Do-it-yourself floor screed repair, from small to major. How do you repair a floor screed with your own hands? How to repair a cement floor

A cracked or crumbling screed is not only an uneven and uncomfortable floor, but also an undistributed load on the floor slabs in the house. If you can more or less put up with the first moment, then things are a little different with the second - excessive loads on the floors, despite the fact that they have a fair margin of safety, can be disastrous, especially when it comes to old houses. The screed must be kept in order - in the event of a major overhaul, change or at least repair. In this article from the website, we will deal with the question of how to repair a floor screed with your own hands?

Repair of cement floor screed photo

Floor screed repair: about its feasibility

Before embarking on a direct solution to the question of how to repair the floor screed with your own hands, first you need to figure out its expediency - perhaps things are so that it makes no sense, and you do not need to restore the surface, but its complete replacement. In what situations does it become necessary to install a new floor screed? There are not so many signs that indicate that the screed has outlived its time.

By by and large, there are no specific criteria according to which it is necessary to completely change the floor screed. There are simply prescriptions and common sense that a new surface is better than an old one. She can serve for a long time, and if you intend to live in an apartment or house long time, then the best thing would be a complete replacement of this surface - naturally, if we are talking about a major overhaul. It is better to spend money on a new screed once than to repair an old floor screed with enviable regularity. Restoration is primarily a temporary measure that resolves the issue for a short period of time.

Repair of cement floor screed: preparatory work

Preparing an old screed for repair is a simple matter, and in most cases comes down to just two steps.

You can not wait for the second layer of primer to dry - while you prepare the solution, it will be absorbed into the old screed and this will be enough. Such repair of cracks in the floor screed (or rather preparatory work associated with its implementation) will give you a guarantee that the subfloor will last at least another ten years.

How to repair a floor screed: the main stage of work

This stage (as, in general, preparatory) can be conditionally divided into two sub-stages - fastening the split fragments of the floor and final alignment grounds. These are two different technologies that should be dealt with separately.

1. Bonding or sealing cracks. This is a fairly simple stage of work, for the implementation of which it is necessary to prepare a solution of a rare consistency. One thing should be understood here - too rare a solution can leak to neighbors on the ceiling. We need a moderately rare mixture that can flow into all cracks and recesses, but at the same time not leak onto the neighbors' heads. In general, all the knocked-out sections of the floor are poured with such a solution. After the repair of the concrete floor screed is completed, you should wait for the complete drying of the repaired areas. After this happens, the repaired floor must be cleaned of dust and dirt and qualitatively opened with a primer, giving Special attention fresh patches. They need to be opened twice.

   

   How to repair a floor screed photo

2. Finishing leveling is at the same time the surface bonding of the floor. To solve this problem, the so-called is used - in the people it is called a self-leveling floor screed, to create which a mass level is used. It is filled with a layer of 3mm (plus or minus). The process is quite simple, but there are many nuances - you can read more about it in another article on our website (). Briefly describe this technology, it can be represented as follows. The mixture prepared in the container using the mixture is poured onto the floor and spread with a notched trowel. Then it rolls out with a plastic roller with spikes, after which it is left to dry. The next day, such a screed is gaining primary strength (it is already possible to walk on it). The full operation of the floor is possible only after complete drying - this is at least 3 days (can be determined by the color of the floor). The finished surface of such a floor can be finished with any decorative materials, including, and.

   

   Floor screed repair photo

In principle, this is the entire repair of the floor screed. It seems to be not difficult, but there are plenty of nuances - they are not obvious. We can say that the subtleties are almost all individual. For example, depending on the degree of destruction of the old floor screed, reinforcement may be needed - naturally, it is better to change such a floor covering as a whole, but the situations are different, and even with large damage, repair may be appropriate.

Often, construction technology provides for the presence of concrete floors. This is due to high technical specifications mixture components. Finished coating It turns out affordable, durable and practical. It perfectly acts independently, and serves as the basis for subsequent finishing with any floor materials. However, for a number of reasons, the base is deformed and becomes unusable - cracks appear, dust formation increases. Formed defects reduce the strength and reliability of the screed. In this connection, during the repair carried out will help prevent further destruction. The article will consider the technology of repairing concrete floors.

• conduct a visual inspection to assess the condition;
• identify the causes that led to the result.

