Frame · AWS D1.1 / CSA W59
Field welding
Certified welders, WPS or WPDS on site, thin primer may stay, hot-dip galvanizing comes off. Touch up after. Visual inspection is not optional.
Governing codes
| United States | Canada |
|---|---|
| AWS D1.1 — Structural Welding Code (Steel) | CSA W59 — Welded Steel Construction |
| AWS D1.3 — Sheet Steel | AWS D1.3 — Sheet Steel |
- Field welds are done by certified welders qualified for the joint type and position.
- In the USA the contractor prepares Welding Procedure Specifications (WPS). In Canada, Welding Procedure Data Sheets (WPDS).
- WPS/WPDS and welder qualification certificates stay on site.
- If the joint is not prequalified, a Procedure Qualification Record (PQR) with testing is required.
- When the drawings specify field welding, qualification, inspection, or NDT, those costs are not the manufacturer’s.
Welding through coatings
AWS D1.1 requires welded surfaces free of loose or thick scale, slag, rust, moisture, grease, and other foreign material that would prevent proper welding. Mill scale that can withstand vigorous wire brushing may remain. A thin rust-inhibitive coating, or anti-spatter, may remain.
- Standard primer and pre-galvanized surfaces are permitted. Primer is a nominal 0.7–1.0 mil coating. Galvanized surfaces up to G90 (~0.002″) are considered to comply with the thin-coating exception.
- Post-fabricated hot-dip galvanized members with thicker coating (greater than ~0.002″) must have the coating ground off before welding. Hot-dip coating left in place can put liquid metal into the weld and crack it.
- Intermittent field welding of galvanized or primer-coated members in the open air is not a health-risk issue by itself. Use ventilation in enclosed spaces.
- Welding destroys the coating in the weld area. Touch up after the metal has cooled.
Inspection tasks
QC is the erector’s certified inspector (AWS CWI / CWB, or AWS B5.1). QA is a third-party when required — pre-approved by the AHJ. Observe (O) is random and does not stop the work. Perform (P) is every welded joint.
Before welding
| Task | QC | QA |
|---|---|---|
| WPS / WPDS available | P | P |
| Manufacturer certifications for consumables | P | P |
| Material identification (type/grade) | O | O |
| Welder identification system | O | O |
| Groove and fillet fit-up (geometry, cleanliness, tacks, backing) | O | O |
| Access-hole configuration | O | O |
| Welding equipment | O | — |
During welding
| Task | QC | QA |
|---|---|---|
| Qualified welders | O | O |
| Consumable packaging and exposure control | O | O |
| No welding over cracked tacks | O | O |
| Wind, precipitation, temperature within limits | O | O |
| WPS followed (settings, travel, filler, gas, preheat) | O | O |
| Each pass cleaned, in profile, meets quality | O | O |
After welding
| Task | QC | QA |
|---|---|---|
| Welds cleaned | O | O |
| Size, length, location | P | P |
| Visual acceptance (cracks, fusion, profile, size, undercut, porosity) | P | P |
| Arc strikes | P | P |
| K-area: inspect web K-area within 3″ of the weld on hot-rolled shapes | P | P |
| Backing removed and weld tabs removed if required | P | P |
| Repair activities | P | P |
| Document accept or reject | P | P |
NDT of field welds other than visual, when required, is by the QA agency, using personnel qualified for the method specified.
After-weld visual
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