Repair of self-leveling floors: causes of cracks and methods for their elimination

Repair of self-leveling floors: causes of cracks and methods for their elimination

The popularity of self-leveling floors is growing every day, as their relatively low cost is combined with good performance.

They are highly durable over time and are not exposed to many chemicals. Nevertheless, even compliance with all the rules during their manufacture, as well as high-quality and professional installation, cannot completely exclude the possibility of various damages that require repair and renovation..

Causes of defects

The main reasons causing the appearance of damage of various types are associated with the violation of technologies at the initial stages:

  • incorrectly or poorly mixed composition;
  • poorly prepared work surface;
  • use of low quality materials.

In most cases, the self-leveling floor is equipped with a concrete screed. It is important to ensure that it is completely dry. Also, there should be no dirt on it. Any dust, dirt or grease stains will further lead to defects in the operation of the floor..

If you leave the base wet, then the release of excess moisture will inevitably lead to the fact that areas of the floor will crack or swell..

The screed must be primed. Any irregularities lead to the fact that the polymer composition and the concrete base do not adhere well, and this leads to the appearance of cracks.

It is necessary to prepare and pour the mixture, observing all the rules and instructions of the manufacturer. The self-leveling floor will be fragile if work is done at the wrong temperature. During the filling of the floor, the temperature in the room should not exceed 25 degrees.

It is also impossible to carry out work in a cold room with a temperature below 15 degrees..

In rare cases, damage to the self-leveling floor may occur due to improper use.. Improperly selected detergents and cleaning agents can compromise the integrity of the top coat, and then it will crack. Excess moisture can also lead to problems with self-leveling floors..

The most common problems

Frequent problems with self-leveling floors include cracks. They are shallow, and they can even reach the concrete base. Most often, their appearance is caused by the fact that the subfloor was poorly made. If it was fragile, mobile or insufficiently dried, this will inevitably lead to the occurrence of various kinds of cracks during operation..

The self-leveling floor also often cracks if the mixture was not prepared correctly. Causes may be the addition of too much water or the use of an expired solution..

In some cases, it is not required to completely fill the floor, and you can do with the use of a self-leveling solution.

It happens that the appearance of cracks in the self-leveling floor is accompanied by delamination. Another name for this phenomenon is boiling. When coiled, the part of the surface on which cracks appear can come off the base. Then she starts to creak and move. Plumping may occur if, if a waterproofing layer has not been applied to the base or if there are cracks in the concrete screed. Then moisture easily seeps out, and the connection between the self-leveling floor and the base is broken..

A bumpy uneven self-leveling floor or a surface with depressions does not look neat at all. In addition, any irregularities will significantly complicate the installation of other coatings on the self-leveling floor..

These defects are often caused by inaccurate pouring of the mixture or non-observance of the proportions during its preparation..

Repair features

Repair of polymer coatings usually requires only surface treatment of the top layer or its removal. For more serious defects, it may be necessary to dismantle the coating, or it may be necessary to redo the concrete screed..

It is possible to restore the original shine or eliminate scratches from the surface using polishing. This operation is carried out with a special rotary polishing machine using felt wheels. A special composition is applied to them. Restoration of polyurethane floors is performed using a protective varnish.

Before any surface treatment, it is very important to thoroughly clean it from dust and dirt, as well as degrease it..

After grinding the surface layer and removing small defects such as bubbles or sagging from it, it is enough to fill the finishing layer. Various cracks and delamination require complete removal of the polymer coating. Sometimes it is enough to restrict ourselves to a certain area, but it may also be necessary to replace the surface layer along the entire perimeter, while the coating is cut to the concrete, the concrete screed is sanded.

Next, perform the same actions as during the initial installation of the self-leveling floor:

  • degrease the surface of the screed;
  • primed it;
  • apply the necessary layers.

When updating a small area of ​​the floor, it is important to carefully grind all joints, process them with a special mastic.

Usually, a complete replacement of a self-leveling floor is done if the damage affects at least 30% of the area. Repair of the concrete screed may be required if its poor quality and possible irregularities provoked defects in the self-leveling floor.

If the concrete is of satisfactory quality, but cracks are present in the screed, restoration of the substrate is necessary. To do this, the cracks are sewn to a sufficient level, then everything is dedusted, primed and poured with a repair compound.

Alternatively, injection technology can be used. First, the polymer layer is removed to completely expose the crack. Then a hole is made in the concrete at an angle, packers are inserted there. Using an injection pump, a waterproofing compound is injected through the packers until it completely fills the crack.

Cracks or delaminations grow in size rather quickly, so do not delay the repair time, so that later, instead of a separate area, you do not have to re-fill the entire floor.

Crack elimination methods

If the self-leveling floor is cracked, you need to fix the damage as soon as possible. How to fix them depends on the depth of the crack and its size. In case of minor damage no more than 1 cm in length, there is no need to re-fill the flooring.

It is enough to follow these steps:

  • with the help of tools, the crack is expanded to 2 cm along its entire length;
  • all dirt is removed with a vacuum cleaner;
  • on the base and walls, the crack is treated with a primer;
  • then a polymer mixture is poured into the cracks, the surface is leveled.

If the area on which the floor is cracked is quite large, the entire damaged area of ​​the flooring must be removed and refilled.. They do it as follows:

  • the filler layer is chipped off, cleaned and the base is looked at;
  • if the concrete base contains cracks, use a cement putty;
  • the site is cleaned of contamination;
  • are engaged in priming the exposed side surfaces, priming the concrete base itself;
  • everything is poured with a new solution and leveled.


To repair a self-leveling coating in an apartment, you need to stock up on a certain set of tools and devices. It is recommended to use a respirator. For high-quality mixing of the solution, it is better to use a powerful electric drill, since a poorly mixed composition will cause defects on the self-leveling floor in the future..

You can level the surface or remove the damaged layer using a grinder..

If repairing the coating requires a full re-pot or topcoat, a notched trowel should be used. It is easier with this tool to distribute the substance over the concrete base, and then the product will level itself on the surface..

It is important to choose a tool with a tooth height that is half the thickness of the layer. The trowel width should not exceed 1 m.

The finishing coat is usually applied using a squeegee. This tool is similar to a notched trowel, but the width and length of the teeth can be adjusted so that it is possible to evenly cover the surface with a thin finishing layer..

With the help of a needle roller, you can restore a section of a self-leveling floor of any area. They evenly distribute the mixture and remove air bubbles. Depending on the area of ​​the repaired area, a tool of different widths and with different length of pins is chosen..

The building level controls how flat the base of the floor and the topcoat are. In this case. it is better to use a device with a length of about 2 m.Apply a primer with a roller on the areas from which the damaged material was previously removed.

It is advisable to choose a long pile.

All instruments must be immersed in solvent for at least 4 hours to remove preservative grease. Otherwise, oil may spill onto the floor and cause defects again..

Additional tools may be required to restore self-leveling floors in a warehouse. You should never delay repairing even minor cracks in the self-leveling floor, since their timely elimination will help to avoid the occurrence of more serious problems, which will lead to the need for a complete re-pouring of the solution.

You will learn how to repair cracks in a concrete screed in the next video..

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