Don't take chances. Locate rebar in concrete before you find it with your drill bit, core barrel or saw!
You should always check any concrete for rebar and other embedded objects before cutting, drilling, sawing or other intrusive works. Whether it’s a concrete slab, beam column, wall, foundation, footing, retaining wall, pavement, etc; check first!
It’s usually rebar that you need to locate in concrete, but, it also applies to post tensioned tendons, prestressing strands, conduits and services. N.B. It’s not always metallic; it could be glass fibre reinforcement, fibreoptic cables or plastic pipes.
In most cases, professionals are looking for rebar, conduits and post-tension cables to avoid them when cutting or coring concrete. Failure to do so could result in:
Determining rebar distribution, depth of cover and tendon location/profile could also be required for construction verification purposes, structural analysis or materials testing.
There are two main methods of locating rebar and other embedded objects in concrete:
Electromagnetic induction methods are relatively low cost and straightforward operation; therefore, most rebar detectors are based on this principle These rebar detectors, commonly referred to as Covemeters range from simple rebar locators, to more advanced instruments, such as the Hilti Ferroscan, which will map reinforcement within a scanned area and provide estimates of rebar diameter. – For a more detailed comparison, see our article about Ferroscan and GPR rebar mapping surveys.
Pros and cons
GPR is our preferred method of rebar location and mapping. It uses pulses of electromagnetic radiation to image the subsurface and detects changes in material types, rather than specific materials. You can find more information about GPR, including how it works, on our Ground Penetrating Radar page.