40 Hour Property and Building Inspection Practice Test

Which factor is a primary cause of foundation heaving?

1. Soil expansion due to moisture

2. Excessive wind

3. Shallow excavation

4. Low-quality materials

The correct answer is: Soil expansion due to moisture

Foundation heaving primarily occurs due to soil expansion resulting from moisture changes. When soil becomes saturated with water, it absorbs moisture and expands. This process can be particularly pronounced in clay soils, which have a high capacity for moisture retention and significant volume changes. As the soil expands, it exerts upward pressure on the foundation, leading to heaving. This phenomenon is often exacerbated by seasonal fluctuations in temperature and precipitation, where wet seasons can increase moisture levels in the soil, causing it to swell, and dry seasons can lead to shrinkage. Proper drainage and moisture control around the foundation are critical to mitigating this issue and preserving the integrity of the structure. The other factors listed, such as excessive wind, shallow excavation, and low-quality materials, do not directly cause foundation heaving. Instead, they may contribute to structural integrity concerns in other ways but are not related to the moisture-driven expansion of soil that leads to this specific issue.