As anyone who has ever tried to plant a garden here knows, the southeast is full of clay-rich soils. These soils may be good for hot peppers and peanuts, but they are very damaging to foundations. Clay-rich soils expand and contract when the moisture changes. You may find that cracks in your home become more prominent before or after it rains or when the weather changes. This is because clay-rich soils are “elastic” in nature. In other words, they expand and contract as moisture is absorbed or evaporated. When the soil around your home becomes saturated with water, the clay expands and loses density. This condition allows the foundation to sink much the same as you would standing on the beach as the tide rushes in.
When the water evaporates, the cray becomes hard and dense again. The problem, as any gardener knows, is that soils don’t lose moisture evenly. If one area of the soil beneath your home’s foundation becomes oversaturated with water and another portion is less saturated, the water saturation beneath your home can evaporate unevenly. The oversaturated soil loses density and cannot support the pressure of your home’s foundation. This is the primary cause of foundation settlement.
Do I Have Unstable Or Expansive Soil?
Clay is the predominant type of soil under homes in the southeast. If you live in Charleston, Columbia, Florence, Myrtle Beach, or anywhere in South Carolina or over the state lines, there’s a good chance that your home sits on soil that has a major consistency of clay. However, whether your home sits on southeastern clay or beachfront sand, it’s important to watch for the signs of foundation failure to see if your home’s foundation is compromised by expansive soils.