PEMB Structural Welding: WPS Requirements Under AWS D1.1
Pre-engineered metal building fabricators still must comply with AWS D1.1 for structural welds. Here's what your WPS package must include for PEMB primary and secondary framing.
Pre-engineered metal buildings (PEMBs) are often thought of as a simplified category of construction — faster to design, faster to erect, and cheaper than conventional structural steel. But from a welding quality standpoint, a PEMB fabrication shop is a structural steel fabricator, and the welds in a PEMB primary frame are structural welds. When the project specification or building code invokes AWS D1.1, there is no PEMB exemption.
CWIs and QC managers at PEMB shops routinely encounter contract requirements that reference D1.1 but are handed a WPS folder that was written ten years ago, signed by a CWI who no longer works there, or that covers only one process when three are actually used in production. This article walks through what AWS D1.1:2025 actually requires of a PEMB fabricator's WPS package.
Why AWS D1.1 Applies to PEMB Work
The International Building Code references AISC 360 for the design and quality of structural steel. AISC 360 in turn references AWS D1.1 as the governing standard for structural welding. When a PEMB primary frame — rafters, columns, endwall columns, moment connections — is fabricated from ASTM A572, A992, A36, or similar structural grades, those welds fall under D1.1.
Some general contractors or owners add explicit D1.1 language in Division 05 specifications. Others rely on the default AISC-referenced path. Either way, by the time an AISC-certified fabricator (or a fabricator seeking that certification) shows up for audit, the auditor will look for D1.1-compliant WPS documentation.
The MBMA Metal Building Systems Manual does not override AWS D1.1. It provides design guidance for the system, not a substitute welding quality program.
Primary Frame Connections: Where D1.1 Complexity Lives
PEMB primary frames are typically tapered welded plate girders. The rafter-to-column moment connection, the ridge connection, and any splice locations are where structural weld quality matters most. These are partial joint penetration or complete joint penetration groove welds, often made with FCAW-G or SMAW in a shop environment, sometimes in unusual positions due to the tapered geometry.
For each weld type in production, the fabricator must have a WPS that covers:
Process and filler metal. If you weld rafter flanges with FCAW-G using an E71T-1C/-9C electrode, that process and classification must appear on the WPS. A WPS written for E71T-1M won't cover E71T-1C unless the WPS specifically lists both. AWS D1.1:2025 Table 6.6 identifies filler metal classification as an essential variable — a change requires either a new WPS or requalification.
Base metal. ASTM A572 Grade 50, A992 wide flange (sometimes used for built-up PEMB columns), and A36 plate are all prequalified base metals under AWS D1.1 Table 5.6. Verify the specific ASTM designation and grade for your production material against the prequalified list before claiming a prequalified WPS.
Joint geometry and groove angle. Prequalified groove joint details are defined in AWS D1.1 Clause 5 Figures 5.1, 5.2, and 5.3. A taper-transitioned flange-to-web weld that uses a bevel groove at less than the minimum prequalified groove angle is not prequalified — it requires a tested WPS. This catches PEMB shops by surprise when rafter flange geometry is optimized for light weight at the cost of minimum code geometry.
Preheat. AWS D1.1 Table 5.11 specifies minimum preheat temperatures based on process, base metal, and weld heat input category. For FCAW-G on A572 Grade 50 material up to 3/4 inch, the minimum preheat is typically 50°F (10°C). Your WPS must specify the preheat temperature range, and your CWI must verify it before welding starts. Rule library based on AWS D1.1:2025; verify against your governing edition.
Position. Flat (1G/1F) and horizontal (2G/2F) positions are the most common in PEMB shop fabrication. If your WPS only qualifies the flat position and your shop welds rafter flanges in horizontal on the production fixture, you have a gap. Either the WPS must be written for the actual production position, or your welding fixture must place the joint in a position the WPS covers.
Prequalified WPS vs. Tested WPS for PEMB
Many PEMB structural welds qualify for a prequalified WPS under AWS D1.1 Clause 5 — provided all parameters (process, joint type, base metal, filler metal, position, preheat, and interpass temperature) remain within the prequalified limits. A prequalified WPS does not require a PQR. The fabricator writes the WPS, a responsible welding engineer or designated individual signs it, and production can proceed.
