Foundation Cracks: Causes and How to Fix Them

Foundation cracks usually appear in spring after snow melting. The reasons may be different: heaving of the soil during frost, violation of the foundation construction technology, etc. To avoid such problems, first of all, you need to choose the right foundation that meets the characteristics of the soil, follow the technology of foundation and correctly calculate the load from the weight of your building.

If you choose the option of buying a ready-made house, then when choosing it, you should carefully examine the foundation. There should be no cracks, even small ones, as they can grow over time. It means that the foundation has been built with violations. The probability of cracks is less if the house is built according to standards.

Causes of Cracks

Basically, the problem worsens in the off-season. During winter frosts, the soil heaves. It often happens that the technology of the foundation has been violated. In spring, the soil thaws at different rates, which is why its shrinkage occurs unevenly. Only a high-quality foundation will cope with this load. To check the quality of foundation construction by building companies, you can use samples of ready-made objects.

If there were some violations during the construction of the foundation, cracks and fractures may appear in a year. The causes of foundation cracks can be divided into three groups:

  1.   The load on the foundation was incorrectly calculated, and some geological studies were not performed. As a result, soil properties and local terrain features weren’t taken into account. If you choose which is better: an individual or a standard project, the advantage of standard projects is that they eliminate all violations that may appear during the operation of the house. It’s possible to avoid cracks by choosing a standard project. At the same time, it’s important to observe the rules of operation of the house in the future.
  2.   The technology of foundation construction was violated. It refers to improperly built formwork and a low grade of concrete. For example, when builders construct a strip foundation wrong or install the foundation below the underground water level.
  3.   This group includes violations that were committed during the operation of the house. The load on the foundation has increased and become greater than the design load (for example, when replacing the roof, some heavier materials have been chosen, the second floor has been completed, etc.). If there is no drainage system (both storm and deep), perhaps, you could discover humidity in the basement.

A special mixture is used to repair cracks. Water is added to it until a paste-like mass is formed. After dilution, the mixture dries quickly, so it should immediately fill the cracks with a trowel. It should be applied with a margin. When the solution begins to drag, the surface needs to be leveled. Then the repaired cracks are covered with a damp cloth and kept in such a condition for several days. Remember that if you don’t have much experience, it’s better to contact a foundation crack repair service. It can help you cope with your problem fast and guarantee the desired result.

How to Fix Cracks

Correctly identifying the cause is a big part of solving the problem. This universal rule also applies to foundation repairs. So, if there are small surface cracks in the foundation after pouring, you can implement some cosmetic measures, e.g. seal them with cement mortar, just to avoid further destruction. It’s impossible to completely ignore such damage – under the influence of moisture, temperature changes, freezing and thawing, even such minor violations of integrity can eventually lead to serious problems.

However, such measures are effective only if the cracks on the foundation surface have a small depth of no more than a few millimeters. If deeper cracks appear, more serious actions are taken. One of the methods of eliminating small cracks (up to several centimeters deep) is to fill them with epoxy resin. Before repairing a crack in the foundation, it’s necessary to thoroughly clean and dry the surface. Filling with resin should start at the bottom to avoid smudges. After the resin has finally solidified, treat the outer surface with special materials that make it difficult for moisture to access. It will help to avoid cracks in the future. A concrete crack repair has to be done on time.

A vertical crack in a monolithic foundation can lead to the destruction of the entire house. At least, the formation of wide cracks in the walls leads to the disruption of communications (electrical wiring, water supply). In these cases, you need major repairs of the damaged area or even the entire foundation.

If the vertical displacement of the foundation leads to the “spreading” of the building, not only the crack is repaired, but also the walls are fixed either with an external frame or with a reinforced seam.

You should pay attention to the features of the materials which were used during your house construction. You need to assess the conditions of the entire building. Sometimes, it’s necessary to replace the part of the construction that is directly adjacent to the foundation (logs, beams) before repairing a crack in the foundation of a wooden house. The more extensive the damage to the foundation, the more part of the construction will have to be repaired.