Direct Answer
Structural steel shops must have AWS D1.1-certified welders for all structural welding. Shops performing special inspection work (seismic, bridge, or pressure vessel) may also need AWS Certified Welding Inspector (CWI) on staff or available for inspection. Certifications must be current, project-specific procedure qualifications (WPS/PQR) must be on file, and personnel qualifications (WPQ) must match the process and position being welded.
Full Explanation
AWS D1.1 (Structural Welding Code — Steel) governs all structural steel welding. Each welder must have a current Welder Performance Qualification (WPQ) for the process (SMAW, FCAW, GMAW, SAW) and position (flat, horizontal, vertical, overhead) they will use on the project. The shop must also have written Welding Procedure Specifications (WPS) and supporting Procedure Qualification Records (PQR) that define the welding parameters. These documents must be available to the special inspector on request.
What This Means for Your Shop
An expired welder cert or a missing WPS discovered during special inspection causes a work stoppage. Maintain a certification tracker and set renewal reminders 60 days before expiration.
Common Mistakes
Using a welder who is qualified in position 1F (flat fillet) to weld in position 4F (overhead fillet) without a qualification record for overhead. Each position requires separate testing and documentation.
Recommended Process
Maintain a welder certification matrix showing each welder's name, processes, positions, test dates, and expiration dates. Audit the matrix quarterly. Ensure your WPS/PQR library covers all processes and base metal combinations you will use.