Numerous factors can contribute to differential foundation settlement, including the following:
One of the primary causes of differential foundation settlement is the type and quality of soil underlying the foundation. Different soil types have varying levels of compressibility and load-bearing capacity, which can impact how much settlement will occur and how evenly it will distribute. For example, clay soil has a high potential for swelling and shrinking with changes in moisture content, which causes movement in the ground under the foundation and can lead to differential settlement. However, other soil types can also be prone to settlement.
Soil erosion is another cause of differential foundation settlement. It occurs when the soil beneath the foundation is washed away, leading to weakened support and differential settlement. Soil erosion can be caused by natural factors such as rainfall, flooding or man-made factors such as construction activity.
Inadequate site preparation can also lead to differential foundation settlement. This may include failing to remove vegetation or debris, not properly grading the land, or not adequately compacting the soil before building. Any deviation from established building codes can ultimately lead to foundation issues.
Excess moisture in the ground around a foundation can also cause differential settlement. When water infiltrates the soil under the foundation, it can create areas of saturated soil that may lead to differential settlement. This can occur due to poor drainage, damaged or clogged gutters, or a high water table.