General Regulations, Permits, and Inspections
The Regulatory Framework
Plumbing work is governed by an adopted code, local amendments, and the authority having jurisdiction (AHJ). Understand the permit process: application, plan review, permit issuance, inspections at defined stages, and final approval. Know who may perform work (licensed contractor, homeowner exceptions where allowed) and when a permit is required versus exempt (minor repairs, some fixture replacements).
Inspection Stages
Typical required inspections include underground/rough-in (before concealment), drainage and vent testing (water or air test), water supply testing, and final inspection. Know that concealed work must be inspected before covering, and that testing must be witnessed or documented as the AHJ requires. Questions often ask what must happen before backfilling or before drywall.
Traps in Questions
Distractors suggest work may proceed without inspection if the contractor is licensed, or that a permit covers later unlisted work. Another common trap: assuming the inspector approves deviations verbally. Code requires approval and often written documentation. Also watch for questions on who may inspect (only the AHJ or approved agency) and on stop-work orders.
Coordination and Records
Permits trigger coordination with building, electrical, and mechanical trades. Know that alteration of structural members for pipe routing may need separate approval, and that firestopping of penetrations is inspected. Keep as-built records and test reports.
Worked Example
Rule of thumb: "If it will be hidden, it must be seen first." Any pipe that will be buried, enclosed, or covered requires rough-in inspection and successful testing before concealment. When a question asks the next step, choose inspection over installation.