Why does the cement screed crumble, what should I do? How to strengthen a concrete screed that crumbles What to do if cement is poured on the floor

The reasons why the screed will turn out to be weak are different:

• Not observing the proportions of water and cement.
• Old cement (with lumps).
• Increased clay content in sand.
• Incorrect preparation and care after laying when conditions of rapid dehydration occur.

But if this happened, then something needs to be done about it - because with further finishing, difficulties are possible.

You can't leave it unchanged either. Dust is constantly formed on such a floor. The weak layer is easily destroyed by feet.

First way. Strengthening with a primer.

The first thing most come to is to strengthen with a primer. The option is real, affordable and on everyone's lips. But rarely gives the result:

A short commentary on the video.

Judging by the test with a nail, the screed is quite suitable for tiling indoors. There are examples of a more deplorable state of the base, which they tried to strengthen with a primer:

Why did the tile bounce off the screed?

They tried to strengthen the loose screed with a primer. But the primer, the primer is different. Judging by the color and the resulting film, the primer-concentrate was used in shock proportion. Or primed several times, with the complete drying of each layer (as written on the canister). This gave a film on the surface. A tile with glue was fixed behind it. But under the film remained the same weak layer. On it, the tile came off.

Alternatively, you need a deep penetration primer and pour it in buckets at a time. To fix a weak layer to a greater depth. At the primer deep penetration(according to manufacturers) smaller particles and therefore, can penetrate deeper without creating a film on the surface.

Strengthening the cement screed with silicates (liquid glass).

The idea to use liquid glass to repair weak surfaces did not appear on empty place. Liquid glass in construction for a long time:

• Additives in concrete and mortars to accelerate setting (1-15% by weight of cement).
• Production of refractory paints, putties and putties with the addition of fillers (talc, marble dust, fine sand).
• Waterproofing of concrete and wooden structures.
• Fight fungus and mold.
• In metallurgy, the arch of furnaces is laid out from fireclay bricks on a binder of sodium silicate.

There are three main types (depending on the composition) liquid glass: potassium, sodium and lithium. They have different properties, what gives different benefits and different prices.

More common is sodium. They are trying to strengthen the screeds in garages and basements:

You can experiment with this method. It is useful to have at least some other people's experience.

Below are collected the most interesting details of the use of liquid glass. Quality material it's hard to draw conclusions. But still:

It would be possible to call all this fuss with liquid glass a collective farm and forget it, if it were not for such a detail as recommendations for strengthening loose screeds with silicates from many mixture manufacturers. One of them from “MAPEY”:

Important points in the video:

• Viscosity impregnation is more like a primer than liquid glass in jars, which they try to strengthen floors in garages.
• Impregnation must be applied continuously, preventing the top layer from forming a crust.
• Consumption can be significant, and 3-4 liters per meter.

It is clear that the strengthening primer "Prosfas" does not consist of silicate alone. Therefore, its price differs from the price of liquid glass. If we compare the cost of strengthening a loose screed with MAPEY silicate and ordinary liquid glass, taking into account its consumption and the similar consumption of liquid glass, then the discrepancy will be significant:

Prosfas and liquid glass.

But Mapei is not the only company that prepares impregnations for concrete and screeds.

An entire industry has been created on this issue. A simple chemical reaction (Ca(OH)2 is converted to C-S-H) between silicate in impregnation and calcium hydroxide in concrete has built millions of businesses. The composition of the impregnations is not disclosed, except for the name of one of the silicates, on the basis of which it was created.

Like different types liquid glass created and various strengthening impregnations based on potassium, sodium, magnesium and lithium. An important difference between them is the size of the molecule. It depends on how deeply the silicate can soak the screed:

Impregnation based on sodium silicates.

Sodium impregnations.

Here are selected examples of sodium impregnations. That's not all. New ones may appear, cheaper and more effective. Some reduce production and leave the market:

1. Ashford Formula– Brand Ashford Formula. Manufacturer Curecrete Chemical Co (USA). The country of manufacture may be different.
2. Lithurin.
3. Diamond Hard(Diamond Hard). Product of the American chemical concern "EUCLID CHEMICAL".
4. Liquid Hard from W.R. Meadows (USA). The manufacturer may be the Czech Republic.

All impregnations are similar in application method:

Apply so that the entire surface remains wet for 30-60 minutes. Without puddles and drying out in some areas. This is achieved with a soft whisk, redistributing the liquid over the screed. The excess is moved to neighboring areas and removed with a water vacuum cleaner.

