Safety, Tools, Testing and Jobsite Practices
Safety first, on the exam and on the job
Personal protective equipment, ladder use, trench protection (required at 5 ft depth in most jurisdictions), confined-space entry, and hot-work permits for soldering and grinding. Gas piping work requires ventilation and leak detection. Solder joints need a fire watch and protection of combustibles; a torch near framing is a classic loss-of-life scenario. Lockout/tagout applies to any work on a circuit or a pressurized system.
Tools
Know the purpose, not just the name: soil pipe cutter, snap cutter, auger and drain snake, press tool, PEX crimper or expander, flaring and swaging tools, manometer, test pump, hydrostatic test rig, smoke blower, mirror and flashlight. Using a drain snake on a pressure line, or a press tool on the wrong fitting, is a costly mistake.
Testing
DWV systems are tested before concealment - commonly with a water test (about 10 ft of head for 15 minutes) or an air test (about 5 psi for 15 minutes), depending on the code and the AHJ. Water supply is tested hydrostatically at working pressure plus a margin, or with air where allowed. Gas piping is tested with air or inert gas and a gauge. Record what you tested, at what pressure, and for how long.
Traps
- Testing after the walls are closed.
- Substituting a smoke test where a water test is required, without AHJ approval.
- Leaving a test gauge that can be isolated by a closed valve.
- Skipping the final leak check at fixtures and appliance connectors.
Rule of thumb
Test before you cover. A failed inspection is cheap; a failed joint behind tile is not.
Example: cap all openings, fill the DWV system to 10 ft of head, hold 15 minutes, and inspect every joint before calling for the rough-in inspection.