Based on the data obtained, the elimination technology is selected. For minor damage (potholes, single cracks), it will be enough to carry out local repairs. If the area of ​​​​the site to be repaired is more than 30-35% of the area of ​​​​the entire premises, then here we will talk about capital work.

Reasons for the destruction of the concrete floor

There are several main reasons that negatively affect the concrete pavement. Conventionally, they are classified into 3 groups: soil impact; external influence; internal factors.

• To the first point include poor-quality soil compaction, winter heaving of the earth and close proximity ground water. Such factors lead to formation movements, and as a result, the destruction of the concrete floor.
• Second paragraph suggests Negative influence on the base due to the use of low-quality mortar, as well as pouring carried out in violation of technology. Here it is necessary to note such a common reason as house shrinkage, which creates some progress.
• In the third paragraph there are such factors as: natural wear of the coating, mechanical impact (falling of heavy objects) and prolonged exposure to moisture, for example, during flooding.

Having analyzed this information, you can proceed to eliminate the causes. Only after that you can talk about the benefits repair work, otherwise all the restorations performed will be useless.

Preparing to repair an old concrete floor

• Work begins with the release of the premises from furniture and other interior items. If there is a floor covering on the screed, then it is dismantled. All debris and dust is removed. Much attention is paid to damaged areas. It is there that a large number of exfoliating elements accumulate.
• With a metal brush, old layers of primer, rust and other contaminants are removed. Then it is necessary to make notches on the repaired area, which will increase the adhesion between the material and the new concrete.
• Chips and dust formed in the process are swept with a broom. Good result in cleaning will show a construction vacuum cleaner. The surface must be treated with a degreasing impregnation or primer.

The degree of damage to the coating determines the complexity and type of subsequent work. If financial resources allow, then it is possible to carry out a major overhaul of the concrete surface in order to significantly extend the operational life of the floor.

Preparation of the working mixture for the repair of concrete floors

• To eliminate shallow potholes and crevices, you can use a solution with the addition of PVA, prepared at home. First, dilute 1 part of glue with 4 parts of water. Then diluted PVA is poured into the prepared dry cement-sand mixture (1: 3) until the optimum consistency is reached.
• More serious problems are solved by using building mixtures. In these concrete floor repair compounds, specially selected ingredients guarantee ultimate strength and durability. high stability to mechanical damage.
• The closed powder composition is thoroughly mixed with a mixer. The use of such equipment will allow you to perform the process more efficiently. Ready mortar penetrates deeply into the structure of concrete and forms a single monolith with the original surface.

Partial renovation

For damaged areas small areas you can do local work. cosmetic repairs are subjected to:

• recesses;
• cracks of various depths and widths;
• hair crevices (cobweb);
• minor irregularities.

Despite minor defects, work must begin immediately. The smaller their size, the easier it is to arrange the surface in order. The increase in existing cracks will lead to their growth, and as a result, to the deformation of the floor covering.

pothole patching

Usually they appear as a result of a long stay of furniture or bulky equipment in one place. Often the causes of the appearance are mechanical effects, for example, the fall of an object from a height.

Elimination technology

• With the help of the tool, the defect expands and deepens. This is done in order to exclude the possibility of leaving weakened pieces of concrete on the site. The recess is cleaned and primed. Filling is done with epoxy mixture or adhesive composition.

• The solution is pierced several times with a metal pin. It is important to remove air voids and evenly distribute the mixture in the resulting recess. Horizontal alignment is performed with a wide trowel or building rule. After drying, the area is polished.
• If the depth of the pothole is more than 5 cm, the mortar laying technology is somewhat different. Here the mixture should be poured in several stages, in order to avoid the formation of cavities.

Repair of cracks in concrete floors

This kind of flaws appear due to shrinkage of the structure or foundation. Temperature changes, incorrect proportions of the concrete composition, and the absence of reinforcing elements can lead to deformation.

Elimination technology

• With the help of a perforator or a hammer with a chisel, the gap expands both in width and depth. Carefully inspect the adjacent area for hidden defects, which after a while will lead to a second repair of the surface.
• The groove cleans concrete debris and dust. For processing, a polyurethane primer is used. A mixture is laid in the crack, and then leveled with a spatula or level.

