When a structural drawing's weld symbol specifies something your WPS doesn't cover, here's the resolution path—who calls it, what changes, and how to document the decision.
Structural drawings and welding procedure specifications are written independently, usually by different people working from the same project specs. Most of the time they align without issue. But in a busy shop with complex connection details, a CWI or QC manager will eventually face a stack of drawings where the weld symbol shows something the qualified WPS does not cleanly cover.
This article covers the most common conflict types, the resolution path under AWS D1.1, and the documentation required to keep the project file clean.
Why Conflicts Happen
Structural engineers detail welds based on load demand and connection geometry. They specify weld type (CJP, PJP, fillet), size, length, and position on the joint. They generally do not consult the fabricator's WPS library when doing so—and they should not have to. The WPS is the fabricator's responsibility, and the engineer's job is to design a structurally adequate connection.
The fabricator's QC manager and CWI are the first line of defense for catching gaps between what the drawing requires and what the existing WPS library covers. This should happen during the pre-production WPS review, not during first-piece inspection.
Common sources of conflict:
- Weld size out of WPS qualified range (too large or too small for the thickness and process documented)
- Weld type mismatch (drawing shows CJP, existing WPS covers only PJP for that joint geometry)
- Position not qualified (drawing shows an overhead fillet, WPS covers only flat and horizontal)
- Base metal not covered (drawing specifies a steel grade not listed in the WPS's qualified base metal range)
- Joint geometry not matching (groove angle, root opening, or root face outside the WPS prequalified or qualified range)
- Electrode classification not matching (drawing note or project spec requires a specific filler; WPS lists a different one)
The Document Hierarchy Under AWS D1.1
AWS D1.1 establishes a clear priority: welds are made in accordance with an applicable WPS. The drawing shows the desired result; the WPS governs the execution. A drawing note cannot override the WPS's qualified parameters—it can only tell you what the final weld needs to look like and how large it needs to be.
When a drawing symbol is in conflict with the WPS, the resolution is not for the welder or CWI to pick one and proceed. The fabricator's QC manager needs to identify the conflict, determine whether it represents a drawing deficiency or a WPS gap, and obtain written resolution before welding.
If the drawing is wrong or ambiguous: Issue a Request for Information (RFI) to the engineer of record (EOR). The EOR's written response—clarifying or revising the weld symbol—becomes part of the project record. The WPS may already cover the revised or clarified requirement.
If the WPS doesn't cover the drawing requirement: Revise or supplement the WPS to cover it. This may mean:
- Writing a new WPS that covers the specific joint configuration
- Extending an existing WPS via a new PQR coupon
- Invoking a prequalified WPS per AWS D1.1 Clause 5 if all Clause 5 conditions are met
If the drawing requirement cannot be met with the available welding processes or base metals: The EOR needs to redesign the connection or accept a formal engineering change. This is rare but happens when a drawing specifies a weld size that exceeds the structural capacity of the available process.
Common Conflict Scenarios and Resolution Paths
Fillet Weld Size Outside WPS Range
A fillet weld WPS qualified for 3/16 through 5/16 inch fillets may not cover a 1/2 inch fillet the drawing requires, even if both are fillet welds. Larger fillets may require multiple passes, different wire diameter, or higher heat input that exceeds the WPS qualified range.
Resolution: If the connection legitimately requires the larger fillet for structural reasons, extend the WPS to cover it with appropriate test documentation. If the drawing shows an oversized fillet that provides unnecessary strength, an RFI may reveal the EOR will accept a smaller conforming size.
Do not simply deposit more metal using the same WPS settings without updating the procedure. Overwelding is a separate issue—AWS D1.1 addresses it because excess weld metal increases distortion and residual stress without adding structural capacity—but the more immediate problem is using an unqualified procedure.
CJP vs PJP Joint Type Conflict
If a drawing calls for a complete joint penetration (CJP) groove weld and the shop's WPS covers only a partial joint penetration (PJP) for that joint configuration, there is a code-level gap. CJP and PJP groove welds have different acceptance criteria, different effective throat requirements, and different qualification paths. A PJP executed where a CJP is required is a code nonconformance regardless of how well the weld looks.
