Concrete Scanning in London
Locate rebar, post-tension cables and conduits before you core, cut or drill.
ACUO Structural Insights provides specialist GPR concrete scanning across all London boroughs and the South East. Constructionline Gold and SSIP accredited. Led by Gary Stringer — GPR NDT Civil Engineer with 20+ years of experience.
GPR Concrete Scanning Across London
Ground-penetrating radar (GPR) concrete scanning uses radar pulses to image the interior of a slab or wall without any drilling or damage. The scanner is passed across the surface in a systematic grid, and reflections from changes in material — steel, plastic, air, water — build a cross-section of everything beneath.
ACUO carries out GPR concrete scanning across all London boroughs — from the City and Canary Wharf to Croydon, Hackney and Hammersmith. We work on commercial offices, residential towers, car parks, hospitals, schools, infrastructure and heritage buildings. Whether you need a single core location checked or a full floor plate mapped, we provide the same level of care and accuracy.
All surveys are carried out by Gary Stringer, a GPR NDT Civil Engineer with over 20 years of experience. We are Constructionline Gold and SSIP accredited — pre-qualified for construction procurement across London and the UK.
Full concrete scanning service detailsWorking in the City, Westminster or Canary Wharf? See our Central London concrete scanning page.
Get a concrete scanning quote
Tell us the area to be scanned, the location and any access constraints. We'll provide a fixed-price quotation, typically within 24 hours.
Send an enquiry
What We Locate
GPR concrete scanning detects a wide range of embedded features. Before any coring, cutting, drilling or fixing, knowing what is inside the slab is essential. We locate:
- Steel reinforcement bars (rebar) — location, spacing and cover depth
- Post-tension tendons and ducts in post-tensioned slabs
- Electrical conduits, data cables and plastic pipes
- Voids, delaminations and areas of poor compaction
- Slab thickness and depth to the underside
- Embedded metallic and non-metallic services
Where precise cover depth and bar diameter data is required, we supplement GPR with the Proceq Profometer electromagnetic covermeter. See our dedicated rebar detection service for more detail.
Scanning Before Coring, Cutting and Drilling
Concrete scanning before any intrusive works is not just best practice — on many London construction and refurbishment projects it is a contractual requirement. Striking a reinforcement bar can damage expensive drill bits and delay the programme. Cutting through an electrical conduit creates a safety incident. Hitting a post-tension tendon can cause sudden, catastrophic slab failure.
ACUO scans the proposed core or drill location, marks all detected features on the slab surface, and confirms a safe zone for the works to proceed. We work alongside your drilling or coring team on site, providing real-time results so the programme is not delayed.
Where proposed locations cannot be made safe, we advise on alternative positions. Our written report documents the findings and provides a clear record for the project file.
Post-tension cable detection servicePost-Tension Slabs, Car Parks and Commercial Floors
Post-tensioned concrete is widely used in London's commercial offices, residential towers, car parks and retail developments. The tendons run through the slab under high tension — if one is severed, the consequences are severe and the repair costs are substantial. GPR is the only reliable non-destructive method for locating post-tension tendons before any cutting or coring.
Multi-storey car parks present a particular challenge: the slabs are often thin, the reinforcement is dense, and the tendons run in two directions. ACUO has extensive experience scanning car park slabs across London — providing tendon layout plans, safe zone marking and written reports for M&E installations, drainage penetrations and structural repairs.
For large commercial floor plates, we use the Proceq GS8000 multi-channel GPR array to scan efficiently across the full area, producing 3D depth-slice images that show the complete reinforcement and tendon layout at each depth level.
Equipment
We use Proceq GPR and covermeter equipment — the same instruments used by specialist NDT engineers on major infrastructure and construction projects across the UK. All equipment is maintained and calibrated to manufacturer standards.
High-resolution GPR antenna for concrete scanning. Produces real-time B-scan and C-scan images. Used for rebar detection, post-tension mapping and slab thickness measurement.
Multi-channel GPR array for 3D concrete scanning. Captures multiple parallel scan lines simultaneously, enabling rapid coverage of large floor plates with depth-slice imaging.