• In the presence of cracks of large width on both sides of the grinder, auxiliary grooves are made. They will serve for laying metal grips, the distance between which should be 25-30 cm. All recesses are filled with mortar.

Close up of a cobweb

This kind of deformation cracks can appear during excessive fast drying solution. They are not fraught with danger, but they are quite capable of expanding over time. The web is almost invisible. Its detection is possible when the surface is wetted.

Elimination technology

• The so-called hairline gaps are sufficient to be treated with a primer and sealed with an elastic sealant. If weakened areas are observed along the edges of the crack, then it is recommended to clean the delaminations.
• The resulting groove is cleaned of foreign inclusions and treated with primer solutions. For embedding, you can use a composition of your own preparation or purchase ready-made mixtures of various grain sizes.

Minor bumps

As a result of pouring, it is not always possible to obtain a perfectly flat floor. This is due to non-compliance with the technology of these works. Flaws appear due to neglect of the installation of beacons, improperly mixed cement mass (too liquid or thick). Therefore, after drying, “waves” are formed.

Elimination technology

• The crests of the wave are removed using a grinder with a trowel disc. The work is dusty, so personal protective equipment must be used. If the cultivated area is large, it makes sense to contact specialized companies. They have equipment in their arsenal that, along with grinding, sucks up dust.
• The depressions are cleaned and deepened. They are treated with primers or diluted solvent. The recesses are being filled building mixtures You can also use self leveling mortars.

Do-it-yourself overhaul of a concrete floor

Fundamental work will be needed if:

• there are extensive damages (over a third of the entire area);
• installation of the "warm floor" system;
• there is a desire to completely update the old concrete screed.

Such work can be carried out using the following technologies:

• laying a wet screed using a standard cement-sand mortar;
• pouring a self-leveling mixture, which includes plasticizers, stabilizers and fiber fibers;
• installation of a dry screed, including filling, followed by laying gypsum-fiber sheets (GVL).

In each case, a different set of materials is required to repair the concrete floor.

Wet screed laying

• Repair work begins with the removal of construction debris and dust removal of the surface. It is necessary to remove all flaking areas, which subsequently can significantly affect strength characteristics new floor.
• Next is the flooring of waterproofing materials. A huge selection will allow you to purchase products with the most suitable properties at an affordable price. The next step is to place the beacons. Their step should be slightly less than the length of the rule used.
• Mixing of concrete mortar is carried out in accordance with the current proportions. The ratios used are entirely dependent on the grade of cement used and the desired strength. ready mix. Water is added until the required viscosity is reached.

• Filling is carried out in small portions. This will help spread the mixture evenly without creating voids. It takes about 30 days for complete drying, during this time it is desirable to avoid any mechanical effects on the surface.

Pouring self leveling compound

• Special compositions allow alignment with minimal labor. After inspecting the surface, all existing delaminations are removed. In the presence of contamination, treatment with a solution of copper sulphate is performed.
• Seams and cracks are sealed with a repair mixture. Mandatory spread out waterproofing materials. If the pouring is done on an old coating in fairly good condition, then the step with waterproofing can be skipped.
• If you plan to fill the mixture with a thickness of more than 10 mm, it is recommended to pre-install profile beacons. Work begins from the far corner of the room. The solution is fed in parts and leveled with a needle tool.

• Already after 8 hours, small effects can be exerted on the surface. The floor will be ready for full operation after 5 days. Then already go to finishing(laying decorative flooring).

Dry screed installation

Such a device has some advantages over "wet" work. For example, there is no need for drying time, installation can be carried out regardless of temperature regime. In addition, the floor is characterized by high rates of noise and heat insulation.

• First, the floor is marked. A plastic film or any vapor barrier material is spread. Then beacon rails are installed, which allow you to adhere to the desired level. Horizontalness is checked with special tools.
• Expanded clay, vermiculite, perlite or compavite are poured between the profiles. Starting from the doors, sheet material is mounted from right to left. Its spreading is carried out in a run (at least 25-30 cm). On the stacked sheets move with caution.

• Fastening is carried out with special self-tapping screws, the pitch of the screws must be at least 30 cm. Mastic is used for additional fixation. If necessary, you can lay a second layer sheet material without matching joints in any direction.

