Home > Fire & Life Safety Education > FAQs > Answers

Smoke Alarms

Q. How many smoke alarms do I need in my house?

A. According to the Manitoba Building Code Section 9.10.18.1 - Smoke alarms shall be installed in each dwelling unit and in each sleeping room not within a dwelling unit.

Smoke alarms will be installed so that:

  • There is at least one smoke alarm on each floor level, including basements.
  • Each bedroom is protected by a smoke alarm either inside the bedroom or, if outside, within 5 m of the bedroom door.

top of page

Q. Can you recommend a smoke alarms and where can I buy one?

A. The Office of the Fire Commissioner cannot recommend a particular brand of smoke alarm. We do recommend that all smoke alarms purchased be Canadian Standards Association (CSA) or Underwriter's Laboratories of Canada (ULC) approved. Most department and hardware stores carry a variety of smoke alarms.

top of page

Q. How many types of smoke alarms are there?

A. There are two types of smoke alarms - ionization and photoelectric.

Ionization type smoke alarms - use a small amount of radioactive material to ionize air in the sensing chamber. As a result the air chamber becomes conductive permitting current to flow between two charged electrodes. When smoke particles enter the chamber, the conductivity of the chamber air decreases. When the conductivity is reduced to a predetermined level, the alarm is set off.

  • Fastest type to respond to flaming fires (where flames are visible). According to the National Fire Protection Association (NFPA), 70 percent of home fires are of the fast-flaming type. The Underwriters' Laboratories of Canada, the smoke alarm testing and certification agency, states that ionization alarms are often recognized for being better suited in detecting fast-flaming fires.
  • Lowest cost and most commonly sold.
  • Test buttons allow periodic testing.
  • Some models have a hush or temporary silence feature that allows silencing without removing the battery.
  • Power source may be a battery or household current.
  • Some models are available with a long life battery.
    Photoelectric Type Smoke Alarms - consists of a light emitting diode and a light sensitive sensor in the sensing chamber. In one design, the presence of suspended smoke particles in the chamber scatters the light beam. This scattered light is detected and set off the alarm. A similar design relies on obscuration of light between the source and sensor to activate the alarm.
  • Fastest type to respond to slow smoldering fires (such as those caused by a burning cigarette in a sofa or a smouldering rug). According to NFPA 30 percent of home fires are of the smouldering type. The ULC states that photoelectric alarms are recognized for being better suited in detecting smouldering fires.
  • Less prone to nuisance alarms from cooking.
  • Test buttons allow periodic testing.

top of page

Q. How do I install my smoke alarm?

A. Smoke alarms should be installed according to manufacturer's instructions.

top of page

Q. How do I maintain my smoke alarm?

A. Install a new battery at least once a year. If the low battery warning beeps, replace the battery immediately. Every year, we move the clocks forward in the spring and move them back in the fall - this is a good time to "Change Your Clocks, Change Your Batteries."

Dust can clog a smoke alarm, so carefully vacuum the inside of the battery unit. It electrically connected, shut off the power and vacuum the outside vents only. Restore power and test the unit when finished.

Smoke alarms must be replaced every 10 years.

top of page

General Fire Safety

Q. Where can I order fire safety materials?

A. You may order fire safety materials by calling the Office of the Fire Commissioner - 1-888-253-1488.

Manitoba Emergency Services College    Codes & Standards     Investigations   Municipal Support    Emergency Response   Administration

top of page

Copyright (c) 2000 Office of the Fire Commissioner