Frequently asked questions.

Yes. GPR is the standard non-destructive method for finding and mapping post-tension cables in concrete floors. Skilled interpretation by a qualified surveyor is essential.

Yes — GPR can scan through typical floor screed to detect reinforcement and embedded items in the structural slab below. Thick screeds and heating layers may complicate interpretation.

For any drilling into structural concrete where as-built records are incomplete, GPR pre-drill scanning is the standard mitigation. For post-tension floors it is non-negotiable.

Survey-grade terrestrial LiDAR produces a registered point cloud accurate to a few millimetres across the captured space. Mobile and SLAM-based systems are typically centimetre-grade.

GPR depth depends on antenna frequency and material. High-frequency concrete antennas reach roughly 400 mm in good concrete; low-frequency ground antennas reach several metres in clean ground.

Send the site address, the element to be scanned, the brief, and any drawings to a reputable scanning company. You should receive a quote, a method statement, and a date in the diary the same working day.

Send the location, the element to be scanned, the brief, and any drawings to Corvus. We come back the same working day with a quote, method, and a date in the diary.

LiDAR uses laser pulses to measure distance to surfaces. Combined with the known direction of each pulse, it builds a 3D point cloud of the captured space at engineering accuracy.

GPR data is delivered as on-slab markings on the day, plus a written PDF report and a CAD-ready DXF/DWG plan typically the next morning. Calibration record and surveyor sign-off are included.

A typical pre-drill scan on a small area takes 1–2 hours on site, with the report delivered the next morning. Larger reinforcement-mapping or PT scans usually take a full day on site.

UK GPR scanning costs vary by scope, but a typical pre-drill scan on a single small area is a half-day job priced in the low hundreds of pounds. Larger or specialist work is priced by site time.

GPR scanning is highly accurate for position and depth of targets when the equipment is calibrated and the surveyor is qualified. Typical accuracy on concrete scanning is within 10 mm in plan and 10–15% on depth.

We cover projects across the UK. Mobilisation, minimum charges and travel costs depend on location, scope and programme — contact us for a specific quote.

Corvus surveyors hold or work toward EuroGPR Certified Surveyor status. The company is registered with industry PQQ schemes, holds full insurance, and works with UKAS-accredited laboratory partners for NDT testing.

Drilling through rebar damages the bar locally, weakens the structural element, and can compromise design capacity. On post-tension elements it can have severe consequences.

Drone surveys are used for site progress capture, photogrammetry, orthomosaic mapping, aerial inspection, and stockpile volumetrics on UK construction sites.

A point cloud is the measurable 3D record of a space or structure. It is used for design, BIM coordination, structural monitoring, drawings, inspection, dispute resolution, and heritage records.

Cover depth is the distance from the surface of a concrete element to the nearest reinforcement bar. It protects the steel from corrosion, fire, and chemical attack.

Rebar mapping is the non-destructive surveying of reinforcement in a concrete element to record bar position, depth, and (where possible) diameter — typically using GPR and ferro scanning.

GPR sees deeper and detects non-ferrous items like conduits and post-tension cables; ferro scanning measures cover and bar diameter accurately at shallow depth. They are complementary and often used together.