Some impregnations are diluted with water (Lithurin I). Some have features - Ashford Formula is not effective on concrete grades below M 300 and on cement-sand screeds:

Strengthening impregnations based on lithium.

According to the American Concrete Institute (ACI Concrete Institute), lithium-based impregnations have a number of advantages:

• Increases the strength of concrete by more than 45% (sodium - 37%).
• Compacts concrete and completes chemical reaction within 7-14 days (operation after 2 hours). Sodium has 6-12 months.
• There is no need to rinse it with water.
• Penetrates 1-5 mm, forming a chemical reaction with the top layer.

Lithium-based impregnations.

ULTRALIT HARD (1)

If you believe the prices and consumption (for 20 squares - 1 one liter), then the impregnation of one square concrete surface costs $0.05. The country of origin is the Czech Republic (technology, most likely, the USA).

The production of three varieties of Ultralit Hard Standard, Ultralit Hard Premium, Ultralit Hard Extra has been launched.

Mapecrete LI Hardener (2)

Lithium-based liquid cleaner for new and old concrete floors from MAPEI.

$ 5.8 - impregnation of one square meter, at a consumption of 0.4 kg / m2 (the real price can only be found at the time of purchase).

"Concria Super Hard" and "Concria Hard" (5)

Country of origin USA. Based on the consumption of 1 liter per 10-20m2, we get the cost of one square meter: 1.2-2.2$. C2 Hard can be used on floors that have already been treated with other silicate impregnations and whose surface has begun to dust and flake.

In addition to these two impregnations for strengthening, the release of others has been launched, for coloring, glossing ....

SPEKTRIN LITHIUM(4) - made in Sweden / Ukraine. Lithium impregnation for concrete and stone (marble). Penetration depth - about 7 mm. Strength increase up to 16%. Reducing water absorption by 3.3 times. The impregnation can be used in the food and pharmaceutical industries. Costs (impregnation cost) per 1 square meter -1.5 $. Used for indoor and outdoor work on durable and dense concrete (M 300 and above):

The first impregnations appeared on the American market about 50 years ago. The search for new compositions does not stop. The competition is growing. Without experience, it is difficult to understand the features of each and the veracity of the declared properties. The indication in some of those maps of strengthening impregnations is alarming: "Do not apply on dusty, crumbling and fragile bases." Marketing wars lead to even more confusion:

A good warning was placed before purchasing one of the impregnations:

As a way out - you need a test area 1.5m x 1.5m. If a different surfaces, then for each type of surface - a separate site. After doing everything according to the instructions, let it dry for 3-7 days. Then draw a conclusion on consumption, costs, obtained and expected surface strength.

Floor screed repair is a fairly common type of repair work. The rough floor experiences significant loads, as a result of which it gradually wears out and weakens. You can strengthen the concrete base and eliminate defects yourself.

Malfunctions and their causes

The most common subfloor damages are:

• general loosening of the screed. It is characterized by the appearance of a large amount of cement dust as a result of a violation of the technology for preparing a solution or Low quality cement;
• potholes and cracks. Formed due to excessive point load on the floor surface. The presence of voids in the upper layer concrete base also causes the screed to crack and deform. This defect is considered the most dangerous for decorative flooring: the area located above the damage and devoid of solid support quickly becomes unusable and collapses;

• exfoliation. Diagnosis of this malfunction is made by tapping the floor surface with a hammer. In the exfoliated areas, the sound from the impact will be deaf, and dust will begin to come out through the cracks formed. Delamination can be expressed in visual swelling of the top layer and raising the corners after the mortar dries. The reasons are often the uneven drying of concrete, the lack of a primer layer under the base and the use of low-quality cement;
• excessive dusting. Due to excessive loads and general aging of the screed, a large number of cement dust. Sometimes floor dusting is associated with poor quality cement and violation of pouring technology.

Repair composition

Mixtures for the restoration of cement screeds are widely represented on the modern construction market. They include polyurethane components and synthetic resins and are more intended for industrial use. When carrying out repair work in an apartment, the purchase of expensive compounds is not always rational, therefore for minor repairs, the mixture can be prepared by hand.

For this it is necessary mix PVA glue with water at a ratio of 1: 3, then add one part sand and three parts cement. The resulting composition should be carefully moved using a construction mixer or a drill with a paddle nozzle.

