When a weld gets rejected on a structural steel project, two different parties may be involved in the dispute: the fabricator's own quality control inspector and the owner's verification inspector. AWS D1.1:2025 assigns these roles specific responsibilities, and understanding where each role begins and ends prevents both missed rejections and inspection authority conflicts.
The Two-Layer Inspection Model
AWS D1.1:2025 Clause 7.1 establishes a two-layer inspection model. The first layer is the contractor's quality control (QC) inspection — the fabricator or erector is responsible for ensuring their work conforms to the approved WPS and the requirements of the code before presenting it for acceptance. The second layer is verification inspection — the owner, engineer of record, or a designated third party independently confirms that the work actually meets the contract requirements.
These layers are not redundant bureaucracy. They serve different purposes and report to different principals. The contractor's QC inspection catches problems during production, when correction is cheapest. The verification inspector confirms the final product is acceptable — they are not there to supervise the fabricator's work in real time.
AWS D1.1:2025 Clause 7.1.1 states: "The Contractor shall be responsible for the quality of welding performed and shall provide the necessary inspection to assure conformance with this code." The code is unambiguous — quality is the contractor's responsibility first.
The Contractor's Quality Control Inspection
The contractor's QC function must be staffed by qualified personnel. AWS D1.1:2025 Clause 7.3 requires that the inspector responsible for QC be a qualified welding inspector. In practice, this means a Certified Welding Inspector (CWI) per AWS QC1, or someone with equivalent qualification as accepted by the Engineer of Record.
The contractor's QC inspector is responsible for:
Before welding: Verifying that the WPS is approved and posted or available at the work station. Confirming that welders are qualified for the positions and processes required by the joint. Verifying preheat conditions are met before arc ignition. Checking fit-up — root opening, root face, bevel angle, joint alignment — against WPS and drawing tolerances.
During welding: Monitoring interpass temperature between passes. Confirming the welder is using the electrode classification, diameter, and storage conditions called out on the WPS. Verifying travel speed, arc energy, and deposition sequence are within WPS parameters.
After welding: Visual inspection of completed welds against the acceptance criteria in AWS D1.1:2025 Clause 7.24 (visual inspection). Documenting any rejections and tracking corrective action (repair or removal and replacement). Signing off inspection records before the weld is offered for verification.
The contractor's QC inspector is the first line of defense. If they are doing their job, most nonconformances should be caught and corrected before the verification inspector arrives. See production welding parameter log requirements for what ongoing documentation a contractor QC program should capture.
The Verification Inspector's Role
The verification inspector — often called the QA inspector or, under IBC, the Special Inspector — works for or reports to the owner, engineer of record, or their designated agent. Their job is independent confirmation, not supervision. AWS D1.1:2025 Clause 7.2 describes the responsibilities of the owner's inspection agency.
Key distinctions:
Independence. The verification inspector cannot be employed by or report to the contractor. Their acceptance or rejection of work is independent of the contractor's QC finding. A weld the contractor's CWI cleared can still be rejected by the verification inspector if it does not meet code. Conversely, the verification inspector is not there to help the contractor identify problems before they occur — that is the QC function.
Scope. The verification inspector typically performs work at designated hold points (mandatory stops) or witness points (optional observation) defined in the quality plan or Inspection and Test Plan (ITP). They do not shadow every welder throughout the day. Their presence is controlled and documented. See weld inspection hold points and CWI intervention for how hold vs. witness points are typically structured.
Authority. The verification inspector has authority to reject nonconforming work. Once they reject a weld, the contractor must correct it and present it for re-inspection. The verification inspector does not direct the contractor on how to correct the problem — that is the contractor's engineering and WPS responsibility.
Records review. A significant portion of verification inspection is records review, not hands-on measurement. The verification inspector reviews the contractor's QC records — WPS records, WPQ records, preheat logs, NDE reports — to confirm the work was performed as documented. If records are incomplete or absent, the verification inspector may reject the work even if the weld looks visually acceptable, because the required documentation is part of the deliverable.
Rule library based on AWS D1.1:2025; verify against your governing edition.