However, PEMB fabricators frequently push design efficiency beyond prequalified limits:
Thin web plates in tapered rafters may fall below the minimum thickness where FCAW-G is prequalified for CJP groove welds.
Non-standard groove angles in butt-welded flange splices may not match any prequalified joint detail in Clause 5.
High-deposition SAW on thick flange material may have heat inputs outside the prequalified range when CVN supplementary essential variables apply.
When production conditions exceed prequalified limits, a tested WPS with a supporting PQR is required. The PQR test coupon must be fabricated using the same joint geometry, material, process, and parameters as production. Mechanical testing confirms the joint meets minimum strength and ductility requirements.
For a PEMB shop, the most economical approach is usually to establish two or three tested WPS/PQR sets — one for groove welds in the flat and horizontal position using FCAW-G, one for fillet welds in flat/horizontal using FCAW-G, and one for SMAW for field repairs or small connection details. This small library covers the vast majority of PEMB production joints.
Welder Qualification and the PEMB WPS Connection
Every welder making structural welds in your PEMB shop must be qualified for the process and position recorded on the WPS. AWS D1.1 Clause 4 governs welder performance qualification. The Welder Performance Qualification test (WPQ) record must be on file and must remain current — AWS D1.1 Clause 6.4.1 requires that a welder demonstrate they have used the process within the preceding six-month period, or they must requalify.
For PEMB shops that run seasonal or project-based production, the six-month continuity rule can be a real compliance risk. A welder who was productive all summer but spent October and November on steel erection rather than shop welding may technically require requalification before returning to production groove welding. Maintaining a log of each welder's last production weld date by process is essential. For more on this, see AWS D1.1 Welder Continuity: The 6-Month Rule Explained.
Field Welds in PEMB Erection
PEMB erection involves field-welded moment connections, base plate fillet welds, and sometimes field-welded flange splices. These field welds require the same WPS coverage as shop welds. If the field welding process differs from the shop process (SMAW in the field, FCAW-G in the shop), a separate WPS covering SMAW must be in the package.
Field welding conditions — wind, temperature, moisture — are addressed by AWS D1.1 weather requirements. The WPS must specify minimum preheat for the applicable material and thickness range, and field welding must not proceed in wind exceeding the D1.1 limit unless shielding is provided for gas-shielded processes.
What the WPS Package Should Include
A D1.1-compliant WPS package for a PEMB fabricator typically includes:
One or more written WPS documents (signed and dated) covering all production joint types and positions
PQR test records if any WPS is a tested WPS (not required for prequalified WPS)
WPQ records for every production welder, showing current qualification status
Welder continuity log showing last production date by process for each welder
Preheat monitoring records for production welding
AISC certification auditors and owner representatives will ask to see all five. Missing or incomplete WPQ records are the most common gap in PEMB fabrication audits.
Start building a proper WPS library before the project specifications arrive — at wpswelding.com/pricing, the Solo plan gives you a cloud-based WPS generator, qualification matrix, and welder continuity tracker designed for exactly this kind of small-to-mid PEMB fabrication shop.
FAQ
Frequently asked.
Are pre-engineered metal buildings required to follow AWS D1.1?
Yes. When a PEMB contract, IBC, or owner specification invokes AWS D1.1, all structural welding must comply. Most commercial PEMB projects reference D1.1 through AISC 360 or directly in the project specifications.
Do PEMB fabricators need PQRs for tapered rafter and column connections?
If the WPS is prequalified under AWS D1.1 Clause 5 — process, joint geometry, base metal, and filler metal all meet prequalified requirements — no PQR is needed. If any parameter falls outside prequalified limits, a tested WPS backed by a PQR is required.
Do secondary members (purlins, girts, wall panels) need a WPS under AWS D1.1?
AWS D1.1 governs structural steel. Cold-formed secondary members (ASTM A1011 or A570 clip angles lighter than the D1.1 thickness threshold) may fall under AWS D1.3 instead. Confirm which code governs each member type in your project specifications.
Can one WPS cover both primary and secondary PEMB framing welds?
A single WPS can cover multiple joint configurations if all are within the WPS's qualified parameter ranges — process, position, base metal group, thickness range, and filler metal. Most PEMB shops maintain a small library of 3–5 WPS documents that cover the full production scope.