Underground Infrastructure
Underground utilities and structures play a critical role in modern infrastructure—but when the soils around them shift or wash out, the entire system can be compromised. At NCFI, we offer high-performance polyurethane systems to stabilize soils, seal joints, fill voids, and extend the life of underground infrastructure with minimal disruption or downtime.
How Polyurethane is Used for Infrastructure Projects
Polyurethane is injected into or around underground infrastructure to fill voids, seal leaks, and compact soils. Once injected, the material expands and cures rapidly, creating a durable, watertight barrier and improving load-bearing capacity. It’s an ideal solution for aging or damaged systems where digging is impractical or cost-prohibitive. Polyurethane installation is adaptable, clean, and long-lasting—making it an excellent option for both proactive maintenance and emergency repairs.
Warning Signs of Infrastructure Issues
Inflow and Infiltration
Excess water entering sewer systems during storms may signal cracks, gaps, or joint failures underground.
Settlement
Visible soil settlement or sinkholes around manholes, pipes, or tanks often indicate underlying erosion.
Recurring Settlement
Persistent settling around underground utilities may be caused by washout or poorly compacted soils.
Leaking Joints or Pipes
Moisture on the surface or odors in the air could point to failed joints or cracks below ground. Storm water and sewer systems both suffer from these issues.
Common Uses of Polyurethane for Underground Infrastructure
Lateral Line Joint Sealing
When lateral lines start to crack or leak, water can start to seep out of the line connections, leading to groundwater contamination, sinkholes, or other issues. Our specially formulated polyurethanes have hydrophobic properties that repel water, making them ideal solutions for preventing inflow and infiltration problems within sewer systems. Injected from either inside or outside the line, our foam systems seal the joints and compact the soil to prevent future issues, quickly, cost-effectively, and sustainably. Our polyurethanes are environmentally inert, meaning they do not leach chemicals into the environment or groundwater, and are available with NSF/ANSI 61 safe drinking water certifications.
Pipe Joint Sealing
When sanitary and stormwater pipe joints begin to leak, it can lead to soil erosion, structural damage, and costly repairs. Polyurethane injection offers a fast, reliable solution to seal joints and restore pipe integrity, providing long-lasting protection with minimal disruption. In one application, NCFI’s polyurethane system simultaneously fills voids, densifies soils, and seals leaking joints and cracks. For pipe joint sealing, the product can be injected from within the pipe or from the surface, depending on accessibility and pipe diameter.
Pipe and Tank Abandonment
Polyurethane is an ideal solution for the safe, efficient abandonment of old pipes and tanks. When injected into defunct systems, such as septic or gas, these grouts expand to fill the entire void, stabilizing the surrounding soil and providing long-term structural integrity. The polyurethane bonds to the pipe and surrounding soil, sealing joints and cracks to prevent future seepage, water infiltration, or soil erosion. This creates a durable, impermeable barrier that ensures the safety of the site in the long-term. As the foam sets and cures, it provides structural stability, reducing the risk of soil subsidence, erosion, or settlement. The highly expansive nature of polyurethane ensures that the surrounding environment remains intact and unaffected by the abandonment process.
Culvert Repair
Compromised culverts have ramifications for the structures they support, and the stormwater drainage systems they are connected to. Polyurethane injection is an adaptable solution for culvert repair and repairing soil-related culvert issues. When culverts settle, the joints become susceptible to water infiltration, which causes subsidence of the support soils. This can lead to catastrophic conditions for the stormwater drainage system and the structures the soil supports, like roadways, dams, and buildings. In one application, polyurethane injection restores density and the bearing capacity of support soils, seals leaking joints, fills voids, and lifts and levels settled culverts. These solutions help alleviate stress for stormwater drainage system managers and the communities who rely on this key infrastructure.
Manhole Rehabilitation
Manhole rehabilitation with polyurethane injection repairs and restores the manholes back to working capacity by compacting and bonding soils, filling voids, and sealing joints against inflow and infiltration. In addition to stabilizing the manhole, the soil stabilization benefits adjacent structures such as roadways, buildings, and walkways. The injection process is highly adaptable and can be installed from within the manhole, from above the structure, and in remote locations.
Solutions for Any Project
Beyond the applications highlighted above, our geotechnical polyurethane solutions can be utilized for an even wider range of underground infrastructure needs. Our team will work with you to find the right foam formulation for your unique project.
- Ground Consolidation
- Sealing Water Ingress in Tunnels
- Grout Curtain Walls
The Advantages of NCFI Polyurethane for Infrastructure
No Excavation
There’s no need to dig up or disrupt surrounding infrastructure, which reduces labor costs, project duration, and environmental impact.
Environmentally Inert
Our polyurethane systems are environmentally safe, with no leaching of harmful chemicals into soil or groundwater and are available with NSF 61 Certification.
Long-Lasting
NCFI's systems create a durable, long-lasting bond with the soil, providing resistance to environmental factors.
Made in America
NCFI polyurethane is proudly manufactured in the U.S., ensuring quality and reliability.
Customizable
With a variety of single- and dual-component systems, our products can be tailored to specific soil types, environmental conditions, and application needs.
Polyurethane Systems
Our lines of Dual-Component Systems and Light-Weight Fill Systems polyurethanes have a variety of densities and cure times to meet your application’s needs. Each batch meets strict testing and quality assurance standards, ensuring reliability in the field. See Our Products.
Single-Component Systems
Single-Component Polyurethane Systems are a suite of hydrophobic permeation grouts formulated for soil stabilization, void filling, joint sealing, and soil compaction.
Explore ProductDual-Component Systems
Dual-Component Polyurethane Systems by NCFI are uniquely formulated, dual component systems formulated for a variety of geotechnical applications.
Explore ProductLightweight Fill Systems
The Light-Weight Fill product line is comprised of dual-component systems formulated for a variety of applications that require low exothermic heat generation for filling large voids and cavities, or building many layers quickly.
Explore ProductFrequently Asked Questions about Underground Polyurethane Injection
Applications include utility vaults, manholes, box culverts, storm drains, and sewer mains.
Yes. NCFI’s closed-cell, hydrophobic foams are designed to seal joints and leaks in subgrade structures, protecting surrounding soils from erosion.
NCFI works with contractors and municipalities to meet documentation and submittal requirements for infrastructure rehabilitation.
Once cured, NCFI’s polyurethane remains stable, resisting breakdown, water intrusion, and chemical exposure, over the long term.
Yes. Select NCFI foams are NSF/ANSI 61 certified and safe for use in proximity to potable water infrastructure.
Yes. NCFI provides comprehensive training and field support for contractors performing underground infrastructure work.
Real-World Results
About Us
NCFI has been a global leader in polyurethane foam production since 1964. Seeing the ever-growing applications of polyurethane in the geotechnical stabilization market, NCFI opened the geotechnical division in 2008 in order to provide better service and products to our customers and contractors. Our foam systems are an adaptable, no-excavation solution for meeting geotechnical engineering challenges.