There are quite a few underlying problems for homeowners in the Fredericksburg area. We’ll discuss these in detail below and offer some insight into the damages each can cause.
Expansive Soil
Many homes in Northern Virginia, including those in Fredericksburg, are built on soil with an abundance of clay. Clay is exceptionally absorbent and grows in volume as it gets wet, sometimes up to 110% of its original volume. This type of dirt is called “expansive soil,” and it creates several problems for home foundations.
Soil expansion places significant stress – called hydrostatic pressure – on your foundation walls and concrete slab. The pressure can cause inward movement of your walls, cracking, and eventually the loss of structural integrity. Hydrostatic pressure is one of the leading causes of foundation damage, and homes in Fredericksburg are at an incredibly high risk of being affected due to the clay in the dirt.
Clay soil also takes longer to dry, which means it holds moisture from runoff against your concrete for extended periods. With these long exposure times and the added pressure from the expanding soil, the water can force its way through foundation cracks and even directly through the pores in undamaged concrete, leading to water damage inside, widening gaps if the water freezes, and moisture problems in your basement or crawlspace.
Additionally, expansive soil loses volume when it dries. If the soil around your home loses too much moisture, it can shrink away from parts of your foundation, leaving them unsupported by the earth. These sections commonly crack without the support they need and sink into the ground, leaving your home with severe structural damage.
Acid Sulfate Soils
As if expansive soil wasn’t detrimental enough, Fredericksburg and the surrounding cities are also afflicted with acid sulfate soils. Acid sulfate soils contain abnormally high concentrations of iron sulfides. These minerals can be highly corrosive under certain conditions, including after excavation or some other movement that exposes them to oxygen, when they’re converted to sulfuric acid.
Sulfuric acid can quickly degrade concrete and other building materials, eventually causing structural damage and sometimes collapse of foundation walls.

Low Elevation & Flooding
Fredericksburg is about 60 miles west of the shoreline, but the city’s average elevation is just over 50 feet above sea level.
The low elevation means that runoff from surrounding towns with a higher elevation naturally makes its way into Fredericksburg, making flooding a problem for homes in the area. Minor floods are somewhat common in the city, and the proximity to the Rappahannock River leaves homes open to significant floods on a less frequent basis.
Flooding of any magnitude can spell disaster for foundations because it regularly leads to water intrusion and differential settling of the earth. The presence of expansive soil compounds the flooding risks for foundations in the area.
Frost Heave
Frost heave is the upward movement of soil as the water suspended in it freezes and expands. It can occur in any area, regardless of the clay content, but it’s a particular problem in Fredericksburg because of the presence of clay and the risk of heaving.
Frost heave can force sections of your foundation to lift, eventually leading to cracking, separation from the rest of your home, and a loss of structural stability. The differential settling of the foundation after the ground thaws can create even more disparate earth movement under your foundation, worsening the problem.
Tropical Storms and Hurricanes
Lastly, much of Virginia is prone to tropical storms and hurricanes. Fredericksburg is located inland, so it doesn’t experience conditions quite as severe as the coastal cities. However, the area is subjected to frequent heavy rainfall, and the annual precipitation is nearly 50% higher than the national average.
Runoff can create problems with water intrusion in any home, but the expansive soil, risk of frost heave, and low elevation of Fredericksburg make the risk of water and moisture issues significantly higher.