Do-it-yourself repair of concrete floor screed potholes

When replacing flooring, apartment owners often have to repair concrete floors, which can be concrete screed, and the floor slab itself. Despite the fact that concrete is a durable and reliable material, under the influence of various factors, potholes and cracks may appear on it. Timely measures are necessary to prevent further destruction, because the service life of the finish floor depends on the condition of the concrete base. We will find out how to repair a concrete coating using special mixtures for repairing a concrete floor.

Causes of defects on concrete

Defects on the concrete floor can be formed for various reasons, which are primarily associated with violations in the process of its arrangement.

Cracks often appear due to the absence, untimely cutting or incorrect calculation of the thickness of the joints in concrete floors designed to prevent concrete stress during thermal expansion and during shrinkage. Properly made temperature-shrink seam will avoid many problems.

Other causes of cracking include:

• a large amount of water in the solution when pouring concrete screed or its lack;
• poor-quality reinforcement;
• lack of waterproofing the base.

Defects can form even with a job well done. Any coating is subject to natural wear and tear, it is adversely affected by excess moisture. Potholes appear due to physical influences. The influence of external factors on the concrete floor cannot be ruled out. The weak point is the joint of the wall and the floor, cracks often appear there.

It is necessary to determine the type of damage. This will allow you to draw up a work plan and choose the right material. Often faced with the following varieties:

• small grooves, potholes;
• cracks of various sizes;
• the finest cracks and chips.

Repair should not be postponed for a long time. The size of the defects can gradually increase, the concrete will begin to crumble and move away in pieces, which will complicate the sealing of problem areas.

The choice of mixture for the repair of concrete surfaces

Before you start repairing the floor in the apartment yourself, you need to prepare a mixture for the restoration of concrete surfaces and structures. In construction stores, they are represented in large numbers. In order to correctly choose the brand of the mixture, you need to determine the degree of damage to the concrete surface:

1. The first degree - there are shells, shrinkage cracks.
2. The second degree is peeling of the surface, small chips.
3. The third degree - cracks within 2 mm with a depth of not more than 40 mm.
4. The fourth degree - cracks more than 2 mm, depth up to 10 cm.
5. Fifth degree - large potholes and cracks, depth more than 20 cm.

The purpose of the repair mixture should be indicated on the packaging. Noteworthy are such manufacturers of concrete restoration mixtures as Emaco, Birss, Ceresit, Bars.

You can use universal repair mixtures, such as Ivsil Render.

Since the price of special thixotropic compositions containing reinforcing microfibers and polymers is quite high, for a small amount of work, the mixture can be prepared independently. For this, 1 part of PVA glue is taken and mixed with 4 parts of water. In this solution, using a construction mixer or a special nozzle on a drill, a sand-cement mixture is mixed in a ratio of 1: 3.

Preparatory work

After selecting a material for the repair of concrete floors, repair should begin. Initially, the preparatory phase:

1. All foreign objects are taken out of the room.
2. Existing rubbish, concrete chips and dust are swept away. Potholes and cracks are thoroughly cleaned with a vacuum cleaner.
3. Any dirt, rust, mold or old soil is removed with a hard metal brush.
4. To eliminate greasy stains, you need to use a special solution.
5. The concrete floor is swept with a wet broom, then it needs to be dried.
6. If the reinforcement is visible, then it should be cleaned with sandpaper and primed with a composition with anti-corrosion properties.

Areas of concrete surfaces that have lost strength should be tapped with a hammer and cleaned. The rule applies to the edges of problem areas.

Potholes in concrete floor

Repair of concrete floors begins with the expansion and deepening of the pothole along the perimeter. It is better to use a grinder with a diamond disk.

• Propyl is made 1 cm deeper than the defect. In the direction of the pothole expands by 2-3 cm. If necessary, these indicators are increased.
• With the help of a puncher or a hammer with a chisel, a recess is made at the place of the pothole, a rectangular recess should be obtained. If a puncher is used, then it is better for outsiders to move away.
• The recess is thoroughly cleaned with a vacuum cleaner and primed.
• Potholes can be closed after the soil has dried. The mixture is carefully leveled, it is pierced several times to remove air. You can use a metal pin or trowel. Level the surface using a rule.

The depth of the pothole matters. If it is more than 5-6 cm, then the composition is poured into several layers. The maximum layer thickness is 2 cm.

• After solidification, they proceed to grinding. To achieve a smooth concrete foundation will help the construction level.

Work is recommended in a respirator, goggles and gloves. Windows in the repair process must be open. The floor can be coated with concrete paint, which will provide additional protection. It is selected specifically for residential premises. A floor repaired in this way will last a long time.

Crack Repair Rules

The process of closing cracks in a concrete floor differs depending on their size.

• Small gaps widen in depth and width by 2–5 cm. To do this, you can use a chisel or grinder.
• The recess is cleaned of pieces of concrete and dust, then processed primer.
• To repair cracks in the concrete floor, a homemade PVA-based mixture is used. They fill the crack and wait for shrinkage.
• The second layer is coated, dried and ground.

In those cases when the cut is accompanied by strong dusting, which indicates that the concrete is weakened, it is necessary to use only special thixotropic compounds.

Crack repair in concrete floors should not be delayed for long. If they are deformation, then they need to be treated with special attention. You can determine their appearance using strips of paper. A few months before the repair, they are glued to cracks in the concrete floor. With shrinkage cracks, the paper remains intact, with deformation strips tear, which indicates their expansion.

• Such a crack is sawn 5 cm deep and 3 cm wide.
• The edges of the cut are knocked down, a triangular recess is formed.
• After thorough cleaning, the recess is primed.
• Markers are inserted into the crack with a step of 3 m.

Markers are thin, smooth metal rods. You can make them yourself from the spokes of the bicycle wheel.

• The crack is filled with a thixotropic composition, the use of home-made mixtures in such cases is not recommended
• The concrete area is polished after drying.
• Marker rods are removed, a new deformation seam is cut out through the holes remaining after them.
• Dust is removed from the seam, and the Vilotherm cord or its equivalent is placed in it.
• The seam is finally sealed with silicone or polyurethane based sealant.

Some notice small cracks in the cobwebs on the floor, as in the following photo. Over time, they can become wider. When concrete weakens in this part, they are cleaned and covered with soil. To seal, you can prepare your own composition or use the store.

To ensure that the furniture is level after repairing the concrete floor in the apartment, it is necessary to use the building level throughout the process.

Overhaul of concrete floor: cost

In case of severe damage to the concrete pavement or during installation floor heating systems will have to undergo major repairs - a complete replacement of the concrete screed. When contacting specialists, this procedure, taking into account the materials, will cost the following amount:

• in Moscow - from 420 rubles / m2;
• in St. Petersburg - from 380 rubles / m2.

Dismantling the old concrete screed is not included in this amount, the price depends on the area of ​​work: the larger it is, the cheaper.