How Soil Conditions Drive Foundation Movement in Central Texas
When people think about buying a home in Austin, Kyle, or Buda, they usually focus on the floor plan, the neighborhood, or the schools. What most folks don’t think about is what’s under the house — the soil.
As a home inspector, I can tell you that soil conditions play a huge role in how stable a foundation will be over time. In Central Texas, our soils are tricky, and that means homeowners need to understand what’s happening beneath their homes.
Common Soil Types in Central Texas
Expansive Clay (Blackland/Vertisols)
Absorbs water like a sponge, then shrinks dramatically during dry spells.
Constant swelling and shrinking stresses slab foundations.
Widespread in Hays and Travis Counties.
Loam
A balanced mix of sand, silt, and clay.
Provides decent drainage while still holding moisture.
Less problematic than pure clay, but not immune to movement.
Caliche & Rocky Soils
Areas with limestone or caliche (hard, compacted soil).
More stable, but can worsen drainage if water has nowhere to go.
Fill or Cut-and-Fill Lots
Imported fill that isn’t compacted well can settle over time.
Creates uneven foundation movement.
How Moisture Makes It Worse
Soil movement becomes a problem when water levels change. Some of the biggest culprits I see on inspections are:
Poor drainage around the foundation.
No gutters or short downspouts that dump water next to the slab.
Overwatering one side of the yard while the other side stays dry.
Trees and shrubs pulling moisture out unevenly.
Plumbing leaks that saturate soils under or near the slab.
👉 Rule of thumb: foundations love consistency. It’s the extreme wet–dry swings that cause the most damage.
Signs of Soil-Driven Foundation Movement
Diagonal cracks at door or window corners.
Doors that rub or won’t latch.
Uneven or sloping floors.
Gaps at trim or crown molding.
Step cracks in exterior brick.
One crack alone doesn’t condemn a house. What matters is the pattern and whether it’s getting worse.
What Homeowners Can Do
Drainage & Grading
Slope soil away from the house (about 6 inches drop over 10 feet).
Keep gutters clean and extend downspouts at least 4–6 feet away.
Consistent Moisture
During drought, use a soaker hose 12–18 inches from the foundation.
Water lightly and evenly, not in big bursts.
Landscaping
Plant large trees at least two-thirds of their mature height away from the house.
Consider root barriers if trees are already close.
Plumbing Checks
Investigate unexplained water bills.
Have a plumber check for leaks under the slab if you suspect one.
Monitor Cracks
Take photos to track changes over time.
Periodic elevation checks help identify early movement.
The Bottom Line
You can’t change the soil your house sits on, but you can control water and drainage around your foundation. Good grading, consistent moisture, and smart landscaping go a long way toward keeping a home stable in Central Texas.
At Precision Property Inspections, I look for early warning signs of soil-related foundation movement so you can protect your investment before small issues become big repairs.
