Leak Sealing for Manholes & Vaults
Groundwater infiltration through manholes and utility vaults is one of the most persistent and costly problems in aging infrastructure. These leaks increase inflow and infiltration (I&I), accelerate soil erosion, and compromise system performance. Our injection-based leak sealing solution stops active leaks, restores structural contact with surrounding soils, and extends the life of subgrade access structures—without the need for excavation.
What Is Leak Sealing for Manholes & Vaults?
Leak sealing is a trenchless rehabilitation method that uses hydrophobic polyurethane injection to seal groundwater intrusion points in manholes, vaults, and access structures. The resin is injected through small ports, expands into surrounding soils, and creates a water-tight barrier at the source of infiltration.
In certain cases, a polyurethane lining system may also be applied inside the structure to provide additional internal sealing and surface protection—but injection remains the preferred method for addressing external leak paths and soil loss.
Where Might Leak Sealing Be Needed?
- Sanitary sewer manholes
- Telecommunications or electrical vaults
- Lift stations and pump chambers
- Brick or precast utility access structures
- Structures below the water table
- Vaults near storm drains or rivers
- Subgrade infrastructure in flood zones
- Aging municipal sewer systems
We Recommend Leak Sealing If You See:
- Groundwater entering through wall joints
- Soil or sand infiltration into the structure
- Visible voids around the exterior
- Surcharging or overflow during storms
- Excessive I&I inflating treatment volumes
- Cable entry or conduit leaks
- Deteriorated gaskets or joint separation
- Repetitive maintenance of affected vaults
- Surface settlement above the structure
- Chronic ponding near buried access points
Is Leak Sealing Really Needed?
Yes—especially for municipalities and utility providers managing aging infrastructure. Left untreated, groundwater infiltration can displace surrounding soils, create voids beneath roadways, and lead to expensive structural failure.
Injection-based leak sealing is a cost-effective solution that restores structural stability, reduces I&I costs, and extends the service life of critical assets. It also serves as a first line of defense before more extensive rehabilitation is considered.
What Are the Advantages of Leak Sealing?
This trenchless repair method minimizes disruption while delivering long-term structural value.
Stops Active Groundwater Leaks: Seals exterior pathways without excavation.
Stabilizes Surrounding Soil: Restores contact between the structure and its subgrade.
Reduces I&I and Treatment Costs: Limits excess flow into treatment systems.
Quick, Non-Invasive Installation: Work is completed from inside the structure or surface.
Complements Other Rehabilitation Methods: Compatible with lining systems or structural rebuilds.
Common Problem Areas
- Brick manholes
- Precast utility vaults
- Aging sewer access points
- Structures below grade in sandy soils
- Lift stations in wet zones
- Subgrade systems with long service lives
Protect Your Manholes with Groundworks’ Efficient, No-Dig Repair Solutions.
How Does Leak Sealing Work?
A trenchless, injection-based process designed for minimal disruption and maximum precision.
- Evaluate leak paths using camera or visual inspection
- Identify structure composition and surrounding conditions
- Drill injection ports from inside structure or above ground
- Inject hydrophobic polyurethane into exterior soil envelope
- Material expands to seal active leak paths and fill voids
- Confirm cessation of water intrusion
- Remove ports and restore access covers
- Optional internal polyurethane lining if needed
- Provide final inspection report and follow-up recommendations
Why This Is the Best Choice
- Trenchless and low disruption
- Seals leaks and reinforces surrounding soils
- Fast cure times with immediate results
- Ideal for active or wet environments
- Reduces inflow without bypass pumping
- Scalable for small or large systems
- Compatible with vault geometry and depth
- Optional lining for internal surface protection
Contact Groundworks for Leak Sealing
Leak Sealing for Manholes & Vaults
Groundworks provides injection-based leak sealing to stop groundwater infiltration, protect surrounding soils, and reduce I&I-related treatment burdens. We also offer polyurethane lining options where internal protection is needed. Contact us today to evaluate your infrastructure and extend its service life.
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FAQs
No. Our leak sealing process is trenchless and performed from inside or above the vault.
Injection sealing targets the exterior leak path and stabilizes soil. Lining protects interior surfaces. Both may be used when necessary.
Yes. Hydrophobic polyurethane performs well in wet environments and doesn’t require bypass pumping in most cases.
Yes. It’s effective for brick, precast, and poured-in-place systems—even those with decades of service.
Most structures are sealed in a single day, with immediate reduction in infiltration.
Disclaimer / Terminology
Leak Sealing: Injection-based method to prevent groundwater infiltration in subgrade structures.
Hydrophobic Polyurethane: Water-reactive material used to fill voids and seal leaks.
Polyurethane Lining: Internal spray-applied coating that seals interior surfaces.
I&I (Inflow and Infiltration): Unwanted water entering sewer systems through leaks.
Annular Space: Void between a structure’s wall and the surrounding soil.