What the special inspector may verify
- Structural member identification, orientation and connection details
- Base plates, anchor rods, bearing and required erection tolerances
- Welder qualification records and the applicable Welding Procedure Specification
- Joint preparation, fit-up, backing, electrodes and interpass cleaning
- Weld size, length, profile and visible discontinuities
- Bolt, nut and washer identification and condition
- Faying surfaces, joint fit-up and the specified bolting installation method
- Required pretensioning and final bolting condition
Call before structural welding begins
Welder qualifications, the applicable Welding Procedure Specification, materials, joint preparation and fit-up may need to be verified before or during welding. Schedule ASI before work begins so required observations can be completed without delaying the connection or requiring additional evaluation.
Welding Procedure Specifications and welder qualifications
A Welding Procedure Specification describes how the weld is to be made. A welder qualification documents the individual’s demonstrated ability within a qualified range. They are different documents, and structural welding may require both to be available before welding begins.
Visual inspection and nondestructive testing are separate
Special inspection commonly includes visual observation before, during and after welding. Ultrasonic, magnetic-particle, dye-penetrant and radiographic testing are separate nondestructive-testing services provided only when required by the approved documents or building official.
Structural steel, welding and bolting questions
When should the welding special inspector be scheduled?
Schedule the special inspector before structural welding begins. Welder qualifications, the applicable Welding Procedure Specification, materials, joint preparation and fit-up may need to be verified before or during welding. Completed welds can conceal required in-process observations.
Does the special inspector have to watch every structural weld?
Not every welding task has the same inspection frequency. Required coverage depends on the approved Statement of Special Inspections, the applicable building-code provisions, the referenced steel and welding standards, the connection, and the jurisdiction. ASI reviews the scope before confirming the assignment.
What is the difference between a WPS and a welder qualification?
A Welding Procedure Specification describes how the weld is to be made, including the process, materials and required variables. A welder qualification documents that the individual demonstrated ability within a particular qualified range. Structural welding may require both documents before work begins.
Can completed structural welding be inspected afterward?
A special inspector may visually examine accessible completed welds, but cannot retroactively verify required fit-up, root-pass or other in-process conditions that were not observed. Ask the building inspector or design professional what additional evaluation, nondestructive testing or corrective work will be accepted.
Is nondestructive testing included with welding special inspection?
Visual special inspection and nondestructive testing are different services. Ultrasonic, magnetic-particle, dye-penetrant or radiographic testing is provided when required by the approved project documents or building official and must be separately coordinated.
What does the special inspector check on high-strength bolts?
Depending on the approved documents, the special inspector may verify the fastener assemblies, connected parts, faying surfaces, joint fit-up, installation method, pretensioning procedure and final condition. The required observations depend on the specified joint and bolting method.
Common field problems
- Unapproved field-modified connections
- Missing or incomplete Welding Procedure Specifications or welder qualifications
- Poor fit-up, incorrect weld size or incomplete welds
- Cracks, undercut, porosity, overlap or unacceptable weld profiles
- Incorrect fastener assemblies, installation method or pretensioning
- Welding or bolting completed before required observations