General Trade Knowledge, Safety, and Jobsite Practices
This domain tests the practical side of sprinkler work: safe installation practices, coordination with other trades, protection of materials, and the jobsite behaviors that prevent injuries and failed inspections.
Safety fundamentals
Follow OSHA construction requirements and the site-specific safety plan. Wear eye protection, head protection, gloves, and hearing protection where required. Fall protection is required at the OSHA threshold, commonly 6 ft for construction work. Use ladders and scaffolds per the manufacturer and OSHA. Hot work such as soldering or cutting requires a permit, fire watch, and removal of combustibles. Lock out and tag out before servicing equipment. Treat pressure testing as a hazardous operation: air or water under pressure can eject fittings or caps, so barricade the area and never stand in line with a test cap.
Installation and coordination
Coordinate hanger locations, sleeve openings, and ceiling heights with structural, mechanical, and electrical trades before rough-in. Keep sprinkler heads clean and protected; never paint a sprinkler, and replace any head that has been damaged, painted, or exposed to fire. Use listed components and the manufacturer's approved joining methods for steel, CPVC, and grooved pipe. Slope dry-pipe and preaction piping so it drains, and protect low points with auxiliary drains. Pressure-test before concealment and document the result.
Worked example
A crew is ready to hydrostatically test a new wet system at 200 psi. The test cap is aimed at a walkway and a worker is standing beside it. Correct practice: clear the area, barricade the test location, verify the gauge and relief arrangement, fill slowly, and keep personnel out of the line of potential failure. The test pressure, duration, and result are recorded, then the system is drained and restored. The safety step is part of the test procedure, not an optional extra.
Traps that cost marks
Assuming a hard hat substitutes for fall protection. Painting or touching up sprinkler heads. Using unlisted or mismatched fittings. Leaving a test cap unsecured. Failing to protect CPVC from solvents or incompatible materials. Hiding piping before the rough-in inspection. Treating housekeeping and access as someone else's responsibility.