Corrected for structural, detection and reporting accuracy on 20 July 2026.
Structural concrete scanning can help a project investigate selected reinforcement, post-tensioning and embedded services before cutting, drilling, anchoring or altering a slab or wall. It does not reveal everything inside concrete, measure load capacity, diagnose the cause of a crack or certify that a structure or foundation is sound.
This Brisbane and South East Queensland guide explains how to scope scanning for a proposed structural alteration. It separates the scanning operator's interpreted findings from the engineer's design, condition-assessment and approval decisions so each party receives evidence they can use without overstating what the method proves.
Start with the proposed alteration
Provide the location, dimensions, depth, orientation and purpose of every proposed cut, core, chase or fixing. Identify the concrete element, level, grid, drilling face and conditions behind or below it. Mark the approved set-out and name the person who can authorise a change.
The structural question should be clear. The project may need to avoid selected reinforcement or post-tensioning, understand the reinforcement arrangement around an opening, check a proposed fixing zone, compare visible construction with drawings, or gather one input for an engineer's alteration design. A request to "scan the structure" is too broad to define useful coverage or conclusions.
Separate locating from structural assessment
A scanning operator can collect and interpret data within the method and site limitations. The responsible engineer determines what the findings mean for load paths, reinforcement changes, opening groups, edge distances, temporary support, repair or the adequacy of the remaining element.
Concrete scanning alone does not establish:
- compressive strength, material composition or concrete durability;
- the cause, activity, depth or structural significance of a crack;
- corrosion, bond, tendon force or reinforcement condition;
- the size, cause or structural effect of every void or anomaly;
- foundation bearing capacity, settlement or soil condition;
- that every embedded service or tendon has been found; or
- that an unmarked area is approved or safe to cut.
Those questions may require engineering inspection, records, testing, exposure, monitoring, laboratory work or another investigation method. The responsible professional should define the required evidence rather than treating a scan image as a universal integrity check.
Gather drawings and records without treating them as proof
- structural and post-tension drawings, schedules and approved shop details;
- as-built information, prior scans and alteration records;
- service drawings, isolations and visible entry or exit points;
- photographs of both faces and the surrounding structure;
- the proposed cutting, drilling, anchoring or demolition method; and
- any engineer-defined targets, exclusions, hold points or report format.
Compare records with site evidence and document discrepancies. Concrete can differ from a drawing because of construction tolerances, design changes, repairs and later work. A drawing may guide the investigation, but it should not be used to dismiss a conflicting finding without review.
Define the targets that matter
Scanning works best when the team specifies the target and decision. Reinforcement, post-tensioning and selected metallic or non-metallic service features can respond differently to available methods. Their depth, orientation, spacing, size, material and relationship to nearby targets affect interpretation.
Ask the engineer or project representative what needs to be marked or recorded. Examples include a reinforcement grid across a proposed opening, selected tendon routes, a fixing strip, a clear-zone proposal with stated limitations, or a comparison between two work faces. Avoid expanding a local scan into a claim about the entire floor or building.
Choose methods from the concrete and target
Ground-penetrating radar and electromagnetic locating are different tools with different constraints. Useful method selection depends on the target, concrete thickness, reinforcement congestion, moisture, surface condition, access, nearby interference and whether one or both faces can be inspected.
Signal responses require interpretation. Closely spaced targets, multiple reinforcement layers, limited calibration, obstructions, topping slabs, coatings, mesh and unavailable faces can reduce confidence. The appropriate frequency, antenna, scan direction, grid and processing should be selected by the competent operator for the actual question, not copied from a claim that one frequency penetrates a guaranteed depth.
Do not promise ±2-millimetre cover accuracy, exact tendon depth, full slab thickness or a fixed detection range. Accuracy and uncertainty depend on the system, setup, target, calibration information, material and site conditions.
Plan coverage and references
Agree the scan boundaries and a physical reference system before attendance. A useful plan may identify grids, levels, control points, dimensions from permanent features and the face from which data was collected. Photographs should show the work area, reference marks and proposed alteration.
Coverage needs to extend far enough for the project decision, but more area is not automatically better if the question remains undefined. Record inaccessible zones, surface obstructions, edges, penetrations and areas where the method could not produce a reliable interpretation.
