Specialist Scanning Service
Post-Tension Cable Detection
Post-tension cables are among the most dangerous hidden elements in concrete structures. Under extreme tension, a single severed cable can cause catastrophic structural failure and serious injury. Our professional PT cable scanning service uses advanced GPR technology to locate every post-tension cable before you cut, core, or drill, keeping your workers safe and your project on track.
Understanding the Danger
Why Post-Tension Cable Detection is Critical
Post-tensioned concrete is widely used in commercial buildings, multi-storey car parks, bridges, and large residential structures across South East Queensland. The post-tension system works by threading high-strength steel cables, known as tendons, through ducts within the concrete slab or beam. Once the concrete has reached sufficient strength, these cables are tensioned using hydraulic jacks, typically to loads of 15 to 30 tonnes per cable, and then anchored in place.
This pre-compression gives the concrete significantly greater spanning capability and load-carrying capacity than conventionally reinforced concrete. However, it also means that every post-tension cable is storing an enormous amount of energy. If a cable is cut, nicked, or damaged during construction works, that energy is released violently and instantaneously.
The consequences of striking a post-tension cable are severe. A severed cable can whip through the concrete with lethal force, endangering everyone nearby. The structural integrity of the slab is immediately compromised, potentially leading to localised or progressive collapse. The financial impact is equally devastating: emergency structural engineering assessments, temporary propping, cable re-stressing or replacement, concrete reinstatement, project delays, and potential legal liability can collectively cost tens or hundreds of thousands of dollars.
Professional post-tension cable detection eliminates these risks. By using Ground Penetrating Radar to map PT cable locations before any cutting, coring, or drilling works commence, we identify exactly where every cable runs, at what depth, and along what trajectory. This information allows your team to plan penetrations safely, avoiding cables entirely or adjusting their approach to work around them.
Our Technology
How We Detect Post-Tension Cables
Ground Penetrating Radar (GPR)
GPR is the primary technology for post-tension cable detection. It transmits electromagnetic pulses into the concrete and analyses the reflected signals to build a detailed picture of what lies beneath the surface. Our industry-leading GPR equipment provides high-resolution imaging that allows us to identify PT cables, standard reinforcement, conduits, and other embedded services with precision. The process is completely non-destructive, requires no special site preparation, and delivers real-time results.
Expert Cable Identification
Accurately identifying post-tension cables in GPR data requires experience and expertise. PT cables have characteristic curved profiles, known as cable drapes, that follow specific trajectories through the slab. Our technicians are trained to recognise these patterns and distinguish post-tension cables from conventional reinforcement, conduits, and other embedded elements. We map cable paths, determine depths at critical points, and identify cable groupings to give you a comprehensive picture of the PT system within your structure.
Common Applications
When You Need PT Cable Detection
Post-tension cable scanning should be carried out before any works that involve penetrating or cutting concrete in a post-tensioned structure. If you are unsure whether a structure contains post-tension cables, scanning can confirm this quickly and non-destructively. Common scenarios requiring PT cable detection include:
Serious Consequences
The Risks of Not Scanning
Structural Collapse
Post-tension cables carry enormous loads. Cutting a single cable can trigger progressive structural failure, potentially collapsing entire floor sections or even the whole structure.
Serious Worker Injury
A severed PT cable releases stored energy violently. The cable can whip at high speed, causing catastrophic injuries or fatalities to anyone in the vicinity of the strike.
Extended Project Delays
Striking a post-tension cable halts all work immediately. Structural engineering assessments, remediation design, and repair works can delay your project by weeks or months.
Insurance & Liability Exposure
Damage to post-tension cables creates significant insurance claims and potential legal liability. Without evidence of pre-scan clearance, contractors face substantial financial exposure.
Costly Remediation Works
Repairing a severed post-tension cable is extremely expensive. It often requires specialist engineers, temporary propping, re-stressing, and extensive concrete reinstatement.
How It Works
Our Post-Tension Cable Detection Process
Contact & Consultation
Call us on 0448 814 010 or submit a quote request. Our team discusses your project requirements, the type of structure, and the scope of works to determine the scanning approach needed for your post-tension cable detection.
On-Site GPR Scanning
Our experienced technicians arrive on site with industry-leading GPR equipment. We systematically scan the concrete to identify post-tension cable locations, depths, and profiles throughout the designated area.
Cable Mapping & Analysis
Scan data is analysed to map PT cable paths accurately. We identify cable trajectories, depths, and spacing patterns, distinguishing post-tension cables from standard reinforcement and other embedded services.
Clearance & Safe Zone Marking
We clearly mark safe zones and no-go areas directly on the concrete surface. You receive clear, actionable results so your team can proceed with cutting, coring, or drilling with confidence.
Coverage Area
Post-Tension Cable Scanning Across SE QLD & Northern NSW
KCT Scan provides professional post-tension cable detection services across South East Queensland and Northern New South Wales. Whether you are working on a high-rise in Brisbane CBD, a commercial development on the Gold Coast, or an infrastructure project on the Sunshine Coast, our experienced team can be on site quickly with the right equipment for the job.
Common Questions
Post-Tension Cable Detection FAQ
What is a post-tension cable and why is it dangerous to cut?
Post-tension cables are high-strength steel tendons embedded within concrete slabs and beams. They are tensioned to very high loads after the concrete has cured, placing the concrete in compression to increase its load-carrying capacity. Because these cables are under extreme tension, typically between 15 and 30 tonnes per cable, cutting or nicking one releases that stored energy instantaneously. This can cause the cable to whip violently, creating a serious risk of injury or death, while also compromising the structural integrity of the entire slab or beam.
How does GPR detect post-tension cables in concrete?
Ground Penetrating Radar sends electromagnetic pulses into the concrete and records the reflections from embedded objects. Post-tension cables produce distinctive reflection patterns that our experienced technicians can identify and differentiate from standard reinforcement steel, conduits, and other embedded services. GPR allows us to map cable paths, determine depths, and identify cable profiles without any damage to the structure. The technology is completely non-destructive and provides real-time results on site.
How much does post-tension cable detection cost?
The cost of PT cable scanning depends on the size of the area to be scanned, the number of penetration points requiring clearance, and the complexity of the structure. We provide competitive, transparent pricing and are happy to quote on your specific project. Contact us on 0448 814 010 for a tailored quote. When you consider the cost of striking a post-tension cable, which can run into tens or hundreds of thousands of dollars in remediation, delays, and liability, scanning is always a worthwhile investment.
Can you tell the difference between PT cables and rebar?
Yes. Our experienced technicians are trained to differentiate between post-tension cables and standard reinforcement steel in GPR scan data. PT cables have distinct characteristics in their reflection signatures, including their curved profiles, cable groupings, and typical depth patterns. We also consider construction drawings and structural context when interpreting results to ensure accurate identification of all embedded elements.
How quickly can you get to site for PT cable scanning?
We understand that construction projects often need scanning at short notice. We offer fast response times across South East Queensland and Northern NSW, with same-day and next-day availability in many cases. Call us on 0448 814 010 to discuss your timeline, and we will do everything we can to accommodate your schedule. Our team is experienced at working within tight construction programmes.
Don't Risk It. Scan Before You Cut.
Protect your workers, your project, and your business. Contact KCT Scan today for professional post-tension cable detection across South East Queensland and Northern NSW.
Part of the KCT Group
Need Concrete Cutting or Coring?
KCT Scan is the newest member of the KCT Group of companies. If you also need professional concrete cutting, core drilling, or demolition services, visit our parent company at kct.net.au for a complete scan-to-cut solution. One group, total confidence.