The short answer
Visual inspection finds visible damage. Non-destructive evaluation checks condition without loading the anchor to capacity. Proof load testing applies a controlled load to confirm the anchor holds. OSHA leaves the choice to the qualified person, as long as the criteria are scientifically valid.
Visual inspection
- What it checks: corrosion, cracks, deformation, loose or missing fasteners, and the roof membrane and flashing around the anchor
- Strength: fast, and finds most obvious problems
- Limit: it cannot confirm capacity on its own
Non-destructive evaluation
- What it checks: condition without loading the anchor to its limit, for example fastener checks, measuring material loss from corrosion, or examining welds
- Strength: finds hidden deterioration without stressing the anchor
- Limit: the right method depends on the anchor and how it is installed
Proof load testing
- What it checks: the anchor holds a controlled test load, applied with calibrated equipment
- Strength: direct evidence of performance under load
- Limit: tests the anchor at that moment, so it complements inspection rather than replacing it
In a 2019 interpretation, OSHA gave an example it considers acceptable: an anchorage with a 5,000-pound ultimate capacity and a four-to-one safety factor, tested at 2,500 pounds. Testing to the full 5,000 pounds is also acceptable where a consensus standard requires it or the qualified person decides it is necessary.
Methods compared
| Method | Shows | Does not show |
|---|---|---|
| Visual inspection | Visible damage, corrosion, loose parts | Capacity |
| Non-destructive evaluation | Hidden deterioration, fastener and weld condition | Performance under load |
| Proof load test | The anchor holds a set test load | Future deterioration |
Who chooses the method
The qualified person. OSHA accepts any scientifically valid testing criteria, which generally means criteria accepted by an industry consensus group or certified by a registered professional engineer. Ask your inspector which method they used and why, and make sure the report says so. See what an inspection report should contain.
Through its long-time anchor partner, S&K installs engineered anchor points and inspects, load tests and certifies existing systems, with records you can hand to ownership, insurers or auditors. See anchor installation and inspection.
Not sure where your building stands? Start with a free roof compliance survey, or read the full Roof Anchor and Fall Protection Compliance guide.
