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Sinking Foundation

A sinking foundation can lead to serious structural problems in your home. Recognizing the warning signs and taking immediate action to prevent further damage is essential.

What is a Sinking Foundation?

A sinking foundation refers to the gradual downward movement of a home’s foundation, resulting in uneven settling. This can occur due to various factors, such as soil expansion, poor drainage, insufficient compaction, clay soils, and nearby trees. Ignoring a sinking foundation can lead to severe structural damage and costly repairs.

Signs of a Sinking Foundation

  • Uneven floors: If you notice sloping or uneven floors in your home, it may indicate a sinking foundation. Pay attention to any noticeable changes in the slope of your floors. 
  • Floor cracks: Cracks in your flooring, especially in concrete slabs, can be a sign of a sinking foundation. These cracks may appear wider or longer over time. 
  • Sticking doors and windows: Difficulty opening or closing doors and windows can result from a sinking foundation. If you notice that they no longer fit properly in their frames, it’s time to investigate further. 
  • Cracked exterior bricks: Cracks in the exterior bricks of your home can indicate foundation settlement. Look for diagonal cracks that are wider at the top than at the bottom. 
  • Cracked or tilting chimney: A sinking foundation can cause your chimney to crack or tilt. If you observe any signs of damage to your chimney, it’s crucial to address the underlying foundation issue.

What Causes a Sinking Foundation?

Several factors can contribute to a sinking foundation. Understanding these causes can help you identify the root of the problem and take appropriate action:

Soil Expansion:

Changes in soil moisture content can have a significant impact on the stability of a foundation. When soil becomes saturated with water, it expands and contracts when it dries out. This continuous movement can cause the soil beneath the foundation to shift and settle, leading to foundation settlement and a sinking foundation. When the soil expands abruptly, it exerts pressure on the foundation, often causing it to move or crack. Similarly, when the soil contracts, it creates voids beneath the foundation, which can cause it to sink. Soil expansion is a common issue in areas with high levels of rainfall or poor drainage, as the excess water can penetrate the soil and cause it to expand.

Poor Drainage:

Proper drainage is essential for maintaining the stability of a foundation. When there is inadequate drainage around a home, water can accumulate and saturate the soil. Over time, this excess water weakens the soil and causes it to compress. The compression of the soil can lead to foundation settlement, as the weight of the structure causes it to sink into the compressed soil. Poor drainage can be caused by various factors, such as improper grading, clogged gutters, or lack of proper drainage systems. It is important to address drainage issues promptly to prevent foundation problems.

Insufficient Compaction:

During the construction of a foundation, it is crucial to ensure that the soil beneath it is adequately compacted. Compaction involves compressing the soil to increase its density and stability. If the soil is not properly compacted, it can settle over time, causing the foundation to sink. Insufficient compaction can occur due to various reasons, such as improper construction techniques or inadequate soil testing. When the soil settles, it creates voids beneath the foundation, which can lead to structural instability and sinking.

Clay Soils:

Clay soils are known for their expansive properties. When clay soils are exposed to moisture, they absorb water and swell. This swelling exerts pressure on the foundation, causing it to move or sink. Conversely, when clay soils dry out, they shrink, creating voids beneath the foundation. The expansive nature of clay soils makes them particularly susceptible to foundation settlement. Areas with high clay content in the soil, such as North Carolina, are more prone to this issue. Proper moisture management and foundation design considerations are essential when dealing with clay soils to mitigate the risks of foundation problems.

Nearby Trees:

Large trees planted near a home can have extensive root systems that extract moisture from the soil. As the trees draw water from the soil, it can cause the soil to shrink and dry out. This shrinkage can lead to foundation settlement and a sinking foundation. The roots of the trees can also penetrate the soil beneath the foundation, causing it to become unstable and susceptible to movement. It is important to consider the proximity of trees to the foundation during construction and to implement appropriate measures to prevent tree roots from damaging the foundation. Regular maintenance and monitoring of trees near the home are also necessary to prevent foundation problems.

How to Repair a Sinking Foundation

There are several methods to repair a sinking foundation, depending on the specific needs of your home. Some common solutions include:

  • Push piers: These steel piers are driven deep into the ground until they reach stable soil. They provide support and lift the foundation back to its original position.
  • Helical piers: Similar to push piers, helical piers are also installed deep into the ground. They have helical blades that help stabilize and lift the foundation.
  • Slab piers: These piers are specifically designed for concrete slab foundations. They are installed beneath the slab to provide support and prevent further sinking.

Why Address Sinking Foundations Now

Ignoring a sinking foundation can lead to severe consequences for your home. The longer you wait, the more extensive and expensive the repairs can become. By addressing a sinking foundation promptly, you can:

  • Prevent further damage to your home’s structure
  • Avoid costly repairs in the future
  • Maintain the value of your property
  • Ensure the safety and stability of your home

Contact Tar Heel Basement Systems for Your Foundation Needs

If you suspect a sinking foundation in your North Carolina home, contact Tar Heel Basement Systems today. Our experienced team will provide a free consultation, assessing your foundation, identifying the underlying issues, and providing reliable solutions. Don’t wait until it’s too late – protect your home from further damage by addressing your sinking foundation now.


Foundation repair can cause some disruption, but reputable companies like Tar Heel Basement Systems strive to minimize the inconvenience. Our team will work efficiently and ensure that your home is restored to its original condition as much as possible.

While some factors contributing to a sinking foundation are beyond your control, proper maintenance and proactive measures can help minimize the risk. Regularly inspect your home for signs of foundation issues and address any drainage or soil moisture problems promptly.

The cost of foundation repair varies depending on the extent of the damage, the chosen repair method, and other factors. Tar Heel Basement Systems provides a complementary consultation and estimate to help you plan your financial investment in your foundation. 


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