Expansive Clay Soils in Texas: Locations, Risks, and the Cost of Damage
Expansive Clay Soils in Texas: Locations, Risks, and the Cost of Damage
Expansive clay soil posses a serious threat to homes, infrastructure, and landscapes across
Texas. Known for their ability to swell with moisture and shrink during dry conditions, these soils
can cause significant structural damage. For homeowners, builders, and public officials alike,
understanding where expansive clay soils are most common in Texas—and the financial
impact they can cause—is key to protecting investments and mitigating damage.
In this blog, we will explore the regions in Texas where expansive clay soils are found, the
risks they present, and the staggering dollar amounts associated with damage caused by these
soils.
What Are Expansive Clay Soils?
Expansive clay soils contain a high percentage of minerals like montmorillonite or bentonite,
which have the unique ability to absorb large amounts of water. When wet, these soils swell,
expanding significantly, and during dry periods, they shrink and crack as the moisture
evaporates. This constant movement places pressure on structures such as foundations, roads,
and pipelines, leading to costly damage over time.
Where Are Expansive Clay Soils Found in Texas?
Texas is home to some of the most expansive soils in the country, with large portions of the
state covered by soil types that are prone to swelling and shrinking. The regions most affected
by expansive clay soil in Texas include:
1. Dallas-Fort Worth Area: The DFW metroplex sits atop vast layers of expansive soil,
particularly in suburban areas. Known as the Houston Black clay and Austin chalk
formations, these soils expand rapidly with moisture and shrink significantly during dry
spells.
2. Central Texas: Cities such as Austin, Waco, and San Antonio are all built on top of
expansive clay known as the Eagle Ford Shale. This soil type, combined with Texas’;
unpredictable weather, causes constant soil movement, leading to foundation damage.
3. East Texas: Expansive clays are also prevalent in the Blackland prairies of East Texas,
affecting areas like Tyler and Longview. The soils here contain high concentrations of
clay minerals, and the humid climate further contributes to their swelling.
4. Houston Area: The Houston region is built on a mixture of expansive clays, particularly
the Beaumont clay, which is notorious for foundation problems. The city’s coastal climate
results in frequent shifts between wet and dry conditions, causing extreme soil
movement.
5. West Texas: While West Texas is generally drier, expansive clay soil still poses a threat,
particularly in the Permian Basin. Even small amounts of rainfall can cause swelling in
the region’s clay soils, which can still cause foundation and infrastructure issues over
time.
The Financial Impact of Expansive Clay Soil Damage
The financial impact of expansive clay soil in Texas is staggering. Each year, these soils cause
billions of dollars in damage to homes, roads, pipelines, and other infrastructure. Here’s a look
at some of the ways expansive soil can cause costly problems:
1. Home Foundation Damage: One of the most common forms of damage caused by
expansive soils is to home foundations. As the soil beneath the foundation swells and
contracts, it causes cracks in the foundation walls and floors. According to estimates,
homeowners in Texas spend between $4,000 and $12,000 on average for foundation
repairs due to expansive soil movement. In severe cases, the cost can exceed
$20,000.
2. Infrastructure Repairs: Expansive clay soil also causes significant damage to roads,
bridges, and pipelines. Roads built on expansive soil are prone to cracking and
buckling, while underground pipelines can be damaged by shifting soil. The Texas
Department of Transportation (TxDOT) spends millions annually on road repairs
because of expansive soils. Nationwide, it is estimated that expansive soil causes
between $2 billion and $15 billion in infrastructure damage each year, with Texas
bearing a large portion of this cost.
3. Insurance Claims: Many homeowners in Texas file insurance claims for foundation
damage caused by expansive soil. Unfortunately, standard homeowners' insurance
policies typically don’t cover damage from soil movement, leading to out-of-pocket
expenses for repairs. The Texas Department of Insurance reports that foundation
repair claims related to soil movement are among the most frequent and costly types of
homeowner claims in the state.
4. Commercial and Public Buildings: Expansive soil damage extends beyond homes to
commercial buildings, schools, and hospitals. These structures, like homes, are
vulnerable to foundation cracking and structural damage caused by soil movement.
Repair costs for large commercial buildings can reach hundreds of thousands of
dollars.
Preventing Expansive Soil Damage in Texas
Given the prevalence and risks of expansive clay soil in Texas, taking preventive measures is
essential. Here are some steps homeowners and builders can take to minimize damage:
Soil Testing: Before building a home or commercial structure, soil testing can determine
whether expansive clay soils are present. This allows builders to take necessary
precautions such as soil stabilization.
Clay Soil Stabilization: One of the most effective ways to manage expansive soil is
through chemical soil stabilization. Chemical Soil Stabilization can reduce the soils’
ability to shrink and swell, making it more stable for building.
Drainage Systems: Proper drainage around homes and structures can help control
moisture levels in the soil, reducing its tendency to expand and contract. French drains,
gutters, and sloped landscaping can all help direct water away from foundations.
Regular Monitoring: For homes already built on expansive soil, regular monitoring of
the foundation for signs of cracking or shifting is essential. Catching problems early can
reduce repair costs.
Conclusion
Expansive clay soil is a hidden yet serious threat to homes and infrastructure across Texas.
From the bustling cities of Dallas and Houston to rural areas, these soils can cause significant
and costly damage. With billions of dollars spent annually on repairs, it’s important for
homeowners and builders to understand the risks and take preventive steps.
By stabilizing the soil, improving drainage, and monitoring structures for signs of movement,
Texas residents can protect their investments and minimize the financial impact of expansive
soil damage. Awareness and action are key to reducing the long-term costs associated with
these challenging soils.