Can GPR detect post-tension cables?

Yes. GPR is one of the most reliable methods for locating post-tension cables in concrete slabs. The Proceq GP8000 and GS8000 systems we use produce clear hyperbolic reflections from the cable sheaths, allowing us to map their position and depth accurately before any coring or cutting work takes place.

How accurate is GPR concrete scanning?

In typical reinforced concrete, GPR depth accuracy is within ±10–15% of the true depth. Lateral position accuracy is generally within 10–20mm. Accuracy is affected by concrete mix, moisture content and the density of reinforcement. We always report confidence levels alongside our findings.

What is 3D concrete scanning?

3D concrete scanning uses a grid of closely spaced GPR passes to build a three-dimensional picture of everything embedded in a slab. Unlike a single 2D profile, 3D scanning shows the full extent and layout of rebar, post-tension cables and voids across the entire survey area — making it easier to plan safe coring and cutting routes.

How long does a concrete scanning survey take?

A typical pre-coring scan of a single core location takes 30–60 minutes on site. A full 3D scan of a 10m × 10m area typically takes 2–4 hours including data processing and marking. We can usually mobilise within 24–48 hours for London and the South East.

GPR & 3D Scanning

GPR Concrete Scanning

GPR & 3D Scanning

Get a Quote

About this service

Ground-penetrating radar surveys to locate rebar, post-tension cables, conduits and voids before coring, cutting or drilling. We use the Proceq GP8000 and GS8000 GPR systems to deliver 2D profiles and full 3D concrete scanning with millimetre-accurate depth data — essential for safe, compliant work on reinforced concrete structures.

3D Concrete Scanning

Our 3D concrete scanning service uses the Proceq GS8000 to capture a dense grid of GPR profiles across the survey area. The data is processed into a 3D visualisation showing the precise location and depth of every embedded feature — rebar, post-tension cables, conduits and voids — in a single, easy-to-read output. This is particularly valuable on complex slabs, transfer structures and post-tensioned decks where a 2D profile alone may not give sufficient clarity.

Concrete Scanning Before Drilling, Coring and Cutting

Drilling or coring into reinforced concrete without scanning first risks striking rebar, severing post-tension cables or cutting through live services. A severed post-tension tendon can cause sudden, catastrophic slab failure. We carry out pre-coring and pre-drilling GPR scans to mark safe locations on the slab surface, giving your team the confidence to proceed safely. Scans are typically completed on the same day and results are marked directly on the concrete.

What we cover

Rebar detection & mapping
Post-tension cable location
3D concrete scanning (Proceq GS8000)
2D GPR profiling (Proceq GP8000)
Conduit & service location
Void detection in slabs
Pre-coring & pre-drilling clearance

Ready to discuss your project?

Call or email us for a fast, no-obligation response.

07340 549892 [email protected]Get a Quote

Common Questions

Frequently asked questions

Can GPR detect post-tension cables?: Yes. GPR is one of the most reliable methods for locating post-tension cables in concrete slabs. The Proceq GP8000 and GS8000 systems we use produce clear hyperbolic reflections from the cable sheaths, allowing us to map their position and depth accurately before any coring or cutting work takes place.
How accurate is GPR concrete scanning?: In typical reinforced concrete, GPR depth accuracy is within ±10–15% of the true depth. Lateral position accuracy is generally within 10–20mm. Accuracy is affected by concrete mix, moisture content and the density of reinforcement. We always report confidence levels alongside our findings.
What is 3D concrete scanning?: 3D concrete scanning uses a grid of closely spaced GPR passes to build a three-dimensional picture of everything embedded in a slab. Unlike a single 2D profile, 3D scanning shows the full extent and layout of rebar, post-tension cables and voids across the entire survey area — making it easier to plan safe coring and cutting routes.
How long does a concrete scanning survey take?: A typical pre-coring scan of a single core location takes 30–60 minutes on site. A full 3D scan of a 10m × 10m area typically takes 2–4 hours including data processing and marking. We can usually mobilise within 24–48 hours for London and the South East.

Related Insights

What Can GPR Actually See in Concrete?

Read article

Scanning Before Coring: Why Post-Tensioned Slabs Need Extra Care

Read article

How Much Does GPR Concrete Scanning Cost?

Read article

Case Studies

3D GPR Concrete Scanning

Basement Plant Room GPR Scanning, London

3D GPR survey of a basement plant room slab to locate reinforcement, screed layers and possible pile positions — delivered without any surface markings.

1 m × 1 m

3D grid size

Marks made

Read case study