When void filling is the right scope
Voids hide. The visible damage is usually settlement, cracking, or sinkhole-like depressions — but the underlying issue is empty space below the surface that wasn’t there before:
- Active sinkhole investigation requiring void mapping and fill
- Abandoned underground storage tanks or sewer lines that left voids when removed
- Slab or footing settlement caused by water-line or sewer leaks below grade
- Pre-construction site prep where a geotech report flagged subsurface voids
- Erosion behind seawalls, retaining walls, or culverts where backfill has washed out
- Industrial slabs and pads showing localized settlement over former excavations
How voids form under Florida structures
Five common origins. The geotechnical investigation tells us which is active so the grout type and injection plan are matched to the cause:
- Karst dissolution — naturally occurring voids in limestone bedrock, sometimes mapped, often not
- Leak-driven erosion — water or sewer line failures wash soil away over months or years
- Abandoned utilities — old septic tanks, oil tanks, or sewer trenches that weren’t properly filled
- Construction defects — bad compaction during original fill placement leaves voids that consolidate later
- Surge and washout — coastal flooding or downspout failures move soil from one location to another
How we fill subsurface voids
Investigation comes first — never inject blind. We coordinate with a licensed geotechnical engineer to run probes (SPT, GPR, sometimes coring) to map the void’s size, depth, and the soil profile around it. The geotech report drives the grout selection and injection layout.
For voids under existing slabs, polyurethane is the standard choice — closed-cell, hydrophobic, fills the cavity and supports the slab from below in one operation. For larger voids or deeper cavities, cement compaction grouting through cased holes lets us deliver high volumes at controlled pressure.
Injection happens through engineered port layouts — typically a grid or perimeter pattern sized to the void footprint. Real-time monitoring (volume per port, pressure curves, surface uplift) tells us when each section is full and confirms the void is contained.
Post-fill verification — geotech runs follow-up probes through the same locations to confirm the void is closed and the grout has bonded properly to the surrounding soil. Documentation package goes to the structural engineer of record or insurance carrier.
What you can expect — typical timeline.
- Free inspection & quote — within 3 business days of your call
- Engineer-stamped design — 5–7 business days after acceptance
- Permit pulled and crew scheduled — 1–2 weeks (varies by county)
- Installation — typically 2–5 days for a residential project
- Lift, load test, warranty issued — same day as install completion
Frequently asked questions
Common questions we hear during the free inspection. If yours isn’t covered, call 866-398-9323 — we’ll answer it.
How do you find subsurface voids before injecting?
Geotechnical investigation is the standard tool — standard penetration tests (SPT) at engineered locations, ground-penetrating radar (GPR) where access permits, and selective coring for confirmation. For active sinkholes the geotech investigation is usually part of the insurance-mandated scope. For pre-construction site prep it’s part of the geotech report driving design.
What's the difference between polyurethane and cement compaction grouting?
Polyurethane is a two-component resin that expands rapidly in place — best for filling defined voids under existing slabs, light weight, fast set. Cement compaction grouting is a stiff mortar pumped at high pressure — best for densifying loose soils or filling larger cavities at depth, heavier, slower set. Sometimes both are used on the same project: cement for deep void fill, polyurethane for the final slab support layer.
Will grouting fix a sinkhole on its own?
For minor void fill with no significant settlement, sometimes yes. For active sinkholes where the structure has settled, grouting alone isn’t enough — it stabilizes the soil but doesn’t transfer the structure’s load below the affected zone. Engineered repair pairs grouting (to fill the void) with helical piers (to carry the load to competent bedrock). See our sinkhole repair page for the full sequence.
How long does void filling take?
Mobilization and pre-injection setup: 1 day. Active injection: 1–5 days depending on void volume. Cement compaction grouting on larger voids can run a week or two. Post-injection verification by the geotech: 1–3 days. Most commercial void-fill scopes complete in 1–2 weeks from mobilization.
Is void filling covered by insurance?
When the cause is a covered peril (sinkhole, sudden water-line failure with covered consequential damage), often yes. When the cause is gradual erosion, drainage failure, or pre-existing construction defects, generally no. We document the cause with the geotech and PE so the engineering substantiation is in place if a claim is filed.
Do you handle commercial void filling for GCs and developers?
Yes — pre-construction site prep, ongoing remediation under occupied buildings, and emergency response after subsurface failures discovered during construction. We coordinate with the geotechnical engineer, structural engineer of record, and your project schedule. Documentation deliverable includes engineered drawings, injection logs, volume records, and post-fill verification.
Void Filling Grouting by region
We deliver this service across all 8 of our Florida regions. Click any region to see local soil conditions and recent project context:
- Void Filling Grouting in Jacksonville — Northeast Florida
- Void Filling Grouting in Treasure & Space Coast — Daytona to Stuart
- Void Filling Grouting in Miami / South Florida — South Florida
- Void Filling Grouting in Tampa Bay — Gulf Coast
- Void Filling Grouting in SW Florida — Sarasota / Naples
- Void Filling Grouting in Orlando — Central Florida
- Void Filling Grouting in North Central FL — Lake City / Gainesville
- Void Filling Grouting in Florida Panhandle — Pensacola / Tallahassee
Void Filling Grouting in Florida Cities
The 20 most-served Florida cities for this service — click any city for local soil conditions and a free on-site quote:
- Void Filling Grouting in Jacksonville
- Void Filling Grouting in Tampa
- Void Filling Grouting in Orlando
- Void Filling Grouting in Miami
- Void Filling Grouting in St. Petersburg
- Void Filling Grouting in Hialeah
- Void Filling Grouting in Tallahassee
- Void Filling Grouting in Fort Lauderdale
- Void Filling Grouting in Cape Coral
- Void Filling Grouting in Pembroke Pines
- Void Filling Grouting in Hollywood
- Void Filling Grouting in Gainesville
- Void Filling Grouting in Sarasota
- Void Filling Grouting in Naples
- Void Filling Grouting in Clearwater
- Void Filling Grouting in Fort Myers
- Void Filling Grouting in Daytona Beach
- Void Filling Grouting in Vero Beach
- Void Filling Grouting in Pensacola
- Void Filling Grouting in Panama City