Concrete primer: review of compositions, recommendations for use

Although concrete surfaces are strong and long-lasting, they require occasional maintenance to maintain their best. Concrete primer is one tool that can be used to prepare and protect these surfaces. This necessary product ensures better adhesion and a longer-lasting result by creating a smooth, uniform base for paints, sealers, or other finishes.

We’ll look at the various kinds of concrete primers that are out there in this post. Every kind, from epoxy-based to water-based, has special qualities and uses. We’ll weigh the benefits and drawbacks of each to assist you in selecting the ideal primer for the demands of your particular project.

We’ll also provide helpful hints on how to correctly apply concrete primer. Whether you’re restoring an old surface or starting from scratch, our detailed instructions will guarantee a perfect finish. By using the appropriate primer and technique, you can prolong the life of your concrete in addition to improving its appearance.

Composition	Recommendations for Use
Acrylic Primer	Ideal for indoor use on dry surfaces; enhances adhesion for paint and coatings.
Epoxy Primer	Best for sealing and waterproofing; suitable for both indoor and outdoor applications.
Polyurethane Primer	Recommended for high-traffic areas; provides excellent durability and chemical resistance.
Alkyd Primer	Useful for surfaces prone to rust; works well on metal and wood in addition to concrete.
Silicone Primer	Effective for weatherproofing; ideal for exterior surfaces exposed to harsh conditions.

Concrete primers are essential for preparing surfaces before applying paints, coatings, or adhesives. This article explores different types of concrete primers, highlighting their compositions and the specific benefits each type offers. It also provides practical tips on choosing the right primer and applying it effectively to ensure a durable and long-lasting finish. Whether you"re a professional or a DIY enthusiast, understanding these basics can help you achieve the best results for your concrete projects.

Why is it important to treat a concrete surface with a primer

A common misconception is that a concrete base doesn’t need to be protected.

Concrete is sensitive to the effects of different aggressive environments and loads, even though it is a material with a long service life.

• Water that gets through the pores, freezing, can lead to stratification of the material, the appearance of microcracks.
• The reinforcement in the concrete body begins to rust under the influence of water, gas, salts, which also gradually leads to destruction.

• If we talk about concrete floors, then the top layer of the base is quite fragile, during operation it begins to deteriorate, dust appears, which is harmful to human health and worsens the characteristics of the floor.

When a concrete surface is primed, it provides:

1. The primer binds dust particles and the surface is dust-free.
2. Primer for concrete surfaces protects the base from the formation of fungus and mold.
3. With the help of such compounds, the adhesion of a smooth concrete base with subsequently applied coatings is improved. Otherwise, after finishing work, cracks in the plaster and paint may appear, and the wallpaper may peel off.
4. As a result of using a primer, the quality of application is improved and the consumption of liquid and paste finishing materials is reduced.
5. Primers close the pores of concrete, thereby protecting it from external influences and increasing its service life.
6. The use of primer allows you to strengthen the top layer of concrete, make it more resistant to loads.

Taking everything into account, we can say that applying a primer to the floor, walls, ceiling, and other concrete bases is essential. GOST 31384-2008 "Protection of concrete and reinforced concrete structures from corrosion" lays out the specifications for the materials that must be used to protect concrete.

Types of primers

The following elements need to be considered when selecting a primer:

• the area where the work is carried out: outdoors or indoors;
• the conditions under which the treatment takes place: temperature, humidity;
• the loads that concrete surfaces will have to withstand;
• possible effects of various environments on concrete during operation: moisture, ultraviolet light, chemicals, temperature changes;
• type of concrete surface (for example, primer for foam concrete or aerated concrete should be suitable for porous surfaces);
• often the drying time of primers is quite important, so when choosing a coating you should inquire how long the primer dries on concrete;
• the type of finishing material used after priming, since the compositions must be compatible.

Let’s determine which methods for priming concrete bases ought to be applied in which circumstances.

1. Depending on the location of the object, the concrete surface of which needs to be treated, there are primers for internal and external work.
2. Based on the type of surface to which the primer is applied, you can use compositions for fresh and old bases, for smooth concrete or for cellular materials. In the latter, fillers are additionally introduced to fill the pores.