The final stage of repairing the concrete floor in the apartment

The concrete surface, with its solidity, has the property of dust formation, which occurs due to various mechanical loads. Invisible particles adversely affect human health. Wet cleaning cannot solve this problem.

To avoid harmful effects the following will help:

• clean the surface as much as possible;
• carry out the treatment with a primer;
• paint with a material that will prevent concrete peeling.

Here you can use products based on polymers that form a protective layer of various thicknesses. For rooms with minimal loads, thin-layer materials (up to 150 microns) are used. Neomer-LP or Elakor-PU.

V living rooms with intensive patency, Elakor-ED, Retroplate or GruntElast-PU are used. The protective layer of such products is over 250 microns, which makes it possible to withstand high loads.

Due to deep penetration, the concrete screed is characterized by:

• resistance to temperature extremes;
• moisture resistance;
• lack of dust formation;
• high wear resistance.

Timely noticed flaws and their immediate elimination will help to increase the life of the surface. In addition, this will avoid more expensive and time-consuming work to restore the concrete floor. Accurate observance of all stages of repair work will lead to an impeccable result.

To level concrete or wooden flooring, as well as to create it on the ground in private homes, a concrete screed is used. Often, after some time from the start of operation or immediately after drying, cracks form on the coating, in most cases this defect can be corrected.

To know what to do if cracks occur in the floor screed, you must first understand the reasons for their formation.

There are several reasons for the formation of such defects. Depending on the nature of the appearance of a crack in concrete, different methods of its removal are used.

Foundation problems

If the base has not been properly prepared, then the screed will crack immediately after drying. This happens when the soil, sand or gravel has not been well compacted. Rotting and chipped floorboards that have been covered with concrete also cause it to crack quickly. The presence of large holes different materials, improperly carried out waterproofing - all this also provokes the appearance of a crack in the floor screed.

Gross violations of the base preparation technology lead to radical defects

Incorrectly arranged expansion joints and lack of damper tape

During the drying of the concrete floor covering, the entire structure experiences various mechanical loads. The screed is made in order to level the floor, which means that its thickness in different places will be different, as a result, the shrinkage of the material also occurs unevenly. The following factors influence the duration of this process:

• The thickness of the solution layer. It usually takes about 4 weeks to dry and harden, but with a layer of 5-7 cm, it may take more than a month.
• Temperature difference at opposite ends of the room. Near heaters or on sunny side drying is much faster.
• Mechanical impact of other elements of the structure. Especially in the area doorways where cracks in the screed are formed most often. In this area, the solution dries faster, because it is in a ventilated place, but at the same time it experiences mechanical impact from neighboring rooms.

As a result of this, the screed does not withstand and cracks, but these problems do not pose any danger, they can simply be repaired with a finishing putty. At correct design expansion joints at the time of pouring the floor cracks would not have appeared.

On a note! To avoid the appearance of defects in places that are subject to increased loads, make out the seams, they separate the screeds different rooms and do not affect each other.

If the room is large, then expansion joints are made every 5-6 meters along the entire perimeter of the screed. They look like cuts with a depth of no more than a third of the thickness of the concrete layer. You can make them with a grinder or hand tools.

Incorrectly made solution

If the question arose of why the screed is cracking, then the answer most often lies in a violation of the mortar manufacturing technology, usually this is the addition of an excessive amount of water. Home craftsmen unknowingly make the solution very liquid to make it easier to apply and level. The result is a mixture that, after drying, does not have a sufficient level of strength, which is why cracks appear in the concrete.

Also, the strength of concrete may fall due to the presence of a large amount of air in the solution, so you can not knead the concrete by hand, you should use a special mixer.

Incorrect layer thickness

The thickness of the concrete layer must be at least 7 mm, a thinner screed will crack from mechanical stress. Due to a too thick layer, the screed will dry unevenly: inside it will remain wet, but dry on the outside, the structure experiences strong internal pressure and the screed begins to crack.

Violation of the solidification process

In order not to wonder why concrete cracks, it is important to properly organize the process of its drying. There is one rule for all concrete surfaces: the longer it remains wet, the better it will gain strength. Attempts to accelerate drying with heating or any other devices lead to the fact that the concrete cracks after pouring.

For the same reason, it is necessary to protect the room from drafts and direct sunlight. To increase the drying time, the surface can be sprinkled with water or covered with plastic wrap with wet sand on top.

