Despite the fact that concrete is rightfully considered one of the most durable building materials, due to exposure to high humidity, high temperatures and other factors, it can collapse. To avoid this trouble, it is customary to use sealants for concrete. What they are and features of the application - in the article.
Why do I need sealant?
If the concrete is not properly mixed or exposed to external adverse factors, the material may begin to break down. At the same time, microcracks are formed in it, which increase in size over time. Sealants for concrete are necessary to prevent cracking of the material and the loss of its qualities.
At the same time, the product should easily tolerate temperature changes, extreme heat or frost, and also be moisture resistant. To seal cracks in concrete, experts recommend using a concrete sealant for outdoor use, the main component of which will be polyurethane. These types of material are also suitable for processing external seams.
Varieties
According to the method of exposure, materials are divided into two main types:
- Surface, which cover the concrete surface with a moisture-resistant film.
- Penetrating, which protect the material from cracking, penetrating the entire depth of the mortar.
According to the variety of the main component, they distinguish:
- silicone - contain silicone, the amount of which is 45% of the total mass, they are used to seal aquarium, window seams, in bathrooms;
- acrylic are used mainly for interior work, as they lose their properties when exposed to low temperatures;
- bituminous are used for installation and repair of roofs, as they easily come into contact with roofing;
- polyurethane are the most versatile, as their properties allow them to be used for both indoor and outdoor applications;
- rubber used for processing roof seams and facade work;
- polymer;
- silicate.
There are also specific two-component concrete sealants that must be thoroughly mixed before use.
Applications
The choice of sealant depends on the purpose of use. When choosing, you should pay attention to the information that is indicated on the package. There is information about moisture resistance, frost resistance, heat resistance and otherparameters to consider when choosing a tool. It is also not recommended to use joint sealants in concrete for internal work in sealing cracks from the outside, as this will lead to rapid deterioration of the material.
When filling joints or cracks that are below the water level, it is necessary to use sealants that are designed for some pressure, this will also be written on the package. To fill voids in roofing or other movable structures, the use of sealants, which have some mobility, is recommended. In addition, there are separate types of sealants for window glass and aquariums that are designed exclusively for this purpose.
Application temperature
Sealants for joints in concrete for outdoor or indoor use have different frost resistance. They must be taken into account when purchasing a particular material. Typically, the temperature stability of universal sealants is from -50 to +200 degrees.
Choosing shade
Acrylic, silicone or polyurethane sealants for concrete are available not only in the classic transparent or white version, but also in color. Some types of materials have the possibility of staining after solidification. This is true for cases where the shade of the sealant does not match the color of the base material.
Benefits
The positive aspects of the building material depend on the specific product chosen, but most of them have similar advantages:
- preventing the penetration of dirt, dust, grease, chemicals and moisture, which greatly increases the service life of concrete and simplifies its maintenance;
- improving the wear resistance of concrete pavement;
- long service life;
- ease of use;
- prevention of defects, cracks.
Quality products have virtually no drawbacks, except for the presence of harmful impurities in some mixtures. When applied correctly and curing conditions are met, interior or exterior concrete sealants have a reasonably long service life.
Required tools
In order to process the seams with a waterproof sealant for concrete, it is necessary to stock up on tools, without which the use of mixtures is not possible.
- Pistol. There are a great many varieties. There are pistols with mechanical and automatic control, closed and open type. The most affordable are the manually operated open-type tools and are often used for home concrete joint sealing.
- A spatula is needed to level the sealant layer. They come in metal, plastic and rubber, and are embossed to form a beautiful seam.
When sealing seams with tools, it is important to avoid contact with the skin of the hands, as most formulations contain substances that can cause skin surface irritation or even chemical burns.
Removal tools
In some cases, concrete grout must be removed from the surface. This may be necessary in case of inaccurate application of the material. There are two main ways to do this:
- Mechanical, which involves the removal of excess sealant from the surface of the concrete using rough action, namely by scraping the mixture with scrapers, spatulas and other tools. Large frozen pieces of material can be cut off with a clerical knife.
- Chemical, which consists in the use of compounds that soften the sealant and make it possible to remove it from the concrete surface. Unfortunately, this method is applicable only for silicone materials, while the rest require rough mechanical action.
Experienced professionals agree that it is much easier to prevent sealant from getting on unwanted surfaces. For this, masking tape is used, which is attached along the entire length of the crack or joint on both sides. After application of the composition, it is removed, leaving behind an even strip of sealing compound.
Apply sealant
To start working with sealant, you must carefully study the instructions for use. If the product is one-component, then it must be used immediately, if it is two-component, then they must be thoroughly mixed. It is recommended to apply the sealant to the concrete using a manual or automatic gun, so that a uniform seal can be achieved.composition distribution.
To ensure good adhesion to the surface, it must be thoroughly cleaned of possible dirt, dust, debris, paint or oils. Sealant can only be applied after cleaning.
It is not recommended to apply the sealant in the presence of weather precipitation, such as rain, snow, hail, as in this case it is impossible to ensure good adhesion of the sealant to concrete. Because of this, after a while, chips and cracks may occur. To seal interpanel type joints, it is allowed to apply concrete sealant directly to the insulation material.
The drying time for a specific type of sealant is indicated by the manufacturer on the packaging and varies from several hours to several weeks. All this time, it is strictly forbidden to allow atmospheric precipitation to enter the surface of the composition, as this will negatively affect the durability and strength of the sealant.
Sealing and injection
Small surface cracks can often be filled with a small coat of concrete sealant, but if the crack is deep, concrete injection may be used. This procedure is the introduction of a sealing compound deep into the defect using high pressure. Inside, it spreads evenly, filling the internal voids.
This method is quite costly, since injection requires equipment that will providenecessary pressure, the consumption of sealant also increases. However, the results are impressive, since even the deepest and largest defects can be eliminated in this way.
Conclusion
Before you buy a sealant for concrete, you need to decide for what work it will be required, since different types of materials are used for different purposes. Experienced builders are always advised to study the instructions from the manufacturer, which is indicated on the product packaging, so you can find out all the nuances of working with a particular composition. The procedure itself for sealing joints or cracks is not particularly difficult, but requires minimal skills in working with concrete and sealants.
