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Corvus
Surveyor scanning a concrete column on a construction site with Hilti ground-penetrating radar
Surveyor using Hilti PS300 to scan a concrete wall for reinforcement cover depth
Engineer reviewing ferroscan data output on a Hilti scanner display
Applied sciences for the built environment

Ferro Scanning

Cover depth, bar spacing and reinforcement layout measured with high-resolution electromagnetic scanning.

CSCS Registered Same-day Response Next-day Report UK Nationwide
Column scanning — rebar mapping
What it is

A non-destructive look first.

Ferro scanning is high-resolution electromagnetic detection of ferrous reinforcement. It complements GPR by giving cover depth and bar spacing readings, with bar diameter estimated where conditions allow on dense or shallow reinforcement.

How it works

Method matters.

A handheld induction probe passes over the surface. As the field interacts with steel, the device records bar position, depth and diameter range. Data is logged and overlaid on a slab map. Calibration is checked on every job to keep readings within manufacturer tolerance.

When you need it

The right call at the right moment.

  • 01

    When cover depth must be verified for compliance

  • 02

    Before drilling small-diameter fixings

  • 03

    When GPR resolution is insufficient at shallow depth

  • 04

    When a structural engineer needs reinforcement detail

  • 05

    During defect investigation on a reinforced element

  • 06

    For pre-condition surveys on heritage structures

What you get

Deliverables built for engineers.

No buried PDFs. No mystery numbers. Every deliverable is built around the question being asked.

  • Bar position plan with measured depths
  • Estimated bar diameter table
  • Cover-depth statistics versus design
  • Annotated PDF report with photographs
  • Digital plan in DXF / DWG
FAQ

Common questions.

How is Ferroscan different from GPR?

Ferroscan uses electromagnetic induction to detect reinforcement at specific scan lines, providing precise bar diameter estimates and cover depth readings. GPR gives a broader picture of the full scan area. We often use both together for the most complete data.

How long does a Ferroscan survey take?

A typical Ferroscan survey takes 2–4 hours depending on the number of scan areas. We'll advise on duration when you enquire.

When do I need to pay?

All surveys are invoiced by proforma. Full payment is required before we mobilise. We'll send the proforma invoice immediately on confirmation and works are scheduled once cleared funds are received.

Do your operatives have CSCS cards?

Yes. All Corvus operatives hold valid CSCS cards and carry full public liability insurance. We can provide method statements and RAMS on request.

What areas do you cover?

We cover the whole of the UK. Travel costs for sites outside London may apply — we'll confirm this when quoting.

Can you work in occupied buildings?

Yes. GPR and Ferroscan equipment is non-intrusive and silent. We regularly work in occupied offices, hospitals, and schools with minimal disruption.

Ready to see what's beneath the surface?

Tell us what you're working on. We'll come back within a working day with a quote, a method, and a date in the diary.

Call 020 3886 3660 Get a Quote