Inspection process
Non-destructive testing (NDT)
Non-destructive testing is any method that confirms the integrity of a material or an assembly without harming it. Examples include ultrasonic and radiographic checks of welds, magnetic-particle and dye-penetrant tests for surface cracks, and ground-penetrating scans to locate rebar. The point is to see inside or beneath the work and leave it fit for service, rather than sawing out a sample. On buildings it is used most where a hidden flaw carries real consequence: structural welds, embedded post-tensioning, critical coatings.
Run it with the Photo Gate
Structural steel inspection checklist
12 items · 27 photos required
Why it matters
Some of the most important work is impossible to judge by eye. A structural weld can look perfect on the surface and hide a crack or lack of fusion inside; NDT is how that gets caught before the connection is loaded and covered. Because it does not damage the work, it can be run on the actual installed connection rather than on a stand-in.
It usually falls to a qualified testing agency or special inspector, and the field role is to coordinate the test at the right moment, observe it and get the report into the record, not to certify the result. Timing matters: many of these tests have to happen before fireproofing or finishes cover the connection.
How it shows up on site
A testing agency shooting or scanning welds at steel connections, penetrant testing on a critical weld, or a scan to confirm rebar location before coring. Results come back as a test report tied to the specific joint, and any rejection becomes a nonconformance with a repair-and-retest loop.
Standards it's verified against
Checklists that put non-destructive testing (ndt) to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- Special inspectorA qualified inspector who verifies specific high-risk work (welds, bolting, concrete, anchors) beyond the routine building inspection.
- Test reportThe documented result of a test run on installed work or material, recording what was tested, how, and whether it met the criteria.
- Third-party inspectionInspection performed by an independent agency retained for the project rather than by the installer or the building department.
- NonconformanceInstalled work that does not meet the drawings, spec or accepted submittal, formally identified so it gets dispositioned, not ignored.
- Visual inspectionJudging work by direct observation against the drawings and standard: the first and most common check on any job.
- Receiving inspectionThe check of materials and equipment when they arrive on site, confirming what showed up matches what was approved before it gets installed.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.
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