Fill Voids Beneath Structures
Voids beneath commercial buildings can lead to settlement, cracking, and long-term structural damage. These voids often result from poor compaction, water infiltration, or shifting soils—and if left untreated, they can compromise the entire building system. Void filling with expanding polyurethane stabilizes the foundation by filling these gaps, restoring contact between slabs or footings and the supporting soil. The process is fast, clean, and highly effective in protecting building performance.
What Is Void Filling?
Void filling is a soil stabilization technique that uses expanding polyurethane to fill gaps beneath concrete slabs, footings, or building additions. These voids can form from washout, erosion, soil shrinkage, or poor compaction during construction.
In commercial applications, voids are typically discovered under slabs-on-grade, along perimeter footings, or beneath additions. Polyurethane injection restores full soil contact and support, helping to prevent differential settlement and damage to structural systems.
Where Might Void Filling Be Needed?
- Slabs with loss of soil contact
- Building additions settled independently
- Perimeter footings exposed after erosion
- Underslab utilities that have leaked or shifted
- Interior floors with vibration or hollow areas
- Mechanical pads or equipment foundations
- Structures near stormwater or sewer features
- Commercial buildings with previous backfill issues
We Recommend Void Filling If You See:
- Slab deflection or movement underfoot
- Cracks forming near joints or column lines
- Visible slab separation from walls
- Water staining along perimeter footings
- Soil erosion after rainfall or drainage events
- Voids observed during core sampling or inspections
- Previous site grading concerns
- Foundation walls bowing inward
- Equipment shifting or vibrating during use
- Trip hazards in walkways or loading zones
Is Void Filling Really Needed?
Yes. Unfilled voids beneath structural elements can lead to progressive settlement, unpredictable building movement, and failures in flooring or equipment alignment. These issues are especially dangerous in commercial buildings, where structural integrity and operational efficiency are paramount.
Polyurethane void filling restores direct support beneath the slab or footing, eliminating air gaps that compromise load distribution. It’s an essential preventative measure that often avoids costlier structural repairs down the line.
What Are the Advantages of Void Filling?
Effective support restoration with minimal downtime.
Prevents Structural Settlement: Restores full soil contact beneath slabs and footings.
Fast Installation: Projects are completed quickly without large-scale disruption.
Precise Material Expansion: Polyurethane conforms to void shape and stabilizes surrounding soils.
No Need for Full Replacement: Repairs isolated issues without slab removal or excavation.
Ideal for Occupied Spaces: Work can proceed with minimal impact to business operations.
Common Problem Areas
- Commercial building slabs with hollow spots
- Additions built over soft or uncompacted soils
- Foundations near utility trenches or culvert crossings
- Mechanical rooms or equipment pads
- High-traffic warehouse zones
- Retail or office flooring with measurable deflection
Secure Your Structures with Groundworks’ Reliable Void-Filling Solutions.
How Does Void Filling Work?
A proven stabilization process using expanding polyurethane.
- Identify void locations with GPR or sounding
- Confirm structural elements affected by voids
- Drill small-diameter injection ports in slab or adjacent soil
- Inject expanding polyurethane into the void
- Material expands, filling the gap and reestablishing contact
- Monitor lift and expansion using dial indicators
- Trim and patch surface access points
- Confirm final stability and seal work area
Why This Is the Best Choice
- Resolves settlement before major damage occurs
- Avoids slab removal or building shutdown
- Compatible with a wide range of commercial properties
- Reduces long-term structural and maintenance risks
- Scalable for localized or widespread conditions
- Rapid mobilization and completion
- Provides lasting support without chemical breakdown
- Engineered for precise application and performance
Contact Groundworks for Void Filling
Void Filling for Commercial Buildings
Groundworks offers expert polyurethane injection services to fill voids beneath commercial buildings. Our solutions restore critical slab and footing support while minimizing impact to your site. Schedule a free evaluation to protect your structure today.
Names You Know Trust Groundworks with Their Toughest Foundation Issues
We want to learn about your project.
FAQs
Signs include hollow sounds when tapped, slab movement, or visible gaps. Ground-penetrating radar or core testing can confirm.
Yes. The material is strong, stable, and designed to restore soil contact and support structural elements.
Yes. The process is low-vibration, non-toxic, and can be performed during business hours in many environments.
Polyurethane expands and cures within minutes, allowing for immediate return to service.
Yes. Void filling is often used alongside slab lifting, structural underpinning, or waterproofing systems.
Disclaimer / Terminology
Void Filling: The process of injecting materials beneath a slab or footing to fill gaps caused by erosion, washout, or poor compaction.
Expanding Polyurethane: A two-part material that expands upon injection to fill spaces and stabilize soils.
Subgrade: The layer of soil directly beneath a slab or footing.
Deflection: Vertical movement of the slab away from its original elevation.
Soil Contact: The critical connection between a structure and the supporting soil beneath it.