Main types of defects

To properly seal cracks in a concrete floor, you need to know what they are.

1. Microcracks. These are defects less than 1.5 cm in size. Most often they occur due to improper drying of the coating. If there are few such defects on the screed, then you can simply cover them with tile adhesive.
2. Big cracks. The size of such defects is from 2 cm. They usually appear due to incorrectly made expansion joints and the absence damper tape. To seal such cracks in the floor screed, a cement-sand mortar or a special sealant is used.
3. "Mobile" concrete. When walking on such a coating, you feel how it "walks". This is due to the presence of air cavities inside. In this case, it is necessary to remove the exfoliated fragments and close up the potholes with a solution.
4. Bulges and potholes no larger than 5 mm. In this case, cracks in concrete are repaired with cement mortar, and the bulges are cleaned with a grinder.
5. Irregularities more than 1.5 cm. Correcting each such defect is long and labor-intensive, so it is easier to pour a new screed about 4 cm thick on top.

Screed repair

Now about how to repair the floor screed with your own hands. To do this, you will need: a puncher, a hammer, Sander(Bulgarian), construction syringe, hacksaw for metal processing, metal staples 12 mm. From the materials you will need: epoxy grout, quartz sand, primer, as well as the composition from which the screed solution was made. Depending on the nature of the damage, the sealing of cracks in concrete occurs in different ways.

microcracks

The first step is to clean the area that will be processed, remove everything from the floor and carefully examine it. It is recommended to circle the places with cracks with a marker so that you do not look for them again later. With the help of a hammer and a chisel, you need to expand and deepen the crack, the result should be a gap that narrows downward. Remove dust and small stones from the crack with a vacuum cleaner. Next, you need to mix the epoxy resin with the solvent in proportions of 1:10, apply the composition to the surface of the groove and allow to dry. It remains to cover the crack with a cement-sand mortar and, after drying, grind this area.

big cracks

To repair a floor with such defects, it is necessary to prepare the surface and make the crack deeper for the entire thickness of the layer using a grinder. With the same tool, you need to make two cuts on both sides, and then remove all the concrete with a chisel. Next, remove dust and debris and apply epoxy to the surface of the groove. In some cases, metal staples are used to increase the strength of the treated area. To do this, you need to make cuts across the crack to a depth of 2 cm, put a metal bracket into the gap formed, pour the cement-sand mortar, wait for it to dry, and then grind it.

Steel staples are used to repair cracks up to 5 - 7 cm deep

potholes

If the surface cracked so badly that a pothole formed, then you will have to use a perforator. With it, you need to expand the pothole to a depth of 2 cm. Further actions are the same as in previous cases: dust and debris are removed, the walls of the crack are treated with an epoxy composition, and the defect is covered with a solution.

moving parts

In this case, more than just sealing with epoxy and subsequent grouting will be required. First of all, you should outline the boundaries of the moving surface with a marker and make cuts with a grinder according to the marking, sometimes at this stage you can remove fragments of concrete. If it sits firmly, it is necessary to remove it with a puncher, removing the entire screed to the base. After that, remove the dust and check the base for defects. If they are not there, then the surface is primed and again poured with concrete to the level with the floor. If there are potholes on the base, then you first need to repair them, wait for them to dry, and only then fill the pothole.

Repair of mobile concrete by injection

Injections building composition- this is one of latest methods repair of surfaces after concreting. For this process, it is necessary to detect a movable area, circle its borders with a marker and drill holes every 2.5 cm over the entire area to a depth of about 1 cm. procedure.

The composition will gradually penetrate into all internal cavities and at the same time impregnate the concrete, which will significantly increase the strength of the coating. After completion of the operation, the floor should not be walked on for a day, so that the epoxy has time to harden. After this time, you need to check the result: if the mobility could not be eliminated, you will have to completely remove the concrete layer.

Important! If the defect occupies more than 30% of the surface, it is necessary to completely remove the coating and fill it again.

Thus, there are a variety of methods for sealing cracks, depending on their type and size.

Summing up, we can say that defects are easier to prevent than to eliminate. Therefore, it is highly recommended to properly mix the mortar, carefully prepare the surface and never speed up the drying process of the concrete. If you follow all these recommendations, cracks in concrete screed will not be.