A Subcontractor's Welding Is Offered Under the Main Certificate
A certified fabricator has subcontracted 40 percent of a structural steel package to a small workshop with no certification of its own. The subcontractor will weld moment connections using the main contractor's WPS and, in the main contractor's view, 'under our certificate'. The subcontractor's welders hold qualifications issued by a different body. The main contractor's welding coordinator has visited once and seen no calibration records for the welding machines, no storage control for electrodes, and no supervision on the afternoon shift. Delivery is in five weeks. The client has not been told about the subcontract.
1. Can the main contractor's certificate properly cover welding performed by an uncertified subcontractor? Explain what certification actually attaches to.
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Certification attaches to the organisation and to its demonstrated control of the activity, not to a piece of paper that can be lent out. A certificate held by the main contractor does not transfer to another legal entity's workshop merely because the work is done to the main contractor's WPS.
If the main contractor certifies the finished work, it must be able to show that it controlled the welding that produced it: qualified procedures, qualified welders, calibrated equipment, controlled consumables, supervision, and records. On the facts, the coordinator has seen failures in three of those controls in a single visit. Certifying on that basis would be certifying activity the main contractor does not control.
The proper courses are: bring the subcontractor's welding under genuine main-contractor control (its procedures, its welder qualification route, its supervision, its records, its equipment checks), or disclose the arrangement to the client and the certifying body and obtain whatever agreement is required. What is not available is silent reliance on a certificate that does not reach the work.
2. List the control gaps observed and state, for each, the risk it creates and the minimum corrective action before welding continues.
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Calibration: no records for welding machines means arc voltage, current, and travel speed are unverified, so the WPS parameters are unproven in practice. Risk is systematic deviation from the qualified procedure across all joints made on those machines. Minimum action: calibrate or verify the machines, tag them, and quarantine output welded since the last known calibration until reviewed.
Consumable storage: uncontrolled electrodes may absorb moisture, producing hydrogen-related defects in structural welds. Minimum action: establish a controlled store with issue records, and re-dry or scrap affected stock.
Supervision on the afternoon shift: unsupervised welding means defects are made and not caught, and records may not reflect what happened. Minimum action: place competent supervision on all shifts before work resumes, or stop the shift.
Welders qualified by another body: the main contractor must verify that those qualifications are recognised for this work and this procedure, and record the verification. Unverified qualifications are not qualifications for certification purposes.
3. The client has not been told about the subcontract. Advise the coordinator on disclosure and on the sequencing of the next two weeks.
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Disclosure should come from the coordinator, in writing, before the client discovers it. Concealment is worse than the fact: if the client learns of an undisclosed subcontractor from a surveillance finding, every certificate the main contractor has issued becomes suspect.
The disclosure should state what has been subcontracted, what the main contractor retains control of, what gaps were found, and what has been done about them. It should not be softened into reassurance; the client needs the facts to judge.
Sequencing for two weeks: Week one: stop afternoon-shift welding until supervision is in place; calibrate and tag machines; set up consumable control; verify subcontractor welder qualifications against the procedure; notify client and certifying body. Week two: review work already produced against records; sample examination where records are weak; confirm in writing that controls are operating before releasing the balance of the package.
Five weeks is enough only if the coordinator acts on the assumption that the subcontractor is not currently under control, which the visit suggests is true.