A homemade cement mixture can repair shallow cracks and small potholes. For large-scale repair and restoration work, you need to purchase professional tools.

How to strengthen?

To strengthen the subfloor screed, it is necessary to drill a series of holes with a puncher, equidistant from each other at a distance of 25 cm and having a diameter of 20 mm. The depth of the channels made should be equal to the thickness of the screed. Work should be carried out using a drill with small angle inclination of the working groove. Openings should be cleaned of dirt and, if possible, dust-free. Next, you need to prepare trimmings of reinforcement, equal in length to the depth of the channels and having a diameter of 12 mm.

Then the holes should be filled with a mixture of epoxy for concrete "Rizopox-350" and quartz sand, then insert iron rods. Reinforcement must be pre-degreased b. The upper, widest part of the channel is also carefully poured until it is level with the base. For installation decorative coating can start after complete drying, subsequent dedusting and priming of the screed.

In the presence of the "warm floor" system this method strengthening the screed is not suitable: drilling channels can damage the cable and thermomat, as well as pierce the water heating pipeline.

How to repair?

After diagnosing the delaminations that have appeared, as well as in cases where the screed is swollen and “swollen”, it is possible to start repairing it only if the damaged surface is no more than 30% of total area bulk floor. There are two ways to repair delaminations. The first is to carry out point injections using liquid repair mix and consists of several steps. Initially, it should be determined by tapping problem areas and outline them with chalk. Then, channels with a diameter of 15 to 20 mm are drilled in places of delamination. The distances between the holes should be 25-30 cm.

Next, the channels should be dedusted and poured into them with a primer mixture, trying to evenly moisten the entire surface of the inner cavity. After pouring, dry the treated surface building hair dryer. As a material for injection, cement-adhesive mixtures or epoxy resins can be used..

An important condition The maintainability of the mortar is good fluidity. To fill the channels, you can use a construction syringe or a plunger pump.

Injections should be carried out slowly, allowing the solution to be evenly distributed throughout the entire internal cavity. The procedure should be carried out until the upper part of the channels is filled with the mixture to the floor level.. The repaired screed should dry for at least a day, after which you can proceed to priming and subsequent installation of the finish coating.

The second way to repair a delaminated screed is to completely dismantle the problem area, dedusting and priming the surface, followed by concrete pouring. The method is used in cases of impossibility of spot repairs when large area damaged area.

Getting rid of cracks

Cracking of the screed surface can occur from uneven load on top coat, bumps and poor hydration concrete base when dry. If the floor surface is cracked, burst or crumbles badly, emergency measures must be taken, because cracks are the most serious defect in screeds. To fix the problem, you need to deepen and widen the crack with a grinder until strong edges are obtained, while using a stone working disc. Then, grooves perpendicular to the direction of the crack should be cut with a depth of 2 and a width of 15 cm. The surface of the recesses is carefully dusted and primed.

Next, the crack must be filled with a repair compound to half its depth and a metal bracket should be installed. To increase the strength of the solution, you can add quartz sand to it. After filling the main crevice, it is required to fill the transverse grooves with mortar and remove excess mortar. Then you need to wait for the complete drying of the repaired surface and proceed with its grinding.

When repairing deep cracks, their cavity must be drilled to the entire depth of the screed. When forming transverse grooves at the ends, it is necessary to drill holes 2-3 cm deep. It is necessary to fill a deep crack in several stages, giving each layer time to harden as much as possible.. The first batch of the mixture should be made a little more liquid. This will allow her to penetrate into the most hard-to-reach places at the base of the floor and fill them evenly. The next batch should be of medium density, it should be poured into the crevice to the level of the transverse grooves.

After the second layer has set, you need to install tightening metal brackets, fixing their ends in drilled holes. Then a plasticizer is added to the solution and a final pour is made, which will hide the bracket underneath. After the solution has completely dried, the repaired area is sanded and the screed is prepared for the installation of a self-leveling floor or the installation of a floor covering.

Elimination of potholes

Repair of potholes and chips should begin with their expansion and deepening, which must be carried out until the edges of the recess stop crumbling. To do this, use a grinder equipped with diamond discs designed for working with stone. For serious potholes, the depth of which exceeds five centimeters, you need to drill through the entire thickness of the screed. Then, construction debris should be removed from the crevice and carefully dusted. Next, you need to apply a primer mixture and let it soak.

