Virginia Beach, Chesapeake, Hampton Roads, Portsmouth, Suffolk, Williamsburg, and many other nearby cities are at risk of foundation damage for several reasons. We’ll go into these factors in depth below.
Location on the Coast
Exposure to water is one of the most common problems for home foundations, and Virginia Beach’s location along the Atlantic Ocean puts homes in the area at exceptionally high risk for water problems.
FEMA has designated much of the city either A or V flood zones. These are considered special flood hazard areas that are very prone to flooding. Surprisingly, the flooding in the area rarely comes from the ocean but is caused by the city’s low elevation. Heavy rains from higher elevations further west move downhill and accumulate in the Virginia Beach area.
This regularly leads to water-soaked soil, which is detrimental to foundations for two reasons. First, the ground gets heavier as it absorbs water, placing additional pressure against your home’s foundation walls. This can lead to walls bowing inward and even cracking in response to the stress.
Second, when the soil against your foundation walls is continuously wet, the moisture being held against the concrete can easily make its way into your home. It can seep through cracks in the foundation walls or floor, and it can wick through undamaged concrete and evaporate into your basement or crawlspace.
Expansive Soil
Virginia’s state soil is Pamunkey soil, the quality of which in Virginia Beach makes the already dangerous flooding problems even more hazardous. The area has a comparatively high concentration of clay in the dirt, leading to what is called expansive soil.
Clay soil readily absorbs water, holds it for more extended periods than typical dirt, and expands when it gets wet, sometimes up to 10% of its original volume. The expansive soil in Virginia Beach is harmful to foundations for three primary reasons.
First, it’s more likely to create hydrostatic pressure on your foundation walls when it gets wet. This inward stress caused by a growth in soil volume can quickly lead to structural instability, especially since the city is prone to flooding.
Second, the expansive clay soil loses volume when it dries, often leading to the ground shrinking away from your concrete slab or basement walls. This leaves your foundation without the support it needs to hold up your home. The uneven ground movement that occurs, as a result, is called differential settling, and it can lead to a loss of structural integrity.
Finally, the expansive soil in Virginia Beach holds runoff and groundwater against your concrete walls for more extended periods than soil that dries more quickly. This allows the water more time to seep into your home and cause moisture problems.
High Water Table
Virginia Beach has a high water table due to its low elevation, which means groundwater is located relatively close to the surface. Groundwater can create two primary issues for foundation stability.
It can quickly soak into the soil around your home and make the problems we discussed above worse. However, it also lends itself to frost heave, which is when water in the ground freezes, causing the soil to push upward.
Frost heave puts upward pressure on your concrete slab and foundation walls that can lead to severe cracking and differential settling once the ground thaws. Structural issues are common in Virginia Beach as a result of this ground movement.
Tropical Storms and Hurricanes
Lastly, Virginia Beach experiences a relatively high number of storms that produce rainfall. Thankfully, hurricanes in the area typically don’t hit land directly, as they’re blocked by the Delmarva area of North Carolina. However, Virginia does have a higher-than-average rainfall due to the precipitation from passing hurricanes and tropical storms.
The rainfall from these storms in Virginia commonly creates problems with flooding. When combined with the expansive soil, the already high risk of flooding because of the elevation and the high water table, the rainfall from these storms is enough to put home foundations at a very high risk of damage.