly becomes “wooden”. Moreover, even in this case, after some time the pile will become clogged with sand. As you work, remove the sand on the edge of the bucket, you can try with a spatula. Basically, clean it up. If it can no longer be cleaned and “doesn’t work”, get a new one.
For processing not too large surfaces or in corners, it is more convenient to work with a brush. The pile is medium or even short. Here it is more convenient for anyone. It’s just hard to manage the long one when it’s full of sand. During the application process, sand must be periodically removed (on the edge of the bucket). The brush wears out quickly, so with large volumes of work you will have to change it several times.

There is one more trick - attach a brush or roller to a stick about a meter long - and you don’t need a stepladder when working on walls, and keep yourself away from yourself - fewer drops will fly onto your clothes and into your face.

For priming smooth, non-absorbent surfaces there is no alternative to concrete contact.

To prepare for finishing loose, crumbling, porous surfaces, it is necessary to strengthen them by impregnating them to a certain depth, which requires deep penetration soil. It can be used independently or before concrete contact. If you use only concrete contact, the consumption may turn out to be exorbitant.

Is it possible to apply concrete contact to drywall?

Complex application or just a primer or concrete contact - which is better must be decided taking into account all the specific conditions separately for each case.

Concrete contact for external work: features and properties

According to their purpose, concrete contacts are:

for interior work;
combined - for internal and external.

Specialized compositions only for external use are not yet available. For this purpose, concrete contact is used, the instructions of which directly indicate the possibility of its use for priming the surfaces of the facade or foundation of a building for putty or plaster. At the same time, all the characteristics that determine concrete contact remain unchanged.

Is it possible to apply concrete contact to whitewash?

There is some disagreement about whether concrete contact should be used under cement plaster. Or why use it for foam blocks - after all, their surface is initially quite rough, and the structure is such that it requires a deep penetration primer more.

More often, for outdoor surfaces, soils containing coarse-grained fractions of quartz sand are used (expanded clay, marble, etc. chips are also successfully used), capable of holding heavy plaster.

When planning plastering and facing work on the outside using fastening layers of concrete contact, you need to remember that it only works at positive temperatures. When the temperature rises to more than 30 degrees (40 degrees for some brands), the properties deteriorate significantly - the uniformity of drying is disrupted. At temperatures below +5 degrees, concrete contact gradually turns into a viscous sticky mass that is impossible to work with (if the “frost-resistant” property is indicated, then it refers to storage conditions).

Is it possible to apply concrete contact to putty?

But when finished, treated with concrete contact and dried (concrete contact dries very quickly), any surface retains its properties in a wide range of temperatures and under any external atmospheric influence. Therefore, it is used with great success for the conservation of facades - when finishing work has to be suspended, for example, for the winter.

The price for universal concrete contact is not too different from the price for concrete contact for interior work.