What Is Clay Soil?

What Exactly Is Clay Soil? 

When a type of sedimentary rock called humic shale disintegrates, it creates clay soil. This fine-grained natural soil is rich in minerals such as zinc, calcium, and others. If you think you will be able to tell whether you have clay soil in your yard based on the color or structure, think again. Although clay can change its color, shape, and structure, it has some attributes that distinguish it from other fine-grained soils. First, clay soil is made from extremely tiny particles that measure 0.002 mm in diameter. When it becomes wet, clay develops plasticity. It is the property of a substance to get deformed under a force and restore its original shape once the force is removed. Due to this trait, clay soil can affect structures such as retaining walls. This type of soil contains mineral particles that swell up when it rains, and they allow the soil to hold a lot of water. This can also be bad news for your foundation. In addition, when clay gets exposed to heat, it becomes hard and rigid. 

How Prevalent Is Clay Soil? 

Although it is possible to come across clay soils all over the country, especially in the South, some parts of North Carolina have clay as well. Unfortunate homeowners who have expansive soils such as clay in their yard need to go the extra mile to make their home safe for their family. Since clay soil can swell up in the spring due to frequent rains and then shrink in the summer, it can cause foundations to shift and crack. 

Clay Soil Movement 

Soils rich in clay have the potential to damage a foundation. Since this type of soil absorbs water and swells, it can cause foundation damage such as cracks. On the other hand, when clay soil dries out, it shrinks and leaves gaps around the foundation. The volume of these shrink-swell movements is determined by several factors, such as evaporation, compaction, and the presence of below-slab depressions. If you have clay-based soil in your yard, keeping it moist at all times can minimize the volume of these movements. 

What Kind of Problems Can Clay Soil Cause? 

There are several ways clay soil can affect your foundation. 

• When soil particles absorb the water, they expand and put extra pressure on a home’s foundation walls. Eventually, these soil particles can cause the walls to bow inward and crack, creating an ideal setting for water seepage. 
• Prolonged dry periods cause clay soil to dry out and shrink. When this happens underneath your foundation, it causes a part of the foundation to crack and settle into the hollow area where settlement has occurred. 
• As mentioned, clay soil drains slowly. Due to the shrink-swell movement, gaps are created between the soil and the foundation, and water can easily accumulate behind retaining walls. This can cause various issues such as rot and mold infestation. 

Solving the Problem 

It can be difficult to waterproof and ensure the stability of a foundation built on clay soils. Waterproofing should never be a DIY project. If you have noticed that there is something wrong with your foundation as a result of poor supporting soil, contact professional contractors in your area. Several methods can eliminate these problems and keep your home in top condition. 

Foundation push piers: These steel piers are designed to extend far below the foundation and to reach strong supporting soils. The level of damage will dictate the number of piers needed to stabilize and potentially lift your home back toward its original position. 

Foundation helical piers: While push piers are driven into the soil, helical piers have helical blades, and they are screwed into the ground. When all piers are in place, they will work together to transfer the weight of the structure to more stable soil. 

Drainage system: Since water can easily accumulate behind foundation walls, keeping your foundation dry and moisture-free can be difficult without a proper drainage system. The BasementGutter™ Interior Drainage System can be installed along the perimeter of your home to trap water before any damage happens to the interior of your basement. This system features a clog-free design and works best when paired with an efficient sump pump, so you won’t have to worry about moisture issues for decades to come. 

Grading the soil: Go outside when it rains and see whether the water is rushing toward your home’s foundation or away from it. If it is directed toward your home, you need to regrade the soil so it is sloped away from the house. 

Whether you wish to waterproof your basement or fix your damaged foundation, experts at Tar Heel Basement Systems are at your disposal. Contact our team to schedule a free inspection and repair quote today. 

Holly Richards-Purpura

Content Writer

Holly is a Content Writer for Groundworks who has written and edited web content for the foundation services industry for almost 10 years. With a background in journalism, her passion for the written word runs deep. Holly lives in Columbus, OH, with her husband. Along with educating homeowners, she also has a big heart for the Big Apple.