Electromagnetic covermeter for reinforcement detection, cover depth measurement and bar diameter estimation. Used alongside GPR to provide complementary data on rebar layout.
What You Receive
Every concrete scanning survey includes a clear set of deliverables. There are no hidden extras — the following are provided as standard with every survey:
- On-slab mark-up of all detected features using spray paint or chalk
- Annotated site photographs showing marked-up findings
- Written survey report with scan images, depth data and interpretation
- Safe zone recommendations for proposed core or drill locations
- 3D depth-slice images where multi-channel scanning is used
Reports are typically issued within 24–48 hours of the survey. For urgent programmes, same-day reporting can be arranged — discuss this when you enquire.
Post-Tension Slab Mapping — Central London Office
ACUO was instructed to scan a post-tensioned concrete floor plate in a Central London commercial office prior to M&E installation. The survey located all tendons, conduits and rebar across the full floor area, enabling the contractor to core safely without programme delay.
Read the case studyAreas We Cover
We cover all 33 London boroughs — from the City of London and Westminster to Croydon, Hackney and Havering. We also cover Kent, Essex, Surrey, Sussex, Hertfordshire and the wider South East, and work nationally across the UK. There is no additional travel charge for most London locations.
Also covering: Kent • Essex • Surrey • Sussex • Hertfordshire • Berkshire • UK-wide
Who We Work With
We work with a wide range of clients across the construction, engineering and property sectors in London. Our Constructionline Gold and SSIP accreditations mean we are pre-qualified for most major contractor supply chains.
Contractors & Main Contractors
Tier 1 and Tier 2 contractors requiring pre-works scanning before coring, cutting or fixing on commercial, residential and infrastructure projects.
Drilling & Coring Firms
Specialist drilling and coring contractors who need safe zone confirmation before every core. We work alongside your team on site and mark up in real time.
Structural Engineers
Engineers requiring accurate reinforcement data, cover depths and slab thickness for structural assessments, load calculations and remediation design.
Developers & Project Managers
Developers and PMs managing fit-out, refurbishment or new-build programmes who need scanning coordinated across multiple floors or phases.
Facilities Managers
FM teams managing ongoing maintenance, M&E installations or building alterations who need scanning before any penetration of the structure.
Concrete scanning and GPR services in London
Frequently Asked Questions
- How long does a concrete scanning survey take?
- A localised area — a single core location or a few square metres — can typically be scanned and marked up in under an hour. A full floor plate of 500–1,000 m² usually takes a day. We give you a realistic time estimate when we quote, based on the area, access and report requirements.
- How much notice do you need to mobilise in London?
- For most London surveys we can mobilise within 24–48 hours of instruction. For urgent or same-day requirements, call us directly on 07340 549892 and we will do our best to accommodate you.
- Does GPR find post-tension cables?
- Yes. GPR is the primary method for locating post-tension tendons and ducts in concrete slabs. The tendons appear as strong reflectors in the scan data. We use the Proceq GP8000 and GS8000 to produce clear B-scan and 3D depth-slice images showing tendon layout and spacing before any coring or cutting.
- What is the difference between GPR and a covermeter?
- GPR (ground-penetrating radar) uses radar pulses to image the full depth of a slab, detecting rebar, post-tension cables, conduits, voids and slab thickness. A covermeter uses electromagnetic induction to measure the depth of the nearest steel bar. We use both: GPR for a complete picture of the slab interior, and the Proceq Profometer covermeter where precise cover depth and bar diameter data is needed.
- Do you provide a written report?
- Yes. Every survey includes a written report with annotated scan images, depth data, interpretation and safe zone recommendations. On-slab mark-up and site photographs are provided as standard. Reports are typically issued within 24–48 hours of the survey.
- Is ACUO accredited for concrete scanning in London?
- Yes. ACUO Structural Insights is Constructionline Gold accredited and SSIP accredited. Every survey is carried out by Gary Stringer, a GPR NDT Civil Engineer with over 20 years of experience in concrete scanning and non-destructive testing.
Ready to book concrete scanning in London?
Call 07340 549892 or send an enquiry. We typically respond within 24 hours and can mobilise across London within 24–48 hours of instruction.