Expansive Soil Knowledge Base

Understanding Types of Expansive Soil

Different types of expansive soil are found in every U.S. state, and their characteristic shrink–swell behavior causes widespread structural damage. From cracked slabs to heaved foundations, expansive soil results in an estimated $13 billion in damage annually.

Because each expansive soil type exhibits unique characteristics, understanding site-specific conditions is critical to selecting the right mitigation strategy to achieve long-term structural stability.

Building on Expansive Soils in the South: Strategies for Arkansas, Mississippi, Louisiana & AlabamaSoil Education

Building on Expansive Soils in the South: Strategies for Arkansas, Mississippi, Louisiana & Alabama

December 18, 2025
Across the United States, expansive soils cause $13 billion in annual damage to buildings and infrastructure (Puppala & Cerato, 2009), and the South is not immune to this risk.  Arkansas, Mississippi, Louisiana, and Alabama all sit atop unique geological deposits…
Building on Porters Creek Clay: Proven Strategies for Structural StabilitySoil Education

Building on Porters Creek Clay: Proven Strategies for Structural Stability

December 2, 2025
Porters Creek Clay is a Paleocene-age clay found across the South Gulf Coastal Plain, stretching through Arkansas, Mississippi, Tennessee, and beyond. Beneath its dense, fossil-rich composition lies a serious engineering challenge: a dramatic shrink–swell cycle following changes in moisture. It's…
Building on Yazoo Clay in Mississippi & BeyondSoil Education

Building on Yazoo Clay in Mississippi & Beyond

October 29, 2025
Yazoo Clay is a highly expansive soil formation known by several names. There's Mississippi's "Blue Yazoo," owing to its distinctive bluish-gray color, and "Gumbo," for its thick, sticky texture. But regardless of what it's called, this clay is notorious for…
Blackland Prairie Soil: Solutions for Texas’ Most Reactive SoilSoil Education

Blackland Prairie Soil: Solutions for Texas’ Most Reactive Soil

June 9, 2025
From an agricultural standpoint, Blackland Prairie soil is among the most mineral-rich in the world. But that same richness comes with a caveat—its composition can exceed 60% clay, making it one of the most challenging soils to build on. Highly…
Pyritic Shale
Building on Pyritic Shale: Pre-Construction SolutionsSoil Education

Building on Pyritic Shale: Pre-Construction Solutions

June 3, 2025
Pyritic shale may have a shimmer of gold, but when disturbed, it can become one of the most damaging soil conditions faced in construction. Found across much of North America, this mineral-rich shale can expand, crack foundations, and corrode infrastructure…