Cracks in the cladding under the windows. What to do if the facing brick bursts? Shootings and ways to deal with them

Factors influencing crack formation

Cracking of brick walls has many causes. The destruction process is triggered by one phenomenon or can be caused by a whole range of problems. The integrity of the building and the choice of repair method depend on their exact determination.

The sources of cracks in a brick wall can be divided into 2 groups: permanent and temporary.

The first option includes:

• uneven shrinkage of the building due
  to different pressure on the foundation;
• external influence is manifested in digging pits, pumping out groundwater in the immediate vicinity of the object;
• the specific features of the soil are determined by the heterogeneity of the composition, so it differently
  at low temperatures and during thawing;
• mechanical factors come into force when using a smaller number of reinforcement elements, the absence or omission of expansion joints;
• dynamic destruction is a consequence of the operation of heavy equipment and the close proximity of highways or railways.

Uneven shrinkage of the building due to different pressures on the foundation may cause a crack to appear in a brick wall.
Temporary type includes the following factors:

• natural shrinkage process upon completion of construction work;
• possible deviations during the construction of structural elements;
• destruction of bricks in conditions of high humidity or due to long service life.

The nature of the crack in the brickwork will help diagnose the cause of its appearance.

1. The expansion of the fault towards the lower part indicates a weak ceiling that cannot cope with the load. In this case, the result is a network of closely spaced cracks of small depth.
2. An increase in the width of the defect at the top indicates uneven settlement of the foundation. The cracks are located at an angle in different directions, at a great distance from each other and are widely open.
3. In the end part of the building, faults appear due to temperature changes, as well as violations of the technology for creating lintels.

Violation in floor laying technology

Improper roofing also often causes the destruction of a house. This occurs as a result of the load on the load-bearing walls occurring unevenly, the center of gravity shifts and that part of the wall on which the pressure is applied the most begins to sag, giving cracks above the windows and along the top of the walls.

Experienced builders who have seen many such problems have noticed that if a crack is narrower at the base, below, and wider towards the top, then the reason for its appearance is precisely in the foundation, and if it widens towards the bottom, it will form as a result of the pressure of the roof.

General recommendations and technology for eliminating cracks

Work to eliminate defects is carried out in several steps. Before deciding how to repair cracks in brickwork, it is important to correctly determine the cause of their appearance. If it is difficult to figure out on your own what to do when a crack appears in a brick wall, then you should resort to the services of professionals.

The next stage is aimed at eliminating shortcomings. It may require strengthening the foundation, screeding with metal locks, strengthening the load-bearing capacity of the wall, etc.

The results of monitoring the condition of the crack serve as permission to begin work. For these purposes, different methods are used.

• Place a strip of paper across the break indicating the date of installation.
• Plaster mortar overlay 10 cm long, 4 cm wide, no more than 1 cm thick.
• Installation by a guest master of a plate-type device with a scale.

It is recommended to place beacons along the entire length of the damage every meter.

Their condition has been assessed over several months. According to experts, the optimal period is from 8 to 12 months. If the integrity of the mark is violated, we can conclude that the gap will further widen. The resulting distance allows you to determine the speed of the process. If the beacon is not destroyed, this indicates a lack of tension and you can safely proceed to the final procedure.

Options for eliminating cracks in a brick wall

To seal small and medium-sized cracks in brick walls, cement mortar and polyurethane foam are used. The choice of method depends on the width and nature of the defect.

Preparation of cement mortar

For small cracks, use a cement solution. In case of defects with a width of more than 5 mm, a cement-sand mixture is used in a ratio of 1:2 or 1:3. It is diluted with water to the desired consistency.

For these works, it is recommended to replace part of the conventional cement with a special version, which has the ability to expand during the curing process.

It is recommended to replace part of the conventional cement with a special version that has the ability to expand

Adding PVA glue to the solution helps increase adhesion.

Fill the gap with the selected mixture using a spatula. The working area is pre-moistened with water. The solution should completely cover the defect, and even protrude slightly above the surface. The reinforcing mesh is pressed into the mass, after a few minutes it is completely covered with cement mortar. To level the wall, treat it with a float.

Polyurethane foam

If repairing cracks in brick walls is carried out with polyurethane foam, then you should remember about its high expansion ability. Therefore, the product is applied in small quantities. If necessary, treatment is carried out in several stages. After drying, the protruding part is cut off with a knife and a recess is made along the entire length of several millimeters. This will allow for high-quality plastering work and protect the foam from the destructive effects of sunlight. Mesh tape will help strengthen the strength of the finishing layer of plaster.

