What causes cracks ?

The causes of cracks are numerous and varied, and understanding the main ones can help better grasp the phenomenon.

A few explanations about cracks about cracks in buildings

Cracks are the most common manifestation of structural issues in buildings, affecting exterior and interior walls, facades, partitions, floors, coatings, tiles, slabs, and more.

Causes of cracks in walls

Cracks in a building can have various causes, and identifying the source of the problem is essential for implementing appropriate repairs. Below are some common causes of cracks in buildings:

Shrink-swell of clay soils

Clay soils contract and expand depending on their water content. Alternating periods of rain and drought can cause significant variations in the soil beneath the building, leading to differential movements and resulting in cracks.
This effect can be exacerbated by vegetation near the building, as plants absorb water during dry periods, increasing the shrinkage effect.

Soil Settlement or Subsidence

This phenomenon may be natural or triggered by human activities such as mining or construction work (e.g., foundation digging, drilling).
Changes in soil structure caused by these activities can lead to ground subsidence, which may result in cracks in nearby buildings.

Foundation problems

Issues such as inadequate design, poor-quality construction materials, or improper construction methods can lead to foundation problems, which are often the source of cracks in walls.
Defective foundations can cause subsidence, cracks, or deformations, placing stress on the building’s structure.

Vibrations and Ground Movements

Cracks in buildings can also be triggered by factors like seismic vibrations, nearby human activities such as construction, or heavy road traffic.

Seismic vibrations from tectonic activity exert pressure on foundations, increasing the risk of cracks. Similarly, construction and road traffic generate ground movements that, over time, can weaken structures.

Temperature variations

Temperature fluctuations, especially freeze-thaw cycles, are another cause of cracks in buildings. These thermal variations create stress on construction materials and foundations, leading to repeated expansion and contraction.

Freezing is particularly damaging, exerting pressure on the structure when water infiltrates stones, bricks, or joints. Frozen soil can also cause heaving movements, destabilizing buildings and causing cracks.

Construction Defects

Cracks can also result from construction defects caused by errors during design or execution.
Poorly executed joints, insufficient structural reinforcement, or defects in materials can compromise the building’s stability. Improper joints allow water infiltration, leading to degradation and cracks.

It is important to call in construction/building experts to assess the cause of cracks and determine the best approach to repairing them sustainably.

In some cases, foundation repair, drainage or waterproofing work may be required to resolve the problem at source. Cracking is a complex subject, with so many causes that it is important to diagnose the origin before carrying out effective repairs.

Why measure the evolution of a crack in a building?

A phenomenon can only be properly analyzed if it can be quantified. By measuring, it becomes possible to determine whether the crack is still active and take appropriate action.

We offer a comprehensive range of tools to monitor cracks in walls. You can find detailed guidance in our technical datasheet to help you choose the appropriate crakc monitor based on the crack or movement to be measured.

How long should a crack be observed? 

There is no single rule, because the answer depends on the context and the cause of the disorder.

In general, it is advisable to take measurements very regularly at the beginning and gradually space them out if no movement is observed.

For cracks related to soil movements, it is typically recommended to leave crack monitors in place for one year to assess whether seasonal changes affect crack movement.
A minimum of four readings per year is recommended, although more frequent readings may be necessary if significant variations are observed.

For specific cases or uncertainties, consulting a building expert is advisable to refine and adapt the monitoring schedule based on the context.

How do you know whether the crack is dormant or active?

A dormant crack (one that is no longer active) is defined as a crack in a building wall whose width does not change over time, regardless of temperature or structural stress.

For cracks caused by soil movements, the minimum duration to consider a crack dormant is one year.

For interpreting your measurements, we recommend consulting a building expert who can identify the cause of the damage, assess whether it is active, and suggest appropriate solutions if needed.