Does a repair weld need its own WPS under AWS D1.1?

Yes, unless the original production WPS covers the repair joint configuration, position, base metal condition, and process. Most fab shops write a dedicated repair WPS to cover the variations that arise when removing and replacing defective weld metal.

What NDE is required after a weld repair under AWS D1.1?

The repaired area must receive the same level of NDE required by the contract for the original weld. If the original weld required UT, the repair weld requires UT. Additional passes are common for high-cycle or CVN-toughness-required joints.

Can a repair be made without a CWI present?

AWS D1.1 requires that repair work is performed under the supervision of a qualified CWI or the Engineer's designee. The repair record must document who authorized and witnessed the repair.

Is a pre-qualified WPS valid for weld repairs?

Generally yes, if the repair meets all the prequalified joint geometry and process constraints. However, the excavation geometry and interrupted interpass conditions common in repairs can push the joint outside prequalified limits, requiring a tested procedure.

Weld Repair Classification and WPS Documentation Under AWS D1.1

AWS D1.1 categorizes repairs into distinct types—each with its own WPS and documentation requirements. Here's how CWIs and QC managers set up a compliant repair program.

When a weld fails NDE—or a CWI flags a dimensional non-conformance during visual inspection—what happens next is more regulated than most shops realize. AWS D1.1 doesn't treat repairs as informal re-do work. There are procedure requirements, documentation obligations, and traceability rules that, if ignored, can cascade a single repair into a systemic audit failure.

Understanding how AWS D1.1 categorizes and controls repair work keeps the QC program sound and gives the Engineer or Owner confidence that the fix is at least as qualified as the original weld.

The Fundamental Rule: Repairs Are Welds

The starting point in AWS D1.1 is that a repair weld is subject to all the same requirements as the original production weld. That means:

A qualified WPS covering the repair process, position, base metal condition, and joint geometry
Welders performing the repair must be qualified for the applicable process and position
Preheat requirements from the original WPS or the governing code apply, often with increased minimum preheat for repairs
NDE after repair must equal or exceed the NDE required for the original weld

There is no "repair exception" that loosens these requirements. In fact, the repair environment—thermal cycling, interrupted weld metal, possibly cold base metal—often demands tighter controls.

Types of Weld Repairs Under AWS D1.1

AWS D1.1 does not use a formal "type A/type B" taxonomy, but in practice QC managers classify repairs by what is being replaced:

Incomplete fusion or inadequate joint penetration repairs involve removing the defective zone by grinding or air-carbon arc gouging back to sound metal, then rewelding. The geometry of the excavation can vary widely. If the excavation becomes a groove weld configuration, the repair WPS must cover that groove.

Porosity and slag inclusion repairs are similar: remove by grinding, verify by PT or MT that the defect boundary is fully excavated, then reweld. The interpass temperature rules on the repair WPS must account for the already-welded parent joint—steel surrounding the repair cavity will hold heat differently than a fresh joint.

Dimensional repairs address welds that are undersized, have insufficient throat or leg dimension, or have failed surface acceptance criteria. These are typically weld metal additions and are often the most straightforward to qualify—the joint configuration is known, the position is fixed, and the original production WPS may cover it directly.

Crack repairs are the most serious classification and carry the most documentation weight. Before a crack repair begins, AWS D1.1 requires identifying the root cause of the cracking. If the cause is not addressed, the repair will re-crack. Required steps typically include:

Mark the crack boundaries (PT or MT to find the full extent, including subsurface)
Drill stop holes at each end before excavating
Excavate at least 2 in. [50 mm] beyond each confirmed end
Inspect the excavation by PT or MT to confirm removal
Preheat to at least the minimum specified, and usually higher
Complete the repair under a qualified WPS, with CWI observation
Apply PWHT if required by the governing spec or Engineer
NDE the full repaired area

A crack repair without documented root-cause analysis is a red flag to any auditor.

WPS Requirements for Repairs

The decision of whether to use the existing production WPS or write a dedicated repair WPS comes down to whether the production WPS covers the actual repair conditions.