Silicone based sealant

Silicone-based sealant can achieve good results when sealing cracks in brickwork. The material is not afraid of humidity, temperature changes, is plastic, and easy to use. The constraint is the high cost, so this option is only suitable for treating minor damage.

Replacing a masonry section

In case of large cracks, it will be necessary to dismantle the bricks in the damaged area and make a new brickwork.

They begin to be removed from the very top row. It is important to remember that you cannot knock out elements of cracked brickwork to carry out repairs.

After clearing the area, the surface is cleaned with a scarpel. New masonry is laid on the cement mortar using the “lock” method. Reinforcement elements are also involved in this process.

Metal overlays, which are placed in such a way that they cover the cracks, will help increase the strength of the installation. Their edges are bent and secured with bolts.

If it is impossible to dismantle damaged bricks, it is recommended to fill the damaged area with cement mortar with the addition of crushed stone. Along the edges of the crack at a distance of 30 cm, anchors are driven in and tied with a metal strip.

Classification of cracks

The degree of destruction of brick walls is determined by several criteria.

1. Amount of opening. With an indicator of up to 0.1 mm, cracks are classified as hairline. Small ones have a value of up to 0.3 mm, developed ones - from 0.3 to 0.5 mm, large ones - from 1 mm or more.
2. Depth. There are through and superficial cracks.
3. Appearance. In the direction of destruction, defects can be located vertically, horizontally and obliquely. The edges of cracks can have straight, curved or closed outlines
4. Nature of destruction. A crack is a shear, tear or crush.
5. Time. This indicator determines how stable the defect is.
6. Risk level. The harmless option only worsens the appearance of the walls. But the second type, which continues to develop over time, can lead to the creation of an emergency situation. The intermediate state is occupied by cracks that significantly worsen operational performance, but they do not threaten the destruction of the building.

Elimination of external defects

We encounter this problem quite often. Elimination of cracks in the walls of a brick house is carried out in the following order.

1. The damaged area is cleaned of plaster, dirt, and dust.
2. The surface is treated with a primer with a deep penetration effect. A special mesh is attached to the top.
3. The prepared area is puttied with a product intended for outdoor use.

If the cracks have reached the brickwork, then a metal mesh is attached to it using bolts.
If the cracks have reached the brickwork, then a metal mesh with 5x5 cm cells is attached to it using bolts that are placed at a distance of 25-50 cm from each other. The surface is plastered cement -

sand solution, leveling the layer so that there are no differences in height.

Repairing internal cracks

The absence of the destructive effects of atmospheric factors makes it possible to use a mixture of gypsum and sand to seal cracks indoors. The composition is plastic, hardens quickly, has a good degree of adhesion and firmly holds the bricks together. It is important to achieve maximum filling of the crack over its entire depth. They do this in several steps. A reinforcing material is attached to the top, which is slightly pressed into the seam. To create a smooth surface, use putty or cement mortar.

Defects in stone structures

Defects in masonry structures of buildings and structures are classified into the following main types:

• wall deformations (deflections, deviations from the vertical);
• chips, sinkholes, potholes and other violations of the continuity of masonry;
• moistening the masonry walls, weathering and washing out the mortar;
• damage to protective and finishing layers;
• destruction of the load-bearing layer of walls and pillars.

The main causes of defects in stone structures are:

• design errors (incorrect consideration of loads, unsuccessful solution of interface nodes, loss of stability due to an insufficient number of connections, unaccounted for eccentricity, incomplete information on the engineering-geological assessment of foundation soils);
• low quality of the material (curvature of stone edges, deviations in size, low strength and frost resistance);
• low quality of work (violation of horizontality, thickness and rules of ligation of seams, deviation of load-bearing walls and pillars from the vertical, violation of anchorage);
• unsatisfactory operating conditions (soaking and moistening, aggressive environmental influences);
• uneven settlements of the foundations of walls and pillars due to underestimation of engineering and geological conditions, violation of the rules for excavation work, accidents of public water supply and sewerage networks, violation of drainage from buildings and structures;
• absence or violation of waterproofing of walls;
• absence or destruction of cornices and drainpipes.

The most characteristic signs of the presence of defects in stone structures, the places and causes of their occurrence, as well as possible consequences are given below.