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Locating services and conduits in concrete slabs

Services and ducts on concrete floor slab

GPR offers an excellent NDT method of detecting and locating service conduits and other embedded features within floor screed layers and reinforced concrete slabs. The method is non-intrusive and can be carried out in occupied premises.

Why locate services and conduits?

Usually construction professionals working on reinforced concrete slabs (e.g. shop or office fit-out) need to locate and map services and conduits before drilling, coring or sawing in order to avoid costly delays or dangerous hits. Detection of services and conduits within screed and reinforced concrete slabs require a different approach to external utility surveys. Other techniques such as CAT scanner, Ferroscan or covermeter have major limitations including limited depth penetration, interference from reinforcing steel and detection of live services or metallic conduits only.

Ground Penetrating Radar (GPR) works by detecting changes in the sub-surface and can detect metallic and non-metallic objects including:

  • Electrical, gas and water services
  • Fibre-optic services
  • Plastic and metallic conduits
  • Pipes and other targets

GPR produces a pseudo cross-section image through the floor slab enabling conduits to be identified and located, even if it is close to rebar. Our GPR Conduit Location Surveys can detect conduits within screed layers, the concrete slab itself or even below the slab.

Site Survey

Our experienced GPR surveyors will be able to assess your site conditions and use the most suitable antenna frequency to provide the best possible results. The use of multiple frequency antennas enables us to detect conduits at depths of a few centimetres down to a metre or more.

GPR radargram showing detected services and conduits in concrete floor slab

GPR radargram showing detected services and conduits in floor slab (indicated by blue arrows) 


Service and conduit location survey results are typically plotted in CAD. Annotated radargrams (cross-section view), depth slices (plan view) and sketches are also used where appropriate. Reports are issued in pdf format; where applicable, original CAD drawings are also issued in AutoCAD .dwg format.




Contact us

Contact us to find out more about GPR surveys to locate services and conduits in concrete slabs and how we can help you:

Telephone: 0207 565 7056

Information sheet

Download our information sheet about GPR surveys to locate services and conduits in concrete slabs.