CSLB General Building (B)Mechanical, Electrical, Plumbing CoordinationEasy
A general contractor is scheduling rough-in work for a new single-family residence. Which sequence best reflects the standard order of rough-in operations after framing is complete?
- AInsulation, drywall, plumbing rough-in, electrical rough-in
- BPlumbing and HVAC rough-in, electrical rough-in, insulation, drywall
- CHVAC rough-in, drywall, plumbing rough-in, electrical rough-in
- DElectrical rough-in, plumbing rough-in, HVAC rough-in, insulation
Show answer & explanationAnswer & explanation
Correct answer: B. Plumbing and HVAC rough-in, electrical rough-in, insulation, drywall
Plumbing and HVAC systems require larger penetrations through framing and are typically installed first, followed by electrical (which can route around them more easily), then insulation and drywall.
Why the other options are wrong
- A. Insulation and drywall cannot go in before rough-ins are inspected and approved.
- C. Drywall before plumbing/electrical rough-in would block access to wall cavities.
- D. Electrical first would force plumbers and HVAC installers to reroute around wiring unnecessarily.
Rough-In Sequencing
The order in which MEP trades install systems inside wall, floor, and ceiling cavities after framing but before insulation and drywall.
- Plumbing and HVAC are typically roughed in before electrical due to larger space needs
- Electrical is more flexible and installed after larger systems
- Sequencing reduces field conflicts and change orders
Memory trick: Pipes and ducts need room first, wires squeeze in last.