There are several factors related to Greenville’s geology and climate that make it a hotspot for foundation issues. We’ll discuss each of these in-depth below and the impact they can have on your property.
Expansive soil is one of the most common causes of foundation damage in the country, and it’s a particular problem in much of South Carolina. Lynchburg soil is named the state soil, given its prevalence throughout the area. The dirt has a high ratio of clay to silt and sand, which creates several problems for your home’s foundation.
Clay is an expansive material, meaning it grows in volume when it gets wet. Runoff from precipitation in South Carolina makes the groundswell, and the lateral and upward movement of the earth can have severe negative effects on foundations.
It creates stress called hydrostatic pressure on your concrete slab and foundation walls. Eventually, the pressure causes concrete to crack and shift inward, leaving your foundation’s stability compromised.
The expansive qualities of clay soil damage homes, but the shrinking qualities when it dries are just as hazardous. During periods of little or no rain, the soil loses excessive volume and can recede from your foundation.
This process happens in all areas of the country, and the concrete typically responds by sinking to stay in contact with the soil. However, the clay in South Carolina’s soil makes differential settling more likely, which is when the concrete loses support in a non-uniform fashion. Differential settling can cause severe structural damage to Greenville foundations, especially since the swelling and shrinking cycle happens frequently and rapidly.
Lastly, clay particles are tiny and retain water more readily than typical soil, meaning runoff is held against your concrete foundation for extended periods after precipitation. The long exposure times and hydrostatic pressure caused by the expansive soil make water intrusion a widespread issue in South Carolina.
Many areas are underlain by clay-rich soil, but the potential for damage in Greenville is higher than usual because the problematic soil is coupled with above-average rainfall. The city experiences an average of approximately 48 inches annually, which is significantly higher than the national average.
The excessive precipitation in Greenville means the ground is saturated for longer periods, increasing the chance of the hydrostatic pressure becoming too much for your foundation to resist. It also exposes your concrete to a more considerable amount of runoff, making water intrusion and moisture build-up under your home more likely.
Cyclones During Hurricane Season
South Carolina is well-known for its hurricane season, extending from June to November. The coastal cities like Charleston and Myrtle Beach experience far worse effects from hurricanes and tropical storms, but inland cities like Greenville and Columbia still see significant precipitation during these months.
The concentrated rainfall that hits northern South Carolina contributes to the already dangerous problems with expansive soil. It can cause flooding in Greenville, which elevates the risks associated with the soil even further.
South Carolina residents enjoy warm weather for much of the year, but the high temperatures are often coupled with high humidity. The average humidity in Greenville is around 70%, and fluctuations throughout the year are very minimal.
The air from outside naturally makes its way into the area under your home, where the humidity gets trapped. Moisture build-up in your crawlspace or basement can cause weakening to your concrete and construction materials, promote mold growth that can eat away at your home’s framing or foundation, and attract insects and rodents that can damage your home.
Lastly, earthquakes are a common occurrence in Greenville. Although the majority of the seismic activity in the area is minimal, there is a chance for relatively powerful earth movements that can shift your foundation. Even small quakes can contribute to hydrostatic pressure, differential settling, and other damage to your foundation over time.