On-Site Responsibilities, Supervision and Quality Control
The duty of care on site
A licensed plumber on site carries personal accountability for work performed, including work done by apprentices or assistants under their supervision. Supervision must be direct and effective - the supervisor must be able to observe and control the work, not simply be contactable by phone. The concepts to master are: supervision levels (direct versus general), competence of the person supervised, the obligation to stop work that is unsafe or non-compliant, and the requirement to work to the National Construction Code, relevant Australian Standards, and manufacturer instructions.
Quality control
Understand inspection and testing obligations: pressure testing, flow testing, and inspection before covering work. Know the role of the nominated supervisor and the contractor's quality assurance responsibilities. Record-keeping matters - test results, compliance certificates, and as-installed drawings should be retained and provided where required.
Traps to watch
- Assuming a licensed plumber can supervise unlimited apprentices across multiple sites.
- Confusing "supervision" with "employment" - a subcontractor can still require supervision if unlicensed for that work.
- Forgetting the duty to report unsafe or non-compliant work to the contractor or regulator.
- Missing that manufacturer instructions override standard practice where they are more specific.
- Overlooking testing before concealment.
Worked example
An apprentice installs a rainwater tank connection while the licensed plumber is at another site. The question asks whether this is acceptable. Answer: only if the apprentice is competent for that task and the supervision is adequate for the risk - generally direct supervision is required for work the apprentice is not yet competent to perform unsupervised.
Rule of thumb
If you would not sign the certificate for the work, you cannot supervise it from a distance.