Use marks as interpreted findings
On-surface marks can help the cutting or drilling team relate findings to the approved set-out. Define colours, symbols, line centres, confidence or uncertainty notation and whether the mark represents an interpreted centreline, boundary or avoidance area. Protect the marks until the follow-on work and confirm how changes will be recorded.
A mark is not a service isolation or an engineering approval. Review uncertain zones and conflicts before cutting. If the project moves an opening after scanning, determine whether the new location requires another scan and approval.
Coordinate post-tensioned and structural concrete
Post-tensioned concrete can present significant structural and safety consequences if a tendon is damaged or released. The responsible engineer or authorised project party should define the alteration, scan requirements, exclusion or investigation process and any temporary support. The scanning operator should not authorise tendon cutting or infer the complete tendon profile from an isolated response.
For other reinforced elements, the engineer should determine whether reinforcement may be interrupted, retained, exposed, supplemented or avoided. A cutting contractor should not decide that a bar is non-structural from diameter, spacing or location alone.
Keep service locating and isolation connected
Service drawings, visible routes, scanning and other locating information should be combined with the applicable identification, isolation and verification process. Before You Dig Australia can obtain plans from affected registered asset owners for relevant outdoor or underground work, but its official FAQs should not be interpreted as a map of every privately owned or building-embedded service.
Workplace Health and Safety Queensland's underground electrical incident guidance also notes that BYDA excludes private property and describes the need for other service information and locating steps. For a building slab or wall, coordinate with the responsible electrical, hydraulic, fire, gas, communications and other service parties.
Define useful deliverables
Deliverables should match the decision and may include:
- on-surface markings referenced to the approved alteration;
- photographs with control dimensions and scan boundaries;
- an annotated plan, sketch or data image where agreed;
- the method, work face, coverage and target priorities;
- interpreted findings with uncertainty and limitations;
- inaccessible or unresolved areas and recommended next steps; and
- a handover discussion with the engineer or follow-on work team.
Do not request a generic "structural integrity certificate" from a scanning contractor. If the project requires an engineering report or approval, define the engineer's scope and the scan information they need.
Plan the follow-on cut or drill
Review the scan findings, limitations, drawings and service controls before intrusive work. Resolve conflicts with the approved set-out and identify the person who can release the hold point. Protect the far side and level below, plan core or cut-section handling, and coordinate support, lifting and reinstatement.
Cutting and drilling also process crystalline-silica-containing concrete. WHSQ publishes current core saw and drill guidance and the crystalline-silica-substance processing framework. Scanning does not replace those task controls, service isolations or the project's risk-management process.
Structural scanning quote checklist
- Site, level, work face, access, programme and contact.
- Proposed cut, core, anchor or alteration with dimensions and depth.
- Element type, drawings, post-tension information and alteration history.
- Engineer-defined targets, exclusions, questions and approving authority.
- Known services, isolations and other locating information.
- Coverage, reference grid, mark-out convention and photograph requirements.
- Required sketch, report, data, limitations and handover format.
- Follow-on method, far-side conditions, structure, support and hold points.
Structural scanning questions
Can a scan prove that a slab or foundation is sound?
No. Scanning may provide selected information within its method limits. Structural or foundation condition and adequacy require assessment by the responsible engineer using the evidence appropriate to the question.
Can scanning show every post-tension tendon?
No method should be presented as a guarantee. Detection and interpretation depend on target, depth, congestion, material, access, equipment and site conditions. Use the result within an engineer-led approval process.
Does a marked clear area authorise cutting?
No. The project must consider the scan limitations, structure, services, isolations, set-out, support, far side and site controls before authorising work.
Scan for the alteration, not a generic promise
Review Cutcore's Brisbane concrete-scanning service, the broader concrete-scanning planning guide and the core-drilling project guide. Request a project discussion with the alteration, drawings, work faces, target priorities, engineer's questions and required deliverables.
This article provides general project information only and is not structural, foundation, utility-locating, electrical, post-tensioning, work-health-and-safety or legal advice. Final investigation, interpretation, design, approvals, service controls and follow-on work must reflect the site and advice from the responsible competent and authorised parties.