Filling the pothole with mortar should be done in several stages., applying each subsequent layer only as the previous one dries. This will ensure uniform drying of the solution throughout the depth and prevent the appearance of cracks.

If, after drying, the screed cracked again, you should increase the opening area of ​​the concrete layer and repeat the procedure. A day after the repair work, it is possible to grind the site and prepare a screed for laying the turnkey coating.

Dust removal

Often old coupler, especially without a decorative coating on top, begins to dust. This problem is most typical for floors of garages, warehouses and industrial premises. Constant weight loads, combined with vibration and regular temperature fluctuations, contribute to the rapid destruction of the coating and the appearance of cement-sand dust. Over time, the dust becomes so much that it is impossible to sweep it away. If you can't completely change concrete screed, you need to immediately strengthen the old foundation.

Initially, the floor should be cleaned of mechanical debris and dirt. Then the surface is dedusted and examined for cracks and potholes. When they are detected, problem areas are repaired, and after the solution dries, they are polished. Then you need to cover the entire surface of the screed with an all-penetrating primer mixture and wait until it is completely absorbed. In rooms with high humidity special water emulsifiers should be used. Next, the surface is painted with wear and frost-resistant enamel for concrete surfaces.

You can cover the dusty floor with a specialized composition that has polymer base. The solution is able to penetrate deep into the concrete screed by 5 mm, completely preventing the formation of dust. The treated surface acquires excellent vapor-permeable properties, and is also characterized by high resistance to chemical substances, sudden changes in temperature and abrasion.

To increase the anti-slip effect of the floor, quartz sand is applied to the uncured composition., which, after drying, forms a rough surface.

More reliable is the method of reinforcing a dusty floor with special fiberglass.

To do this, the surface of the screed is dedusted and primed. After drying primer mixture tile adhesive is applied to the screed and the fabric is laid. Cloths should be laid with an overlap, leaving no open areas.

After the first layer of glue has dried, a second layer should be applied over the fabric. This will securely fix the dusty base and increase adhesion. Then, along the perimeter of the room, it is necessary to install a damper tape, which will act as a compensator. The last step will be the installation of beacons and the installation of a self-leveling mixture.

A flat floor is a prerequisite for the repair of an apartment. It is important to keep it in proper condition and after repair. If the floor has undergone deformation, it is necessary to find out and eliminate its cause, repair the floor screed.

Peculiarities

Floor screed, even if it was made exactly according to competent instruction, will deteriorate over time. This is not surprising, because it experiences enormous loads from the weight of the flooring, furniture, movement of people and other dynamic influences. Therefore, in order to exclude the complete loss of its operational properties periodically it is necessary to repair the floor screed.

To get an idea of ​​the degree of surface deformation, it is first necessary to completely remove the old coating, clean the floor from debris, dust and dirt. Next, you should decide on the type of deformation and repair that will need to be done.

One of the following may occur:

• The flat surface has small pits and some cracks, increased level of dust generation. These damages are not terrible, they are easily eliminated with minimal loss of time and money.
• The screed peels off, the surface cracked deep enough in separate places. This type of deformation is repairable, but it will be necessary to use special building mixtures.
• The surface is significantly curved, the floor is covered with deep cracks. Repair of damage of such magnitude is available only to professionals who have the appropriate skills and equipment.

Before proceeding with the repair, it is worth paying attention to some procedures that will tell you which method of eliminating flaws is suitable for each specific case. Necessary:

• identify the cause of the deformity;
• identify the presence or absence of expansion joints (if they are not, then it is necessary to deal with the gasket);
• define fill method cement mixture and the type of base on which the floor was laid;
• find out if there is concrete flaking by tapping the surface with a hammer.

Types of damage

Before starting the repair of the floor screed, it is necessary to determine the type of damage itself. This can be done by removing the floor covering. visual assessment defects will help identify the specific type of damage, which will allow you to quickly select the necessary tools and start repairs.

The main types of damage include:

• detachment of the screed (in whole or in part) from the base of the floor;
• irregularities, potholes, cracks and pits on the surface;
• excessive dusting, which means weakening the screed material.

The reasons for the appearance of defects can be very diverse. It is necessary to pay special attention to them in order to avoid such errors and further destruction of the screed in the future.

