Reasons For The Appearance Of Cracks On The Cement Floor, How And How To Cover Them Up

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Video: Reasons For The Appearance Of Cracks On The Cement Floor, How And How To Cover Them Up

Video: Reasons For The Appearance Of Cracks On The Cement Floor, How And How To Cover Them Up
Reasons For The Appearance Of Cracks On The Cement Floor, How And How To Cover Them Up
Reasons For The Appearance Of Cracks On The Cement Floor, How And How To Cover Them Up
  • The main causes of defects
  • Floor preparation for renovation
  • How to repair small cracks?
  • What to do with large cracks?

When choosing a screed in bulk, the consumer is guided by its reliability and strength. However, often after drying, cracks, potholes and other defects form on the floor. This is due to a violation of the technology for performing work, as well as non-compliance with the temperature regime. The problem can be eliminated by repair, but for this it is necessary to figure out where the cracks came from.

The main causes of defects

Most often, cracks appear where there is a high concentration of cement. This is due to the following factors:

  • poor-quality cement mixture with impaired manufacturing technology;
  • non-compliance with the proportions of the components of the screed;
  • violation of the temperature regime when pouring the floor and drying it;
  • lack of expansion joints;
  • human factor.

Let's consider in more detail each of the listed reasons.

  1. The quality of the cement mixture depends on which components were used in its manufacture. If the manufacturer saves on the composition, then one should not expect good results. When choosing a self-leveling floor, pay attention to consumer reviews and those brands that have long proven themselves on the positive side.
  2. If, when mixing the self-leveling floor, the proportions of the components were not observed, defects will appear in any case. If you pour water into the solution, then drying will occur unevenly, due to which a crack will appear. A large amount of water reduces the strength of the coating, as well as the appearance of loose areas on the surface. To avoid problems, strictly follow the instructions on the pack and add exactly as much water as indicated by the manufacturer.

Also, do not manually knead the solution. For this there is a special attachment - a whisk for a drill, with the help of which the mixture dissolves evenly, and no lumps of dry matter are formed. There are 8 ways to display beacons for floor pouring.

Temperature is the main factor in the formation of a floor screed. It is also accompanied by the necessary room humidity for uniform drying. If during this process there is a drop in these indicators, defects may occur. With low humidity, water evaporates much faster, which reduces the strength of the surface, high humidity slows down the process and increases the drying time, and therefore delays the time for laying the finishing coating

A high temperature will help the floor harden quickly and cause cracking, while a low temperature will prolong surface drying.

In addition, due to drafts and rapid changes in temperature and humidity, the screed will dry unevenly: the upper layer dries faster than the lower one, which does not correspond to the correct technology.

  1. When pouring the floor, do not forget about the expansion joints in the wall. Such seams will protect the screed from the deformation load of the wall. If there are stairs or columns in the room, they must also be laid with elastic material before pouring the floor, this will prevent cracks.
  2. No one is safe from unskilled workers during renovations. When choosing craftsmen, pay attention to the availability of professional tools and the proper equipment for performing floor work.

In addition to the main causes of cracks, there are also those that are less common:

  • lack of a vapor barrier layer;
  • forced drying of the floor;
  • lack of reinforcement;
  • the layer thickness is incorrectly selected;
  • communications under the floor.

Avoiding the above points will allow you to make the floor even and not be afraid of cracks. A common cause of floor cracks is a violation of dry screed technology.

Floor preparation for renovation

If cracks do appear, do not give up, because you can restore the floor. Before carrying out work, it is necessary to perform certain preparations:

  • Determine the reason for the crack. This factor will be decisive when choosing a method for sealing the defect. If the work on the flooring was carried out by masters, it is worth finding out whether there are expansion joints on the walls, and also in what way the floor was filled.

  • The appearance of cracks due to the absence of an expansion joint between the rooms indicates that it must be laid, and only after that the repair can begin.
  • When cracks resemble small pieces scattered throughout the room, epoxy glue is used to repair them, the solution with which is poured into the defective areas on the surface.
  • Select those areas that have cracks, and also determine the extent of their damage. Besides visible faults, there may also be hidden fractures. They can be detected by tapping a wooden mallet on the screed - a characteristic sonorous sound will be emitted.
  • If, when calculating the total area in need of repair, more than 30% of the surface turns out to be, it is recommended to completely remove the coating and fill the new floor.

How to repair small cracks?

Small cracks in the screed are easier to repair than large ones. To do this, you need to use a chisel with which to deepen the crack by 15 mm, as well as expand it. It is convenient to use a grinder with a diamond disc. The next step is to clean up the crack and areas around it. This can be done with a construction vacuum cleaner. Not the slightest particles should remain on the surface.


Then the cracks are primed. After treatment with such a composition, the adhesion of the crack and mortar increases.

It is convenient and practical to use tile adhesive, it has good performance.

The dried gap is poured with a floor screed solution, and after drying, the repaired area is sanded. When choosing mixtures and compositions for restoration, pay attention to their quality. If a tile adhesive with low strength is applied for example, then the cause of the crack will not disappear anywhere. Moreover, new defects may appear.

What to do with large cracks?

Deep and large cracks must also be repaired. The procedure is similar, but still differs. With the help of a grinder, the crack widens and deepens by at least 50 mm. If a defect is found on the lateral surface, then grooves are filled on it. After that, the expanded crack is thoroughly cleaned of dust and debris.

Along the entire length of the crack, grooves are punched perpendicular to it. Their length should be 15 cm and their depth up to 20 mm, while the distance between them is 30 mm. Using a vacuum cleaner, the surface is cleaned again. The next stage is the treatment of the site with a primer mixture.


The process of sealing the crack itself takes place with the help of cement glue or cement mortar for screed floor, in which one of the components must be sand.

The defect is filled in two approaches. The first step is to fill in the punched grooves. Vertical brackets are installed in them, after which the surface must dry. The second stage consists of filling the crack itself and filling it with the same staples, as well as completely drying the layer.

If the crack is too deep, the repair is carried out in three stages. When the coating is dry, all areas are sanded to an even state. Repair by this method excludes the formation of new cracks due to the reinforcement of old defects with metal staples.

Repairing potholes, cracks and holes in the screed is an expensive and time-consuming procedure. Therefore, the best option to avoid problems is to follow all the rules when pouring the floor.



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