The geology and weather in Westerville are primarily to blame for foundation problems. Below, we’ll explain how they affect the concrete under your home and the severity of the damage each is likely to cause.
Westerville soil is primarily Miami clay loam, a soil series identifiable by a high ratio of clay to both silt and sand. Clay-rich soil tends to drain very slowly, readily holds water, and has a high shrink-swell potential with changes in moisture. These three properties present different threats to your home’s foundation.
The slow drainage and absorbent qualities both pose a problem during and following rainfall, as large volumes of runoff soak into the earth around your concrete and remain suspended there for long periods.
Moisture remains in direct contact with your foundation, increasing the risk of water leaking through foundation cracks or wicking through pores in the undamaged concrete. As a result, water damage and moisture accumulation are prevalent in Westerville.
The absorbent quality of the city’s dirt also means that large amounts of rain can soak into the ground, contributing to the soil’s capacity to swell.
The earth around your foundation grows in volume when it gets wet, forcing your foundation walls inward and putting upward stress on your concrete slab. The ground movement can be intense enough to crack the concrete, often leading to structural damage that is hazardous and costly to repair.
Finally, the potential for the soil to shrink when it dries presents another issue for your foundation. When the ground’s moisture content dips during periods of decreased precipitation, the soil can shrink away from your concrete and cause it to settle further into the ground.
Clay soil contracts more rapidly than sandy or silty soil, so even small disparities in how quickly the ground dries under different sections of concrete can cause differential settling. Erratic movement can cause portions of the foundation to crack and collapse into the earth. Structural repair is often necessary to combat the uneven settlement.
Westerville experiences nearly 44 inches of rain each year, which is almost 150% of the national average. April through June brings a higher monthly average, while the late summer and fall months are significantly drier.
The above-average rainfall makes the issues with expansive soil significantly more problematic. The ground remains saturated with frequent precipitation, maintaining a high soil volume and increased hydrostatic pressure on your foundation.
Additionally, the earth remains saturated with the frequent wetting, meaning the concrete under your home is continuously exposed to moisture and at severe risk of water seeping into your basement or crawlspace.
Flooding is a common occurrence throughout many parts of Ohio. In Westerville, flash flooding and ponding are both possible, often in response to heavy rainfall and severe weather, to which the area is prone.
Flooding saturates the soil and causes ground expansion, increasing the pressure placed on your foundation and the risk of structural cracks forming in response.
Additionally, overly saturated soil means a higher likelihood of your foundation leaking, as the porous concrete will be exposed to water for extended periods during flooding.
Westerville, along with much of Ohio State, is underlain by bedrock composed of limestone and dolomite. Both bedrock materials are rigid and supportive, but they dissolve over time in the presence of water.
Groundwater and draining runoff in the area can gradually deteriorate the bedrock, creating voids deep below the earth’s surface.
The channels and caverns can collapse if they grow too large, creating instability in the ground above them. The karst landscape in the area can lead to sinkholes forming on the surface.
Sinkholes are a nuisance and simply a minor concern on streets and sidewalks, but they can contribute to differential settling and lead to foundation damages if they occur beneath your home.