The Hidden Threat of Gasil fine sandy loam, 1 to 3 percent slopes for Homeowners in Flower Mound

What is Gasil fine sandy loam, 1 to 3 percent slopes?

Gasil fine sandy loam, 1 to 3 percent slopes is a moderate clay soil formation common in Flower Mound. It is characterized by a high silica content that causes it to absorb water and swell volume by up to 0.5%. Engineers value it for agriculture but fear it for construction due to its "shrink-swell" volatility.

Why Flower Mound Foundations Fail

If you live in North Flower Mound Village, South Flower Mound Hills, East Flower Mound Park, or West Flower Mound Heights, your home is interacting with this critical geology. Unlike stable sandy loams, Gasil clay moves.

The defining metric is the Plasticity Index (PI) of 3.0. This PI indicates relatively stable ground, though localized drainage issues can still undermine grade beams.

The "Active Zone" Depth

In Flower Mound, the "Active Zone"—where moisture levels fluctuate—extends 12-15 feet deep. Standard builder piers often stop at 8 feet. This mismatch is why we see repetitive failures in 75028.

3 Signs of Gasil Soil Failure

• Diagonal Shear Cracks: Extending from door/window corners (45-degree angles).
• Friable Soil Gap: Soil pulling 1-2 inches away from the foundation perimeter in summer.
• Sticking Doors: Specifically on the exterior walls relative to the center of the home.

Engineering Protocol: Correct vs. Incorrect

Neighborhood Watch

We are monitoring elevated PI readings in these areas: