When a spec says welding shall conform to AWS D1.1, it is naming the rulebook for every load-bearing weld on the job. For a GC or estimator, you do not need to weld to buy welding well. You need to know what the code requires and what evidence proves a subcontractor is following it. Here is the plain-language version.
What AWS D1.1 covers
AWS D1.1, the Structural Welding Code for steel, is published by the American Welding Society and referenced across commercial construction. It sets the rules for welded structural steel connections: how joints are designed, how welding procedures are qualified, how welders are tested, what workmanship is acceptable, and how welds are inspected. When your structural steel is welded rather than only bolted, D1.1 is almost certainly the standard your engineer is invoking.
The code exists because a structural weld is a load path. A beam-to-column moment connection, a built-up girder, a stair stringer that carries occupants: each depends on welds that must perform under load, sometimes for the life of the building. D1.1 turns “trust us” into a verifiable chain of documents and inspections.
The documents that prove compliance: WPS and PQR
Two records sit at the center of D1.1, and you can ask for both.
| Document | What it is | The plain-language version |
|---|---|---|
| WPS | Welding Procedure Specification | The recipe: process, filler metal, joint type, position, and parameters |
| PQR | Procedure Qualification Record | The proof: test results showing the recipe makes a sound weld |
| Welder qualification | Test record per welder | Evidence each welder can run the WPS to code |
The logic is a chain. A PQR proves a welding procedure produces a sound weld. The qualified WPS then governs production. Individual welders are tested against that WPS and carry their own qualification records. Ask a steel subcontractor for current WPS documents and welder qualifications, and you are asking the right question.
Inspection: the role of the CWI
Qualified procedures and qualified welders still need a check. That is the Certified Welding Inspector (CWI). A CWI verifies that welding in the shop and the field follows the qualified procedures and meets D1.1 acceptance criteria. That includes visual inspection and confirming nondestructive testing, such as ultrasonic testing on complete joint penetration welds, where the code or the engineer requires it. The CWI is the independent set of eyes that signs off before a weld is painted, fireproofed, or covered by the next trade.
How D1.1 fits with AISC Certification
AWS D1.1 and AISC Certification are complementary, not competing. D1.1 is the welding code: the technical rules for the welds themselves. AISC Certification audits the broader quality management system that keeps a shop or erector applying those rules consistently. Put simply: D1.1 governs the weld, AISC Certification governs the system that produces it. A strong steel subcontractor operates under both.
What to ask a steel subcontractor
- Are your welders qualified to AWS D1.1 for the processes and positions on this job?
- Can you provide current WPS documents backed by PQRs?
- Who performs CWI inspection, and how is nondestructive testing handled?
- Do the same welding standards apply in the field as in the shop?
That last question matters most when fabrication and erection are split between two companies. Two firms can mean two welding programs to reconcile. A single-source subcontractor applies one welding quality chain from the shop through field welding, including mobile field welding on erection and repairs.
TMG | Tri-State Metal Group staffs AWS D1.1 qualified welders and runs one welding quality program across fabrication and erection, backed by AISC Certified Fabricator and Certified Steel Erector status. When your spec references D1.1, ask us for the documentation and hold every bidder to the same standard.