Ceiling mounted: At least 4 inches from any adjoining wall surface.
Wall mounted: Between 4 inches and 12 inches from the ceiling.
Peaked or sloped ceilings: Within 36 inches of the peak or the high side of the slope, but no closer than 4 inches vertically or from an adjoining wall surface.
Detectors shall not be installed within 36 inches of heating or cooling registers, the tip of a ceiling paddle fan, a kitchen door or a bathroom containing a tub or shower.
Detectors within 20 foot horizontal path of a cooking appliance shall be equipped with an alarm-silencing means or be of the photo electric type detector.
Where stairs lead to other occupiable levels, a smoke alarm or smoke detector shall be located so that smoke rising in the stairway cannot be prevented from reaching the smoke alarm by an intervening door or obstruction. For stairways leading up from a basement, smoke alarms or smoke detectors shall be located on the basement ceiling near the entry to the stairs.
Near the first bedroom door in a hallway closest to the living area. Carbon Monoxide detectors shall be installed as per the manufacturers recommendations outside each sleeping area.