🏚 What is Differential Settlement?
Differential settlement happens when different parts of a foundation sink or shift at different rates. Instead of the entire house settling evenly (which is usually not a big problem), one side or corner drops lower than the rest.
This uneven movement creates stress on the structure, leading to:
- Cracks in walls, ceilings, and brickwork.
- Sloping or uneven floors.
- Doors and windows sticking or misaligning.
- Gaps between walls and ceilings or baseboards.
In Houston, this is especially common because of expansive clay soil that swells and shrinks dramatically with moisture changes.
🛠 How is Differential Settlement Addressed?
- Steel Piers
- Driven deep into stable strata or bedrock.
- Permanently stabilizes the foundation by bypassing unstable surface soil.
- Helical Piers
- Screw-like anchors twisted into the ground.
- Ideal when soil conditions don’t allow straight piers or for lighter structures.
- Concrete Pressed Piers
- Precast concrete cylinders pushed into the soil.
- More affordable, but not as deep-reaching as steel.
- Slabjacking (Mudjacking or Polyjacking)
- Fills voids under smaller sections of slab that have sunk.
- Works best for minor cases, not severe settlement.
- Drainage Correction & Root Barriers
- Support methods to stop further soil movement by managing water flow and tree root intrusion.
✅ In short: Differential settlement is uneven sinking of a foundation, and the most reliable fix is to lift and stabilize the affected areas with deep foundation piers so the house is supported on stable soil layers.