Smoke alarms are mandatory under the Ontario Fire Code (see: Section 2.13).

The law says..

The Ontario Fire Code requires a working smoke alarm to be installed between each sleeping area and the remainder of the dwelling unit, where the sleeping areas are served by hallways, the smoke alarms shall be installed in the hallways, and on every story of the home.

Always remember that a smoke alarm should be installed and maintained in accordance with the manufacturer's instructions that accompanied the device. A properly maintained and tested smoke alarm is the best insurance your family can have!

REMEMBER!..
Only a working smoke alarm can save you and your family!