Expansive Clay Soils

The expansive clay soils of the North Texas area can cause foundation issues.

Expansive soils shrink during dry conditions and swell when they get wet. Soils like clay, loam, and shale are all expansive, and their condition is determined by their moisture content. These types of soils are common in Texas, particularly the North Texas/DFW Metroplex area. In addition, Texas’ susceptibility to unpredictable weather, such as prolonged drought one year and heavy rain the next, creates a recipe for widely varying soil conditions. In turn, the constant shrinking and swelling of the soil causes foundations to rise or fall, which may cause tilt (slanting) or deflection (bending). This weakens the foundation and causes performance problems that may necessitate foundation repair.

The Dallas-Fort Worth Metroplex spans three soil regions – Texas Blackland Prairie, Cross Timbers, and Grand Prairie. These three areas are characterized by a gently rolling, but overall flat landscape with soils consisting of clay, shale, and loam. These soils are highly susceptible to erosion and variance, particularly clay. Texas clay absorbs water rather than becoming mud and expands. When the water dries, it shrinks to the original size. These factors make it difficult to build foundations, as the shifting ground can lead to foundation tilting, cracking, or deterioration of the home.

Gray: Texas Blackland Prairie. Blue: Eastern Cross Timbers. Tan: Grand Prairie.

To guard against damage to your foundation, the best strategy is to maintain consistent moisture around your home’s foundation year-round. By not allowing the soil to dry out and shrink during the hot summer, or swell during a rainy spring, the ground that the foundation rests upon remains the same so that there is no movement of the slab. Sprinkler systems and soaker hoses can be used to bring moisture to an area that needs it, and keeping track of plumbing leaks or pooling water can maintain the proper dryness.

Expansive Soils