During the repair, it is impossible to do without material that facilitates the connection of two absolutely incompatible elements. In this case, concrete contact comes to the rescue, which helps the finishing materials to firmly anchor on the wall or among themselves. The components for its production are quartz sand, very strong glue, and acrylic. Thanks to this composition, you can get good adhesion and simplify the finishing process..
Primer concrete contact will make the surface rougher, and after that you can start processing with the desired material.
The use of this solution is an occupation that requires a lot of attention. There are many nuances to keep in mind. But it is impossible to do without this primer when you need to finish concrete walls or ceilings. Do not forget about the main rules for applying the mixture. And of course, you need to know how to calculate how much primer floors, ceilings, and other surfaces require. This will allow you to immediately purchase the right amount of mortar for your area..
Where is applied?
It must be said that due to the nature of the primer, it can be used for a wide variety of mixtures. These are concrete ceilings, walls, various tiles. In addition, covering the building with facade decorative plasters will not do without this material.. Absolutely on any surfaces: both inside and outside the concrete contact will successfully cope with the functions assigned to it.
How to calculate?
Concrete contact primer can be used not only on concrete walls, but also on any other surface. You need to know that there are features of consumption, it can vary depending on the type of surface on which it is applied. For example, when working with concrete walls, he is alone, but with brick or drywall it is completely different..
Divide surfaces depending on such parameter as porosity. So, there are three types of such surfaces.
- Porous – among them are brick, concrete with sand and polished. In working with these materials, the consumption of concrete contact per 1 m2 will be about 0.3 – 0.5 kg. In addition, if the surface has high porosity, then it must be treated with special deep penetration impregnating materials..
- Medium porous – it can be monolithic concrete, concrete tiles or self-leveling floor. Here the rate per 1 m2 is as follows: 0.2 – 0.35 kg.
- Low-porous – for example, ceramic tiles, rubbed concrete or paint. For them, it will be enough to use about 0.15 – 0.25 kg of material.
What else does the expense depend on??
If the walls that you have to work with have good moisture absorption, then you will need to use much more primers. By the way, manufacturers on their packages indicate that 300 grams will be needed per square meter of solution. But in fact, this indicator most often does not correspond to the declared one, and the rate of concrete contact has its own characteristics.
In order to obtain information about what the norm of the primer is, you need to use a so-called probe. To do this, you need to select a 1×1 meter square, as well as a certain amount of solution that will be applied. It is necessary to weigh the mixture together with the container in which it is located. After that, you can start applying concrete contact to the surface. In the process of finishing, we check whether the mixture holds tightly, if something is wrong, fix it.
After the work on the whole square is completed, you can weigh the solution again. The difference between these numbers will be the consumption rate for your surface. It is worth noting that the filling of even this test square should be even and smooth, without any gaps..
If in any place there is not enough solution, this will manifest itself in the shedding of sand and cement. In such a situation, it is better to add another layer, which, as a rule, takes 20-30 percent less primer..
How to reduce solution consumption?
Since the peculiarity of the concrete contact is that its cost is not so great in order to save and reduce its consumption, it is better not to ask this question at all. The consequences of a decrease in consumption can lead to the fact that the strength will be significantly lower, the coating will begin to crack, and in the future it can completely peel off..
With a decrease in the amount of concrete contact, adhesion will also decrease – the interaction of the base and the new coating, but even this is not the worst thing. Do not forget that one of the purposes of concrete contact is waterproofing.
Many coatings that interact with the primer are gypsum or Portland cement based and must therefore be diluted with water..
If water quickly leaves the mixture, the coatings will dry out. This is exactly what the concrete contact does not allow, so it is better to get rid of the idea of how to calculate the soil in order to save more.
How to prepare the surface?
In addition to the features of the surface, the consumption of the primer will depend on how well you prepare it before work. First, you need to clean the working area from dust or various kinds of contamination. If there are places that have already begun to flake off or crumble, then it is better to deal with them immediately and remove them. Any irregularities present must also be covered with plaster..
A specific feature of concrete contact is that it cannot stick to a greasy surface. If there are such areas, then it is better to wash and degrease them, only then proceed. Places with paint can be washed with a damp sponge, if this is not possible, then it is better to cover them with a regular primer. This procedure makes it possible to significantly reduce consumption, since the soil will fill the places where there are cracks..
After the processing is over, you need to remove small specks, then you can be sure that the concrete contact will adhere tightly to other materials.
How to apply correctly?
After the package has been opened, the primer must be mixed well. The consistency of this solution is somewhat similar to paint, and due to the fact that pigment is injected into it, the concrete contact is very clearly visible on the surface. It is better not to apply a primer if the air temperature is below 5 degrees Celsius.. This is because humidity can become high at lower temperatures. In addition, under such conditions it cannot be guaranteed that the primer will adhere well and dry..
The primer can be applied using a roller, a special brush and a spatula. It is necessary to apply the solution in a thin layer, it is better to take a wide brush for this. After that, it is necessary to leave for a while to allow to dry. You can check if the surface is completely dry using a special iron spatula. One has only to hold them on the concrete contact and see if nothing will crumble. It is worth noting that in order to be able to carry out further work, you need to wait at least a few hours.
In this case, finishing work cannot be postponed. The longer the break, the greater the likelihood of dust on the surface, and this leads to poor adhesion. If more than 48 hours have passed after the primer has been applied, it must be covered with a deep penetration primer..
You can cope with this process yourself without calling the construction team. The main thing is to observe the application technology, and so that during the application and drying of the concrete contact, the temperature regime is stable.
This material has long been appreciated by builders for a number of its advantages..
- High drying speed, which is important during repairs, when everything needs to be done as quickly as possible.
- Moisture resistance. This is especially useful for those who make the floor screed..
- The service life of this material is 80 years. It is this time, with proper application and compliance with all the rules, according to the manufacturers, you do not have to worry about the full performance of the primer functions.
There are manufacturers “Aquilegia” or Knauf, which have been on the market for quite a long time and produce only high-quality products. Consider the Knauf primer, which is popular with buyers. This material is used when working with dense surfaces, which have a rather low absorbency.. It can be:
- compacted concrete;
- reinforced concrete structures;
- gypsum board.
Knauf manufacturers have tried to ensure that the material has a high level of resistance to alkalis. In addition, this solution can be not only the basis for applying wallpaper glue, putty and other mixtures. It also comes in handy when finishing the base and protects it from various influences..
Knauf features are:
- high vapor permeability;
- the consumption of finishing materials is reduced;
- there is protection against bending and mold;
- has dirt-repellent properties.
Manufacturers of 20 kg packaging Knauf made sure that the buyer was satisfied and returned to this brand more than once. Due to the fact that the jars with the solution are large enough, you do not need to go shopping several times in search of the right primer.
Knowing how to calculate the concrete and how much primer is needed in order to completely cover the surface, you can get the perfect coating that will last a long time..
Tips & Tricks
Choosing a concrete contact, you must be guided by several factors. First of all, it must be a manufacturer who has proven itself. The cost of the material should not be too low compared to the rest. In addition, you should carefully study the expiration date, which is indicated on the packaging..
By the way, if the primer was made more than a year ago, you should refuse to buy it. In addition, you need to pay attention to the homogeneity of the mixture. If there are lumps in it, then this is a substandard product. And lastly, concrete contact cannot be stored at low temperatures, this applies both to the store and at home..
For information on how to use the Ceresit CT 19 concrete contact, see the following video.