Resolution: The fabricator needs either a CJP-qualified WPS for the joint or an RFI response from the EOR confirming that the joint can be redesigned as a PJP (which changes the structural capacity calculation). CJP groove welds in many connection types are non-negotiable from an engineering standpoint.
Position Not Qualified
A common site issue: drawings show field welds in multiple positions—horizontal, vertical, overhead—but the shop's WPS was developed on a positioner and covers only flat and horizontal. The field welding subcontractor may not have qualification for the overhead position.
Under AWS D1.1, welding in a position outside the WPS qualified range requires a qualified procedure covering that position. The fix is straightforward in theory—run a PQR coupon in the needed positions—but it takes lead time the schedule often does not have.
Resolution: Identify position qualification gaps during pre-construction WPS review, before subcontracting the field work. Confirm all subcontractors have WPS coverage and welder WPQs for every position required on the drawings.
Base Metal Not in Qualified Range
An existing SMAW WPS qualified on ASTM A36 may not cover A529 Grade 50 or A572 Grade 50 if the WPS pre-dates the shop's current steel procurement or if the base metal qualification range was written narrowly. Under AWS D1.1 Table 5.6, prequalified base metals are grouped (Group I and Group II are the most common for structural carbon steels). Within the same group, a prequalified WPS covers the group without individual steel qualification, but a WPS qualified by test may have a more restrictive base metal range per the PQR.
Resolution: Check the WPS base metal range against the actual mill cert steel grade for every job. If the steel is in a different group or beyond the qualified range, either use a prequalified WPS covering both groups or run a new PQR with the actual steel.
Filler Metal Classification Mismatch
Project specifications sometimes require specific filler metal classifications—a seismic supplement may require notch-toughness-tested electrodes, or the owner spec may require a specific AWS A5.x designation. If the shop's WPS lists a different filler, the shop cannot simply substitute without addressing the conflict.
Resolution: If the required filler is an essential variable change, a new PQR is needed. If the project spec requirement can be satisfied by the equivalent filler already on the WPS (same classification, different brand), confirm that equivalence in writing and retain the electrode cert of conformance. The CWI should verify filler metal classifications against the WPS at every job setup.
What the CWI Documents
When a drawing-to-WPS conflict is identified and resolved, the project file should contain:
- The original discrepancy description — which drawing detail, what connection, what the conflict was
- The resolution source — RFI response, drawing revision, WPS revision, or EOR written approval
- The revised WPS or WPS supplement — if the procedure was updated to cover the requirement
- The CWI sign-off — confirming the resolution was implemented before welding and that production welds conform to both the revised drawing and the WPS
This documentation trail protects the fabricator in case of a third-party audit, an AISC certification inspection, or a later dispute about the connection design. Without it, there is no evidence that the conflict was identified and resolved by the right parties—only a weld that may or may not match the original drawing.
Pre-Production WPS Review as the First Defense
The best time to find drawing-to-WPS conflicts is during the initial job setup review, before the first arc is struck. A structured WPS review against the full drawing set typically takes a few hours for a standard project and can prevent days of rework and documentation recovery.
A pre-production review checklist should verify for every distinct weld type on the drawings:
- WPS covers the joint type (CJP, PJP, fillet, plug/slot)
- WPS covers the base metal grade(s)
- WPS covers the fillet size range or groove geometry
- WPS covers the required welding position(s)
- WPS filler metal classification matches project spec requirements
- Preheat requirements are documented per AWS D1.1:2025 Table 5.11 and are achievable with available equipment
For a discussion of WPS submittal packages and engineer-of-record review expectations, see WPS submittal packages for EOR review. For the breakdown of who is responsible for WPS development when multiple parties are involved, see WPS responsibility: fabricator, contractor, and EOR.
Managing a WPS library that stays in sync with your drawing submittals is easier when procedure coverage, base metal groups, and position qualifications are searchable in one place. See wpswelding.com/pricing to explore how structured WPS management works in practice.
Rule library based on AWS D1.1:2025; verify against your governing edition.