What is a common cause of subsidence in building foundations?

Subsidence in building foundations often arises from various environmental and structural factors that can create instability in the ground supporting a structure. A significant cause of subsidence is improper drainage, which can lead to the saturation of soil and subsequent weakening of its load-bearing capacity. When water accumulates in the soil due to inadequate drainage systems, it can cause the soil to expand and contract, which may result in shifts and eventual subsidence beneath the foundation.

Excess moisture is another critical factor that frequently contributes to subsidence. When soil becomes overly saturated with water, it can lose its structural integrity. This can happen in heavy rainfall situations or due to plumbing leaks, resulting in the soil being unable to support the weight of the building effectively.

Soil erosion also plays a role in subsidence, particularly when water runoff or other disturbances wash away the soil support around or under the foundation. Erosion can occur due to natural weathering processes or human activities, contributing to a reduction in the support that the soil provides to the foundation.

Since all these factors—improper drainage, excess moisture, and soil erosion—can contribute to foundation subsidence, stating that any of them can lead to this issue collectively underscores the importance of addressing all potential risks in foundation design and maintenance.