Subsurface voids are empty spaces or cavities that form beneath the ground’s surface. They are often caused by natural processes, such as soil erosion, water flow, or the decomposition of organic materials. These voids can compromise the stability of your building’s foundation, leading to structural issues over time.
When left unchecked, voids can lead to uneven settling of the foundation, resulting in cracks, shifting, and other structural problems. Learn everything you need to know about subsurface voids to protect your home or commercial property.
Causes of Voids
The cause of the voids found under your property may affect the type of treatment required. Voids can form due to the following natural processes and human activities:
- Soil settlement: This occurs when the ground beneath a foundation compacts over time due to the weight of the structure, leading to uneven support and potential foundation cracking.
- Erosion: Erosion occurs due to the movement of water removing soil from beneath a foundation, which can cause instability and lead to structural damage if not addressed.
- Construction: Improper backfilling or compaction during the construction process can leave gaps that later settle and impact the foundation’s integrity.
- Decaying organic material: When buried organic materials like tree roots or debris decompose, it can lead to hollow spaces that compromise the soil’s ability to support the structure above.
Impact on Foundations
Subsurface voids can have a detrimental effect on foundations. When the ground beneath a structure shifts or settles unevenly, it can cause the foundation to crack or sink. This process, known as foundation settling, can lead to a range of structural issues that may worsen over time.
Common problems caused by subsurface voids include cracks in walls, floors, and ceilings. Additionally, you may notice doors and windows that no longer close properly or uneven floors that create tripping hazards. Filling the voids and repairing the concrete prevents more extensive damage and makes the property safer.
Other Effects of Voids
Subsurface voids can contribute to more than just foundation damage. Property owners may experience increased pest infestations, as the cavities provide nesting areas for rodents and insects. Additionally, the presence of voids can lead to compromised drainage around the property, causing water accumulation and potential flooding issues.
Void Detection With Ground-Penetrating Radar
One key thing to know about subsurface voids is that they can vary widely in size, from small gaps to large cavities, depending on factors such as the type of void, soil composition, and underlying causes. They may be located anywhere from directly next to the foundation to several feet below the ground’s surface.
Professional inspection is the most effective method for identifying voids. If you suspect subsurface voids under your property, seek professional help for effective remediation. Trained experts can use various tools, like ground-penetrating radar (GPR), to locate and assess gaps in the soil beneath the foundation.
How GPR Works
Ground-penetrating radar is a non-invasive imaging technique that uses electromagnetic waves to map the area below the surface of the ground. It works by emitting radar pulses into the ground and then recording the signals that bounce back, which vary based on the different subsurface materials the pulses encounter.
When ground-penetrating radar pulses encounter subsurface voids, they tend to return with a delayed travel time and exhibit weaker reflections compared to when they hit solid materials. This is because voids contain air or less dense materials, causing the radar waves to travel further and reflect less energy. The difference in signal patterns allows trained technicians to identify and map out voids or changes in soil composition that may indicate the presence of voids.
Polyurethane Void Fill
One of the most effective solutions for addressing subsurface voids is polyurethane void fill. This innovative technique involves injecting a high-density foam beneath the foundation. The foam expands, filling gaps efficiently and aggregating soil to increase its load-bearing capacity. The foam quickly hardens and provides a solid base for the foundation.
The URETEK Deep Injection Method
URETEK’s process of filling voids with polyurethane begins with a thorough assessment of the area to identify the extent and location of the voids. Once those voids are identified, small holes are drilled into the foundation for polyurethane mixture injection. This method does not require excavation or prolonged downtime, making it more efficient and cost-effective than other repair methods and complete replacement.
Our foundation repair company uses the URETEK deep injection (UDI) method to inject our patented polyurethane foam up to 15 feet below grade—once again, without excavation! Targeting problems at depth stabilizes the entire soil column and prevents future settlement, thus enhancing the overall structural integrity of the foundation. This approach provides long-term stability and support by effectively treating deeper problems that surface-level solutions don’t target.
Benefits of Our Inert, Hydrophobic Polymer
A key reason we can inject our patented polymer up to 15 feet below grade is that it’s environmentally inert. This means it does not leach harmful chemicals into the surrounding soil or water sources. It is NSF/ANSI 61 certified as safe to be in contact with potable water.
In addition to being environmentally inert, the geopolymer is hydrophobic, which means it effectively repels moisture. This quality ensures it remains stable and intact over time, even in the presence of groundwater or in moist soil conditions. As a result, the material provides long-lasting protection and durability for foundations, reducing the likelihood of degradation or the need for frequent repairs.
Void Fill Cost Considerations
Repairing subsurface voids can vary in cost depending on several factors. The extent of the voids, the size of your property, and the chosen repair method all influence the total expense. Since voids worsen over time, you don’t want to delay fixing your property’s foundation. If necessary, consider discussing payment plans and financing options that can make the process more affordable.
Polyurethane void fill is generally more cost-effective than traditional foundation repair methods because it requires minimal excavation, reducing labor costs and time. The efficiency of the injection process allows repairs to be completed quickly, which can further save you money. Not to mention, this long-lasting, durable solution minimizes the need for frequent future repairs, offering cost savings over time.
Subsurface voids are empty spaces that develop in soil due to natural processes or human activities, potentially compromising the stability of the structures above. Professional inspection methods like ground-penetrating radar can determine the location of voids. Polyurethane injections fill voids efficiently and enhance the soil’s load-bearing capabilities, improving the levelness and stability of the foundation above. Contact URETEK to see if polyurethane void fill is a suitable solution for your property.