Where should I install smoke alarms?

Question

Where should I install smoke alarms (detectors) in my home?

Answer

The placement of smoke alarms in your home is important to get the maximum amount of warning time if needed to escape. Incorrect placement will result in a decrease in its effectiveness.

For optimal safety, install smoke alarms in every room, including hall, bedrooms, living rooms, the attic and the basement. At the very least, install one smoke alarm on every floor.

Typical single-storey home

Install a smoke alarm on the ceiling or wall inside each bedroom and in the hallway outside each separate sleeping area. If a bedroom area or hallway is more than 9 metres (30 feet) long, install a smoke alarm at each end. If there is a basement, install a smoke alarm on the basement ceiling at the bottom of the stairwell.

Typical multi-story or split-level home

Install a smoke alarm on the ceiling or wall inside each bedroom and in the hallway outside each separate sleeping area. If a bedroom area or hallway is more than 9 metres (30ft) long, install a smoke alarm at each end. Install a smoke alarm on the top of a first-to-second floor stairwell.

Recommended placement of smoke alarms

Locate a smoke alarm in any area where a smoker sleeps or where electrical appliances are operated in sleeping areas.

Smoke, heat and other combustion products rise to the ceiling and spread horizontally. Mounting the smoke alarm on the ceiling in the centre of the room places it closest to all the points in the room.

Ceiling mounting is preferred in ordinary residential construction. However, in mobile homes, wall mounting on an inside partition is preferred to avoid the thermal barrier that may form in the ceiling.

Best locations to install smoke alarms/detectors
Important smoke alarm placement and exception information:

  • Place it as close as possible to the centre of the ceiling as possible, or no closer than 300mm to any wall or corner, and no closer than 900m from the apex (tip) of a pointed ceiling.
  • Install a smoke alarm in each room that is divided by a partial wall.
  • Install a smoke alarm in lived-in attics or attics which house electrical equipment like furnaces, air conditioners, or heaters.

Where not to install smoke alarms

  • Areas near appliances or where normal combustion regularly occurs (near furnaces, hot water heaters).
  • In areas with high humidity, like bathrooms, near dishwashers or washing machines. Install at least 3 meters (10 feet) away from these areas.
  • Air returns or heating and cooling supply vents. Install at least 900mm (3 feet) away from these areas. The air could blow smoke away from the detector, interrupting its alarm.
  • In rooms where temperatures may fall below 5°C or rise above 45°C.
  • In extremely dusty, dirty, or insect-infested areas where loose particles interfere with smoke alarm operation.

See also information on installing carbon monoxide alarms.