People often think that if they live in a private or low-rise building, such a problem as a crack in the wall will not threaten them. But this assumption is wrong because any building can suffer either from natural conditions or from human intervention.
A crack in the wall of a house can appear for a variety of reasons – it can be affected primarily by natural factors, human activity, as well as time. The construction of any house begins with the Foundation, so it plays the most important role in this matter. It often happens that cracks on load-bearing walls begin even deep in the Foundation, and are even invisible at the initial stages. This is mainly because the Foundation was built without taking into account the peculiarities of the post office structure and the climate of the region. Saving on initial ground drainage and waterproofing usually leads to serious problems in the future, including serious cracks in walls.
Because of the movement of the soil layers, the entire structure tilts alternately to one side, then to the other. In the event that there is a crack in the wall of the house, this may mean that the Foundation is very poorly coping with its duties. However, there are many other reasons why cracks can occur even without destroying the Foundation. If the load-bearing soils do not take the load evenly, then the Foundation base is deformed more than the walls of the house can withstand. As a result, it can be assumed that cracks in the walls of buildings are formed due to design errors, incorrect construction of the structure, as well as errors made during the construction of the building. One of the reasons for the appearance of cracks in the walls is that the layer of soil under the base is heterogeneous. Those areas that have a high density, the pressure on them is greater and therefore the building can only rely on a few points. As a result, it is deformed by its own weight. However, there is one feature, and it is that over time, the density of the soil can change significantly due to weather conditions. As well as due to the fact that the soil freezes, there may be a swelling of the soil, and when moistened, the soil on the contrary becomes too soft. It will not be enough to close the crack or hide it, you will need to find out the cause of its occurrence and only then take measures to restore the wall.
The main sources of cracks in walls can be
- Small (insufficient) depth of Foundation: Quite often, found in old buildings, can lead to the mobility of the soil under the Foundation due to heaving or other reasons.
- Exceeding the design load on the ground: this usually occurs if you want to save money by making the Foundation too narrow on the mobile ground.
When filling the Foundation, low-quality building materials were used: low-quality concrete or gravel that does not match the strength or resistance to an aggressive environment. The brand of concrete used for the manufacture of such structures should not be less than M 200. All the above-mentioned reasons can be attributed to the violation of technology during the construction of the Foundation. But there are other reasons that can not always be taken into account: an unpredictable increase in the level of underground water; heterogeneity of the soil under the Foundation; destruction of the Foundation body from time to time; the slope of the site on which the building stands; weather and geological factors also contribute to the formation of cracks in the walls. Violation of the integrity or absence of a blind area around the house can also cause cracks in the walls of the house. In this case, non-monolithic or non-reinforced foundations, which are more prone to uneven shrinkage, suffer more. Not the least role is played by the quality of the building material of the walls themselves, namely its behavior under the influence of external factors and loads: swelling, shrinkage, as well as vibration, which can activate the appearance of cracks. These factors may include the sun, rain, wind, and even the proximity of busy traffic.
Seasonal changes in the soil: provoke subsidence, leaching, and frost heaving, characteristic of a number of soils (clay, loam, dusty soil), as well as changes in the level of underground water. Not a correct or complete assessment of the strength of the Foundation: the problem occurs when various sections of the trench or Foundation pit are not identified filled-in pits (ditches), as well as rigid supports (natural or artificial boulders, concreted wells, etc.). Violations in the operation of the building: usually occur when flooding, but not rarely and washing out the Foundation base with household or atmospheric water (a burst sewer, water pipe, or the destruction of the blind area).
Cracks in walls can be divided into these groups
- Due to shrinkage, deformation, temperature, structural, as well as caused by wear or weathering of the walls.
- By risk level: dangerous and non-dangerous.
- By direction: vertical, inclined, and horizontal.
- By depth: through and surface cracks.
- By time: stable and unstable cracks.
- According to the size of the opening: large-more than 1 mm, small – up to 0.3 mm, developed-up to 0.5 mm.
How do I determine if cracks in walls are dangerous or not?
When even a small crack is detected, the main question arises – is it dangerous? It is quite simple to check this – you need to install a control beacon and observe the” behavior ” of the crack for a long time. Professionals put such control beacons special – plate, which must be registered with the Supervisory authorities. At home, you can use one of the following methods to solve the problem yourself:
- Stick a strip of paper with the installation date on the crack;
- Prepare a plaster solution and put a strip of it on the crack.
Then you just have to wait and periodically check the status of the control beacon. It may take several months before any conclusions can be drawn-experts say that you need to control the crack for 8-12 months.
How dangerous it is will show the gap of the control beacon – if there is such a phenomenon, you will need to use complex technical solutions to fix the problem, if there is no gap in the beacon, then do not worry at all.
If you notice that there are more cracks, or they have increased in size, you need to ask for help from specialists, because they will be able to make an examination. The expertise includes
– monitoring the strength of support structures;
– Analysis of the control soil;
– Identification of uneven load distribution, as well as hidden cracks.
As a result, according to their own observations or observations of specialists, it will be necessary to make a plan to eliminate cracks, strengthen the walls, and the base of the structure.