The compositions are separated into three categories based on the impact on the concrete surface:

• Impregnating primers. Such materials are applied to fairly loose surfaces. They are used to strengthen the top layer. The adhesive components of primers, penetrating into concrete to a depth of 50 mm and hardening, help fill microcracks and pores and bind particles together, as a result of which the concrete surface is given the necessary strength.

Suitable for both internal and external work, "Nova" primer contains silicone emulsion, biocides, and acrylic resins for impregnation of porous and fragile concrete surfaces. With the exception of UV light, it creates a matte film that is weather-resistant on the concrete surface.

Apply with a brush, roller, or spray in 1-2 layers at temperatures above +5 degrees, with an average composition consumption per layer of 0.15 kg/sq.m.m. A five kilogram canister costs seven hundred rubles.

• Deep penetrating soils. These compounds are used to treat strong concrete surfaces. Deep penetration primer for concrete is able to penetrate into the structure of the base to a depth of 5-7 mm. As a rule, a penetrating primer for concrete has latex composition, which allows you to create a continuous protective coating.

By using "Toiler," a penetrating soil additive based on acrylic dispersion, you can decrease the water absorption capacity of concrete and enhance the material’s adherence to finishing touches. The composition’s average consumption is 0.15 l/kV.m. It is advised to apply this deep-penetration soil to concrete in one or two layers. Ten-liter canisters are priced at 380 rubles.

• Adhesive soils. With the help of these products containing particle adhesion, a film that has an excellent clutch with finishing coatings can be created on a poorly subpooring concrete surface. Such soil is very good, for example, if it is planned to lay concrete on concrete on a primer.

One soil composition example of this type is "Unis Concrete Asset." It works well on low-absorbent, smooth concrete surfaces both inside and outside the building. It has antiseptics that keep concrete safe from mold and mildew, as well as a mineral filler that strengthens the bond between the base and applied finishing coatings (such as tile adhesive, plaster, and wallpaper glue).

Applying this composition that dries quickly (it takes no more than four hours) needs to be done at a temperature of +5… +30 degrees. 0.3 l/sq.m. is the average consumption of concrete primer. A ten-liter can costs about 600 rubles.

Primers can be classified into the following categories based on their chemical makeup:

The "Water-dispersion paint and varnish materials" GOST R 52020-2003 contains the composition requirements.

Drying quickly (in two to three hours) The composition based on water has a high penetration rate. Since acrylic primer has no smell, it is safe to use for indoor finishing projects. These primers offer superior adhesion when used with finishing coats. These primers are the best when it comes to economics.

Important: It is not advised to use acrylic-based primer in highly humid rooms.

There are several compositions made with acrylic, such as Henkel’s ST-19, Krasko’s Akrial-Grunt, Betonit VD-AK-020 primer, and Beton-kontakt primer from Lakra.

Smooth surfaces inside are treated with concrete ST-19 primers. They have good adhesion to concrete, are vapor-permeable, and are friendly to the environment. They also contain crushed quartz sand. The primer consumes 0.3 to 0.7 milliliters per square meter and dries in 4 hours. Packages weighing 15 kg are 1,000 rubles.

• Polyurethane composition

Primers made of polyurethane fill in tiny pores and cracks in concrete, offer superior adhesion for base and finishing coats, effectively remove dust, and strengthen the surface’s resistance to wear. The primers’ properties enable their application in the processing of industrial floors.

"Polybetol" is a single-component material that can be used as a stand-alone coating, is chemically resistant, and has no smell because it doesn’t contain solvents. The amount used in 1 m2 is 0.1 kg.

When applying primer, the temperature must be higher than -10 degrees. The high cost of these compositions is a drawback. Ten kilogram cans will set you back 4000 rubles.

• Epoxy primer

Concrete is perfectly protected from chemicals and moisture by epoxy primers. They are suitable for use on damp surfaces. They are resilient to mechanical impacts. Primers can be applied over epoxy paints or as stand-alone coatings.

It is noteworthy to mention that these compositions are used as a foundation for epoxy floors that level themselves on their own. The only drawback is an offensive odor, which needs to be considered when selecting a composition.

"Epoksol" is a green coating that effectively reduces dust from concrete, fortifies the surface, boosts resistance to frost and cracking, and shields it from chemicals and corrosion. Applying the composition to wet concrete is permitted.

