When it comes to the performance of your home’s foundation, the soil beneath it and around it is one of the most key components of long-term performance. I mean, that is typically what is supporting (or not supporting) your house, right? Simple enough! But did you know that it varies by location and climate, and changes throughout the year? This is where problems can arise – especially if you are located in an area that has expansive soil.
In the map above created by the U.S. Army Corps of Engineers, you can see that most of the South/Midwest region (grey shading) is, to some degree, relatively expansive. Let’s dig a little deeper and explain what that means.
Soil is made of three primary components: grains (which can be minerals, rock particles, and other solid granules), water, and air. The water and air are what fill the voids and pockets between the grains. The type of grain is what classifies the soil as either SAND or CLAY.
SAND, which includes gravel, is made up of rock particles that do not expand after absorbing water.
CLAY, which includes silt, is classified as fine soils. Their flaky shape (thin and long) allows for water molecules to adhere, thus expanding its volume.
When soil is susceptible to swelling and shrinkage, it is classified as expansive. Expansive soils, like clay, can potentially wreak havoc on homes and structures built upon it. When expanded past the space the structure allows, it increases pressure on the structure which raises the foundation. As well as during very dry seasons, the water content in the soil is less than needed, creating more air pockets. When this happens, shrinkage occurs and can cause problems such as settling.
Do you live in an area prone to expansive soils? Take a look back at the map – if you’ve been experiencing foundation shifting, bowing walls, cracks, or uneven flooring, chances are your soil is to thank for the headache! Give PierGenius a call to set up an appointment for a FREE estimate.
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