Our nonintrusive GPR surveys can provide thickness readings for concrete slabs, floor slabs, bridge decks, and other structures. Variations in thickness and construction detail can also be detected.

Thickness Surveys

Slab thickness is generally determined by direct measurement; however, this is often not possible. One solution is to drill through and then measure the thickness, but this is not always possible (listed building, no access to the underside or intrusive works are not permitted.

Ground Penetrating Radar (GPR) offers a solution to this problem. It is suitable for most (non-metallic) materials and can even determine the thickness of several layers of construction simultaneously, e.g. asphalt layers in road construction, the thickness of screed and underlying concrete slab, etc. GPR is particularly useful for the following:

  • Concrete slab thickness (reinforced or mass concrete)
  • Screed thickness
  • Asphalt layers in road construction

GPR scans continuously record thickness information along a scan line, effectively providing a cross-section through the substrate. This makes the GPR especially suitable for detecting variations in thickness and changes in construction.

An additional benefit of using GPR is that other information can be collected at the same time, such as reinforcement distribution, depth of cover to rebar, delamination between layers, void location, etc.

Screed and concrete slab thickness surveys

GPR can be used for screed and concrete slab thickness surveys. It is very quick and efficient and suitable for small or large areas, e.g., offices, warehouses, and car parks. It can confirm if thicknesses are within specified tolerances or determine the minimum/maximum thickness of a concrete slab for structural analysis.

Small areas can be scanned with individual scan lines, while larger areas are typically scanned on a regular orthogonal grid.

Advantages of GPR surveys

Sandberg offers GPR surveys to determine the thickness of construction. Our experienced surveyors can undertake anything from simple spot readings to extensive and comprehensive surveys of large areas to determine the thickness of construction and variations in thickness. Advantages of using GPR include:

  • Access to one side only required
  • Non-intrusive
  • Suitable for most non-metallic materials
  • Minimal disruption so can be carried out in occupied premises
  • Suitable for large or small areas
  • Quick and cost-effective

Survey deliverables

Results can be marked on CAD drawings as spot readings, contour plots, or colour-coded thickness zones along scan lines.

Need more information?

Contact us

Contact us to find out more about our GPR wall and slab thickness measurement surveys and how we can help you:

Tel: 0207 565 7056
Email: gpr@sandberg.co.uk

Information sheet

Download our information sheet about GPR wall thickness measurement surveys.

Are you wondering what else GPR can be used for? GPR surveys can investigate the subsurface and detect unseen features. Learn more about our most popular GPR surveys.