If you’ve ever drilled into concrete and hit something you shouldn’t have, you already understand the value of concrete scanning. It’s one of those services that might seem optional—until it saves your project from delays, damage or worse. Whether you're a sparkie, plumber, builder or site manager, knowing when to use concrete scanning can save time, money, and prevent serious safety risks. Let’s break down when concrete scanning should be used on a construction site. Chances are, it’s more often than you'd expect.
First up – What Is Concrete Scanning?
Concrete scanning is a non-destructive testing method that uses Ground Penetrating Radar (GPR) to detect what’s embedded in or below a concrete surface. It allows us to locate things like steel reinforcement (rebar), post-tension cables, electrical conduits, water and gas pipes, and even voids or cracks—without cutting into the concrete.
The equipment works by sending high-frequency radar waves into the concrete, which bounce back when they hit a material with different properties. These echoes are captured and translated into a visual map, giving us a clear idea of what’s going on beneath the surface.
It’s fast, safe, and incredibly accurate. Most importantly, it allows tradies and contractors to work confidently and avoid costly or dangerous mistakes. Whether you’re coring a slab, cutting a trench, or preparing for structural changes, concrete scanning takes the guesswork out of the job and helps you get it right the first time.
1. Before Drilling, Cutting or Coring Into Concrete
This is the most common time to bring in concrete scanning. If you’re about to drill, cut, or core into concrete, and you don’t know what’s underneath, you’re taking a serious risk. You could strike:
- Live electrical conduits
- Post-tension cables (damaging these can be extremely dangerous and costly)
- Steel reinforcement
- Water or gas pipes
Any of these can bring your job to a halt, result in expensive repairs, or worse—lead to serious injury. Scanning before you begin helps ensure your team’s safety and keeps the project running smoothly.
2. Before Structural Modifications or Renovations
Planning to remove a wall, cut into a suspended slab, or widen an opening? You need to know exactly what structural elements are inside the concrete.
GPR scanning can identify rebar patterns, post-tension cables and other embedded materials so your engineer can make accurate assessments. That means you can carry out the modifications safely, with the confidence that you’re not compromising the structural integrity of the building.
3. When As-Built Plans Are Missing or Inaccurate
It’s not unusual to be working off drawings that are outdated, incomplete or simply incorrect. Over time, modifications might have been made onsite that were never documented properly.
Concrete scanning gives you an up-to-date picture of what’s really there—no guesswork. This is especially important on older sites or when taking over from another contractor where the documentation might be unreliable. Having current and accurate information helps prevent unexpected delays or issues.
4. During Concrete Thickness Testing and Quality Control
It’s not always about what’s inside the concrete—sometimes you need to know how much concrete you’re working with.
Whether it’s for compliance, quality control, or peace of mind, GPR scanning allows you to test concrete thickness across slabs and walls without damaging the surface. This is especially useful when confirming the quality of a pour or ensuring the slab can handle additional loads.
5. Locating Voids, Honeycombing or Delamination
Concrete isn’t always as solid as it looks. Poor workmanship, wear and tear, or environmental factors can cause voids, air pockets, honeycombing, or delamination over time.
These internal issues can weaken a structure and lead to bigger problems down the track. GPR scanning can detect these faults early, allowing you to assess the extent of the issue and plan repairs before things get worse.
6. Before Installing Heavy Machinery or Equipment
When you’re installing heavy plant or machinery, it’s essential to know whether the slab can handle the weight.
GPR scanning helps you assess concrete thickness, reinforcement layout, and overall slab condition. That way, you can be confident in your installation plans and avoid structural failures or the need for costly reinforcements after the fact.
7. Safety Audits and Pre-Work Risk Assessments
For many commercial or government sites, scanning is part of the safety protocol before starting certain types of work.
It makes sense—identifying hidden hazards before drilling or cutting reduces the risk of injury, equipment damage, and costly incidents. It also gives your team the information they need to plan work more efficiently and safely, ticking all the right boxes for compliance and WHS requirements.
8. Before Saw Cutting Slabs or Walls
Saw cutting might seem straightforward, but if you cut into a post-tension cable or live electrical conduit, things can go wrong very quickly.
Even shallow cuts can cause major damage if you don’t know what’s beneath the surface. A quick scan can identify safe zones and hazards, so your team can get the job done without unexpected surprises.
Concrete Scanning Isn’t Just a Nice-To-Have – It’s Smart Risk Management
Concrete scanning is one of those services that pays for itself. Whether you’re trying to avoid damaging underground services, prevent safety incidents, or just keep a job running on time, scanning gives you the information you need to make smart decisions.
It’s not about overcomplicating things—it’s about doing things properly the first time.
Don’t Wait Until There’s a Problem
If you’re not sure whether scanning is needed on your next job, it’s usually a sign that it probably is. It’s far cheaper and quicker to scan before the work starts than to deal with repairs, project delays, or injuries later on.
At South East Scanning, we take pride in delivering fast, accurate and reliable scanning services. We work with all types of trades and contractors, and we understand the pressures on modern job sites. You’ll get clear reporting, expert advice, and zero run-around.
Got a job coming up that involves concrete?
Reach out to South East Scanning. We’ll help you get it done safely, efficiently, and without any nasty surprises.
