What is a weld non-conformance under AWS D1.1?

Any deviation from a qualified WPS parameter (wrong filler metal, preheat below the minimum, travel speed outside the qualified range) or a discontinuity that exceeds the acceptance criteria in AWS D1.1:2025 Clause 9 constitutes a non-conformance.

Can a non-conforming weld always be repaired?

Most can be repaired by grinding, back-gouging, and rewelding per the WPS—but the repair itself must also follow a WPS. Some defects, like cracks in fatigue-critical applications, require engineering disposition before any repair work begins.

Does AWS D1.1 require a written NCR for every welding deviation?

AWS D1.1 does not prescribe a specific NCR form, but AISC certification and most QMS frameworks do. A written record is the only defensible way to show the non-conformance was evaluated and dispositioned, not just quietly fixed.

Who can disposition a weld non-conformance—can the welder do it?

No. Disposition must be made by a CWI or an engineer of record. The welder who made the non-conforming weld cannot self-approve a repair. AISC and most owner specifications require documented CWI sign-off on the corrective action.

Weld Non-Conformance Reports: AWS D1.1 Corrective Action

How to document, evaluate, and close out weld non-conformances under AWS D1.1—NCR workflows, repair procedures, and what keeps your QMS defensible.

When Things Go Wrong on the Floor

Every structural fab shop eventually welds outside the WPS—a preheat temperature falls short on a cold morning, a welder grabs the wrong electrode diameter from the rod oven, a pass sequence is altered to work around a fit-up problem. How your shop responds to that deviation is what separates a controlled quality system from a liability waiting to happen.

Non-conformance management is one of the top AISC certification audit findings precisely because many shops treat deviations as production problems to solve quickly rather than quality records to document carefully. This article walks through the AWS D1.1:2025 framework for identifying, documenting, and closing out weld non-conformances—and what an auditable corrective action record looks like.

Two Types of Non-Conformances

Under AWS D1.1:2025, non-conformances in structural welding fall into two broad categories.

Process Non-Conformances (WPS Deviations)

A process non-conformance occurs when a welder or fitter executes a welding operation outside the qualified parameters in the governing WPS. Common examples include:

Preheat temperature below the WPS minimum (or below the Clause 7.6 mandatory minimums)
Interpass temperature exceeded above the WPS maximum
Travel speed outside the qualified range, affecting heat input
Filler metal classification or diameter not matching the WPS
Shielding gas composition or flow rate outside the WPS range
Joint fit-up dimensions (root opening, root face, groove angle) outside the WPS tolerances

These are procedural failures. The key question is whether the deviation was an essential variable change. If it was, the WPS may not cover the weld, and the welder may have been working without a qualified procedure—which is a more serious finding than a simple parameter drift.

Review WPS Essential Variables vs. Nonessential Under AWS D1.1 to understand which deviations require requalification versus which can be documented and accepted by the CWI.

Weld Discontinuity Non-Conformances

A discontinuity non-conformance occurs when a completed weld contains indications that exceed the acceptance criteria in AWS D1.1:2025 Clause 9 for visual inspection, or the applicable NDE sections for RT, UT, MT, or PT. Common examples include:

Cracks (always rejectable regardless of size)
Incomplete fusion exceeding permitted limits
Porosity counts or sizes exceeding Table 9.1 limits
Undercut depth exceeding the Clause 9.4.2 limits
Overlap or incomplete joint penetration in a CJP groove weld

These are product failures. The weld existed but does not meet the acceptance standard.

The NCR Workflow

Whether the non-conformance is process-based or product-based, the response sequence is the same.

1. Identify and Tag

The moment a non-conformance is discovered—whether by a CWI, QC inspector, third-party NDE technician, or the welder—the affected area must be identified and physically tagged. Mark the member with a paint pen or flag to prevent it from being moved to the next operation (fit-up, painting, shipping). Your QMS should define who has authority to place and remove the tag.

2. Document on an NCR Form

Open a Non-Conformance Report. The minimum content of a useful NCR is:

NCR number (sequential, traceable to job number and member mark)
Date discovered and inspector name/certification
Description of the non-conformance (what was found, where on the member, dimension or measurement)
Reference to the acceptance criteria that was violated (WPS parameter, AWS D1.1 Clause 9 criterion, NDE acceptance table)
Disposition options evaluated

3. Disposition

Disposition is the formal decision about what to do with the non-conforming weld. AWS D1.1 and most QMS frameworks recognize three disposition paths:

Use as is (UAI): The non-conformance is evaluated by a CWI or engineer of record and determined to be acceptable based on engineering judgment. This requires written rationale—not just a signature. UAI is appropriate for minor visual discrepancies well within the acceptance band, not for cracks or weld-size underages in load-path welds.

