What happens on the day of a Corvus survey
A practical, minute-by-minute account of what a Corvus survey day looks like from arrival to debrief — written for the site manager who needs to know what to expect.
If you have commissioned a concrete scanning survey and have not seen one before, it helps to know exactly what the day will involve — how long the surveyor will be on site, what they will need from you, and what you will have in hand by the time they leave. None of it is dramatic, but a survey day runs more smoothly when the site team knows what to expect. Here is a practical account of how a Corvus survey day unfolds, from arrival to debrief.
Before arrival
The day starts before the surveyor reaches site. A good survey is planned in advance: the brief is agreed, the scope is confirmed, drawings have been reviewed where they exist, and the surveyor knows the structural type and history of the element being scanned. The surveyor also knows the practical details — the site address, the induction requirement, the working hours, and any access restrictions — because these were settled at commissioning.
For your part, the most useful thing you can do before the day is to mark up the proposed drilling, coring, or cutting positions on the slab or wall, and to make sure the surface is clean and clear. A surveyor who arrives to find the work area accessible and the targets marked can get straight to work.
Arrival and induction
The surveyor arrives at the agreed time and reports to site. Expect the first part of the visit to be the site induction — the same induction any visiting contractor goes through. The surveyor will have the relevant qualifications and insurance documents and the right personal protective equipment, but the induction itself takes whatever time your site procedure requires, and it is worth allowing for it rather than expecting scanning to begin the moment they walk through the gate.
After induction comes a short conversation with whoever on site knows the structure. This is the point to hand over any drawings, point out the area to be scanned, explain anything unusual about the structure, and confirm the brief. Five minutes here saves time later.
Setting up
The surveyor then sets up at the work area. Concrete scanning equipment is portable and quick to deploy — there is no heavy plant and no lengthy rig — so setup is a matter of minutes. The surveyor will check and calibrate the equipment, confirm the survey area, and establish a reference grid or datum on the surface so that everything found can be located accurately and repeatably.
This is also when the surveyor confirms the practical conditions: that the surface is dry and clean enough to scan, that the area is clear of obstructions, and that access to the full extent of the survey is possible. If anything blocks part of the area, this is when it gets raised.
Scanning
The scanning itself is methodical rather than fast-paced. The surveyor moves the instrument across the surface in a series of overlapping passes, building up a picture of what lies within the concrete. As targets are identified — reinforcement, conduit, post-tension tendons, services, voids, and other features — the surveyor marks them directly onto the surface in chalk or paint. The on-surface markup grows as the survey progresses.
How long this takes depends on the size and complexity of the area. A discrete pre-drill scan of a few positions may take an hour or two; mapping the reinforcement across a large slab can take most of a day. Throughout, the surveyor works to a system, records depths and positions, and keeps the markup current. You are welcome to watch and to ask questions; the surveyor would rather answer them as they go than discover a misunderstanding afterwards.
The walkthrough
When scanning is complete, the most valuable part of the day takes place: the walkthrough. The surveyor takes you across the area and explains what the markup shows — where the reinforcement runs, where services or tendons were found, where it is safe to drill or cut and where it is not, and where there is any uncertainty.
Use this properly. Bring the people who will act on the survey — the trades who will do the drilling, and ideally the engineer if a structural question is involved. Ask whatever you need to ask. If a proposed drilling position conflicts with a target, this is the moment to discuss repositioning it. The markup on the surface is a working document, and the walkthrough is where it becomes a plan everyone agrees on.
Debrief and leaving site
Before leaving, the surveyor confirms what will be delivered and when — typically a written report with depths, positions, photographs, and a narrative interpretation, often the following morning. They will note any limitations encountered: areas that could not be accessed, conditions that constrained the scan, anything the report will need to flag.
The surveyor signs out through the site procedure and leaves. The on-surface markup stays where it is, and the formal report follows. If anything is unclear when the report arrives, raise it with the surveyor before any drilling, coring, or cutting takes place — that conversation is always available and always worth having.
A survey day is a calm, methodical piece of work. Knowing the shape of it — induction, setup, scanning, walkthrough, debrief — lets your site team plan around it and get the full value from the surveyor’s time on site.