1. Soil Erosion and Settlement: One primary cause of driveway sinking is soil erosion and settlement. Over time, the soil beneath the driveway may erode due to natural factors such as water runoff, poor drainage, or soil composition. This erosion weakens the foundation, causing the driveway to settle and sink.
2. Poorly Compacted Soil during Construction: In some cases, the sinking issue can be traced back to the initial construction phase. If the soil beneath the driveway was not adequately compacted during installation, it can lead to uneven settling over time, resulting in portions of the driveway sinking.
3. Water-Related Issues: Water is a powerful force that can significantly impact the stability of your driveway. Poor drainage, water pooling, or leaks from nearby pipes can saturate the soil, leading to erosion and weakening of the ground beneath the driveway. This, in turn, contributes to sinking.
4. Tree Roots and Vegetation: The roots of nearby trees and vegetation can exert considerable pressure on the soil, causing it to shift and create voids beneath the driveway. As these voids expand, the driveway loses its support, leading to sinking and uneven surfaces.
5. Underground Pipe Leaks: Undetected leaks in underground pipes, whether for water supply or drainage, can contribute to soil erosion. As water escapes from the pipes, it can wash away the soil beneath the driveway, compromising its stability and causing sinking issues.

Signs of a Void under your Driveway

1. Uneven or Tilting Sections: Sections of the driveway may become uneven, causing a noticeable tilt or slope. This unevenness is a sign that the support beneath the concrete is compromised.

2. Cracks in the Concrete: The development of cracks in the driveway, especially in a pattern that suggests uneven settlement, can signal voids beneath the surface.

3. Gaps Between Slabs: If your driveway consists of multiple slabs, gaps or spaces forming between them could indicate soil erosion or voids beneath.

4. Pooling Water: Puddles or standing water on the driveway surface, especially in specific areas, may indicate an uneven surface caused by voids.

5. Difficulty Closing Doors or Windows: Changes in the driveway’s elevation can impact the alignment of nearby structures. If you notice doors or windows becoming difficult to open or close, it might be linked to driveway settlement.

6. Visible Soil Sinking: Inspection of the surrounding soil can reveal signs of sinking or settling, providing indirect evidence of voids beneath the driveway.

Addressing the Issue

1. Professional Assessment:
   • To accurately diagnose the cause of driveway sinking, seek the expertise of a professional contractor. They can conduct a thorough assessment, including soil testing, to identify the underlying issues.
2. Correcting Drainage Problems:
   • Address any drainage issues around your property to prevent water from accumulating near the driveway. Proper grading, installation of drainage systems, and regular maintenance can mitigate water-related problems.
3. Soil Stabilization Techniques:
   • Implement soil stabilization techniques such as mud-jacking or foam-jacking to lift and level the sinking portions of the driveway. These methods address the voids beneath the surface and provide a stable foundation.
4. Tree Management:
   • If nearby trees are contributing to the sinking issue, consult with an arborist to manage tree roots without compromising the health of the tree. This may involve pruning or installing root barriers.

Conclusion

Understanding why your driveway is sinking is crucial to implementing effective solutions. By addressing the root causes, whether related to soil erosion, construction issues, or water-related problems, homeowners can restore the stability and aesthetics of their driveways. Consulting with professionals ensures a comprehensive approach to tackle the issue and prevent recurrence.