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How can You Tell if Soil is Pushing a Foundation up or if it is Sinking Down?

To determine whether a foundation is sinking (settlement) or being pushed upward (heaving), you must look for specific visual indicators in the cracks, floors, and door frames of the structure.

### Signs of Foundation Settlement (Sinking) Settlement occurs when soil compresses or rotates, pulling the foundation downward. Key indicators include:

  • Crack Patterns: Look for diagonal or "stair-step" cracks in brick or masonry. These cracks are typically wider at the top than at the bottom.
  • Door and Window Behavior: Gaps often form at the top corners of frames, and doors may sag or stick because the frame has shifted out of square.
  • Floor Movement: Floors will generally slope downward toward the center of the home or toward a specific corner.
  • Exterior Gaps: You may notice gaps appearing at the bottom of exterior siding as the structure pulls away from its original position.

### Signs of Foundation Heaving (Rising) Heaving is caused by expansive clay soils swelling with moisture and pushing the foundation upward. Key indicators include:

  • Crack Patterns: Cracks caused by heaving are often wider at the bottom than at the top. You may also see horizontal or vertical cracks in concrete floor slabs.
  • Door and Window Behavior: Instead of sagging, doors often jam at the top of the frame due to upward pressure.
  • Floor and Wall Movement: Floors may bulge or slope upward. You might also notice walls bowing or bulging inward due to the pressure of the expanding soil.
  • Soil Buildup: A strong indicator of heaving is the visible buildup of soil or concrete around the base of the foundation.

Because these signs can sometimes overlap or occur simultaneously on different parts of the same house, a professional geotechnical evaluation or an inspection by a licensed structural engineer is recommended for a definitive diagnosis.


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