Spot the Violation

FramingFire separation, egress & alarmsLevel 22018 IRC

Upstairs bedroom at final

A finished, empty upstairs bedroom in a new house, ready for final inspection. Painted walls and ceiling, carpet, a double-hung window on the back wall, and bifold closet doors on the left wall. The room's entry door, at the right end of the back wall, stands open to a hallway, with the door slab folded back against the right wall. A flush dome light is in the middle of the ceiling. Near the entry door, a round blue electrical box is in the ceiling with a mounting bracket on it, and a short wiring harness with a white plug and black, white and red wires hangs from it. Nothing is mounted on the bracket.
New-construction bedroom, second floor

What's wrong here?

  1. There is no smoke alarm in the bedroom; the alarm box is left with only its wiring harness
  2. A carbon monoxide alarm is required inside every bedroom
  3. Smoke alarms must be mounted on the wall, not the ceiling
  4. Nothing. This installation is compliant
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Show the answer and the code reference

The answer

The bedroom has no smoke alarm. The ceiling box has its bracket and harness, but the alarm itself was never installed, and R314.3 requires one in each sleeping room.

Correct choice: 1. There is no smoke alarm in the bedroom; the alarm box is left with only its wiring harness

R314.3 requires smoke alarms in each sleeping room, outside each separate sleeping area in the immediate vicinity of the bedrooms, and on each additional story including basements. In new construction they must be hardwired with battery backup and interconnected so that every alarm in the house sounds when one does (R314.4, R314.6). Most fire deaths happen at night in bedrooms, and the alarm in the room is the one that wakes a sleeper behind a closed door. Alarm heads often go missing between trim-out and final because they are the last item and are easy to leave in a box in the garage. The harness hanging from a bracket is a common sight at a failed final.

How to fix it

Install a listed smoke alarm that is compatible with the harness, plug it in, and twist it onto the bracket. Then test it with the rest of the alarms to confirm interconnection: pressing test on any one alarm should sound all of them.

Code references

  • IRC 2018 R314.3 — Location

    Smoke alarms are required in each sleeping room, outside each separate sleeping area in the immediate vicinity of the bedrooms, on each additional story including basements and habitable attics, and at least 3 ft horizontally from the door or opening of a bathroom that contains a bathtub or shower unless that would prevent a required placement.

    Drills citing R314.3

  • IRC 2018 R314.4 — Interconnection

    Where more than one smoke alarm is required in a dwelling unit, the alarms must be interconnected so that activating one sounds all of the alarms in the unit. Physical interconnection is not required where listed wireless alarms are installed and all alarms sound on activation of one.

    Drills citing R314.4

  • IRC 2018 R314.6 — Power source

    Smoke alarms must take their primary power from the building wiring, with battery backup, and the wiring must be permanent with no disconnecting switch other than overcurrent protection. Battery-only alarms are allowed in buildings without commercial power and for alarms added to existing areas under R314.2.2.

    Drills citing R314.6

2024 IRC:not yet checked Confidence: low

Minnesota

MN adopts this rule as writtenConfidence: medium

Minnesota adopts the 2018 IRC with Minnesota amendments as the Minnesota Residential Code (Minn. Rules ch. 1309). No Minnesota amendment to R314.3 is known. Minnesota statute separately requires smoke alarms in dwellings (Minn. Stat. 299F.362). DLI is adopting the 2024 IRC as the next edition; see the 2024 IRC note.

About the Minnesota Residential Code

Why the other choices are wrong

  • A carbon monoxide alarm is required inside every bedroom. CO alarms go outside each separate sleeping area, in the immediate vicinity of the bedrooms (R315.3). Minnesota requires one within 10 ft of each sleeping room (Minn. Stat. 299F.51). One is required inside a bedroom only when a fuel-burning appliance is in that bedroom or its attached bathroom.
  • Smoke alarms must be mounted on the wall, not the ceiling. Ceiling mounting is the normal location. NFPA 72, which R314 relies on for installation, permits ceiling mounting or wall mounting near the ceiling.
  • Nothing. This installation is compliant. R314.3 requires a smoke alarm in each sleeping room. Here the box and harness are roughed in but no alarm head is installed, so the room has no smoke alarm.
Safety hazardLevel 2 · Journeyman#smoke alarm#bedroom#final inspection#interconnection

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