The primer is created by mixing and diluting the two components of the composition with water. Its consumption is 200 g/m 2 when applied to a clean surface at an air temperature higher than +8 degrees. The cost of 7 kg of primer is approximately 2300 rubles.

• Alkyd primer

Alkyd primer is long-lasting, abrasion-resistant, deeply penetrates the concrete’s structure, and can be applied in extremely cold temperatures. Its durability is not as high as that of analogs, and it takes at least 12 hours to dry.

Both indoor and outdoor work can be done with the reddish-brown composition "Lakra." It offers superior adhesion of materials and good anti-corrosion qualities. Material consumption on average: 0.1 kg/sq.m. It is put on in one or two layers. It takes 24 hours for drying. About 2000 rubles will get you a 20 kg can.

• Polystyrene primer

Although polystyrene primers dry quickly, they should be applied outside or in an area with good ventilation because of their bad odor. It is advised to process facades or use such hazardous chemicals in production. In residential settings, they are hardly ever applied to surfaces.

• Polyvinyl acetate primer

These compounds are applied after paint or glue containing PVA is applied. Only indoor surface treatment is done with them. Primers made of polyvinyl acetate dry quickly—within an hour.

Apart from pre-made compounds, PVA glue can also be used to create your own primer. Polyvinyl acetate is a solid, colorless, and odorless material that is emulsified to create this adhesive. You’ll need a construction type of glue to prepare the primer.

Simple technology can be used to create soil:

• The breeding process should be carried out in a warm room.
• Glue is poured into the prepared container.
• Dilute it with water in a ratio of 1:2.
• The mixture is vigorously stirred until smooth. Care should be taken not to form a watery film.

Crucial! Use a construction mixer to get a higher-quality mixture.

• To improve the properties of the glue, crushed chalk is added.

Making a primer is not at all difficult, as you can see.

Nevertheless, the properties of the final composition are insufficient to guarantee that the primer will fulfill its necessary functions. Only material adhesion and a limited degree of environmental protection for the concrete can be provided by the artisanal primer. Furthermore, applying a homemade primer may cause the finish coating to peel and develop yellow spots, which are most common on wallpaper.

Factory primers cannot be entirely replaced by the prepared solution. Only non-critical surfaces can be treated with a composition like this. Therefore, it is important to acknowledge that this primer’s primary benefit is its affordability.

Using wallpaper glue to make a primer for treating a concrete surface appears to be a far more acceptable solution. Such a product can be made into a primer by diluting it with more water than needed to make the glue (the ratios are typically listed on the container).

Another kind of primer can be prepared separately from acrylic paint by diluting it 1:1 with water. Applying the mixture to a concrete surface before painting with the same paint is appropriate.

Concentrates (shown) diluted with water can also be used to prime concrete surfaces. Moreover, this choice saves money.

Waterproofing coatings are typically used for the protective treatment of concrete structures that are situated on the street, such as blind areas, walls, plinths, pools, and foundations. Among them are liquid rubber and glass in particular. These coatings give concrete a layer that repels water.

While using rubber, the surface still needs to be primed, but with liquid glass, you can skip the primer.

Primers paint is a paint and primer mixture that can be applied to a concrete surface at a lower cost.

The longevity and aesthetic appeal of your concrete surfaces can be greatly enhanced by using the appropriate concrete primer. Better adhesion and a longer-lasting finish are ensured by using a high-quality primer when prepping a floor, wall, or other concrete structure. It strengthens the bond between the topcoat and the surface, avoiding problems like peeling and cracking.

Think about things like the type of surface, the surrounding conditions, and the desired final finish when selecting a primer. Benefits from improved adhesion to moisture resistance are provided by different compositions. Long-term time and cost savings can be achieved by taking the time to choose the right primer.

Selecting the appropriate primer is not as important as applying it correctly. For optimal results, always adhere to the manufacturer’s instructions. It is essential to properly prepare the surface, which includes cleaning and repairing any damage. This guarantees that the primer will be able to pierce the surface and offer a strong base for layers that follow.

In conclusion, a properly chosen and applied concrete primer is a small investment that yields a more beautiful and long-lasting finish. Whether you work as a professional contractor or are a do-it-yourself enthusiast, knowing the fundamentals of concrete primers can greatly improve your projects.

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