- 1 Causes of cracks and other deformations
- 2 Repair of floor screed with your own hands
- 3 Small cracks in the floor screed: what to do?
- 4 Caulking deep cracks
- 5 Elimination of potholes
- 6 What to do in the case of daily formation of dust on the screed?
- 7 Levelling the substrate
- 8 How to repair the floor
Occurrence of cracks and other defects is typical for both time-tested concrete floors, and for freshly poured screed. Deformations of various kinds occur under the action of many factors. It is recommended to start the repair of the screed with the identification of the causes of defects.
Causes of cracks and other deformations
Considering the technical factors, the following can be highlighted:
Non-compliant base. This may include insufficient thickness of the substrate and its heterogeneity. To correct all the errors in this case, you can only perform a major repair of the screed, removing the top layer and adjusting the base to the required standards.
Poor-quality filling of the screed. Failure to comply with the rules of installation technology:
- the use of substandard construction materials;
- lack of priming preparatory work;
- the use of mortar of improper consistency;
- rapid drying of the screed;
- lack of expansion joints.
Repair of floor screed with your own hands
The method of eliminating screed defects depends on its type. The most common are cracks, chips. Not excluded and the formation of delamination and hidden voids. They are detected by tapping the screed with a metal rod. The presence of voids gives a deafening sound. If this defect spreads over 30% of the area, it is recommended that the floor is overhauled. Less damaged surface can be restored.
Small cracks in the floor screed: what to do?
Partial floor screed repair needs preparatory work. First, the surface should be cleaned of dust and other inclusions. Then proceed to expand the area of each crack. To do this, it is necessary to make a hole in them. We insert a chisel into the hole and hit it with a hammer, so that the auxiliary tool deepened by about 1 cm. The cross section of this depression should have a cone shape. After that, we clean the surface and the cracks themselves from dust with a sandblaster or vacuum cleaner. The walls of the pit are treated with a pre-prepared solution: diluted epoxy primer with solvent in the ratio of 1:10. This procedure makes it possible to create a strong bond between the repair compound and the base. After the primer dries, we fill the cracks with mortar. The cured mixture is sanded and brushed.
Caulking deep cracks
What to do if the floor screed cracked, and deep defects were formed on it? It is worth noting that this category includes defects, the width of which exceeds 2 mm. The building needs a comprehensive repair if the crack increases in parameters. It can be detected by gluing a strip of paper on the width of the formation: if it tears after 2-4 months, it is worth applying drastic measures. Today modern tools allow you to speed up the inspection process.
Deep cracks with a stable width can be eliminated with a certain algorithm of actions:
- using a grinder with a diamond disk expand the parameters of the defect to a depth of 5 cm and a thickness of 2 to 5 cm;
- knock down the cut concrete and clean the excavation with a household vacuum cleaner;
- then make cross cuts 1.5 cm wide and 2 cm deep for the embedding of the embedding material;
- the prepared notches are cleaned and treated with a primer or polyurethane compound. Then the repair mortar is put into the notches and the reinforcement is laid;
- the entire crack is sealed with the mixture of the same composition;
- after drying, the surface can be sanded and cleaned.
Elimination of potholes
Along the perimeter of the delaminated area with a grinder make a rectangular cut, 2 cm deep. After that the old coating, or rather – the damaged fragments of the screed is removed with a chisel and hammer. Eliminate all debris and clean the pothole from dust with a vacuum cleaner. Then we treat the pothole with primer, and after it has dried, we fill it with a specialized compound. The next step is to level the surface with a slat or rule. After the complete polymerization of the sealed area is subjected to sanding and scraping.
What to do in the case of daily formation of dust on the screed?
The screed can be dusty even if the floor covering is installed on it. Modern manufacturers of construction materials have taken care of this problem. Dusty screed surface is possible with a mixture such as Ashfor or Elakor. For each floor an individual brand of composition is selected, which is calculated on the basis of the required load. The surface is cleaned from dust and other inclusions, sanded and primed. After the preparatory work is completed, the above-mentioned type of mixture is applied to the screed. It makes it possible not only to fuse the problem of dusting concrete, but also increases its durability.
Injection for floor screed High-quality floor screed repair is also necessary when it is peeling from the base. Voids resulting from this process are a negative factor for the durability of the surface. Detection of defects is carried out by tapping on the floor with a hammer. The problem areas are those where you will hear a muffled sound. In the areas of delamination should be made several holes with a spacing of 2.4 cm and a diameter of 1.6 cm, drilled with a special tool. Fill a construction syringe with a repair compound of reduced viscosity and fill the holes with it. The compound should be introduced gradually to fill the voids evenly. One day later, a protective layer is applied to the restored surface.
Levelling the substrate
Before proceeding to the installation of various kinds of floor coverings, it is necessary to make the leveling of the base. Eliminate the presence of height differences on the concrete screed can be by applying self-levelling compound. The surface is pre-prepared: cleaned of dust and washed with a soda solution twice. After the base is moistened. The solution is prepared in small quantities and gradually applied to the floor, carefully leveling the surface. Air voids are eliminated with a needle roller.
How to repair the floor
Cracks formed, wallpaper and screed detachment from the base are eliminated quite simply. However, the damage area, which occupies more than 30% of the entire surface of the concrete, requires radical measures – a complete replacement of the screed. The preparatory phase in this case consists of grinding, cleaning the floor with special mixtures from excessive dirt and coverage with a primer. An increased level of humidity in the room requires the use and water-repellent mortar. Self-leveling floor is applied in small portions, rolled with a needled roller to eliminate voids and smoothed with a rule. The thickness of the layer varies from 5 to 10 cm. During the next 3 days, measures are taken to prevent rapid drying of the floor. High-quality restoration work requires strict compliance with all these techniques. The appropriate construction materials must also be chosen thoughtfully.