Repair: The non-conforming area is removed and rewelded per an approved WPS. Note that the repair WPS must be qualified for the repair conditions (position, access, base metal, filler metal)—you cannot simply wave your standard production WPS over a repair operation with different constraints.

Replace/reject: The member is scrapped or the entire weld is removed and the joint re-made from the beginning. Appropriate for cracks in demand-critical welds or situations where repair access is inadequate.

4. Corrective Action and Root Cause

This step is where most shops shortcut. Disposition tells you what you did with the bad weld. Corrective action tells you what you did to prevent the next one. An NCR that lacks root cause analysis and corrective action is a record of past failures, not a quality system improvement.

Root cause categories for weld non-conformances typically include:

Welder knowledge gap (wrong understanding of WPS requirements)
WPS clarity failure (WPS parameter not stated clearly, ambiguous range)
Supervision failure (production pressure overrode preheat check)
Equipment failure (preheat torch malfunction, rod oven temperature drift)
Material control failure (wrong electrode pulled from storage)

Each root cause calls for a different corrective action. A welder knowledge gap gets a documented training event. An equipment failure gets a preventive maintenance entry. A material control failure gets a receiving and issuance procedure update.

5. Verification and Close

The NCR is not closed until:

The repair or disposition is complete
Re-inspection of the repaired area confirms conformance
The CWI or QC manager signs the NCR close-out block
The member tag is removed and the member is cleared to proceed

The closed NCR becomes a permanent quality record, retained per your QMS (see WPS and PQR Record Retention).

Repair Welding Under AWS D1.1:2025

Clause 7.27 of AWS D1.1:2025 governs weld repair. Key requirements that often trip up fabricators:

Crack repair requires investigation first. AWS D1.1 requires that the cause of a crack be determined before repair begins. Grinding out and rewelding a crack without understanding why it formed is not a repair—it is masking a root cause that will recur.

Removal must be verified. After back-gouging to remove a defect, MT or PT is required to confirm complete removal before rewelding. For UT-detected subsurface defects, the removal plan must be engineered to reach the defect location.

Repair WPS must be pre-approved. A repair does not just happen. The CWI must approve the repair plan, including the access method (back-gouging vs. grinding), the WPS to be used, the preheat for the repair, and the NDE method to confirm completion.

Access limitations: If the repair requires welding overhead in a position not included in the production WPS, a separate procedure qualified for that position is needed, or a prequalified joint design must be used.

What AISC Auditors Look For in NCR Records

When an AISC certification auditor reviews your NCR log, they are checking four things:

Completeness: Every known non-conformance from the audit period has an NCR. Gaps in the log during active production periods raise questions.
Traceability: Each NCR references a specific member, job, and WPS. "Several beam welds on the 3rd floor" is not traceable.
Disposition authority: The NCR was dispositional by a CWI or engineer of record, not the welder or shop foreman alone.
Corrective action closure: Systemic findings—particularly recurring electrode storage failures or repeated preheat deviations—show documented corrective actions that were actually implemented and verified, not just described.

See AISC Fabricator Certification Audit WPS/PQR Common Failures for additional audit preparation guidance.

Building a Defensible NCR System

You do not need complex software. An NCR log that works for a 15-person fab shop can be a two-column spreadsheet with numbered entries and scanned paper forms. The critical requirement is that it exists, that it is used consistently, and that it is never back-filled or altered after the fact.

For shops running digital WPS management, linking NCRs directly to the affected WPS and job traveler—so that any future review of a job package automatically surfaces the NCR history—is the strongest audit position. WPS Welding includes an audit-packet export that ties weld logs, NDE results, and quality records together in one download, which is exactly the kind of traceability structure auditors want to see.

The underlying principle is simple: the standard allows that welds will sometimes fail to meet requirements. What the standard, AISC certification, and your customers require is that when failures happen, you know about them, you document them, you disposition them with qualified authority, and you do the work to prevent recurrence. That chain of evidence is what separates a professional welding program from a production shop hoping quality takes care of itself.