Smoke detectors shall not be installed until when?

• A. During drywall installation
• B. After electrical rough-in
• C. Before any construction begins
• D. After final construction cleanup

Answer: (D)

Smoke detectors belong to the life-safety system and should be installed in a finished, clean environment so they can be mounted correctly, wired without interference, and tested reliably. Installing them after final construction cleanup ensures the ceilings and walls are complete, free of drywall dust, paint fumes, and other debris that can cause false alarms or damage sensors during construction. It also allows proper commissioning of the system—power connections, alarm testing, and verification of placement—before occupants move in. If installation happens during drywall, rough-in, or before construction ends, detectors are at higher risk of damage, misplacement, or nuisance alarms, leading to rework and unreliable performance. So the appropriate time is after the final cleanup.