Crack in the wall of a house: how to determine the cause and eliminate the consequences

Recommendation points

• Causes of cracks
• How to determine the cause of a crack
• Eliminate the cause, get rid of the crack
• Swelling as a result of soil soaking
• What to do if the problem lies in the foundation

A cracked wall should not be neglected. A crack in the wall of a house is the result of a violation of the technology for erecting a foundation or walls. After reading our little educational program, you will learn how to correctly determine the cause of cracks by indirect signs. And, as a result, you can quickly eliminate the blemish, avoiding further complications..

Causes of cracks

Due to the movement of soil layers, the entire building tilts in one direction or the other, but in general the building is kept tight and monolithic, thanks to a massive and strong foundation. And this is exactly what scares: if cracks appear on the wall, it means that the foundation does not fulfill its function.

Meanwhile, there are a number of reasons due to which cracks can form without destroying the base. And if the foundation is not rigid enough or the supporting soils do not evenly accept the load, the tape will bend more than the walls can withstand. It is safe to say that cracks appear due to imperfections in the building structure, design errors or shortcomings during construction..

Cracks can be caused by errors in design, construction or improper use of the building

The root cause is the fact that the soil layer under the foundation is not uniform. In areas with high density, the pressure is greater, due to which the building rests on only a few points and deforms under its own weight. The main feature is that the density of sites can change significantly over time or depending on weather conditions. Due to freezing, the soil swells, when it gets wet it becomes too soft, less often geological, seismic and geomorphological factors come into play.

It is not enough just to close or hide the crack, you should find out the reason for its formation and only after that start to restore.

How to determine the cause of a crack

At the first detection of cracks, it is necessary to begin close monitoring of their development, simultaneously recording temperature changes and the presence of precipitation during this period. To have the most complete understanding of the nature of fracturing, it is helpful to keep a detailed log throughout the year..

For a visual representation of the changes in the width of the cracks, small lumps of alabaster, soaked to the consistency of plasticine, are attached to them. Lighthouses are installed along the entire length of the crack every meter. Checking the marks periodically, for example, after a month, two months, and so on, we can conclude about the nature of the damage:

1. If the mark is cracked or fell off, then the crack continues to expand. By the gap in the mark, you can judge the speed of the divergence.
2. If the mark is cracked, there is no gap, the wall is subjected to dynamic loads, but there is no stress in the material, and no further discrepancy is observed.
3. If the mark remains intact, then there is no stress in the wall. The crack was the result of one-off shrinkage.

To obtain more accurate information, observations are continued for a long period, and the damaged marks are replaced with new ones, fixing the previous result.

Any hard but brittle material capable of revealing the slightest deformation of the base is allowed as marks

The shape of the cracks can tell a lot about the nature of the movement. If the place of the fault is even, the edge is sharp and has no chips, then the crack has expanded and simply tore the lighthouse. If the edges of the crack on the lighthouse have chipped edges, or it has completely disappeared, most likely, the crack, on the contrary, has decreased, and the lighthouse collapsed from compression.

The special shape of the tags and beacons helps to identify the smallest fluctuations

By projecting these changes onto the geometric model of the house and foundation, you will be able to establish with high accuracy how the precipitation occurs over a long time, whether it depends on the wetting of the earth during rain, where there are places of high and low density.

And yet the most complete information can only be given by a comprehensive analysis performed by specialists on the basis of an examination, which includes:

• control of the strength of supporting structures;
• analysis of supporting soils;
• detection of hidden cracks or uneven distribution of loads.

Ultimately, with your own observations or with outside help, it will be possible to draw up a plan of measures to strengthen the foundation and walls of the building and eliminate cracks.

Eliminate the cause, get rid of the crack

The most dangerous case is when the crack continues to expand. This suggests that the walls of the building or the foundation will be irreparably destroyed. The problem can be fundamentally solved only by a complete restructuring of the emergency section of the building. However, if you notice the problem in time, then a much less radical method will help – covering the house.

Everything is done quite simply:

1. Steel corners with a shelf of 100 mm are installed at the outer corners..
2. On crutches, at least two lines of smooth reinforcement are laid along the walls – upper and lower.
3. A thread is cut on each rod: left-hand on one side, right-hand on the other. Nuts are screwed onto the fittings, which are welded to the corners.
4. A meter from the corner on the side of the reinforcing bars, it is welded along a small parallel bar so that rotation can be transmitted with an ordinary adjustable wrench.
5. At the final tightening, two people twist the bar at the same time, gradually increasing the tension.