Production WPS coverage is typically adequate when:

The excavation geometry matches a joint type covered by the WPS
The position matches one of the qualified positions
The preheat requirement accounts for the existing-weld thermal mass
The interpass temperature is achievable given the surrounding joint

A dedicated repair WPS is typically required when:

The excavation is open-groove geometry with irregular side walls (not easily mapped to a standard prequalified joint)
The repair position differs from what the production WPS qualified (a weld originally done in flat may need overhead repair in an assembled structure)
The base metal in the repair zone has been heat-affected by multiple weld passes and may have altered metallurgical properties
The contract or Owner specifies a separate repair qualification

For shops doing structural steel work under AISC certification requirements, the quality management system (QMS) typically mandates a separate repair WPS as part of documented repair procedures. See AISC certification audit readiness for WPS and PQR documentation for what auditors look for in the repair procedure package.

Documenting the Repair: What Goes in the Record

Every repair must generate a traceable record that connects the original non-conformance to the disposition and the completed repair. AWS D1.1 doesn't specify a single form, but the record should include at minimum:

Non-conformance identification: the weld ID, location (piece mark, joint number), the defect type, and the NDE method and result that identified it
Repair authorization: the CWI or Engineer authorization, and if applicable, the Owner's representative concurrence for cracks or re-repairs
Repair procedure: the WPS number used, the welder's ID and WPQ reference, the preheat used at repair start, and interpass temperatures measured during repair
Post-repair NDE: the NDE method, report number, acceptance/rejection, and the inspector's signature and certification level
Disposition: final acceptance status and who signed off

This record must be retained as part of the welding documentation package for the life of the structure, alongside the original WPS, PQR, and welder WPQs. Record retention requirements for WPS, PQR, and NDE documentation covers the applicable retention standards.

Re-Repairs and the Escalation Rule

If a repair fails its post-repair NDE, it is a re-repair—and the threshold for Engineer or Owner involvement escalates. AWS D1.1 does not limit the number of repairs a given location can receive, but it is widely understood in the QC community that a second repair failure requires Engineer review of the procedure, the welder qualification, and potentially the base metal.

On Owner-supplied QA programs (common on federal and institutional projects), a second repair failure in the same location typically triggers a hold notice and can stop production work on adjacent joints pending root cause analysis.

From a practical standpoint: if a repair is failing NDE a second time, the problem is either in the joint preparation (defect not fully removed), the process (wrong WPS for the repair geometry), or the welder (qualification insufficient for the position and joint type). Each must be investigated and documented before the third attempt.

Preheat Specifics for Repair Welds

Preheat for repair welds is a common point of confusion. The general rule under AWS D1.1 is that the minimum preheat from the applicable WPS applies. However, several conditions argue for raising preheat above the production minimum:

Thermal mass effect: the surrounding parent joint and heat-affected zone heat up more slowly than the exposed air in an excavation. The preheat temperature must be measured at a point remote enough from the torch that it reflects the true base metal temperature, not just the surface reading.
Multiple thermal cycles: steel that has been heated and cooled repeatedly during the original weld and the excavation process may have reduced toughness in the heat-affected zone. Higher preheat slows the cooling rate and limits further HAZ hardening.
Hydrogen risk: repairs often use different filler metals or electrode lots than the original weld. Verify the hydrogen designation of the filler in the repair WPS; low-hydrogen discipline (electrode storage, oven hold times, maximum atmospheric exposure time) must be maintained.

The carbon equivalent (CE) of the base metal—calculated from the mill CMTR—is the baseline for preheat requirements. See carbon equivalent and preheat requirements under AWS D1.1 for the calculation method and table lookup.

Setting Up a Compliant Repair Program

A shop that handles repairs reactively—writing a quick procedure when a rejection comes in—will eventually be caught short by an auditor or a re-repair that escalates. A proactive repair program, documented in the shop's QMS, covers:

A pre-approved repair WPS covering the most common repair geometries (groove repairs by gouging, dimensional additions, stop-hole crack repairs)
A designated CWI responsible for authorizing and witnessing repairs
A non-conformance report (NCR) form that auto-populates the repair record fields
A welder assignment process that confirms the repairing welder holds a current WPQ for the repair position and process
An NDE scheduling process that ensures post-repair inspection happens before the joint is covered by subsequent work

For shops managing multiple concurrent repair loops across a large project, a digital QC platform—where repair records are linked to the original weld ID and the NDE report chain is kept in one place—reduces the risk of documentation gaps. Learn more about WPS and qualification documentation management at WPS Welding.

Rule library based on AWS D1.1:2025; verify against your governing edition (the AHJ or contract may specify 2020 or earlier).

For further reading, see common WPS deficiencies found in third-party audits and AWS D1.1 repair weld procedures and requalification requirements.