The most common reasons are:

• Violation of kneading technology. Most often this happens when using the finished mixture. It is recommended to strictly follow the manufacturer's instructions, as incorrect proportions lead to a deterioration in the quality of the mixture. Also, you should not knead the solution manually - for this purpose it is better to use a special nozzle on electric drill or construction mixer so that the substances present are mixed evenly.
• Fast drying. When working with concrete, you should always remember that its durability and strength are directly dependent on contact with water. The cement floor should not dry too quickly, it should be sprinkled periodically with a little water and covered with polyethylene to upper layer does not become dry before the concrete has completely cured.
• Too much water in solution. Excess water in the concrete mixture, firstly, deforms the concrete itself and reduces the strength of the screed. Too much water eventually leads to the fact that the screed cracks and the surface becomes loose. To avoid this, after the concrete has dried, the screed must be covered with a deep penetration primer, which will entail new costs and increase the repair time.

Most often, defects appear precisely in the cement screed; when using semi-dry mixtures and gypsum compositions, the probability of cracking is significantly reduced.

• No expansion joints. Incorrectly laid expansion joints or their complete absence most often causes the surface to crack. It is recommended to fill the wall joint with an elastic material like polypropylene foam. It is located along the thickness of the screed, and this reduces the effect of the wall load on it. Intermediate seams divide the screed into equal parts, passing through half of its thickness.
• Absence of damper tape. The presence of an edge tape is especially important when pouring a screed for a warm floor. Concrete tends to expand when heated, thereby creating additional pressure on the walls. Thus, the absence of a pressure-compensating tape can cause destruction not only of the screed, but also of the walls themselves.
• Poor quality reinforcement. The main rule when installing reinforcement is its location in concrete, and not under the screed.

There are many other factors that lead to the destruction of the screed. Most often, this is the poor quality of the mortar, poor-quality cement mixture used in construction, violation of the pouring stages. Delamination of the screed can be caused by impact local loads, improper preparation surfaces to be poured with concrete.

Whatever the error, do not disregard the identified deformation of the screed. Small repair on the initial stage destruction will keep the floor intact and save a significant amount on its subsequent restoration.

How to fix cracks?

The above types of deformation lead to the fact that the screed begins to crack. This is bad because over time, even the smallest recesses expand, because of them you will have to do overhaul gender. Cracks are one of the most severe types of damage that require emergency removal, so they need to be fixed in a timely manner. Cracks are small and deep.

You can repair the screed with your own hands as follows:

• With the help of a grinder, widen and deepen the crack. Special attention it should be noted that after expansion the edges of the crack should not crumble, but should be absolutely solid. If it is not possible to use a grinder, you need to stock up on a hammer and chisel.
• After the expansion of the crack, you need to clean it. For this purpose, only a construction vacuum cleaner is used.
• Cleaned areas are covered with epoxy primer. This must be done several times until the mixture is completely absorbed into the concrete.
• After the primer has completely dried, the damaged areas are filled with a mixture of "Rizopox 3500" and quartz sand. The mixture should fill the crack just above the surface level.
• After the mixture has hardened, the repaired areas are sanded and cleaned.

To close up very small cracks, you can refuse to buy ready mixes and use the usual tile adhesive or a mixture for self-leveling floor. However, it must be borne in mind that this method is unacceptable when repairing screeds in rooms with high humidity.

Repair of minor damage takes a small amount of time and eliminates the need for special tools.

If large cracks have formed in the screed - more than 2 mm wide - the repair process will take place according to the following scheme:

• As in the first case, cracks must be cut to the full depth.
• After the crack widens across it, several strobes must be made.
• Small repair seams (1.5 cm long) are made along the strobe with an interval of 2 cm.
• Prepared recesses should be cleaned with construction vacuum cleaner, treat with a primer and leave to dry.
• After the primer dries, the repair joints will need to be filled with pieces of reinforcement, metal staples or wire.
• Next, the cavities are filled with liquid mortar from a mixture of sand and cement. The surface is leveled with a lath and polished after drying.

Reinforcing the screed helps protect it from stress and extends its life. There is also a little trick that will help you know if the cracks are expanding over time or not. To do this, it is necessary to glue a paper strip to the edges, if it breaks after a while, it means that the forecasts are disappointing. If the paper remains the same as it was, then everything is in order. But this method requires large stock time.

Elimination of flaking

As mentioned above, the cause of concrete peeling in some places is the uneven distribution of loads. It is possible to identify exactly where the areas affected by mechanical impact are located by ear. To do this, it is best to arm yourself with a small hammer and gently tap the entire surface. AT repair work need those places where the sound will be deaf, especially if they are marked with cracks, and the concrete begins to crumble.