At the same time, the cracks literally melt before our eyes, it remains only to replace the protective plaster of the walls and basement, reinforcing it with a steel mesh.

An example of tightening a building on a plinth

It is possible that the markers on the crack will remain intact for a long time, or the gap will constantly widen and narrow, but generally not increase. This is a clear sign that the foundation is working normally, and there were initially excessive stresses in the wall material, which poured out in the form of a crack..

To strengthen the wall in a problem area, use:

• external reinforcement with carbon fiber, steel mesh;
• anchors and metal frames;
• embedded reinforcing elements along the strobes;
• injection method.

It is important to close the crack and restore the strength of the structure. If the reason was improper bandaging of brick rows, then it is quite possible that the only effective remedy would be full or partial re-laying of the wall in the emergency area.

Reinforcement in grooves helps to contain further deformations

Solid reinforcement with external frame, anchored to the wall

Reinforcement of walls with external carbon fiber reinforcement

Elimination of cracks by injection method

To seal any cracks, it is necessary to clean it along its entire length and depth from dirt, dust, remove a layer of mortar and base material, expanding it to 15 mm or more. The resulting gap is filled with a solution, having previously performed reinforcement using one of the above methods.

Swelling as a result of soil soaking

So that the soil under the foundation is not oversaturated with moisture, a blind area is mounted around the house and drain pipes are diverted as far as possible. However, over time, the screed can collapse, and rainwater will seep directly under the foundation, undermining it..

Usually a sign of such a phenomenon is the gradual expansion of cracks, which occurs mainly during heavy precipitation or for some time after them. It is typical for such phenomena that the cracks seem to “chip off” the corners of the house, passing through the nearest window openings.

Frosty heaving can destroy the foundation of a house

The foundation continues to remain intact, but the general inclination of the building may increase from year to year. In addition, no one knows how much the next shrinkage will occur, and how this will affect the integrity of the concrete base. Swelling due to high humidity can also occur due to the raising of the upper water.

A drainage system, assembled around the perimeter of the building to drain groundwater and top water away from the foundation, will help to qualitatively solve the problem. It is necessary to bare the foundation to the base, lay the drainage pipe on a prepared sand and gravel cushion along the perimeter of the foundation and perform a branch to the side. To discharge water, it is necessary to prepare a drainage well or bring a pipe to the nearest reservoir.

Drainage for the removal of groundwater of atmospheric precipitation and melt water from the base of the foundation

Wide blind area will not allow precipitation to flow under the foundation

An obligatory step to eliminate the problem is the restoration of the cement blind area and its expansion. Usually, for a shallow strip foundation, a blind area with a width of about 40-60 cm is sufficient, and for buried foundations – up to one and a half meters. It will also not be superfluous to install ebb tides and discharge rainwater 4-5 meters from the house.

What to do if the problem lies in the foundation

If no measures have been successful, you will have to look for the problem in the foundation. A prerequisite for this may be not only the visible formation of a crack in the exposed area, but also the general structural unsuitability of the base, which causes insufficient stiffness..

Local faults in the foundation should be eliminated immediately. First, a dig is performed to a depth of 60–100 cm under the lower edge of the tape and up to 2 meters wide. A curbstone reinforced with reinforcement is poured under the place of the break, after which the foundation pit is expanded by another meter in each direction and refilled again.

Strengthening the foundation with piles

Do not forget that the reason may be the initial miscalculation in the design of the house or non-compliance with the requirements during construction:

• the properties of supporting soils are not taken into account;
• the depth of the foundation was incorrectly selected to the real depth of freezing;
• the width of the foundation is not sufficient for real loads, etc..

Reinforcement of the foundation with additional pouring with reinforced concrete along the perimeter of the building

If cracks appear in the foundation and walls of the house, then you should immediately take measures to strengthen the foundation, for example, screw piles, side or bottom gravy. It is possible to determine which reinforcement method is required only based on the data of the construction expertise and the preparation of the corresponding project, which is better to entrust to professional designers.