GPR Services · Vancouver Island
Slab Thickness & Void Detection in Nanaimo, BC
Find the washout before it becomes the sinkhole. GPR measures slab thickness and images the voids beneath floors, decks, and pavements. Serving Nanaimo and the Vancouver Island region with certified technicians, non-invasive methods, and insurance-ready documentation — since 1999.
Free phone consult · No pressure · Mon–Sat 8am–6pm PT
Nanaimo ground conditions & what they mean for GPR
Local geology: Nanaimo sits on till and sandstone benches — with documented historic coal workings beneath parts of the city. Standard till performance at surface, but Nanaimo's defining subsurface feature is its coal-mine legacy: old workings and shafts underlie several neighbourhoods, making void detection a local specialty.
Local building stock: Harbour-city mix of heritage districts, mid-century suburbs, and rapid hospital-area densification.
Common slab thickness & void detection work in Nanaimo
- Void scans over historic coal workings
- Pre-development due diligence
- Service leak tracing in mid-century suburbs
- Soft spots in floors
- Pre-sinkhole investigation
- Slab QA verification
How the Nanaimo site visit works
- 1
Grid scan
The slab is scanned in a tight grid; thickness reads continuously and voids appear as distinctive reflections beneath.
- 2
Void boundary mapping
Any void's footprint is walked out and marked so the repair fills the whole cavity, not just the symptomatic corner.
- 3
Cause assessment
Voids have causes — leaking pipes, washed fill, settling organics. We correlate with leak findings so the fix addresses the source.
- 4
Report
Thickness map, void extents, and probable cause delivered for the engineer or contractor handling remediation.
Nanaimo questions, answered
The floor sounds hollow when we walk on it. Is that a void?
Often, yes — a drummy slab is the classic early sinkhole symptom. GPR confirms in minutes whether there is a cavity, how big it is, and how thin the remaining slab bridge is. That last number decides whether the area gets barricaded today or scheduled for repair next month.
What causes voids under BC slabs?
The usual suspects: leaking water or sewer lines washing out fines, poorly compacted fill settling, buried organics decomposing, and in older Vancouver Island areas, karst dissolution in limestone. Identifying which one drives the repair approach.
Can you verify a new slab was poured to spec?
Yes — GPR thickness verification is the non-destructive alternative to coring. Continuous profiles across the pour show exactly where thickness meets or misses the structural drawing, with ±5 mm accuracy.
How urgent is a confirmed void?
Depends on span and bridge thickness, which the scan quantifies. A 30 cm void under a 150 mm slab is monitoring territory; a 2 m void under 80 mm of bridging concrete is a barricade-now finding. The report states which case you have.
How deep can GPR scan in Nanaimo?
Nanaimo sits on till and sandstone benches — with documented historic coal workings beneath parts of the city. Standard till performance at surface, but Nanaimo's defining subsurface feature is its coal-mine legacy: old workings and shafts underlie several neighbourhoods, making void detection a local specialty. We select antenna frequency to match — and where local ground limits radar depth, we pair GPR with electromagnetic locating, acoustic methods, or tracer gas so the survey objective is met regardless of soil conditions.
Do you actually work in Nanaimo, or dispatch from elsewhere?
Nanaimo is part of our standing Vancouver Island service area — the same certified technicians and equipment that cover the rest of the region. Scheduling is typically within 24–72 hours, with same-day response often possible during business hours (Mon–Sat, 8am–6pm Pacific).
What does slab thickness & void detection cost in Nanaimo?
Pricing matches our province-wide structure — no regional premium for Nanaimo. Most residential-scale work falls in the $350–$1,200 range depending on scope; commercial and multi-site projects are quoted after a free phone consult. Call 604-239-9934 and we will give you a tight estimate in five minutes.
Other GPR services in Nanaimo
Slab Leak Detection in Nanaimo
GPR maps the in-slab plumbing and rebar so thermal and acoustic findings convert into a single small repair patch — not a jackhammered floor.
View serviceSewer Leak Detection in Nanaimo
GPR finds the voids and washouts that leaking sewers carve around themselves, while CCTV confirms the failure from inside the pipe.
View serviceConcrete Scanning in Nanaimo
The full picture inside any slab, wall, or beam — rebar, PT cables, conduits, voids, thickness — imaged at 1.6 GHz before a single cut.
View serviceParking Garage Slab Scanning in Nanaimo
Parkade decks fail from the inside — chloride-corroded rebar, delamination, membrane leaks. GPR maps the deterioration before the spalling starts.
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Slab Thickness & Void Detection near Nanaimo
Need slab thickness & void detection in Nanaimo?
Free phone consult with a certified GPR technician — we will tell you whether a survey is warranted and quote it in five minutes. No pressure.