Clay Soil and Your Foundation – What You Need to Know

A map of the different types of soil in Texas

Learning how to properly care for your home’s yard and foundation starts with understanding the types of soil in Texas and how soil impacts the strength of your foundation. Texas is known for being one of the few places in the U.S. with extensive, expansive clay soil. 

Under moderate weather conditions, clay soil isn’t necessarily more temperamental than other types of soil – but during seasons of excessive rain or extreme heat and dryness, expansive clay soils can enlarge and contract, causing significant foundation damage. Here’s what you need to know about your clay soil in order to keep your foundation sturdy come rain or shine. 

Why does clay soil cause foundational issues? 

Texas’ excess of clay soil is one of the main reasons homeowners here see so many foundation issues. The reason for this is the fact clay acts like a sponge, expanding and contracting very quickly with changes in moisture. 

As soil with high clay content absorbs water from rainfall, it will expand and begin to put pressure on a home’s foundation. This can cause foundational cracks and leave the foundation open to absorbing sinking water, which could wreak havoc on basements and floors. 

On the other hand, seasons of excessive heat, dryness and drought cause clay-rich soil to contract. This contraction can create a gap between the foundation wall and surrounding landscape, making it easy for water to collect and settle. 

Another unique feature of clay soil is that it expands unevenly, meaning two different sides of your home’s foundation could move and change in completely different ways. This is why it’s extremely important to understand how to properly care for your soil and recognize the signs of foundational damage early on.   

Understanding the different types of Texas soil 

If you’re not familiar with the makeup of your soil, or have never taken a moment to examine its color and properties, try going out into your yard and scooping out a clump. If you’ve ever taken a pottery class or are familiar with the clay used for art projects, you may notice the soil in your yard takes on a similar texture and can be easily shaped in your hands. 

If your soil is reddish in color, it’s high in iron. This is beneficial for your plants and also indicates good drainage. Soil that is greyish in color indicates a lack of nutrients and poor drainage. 

Experts recommend taking a sample of your soil to your local gardening center to have it tested. The results of this soil test will help you understand the makeup of your soil and what you need to do to keep it healthy. 

How to protect your foundation from the impacts of clay soil 

Although clay soil can challenge the strength of your foundation, its nutrient-rich properties make it extremely beneficial to the health of your plants and shrubs. Its ability to hold water can make upkeep easier and allow your plants to survive with less frequent watering. The key to ensuring healthy clay soil that doesn’t damage your foundation is to maintain consistent moisture levels throughout the year. Here’s how: 

Add organic matter 

In Texas, clay soil naturally has low amounts of organic matter, which leads to more drastic effects from drought and rain. Two effective remedies to make up for this deficiency are cover crops and compost. 

Cover crops are leafy or grassy plants used to cover soil and decompose rather than become harvested. Common winter cover crops that thrive well in Texas soil include fava beans, wheat and crimson clover. In the summertime, opt for black-eyed peas and cream peas. 

Compost is the most common and most effective type of organic matter. Experts recommend adding one to two inches of compost to your soil in spring and fall. Adding a few inches of mulch can also help retain additional moisture. 

Never add sand to clay soil, as the clay willl bind the larger particles together and create an extremely dense texture when dry. If anything, opt for expanded shale, which will help improve soil aeration and drainage.  Also, be sure to only use native soils in flower beds to avoid over-saturation known as the “bathtub effect.”   

Install proper drainage 

Having adequate drainage systems around your yard can work wonders when it comes to minimizing the impact of clay soil on a home’s foundation. Gutters and downspouts will help ensure water deposits far away from the foundation of your home. 

french drain is another common and extremely effective system of keeping water deposits away from your foundation. It serves as a sort of trench that allows excess water to flow quickly and easily into a ditch, sewer system or other location. 

The efficacy of a proper drainage system goes hand-in-hand with an adequate slope. The soil around your foundation must be sloped away from your home in order to stop water from pooling at your foundation and causing damage. Generally speaking, your property should slope down and away from your home by at least 6 inches down for every 10 feet of horizontal distance. 

Practice proper maintenance techniques 

If you’re still in the process of having proper drains installed or having your soil tested, there are a few other things you can do to help minimize the negative impacts of clay soil on your home’s foundation. 

First, consider using a drip irrigation system to water your plants. This type of system will help save water and nutrients and place water directly into the root zone to minimize the risk of overwatering, flooding or pooling water. 

Avoid planting anything within 10 feet of your home’s foundation. Plants absorb water very quickly, and in the dry summer months, they may prevent your clay soil from receiving an adequate amount of moisture. 

Carefully watering the soil directly touching your home’s foundation can also help in the dry summer months. That stated,  if your home has a pier-and-beam foundation, be extremely careful and consult a professional before watering. Pier-and-beam foundations need to be well-ventilated at all times, and too much water can cause not only shifts in your foundation, but can also contribute to rotting of the wood, as well as cause mold and mildew to form. 

Maintain soil and foundation health around your property 

Ultimately, keeping your clay soil healthy and avoiding foundation damage all comes down to maintaining a balanced level of moisture in your soil year-round. Equipping your home and yard with the proper drainage and maintenance systems is a delicate process that requires careful engineering and installation. 

Our experts at Perma-Pier are here to help make sure your clay soil is always well-balanced and that your yard is in great condition to ensure a healthy foundation and successful landscaping. If you have questions, concerns, or problems with the drainage of your property or with your foundation, Perma-Pier is here to help you. Schedule a no-charge evaluation today. 

Payment Options

Perma-Pier’s customized approach to repairing your foundation extends to financing as well. We understand that your financial situation – not unlike your foundation – should have a customized solution.

Learn more