Elimination of flaking occurs as follows:

• After identifying areas in need of repair, it is necessary to mark their boundaries with a chalk or marker.
• Holes with a diameter of no more than 20 mm must be made inside the damage zone in the screed. The distance between the holes should be 25-30 cm.
• The epoxy solution is brought to a liquid consistency, after which it is poured into a building syringe.

• Using a syringe, the solution must be poured into the holes. The essence of this method lies in the fact that the composition will displace the air mass accumulated between the concrete and the base, fill the space and link the screed and the ceiling together.

If the first time the air is not completely out of the cavity, the procedure must be repeated.

A day after it is carried out, you should make sure that the entire surface is reanimated. If this operation was successful, you can start laying the floor covering. Make sure the solution is completely dry. To speed up, you can use a building hair dryer.

It is very important to remember: if at the stage of diagnosis it was revealed that more than 1/3 of the area has peeled off, then it will be necessary to carry out complete dismantling screeds, since such work to strengthen in this case won't help.

How to strengthen?

Strengthening a weak screed is a way of preventive repair. Carrying out some simple manipulations will eliminate the need to remove the screed to the base, as well as protect it from destruction and delay the need for urgent repairs.

If the floor screed is made incorrectly, then over time it can collapse: crumble, crack, swell. In this case, you should not redo it.

You can promsto repair the screed, which will be a more economical option.

When cracks appear in the floor screed, it is necessary to initially determine the cause of their occurrence, and then proceed to eliminate them.

The causes of cracks in the cement screed can be the wrong layer of coating, rapid drying, excess or lack of water in the mortar, lack of edge tape or expansion joints.

If the floor screed has cracked due to the lack of expansion joints, it is necessary to cut the shrinkage joints.

In this case, the depth of the cut must be at least one third of the thickness of the base. The distance between the seams should be within 5 meters. Joints are sealed with a polyurethane-based sealant.

If cracks appear in them, you can make a strobe, thus expanding it. It is necessary to remove dust from the walls of the strobe and prime them. To seal cracks in the floor screed, it is necessary to use a non-shrinking substance, which is applied with a spatula.

If the cracks on the floor screed are minor, and flooring will tile then they can be ignored.

Cracks in the floor screed must be sealed with a composition of PVA glue, cement and water. All these components are mixed in such a way that the mixture can be poured into the slot. After this, the solution must be allowed to harden and proceed with laying the flooring.

Floor screed burst - what to do?

If the floor screed has burst, then it is imperative to correct this defect before laying the floor covering.

If the concrete mixture is poorly compacted, air pockets may appear in the screed, which cause cracks. In this case, it is necessary to remove the screed to the cavity and fill it with mortar.

In order to see the caverns, it is necessary to widen the crack. If you find it, then the solution is knocked out with the help of a pick. The walls of the resulting hole must be primed, and then sealed with cement mortar.

The composition of the cement mixture, which is prepared for sealing the cavity, should include one part of the sand and three cements. Before pouring the mixture, the concrete must be wetted with water.

Compaction of the mortar after pouring must be compacted by piercing. For this purpose, a metal rod is used.

After repairing the floor screed, it is necessary to provide not much high temperature in room. In order to prevent cracks from appearing on it, it is necessary to periodically moisten the place of laying the cement mixture with water.

The screed is bubbling - what to do?

If the floor screed coils, then it is of poor quality. The reason for the screed coiling may be a poor-quality mixture for screeding, lack of primer on the base, dirty and dusty base, which is used under the screed, etc.

In this case, it is necessary to hit the screed with the blunt edge of the hammer. If the mixture is of poor quality, then a dent will remain at the site of impact. The screed may swell in the presence of cracks or in their absence.

If the screed coils in the presence of cracks, then you can try to eliminate it. To do this, it is necessary to widen the crack. Next, a very liquid solution of sand and cement is prepared.

It is best to add PVA glue to this solution. Next, the resulting solution is slowly poured into the expanded mixture. It is necessary to fill the solution in small quantities, allowing it to dry in parts.

In the event that this method did not remove the coiling of the screed, then it must be completely removed and refilled. This is a rather costly option. That is why it is necessary to carry out the screed according to strictly established rules.

Also watch a useful video with expert advice on screed repair: