Home Improvement Skills & Specialties HVAC

Where to Position the Fire and Smoke Detectors in Your Home

Correct Placement for Smoke Detectors, Carbon Monoxide Alarms, and More

Where to Place Smoke Detectors in Your Home

The Spruce / Hilary Allison

Figuring out where to position your fire and smoke alarms is crucial for safety in your home. On average, there are 2,620 deaths from residential home fires each year, according to the National Fire Protection Association. About 60 percent of those deaths are in homes with malfunctioning smoke/fire alarms or no alarms at all, so the lesson is clear: Understanding the mechanics of smoke alarms, and using and maintaining them correctly, can prevent an enormous family tragedy from occurring.

Key Points

  • Smoke detectors: Smoke detectors should be placed in each sleeping room as well as on each level of a house.
  • Carbon monoxide detectors: Carbon monoxide detectors should be placed in each major area of your house, including the kitchen, living room, and bedrooms.
  • Fire extinguishers: Fire extinguishers should be placed in readily accessible places like laundry rooms, kitchens, hallways, and near doors.

Types of Alarms

Although they are often lumped together as "smoke alarms," there are actually five different types of smoke and fire alarms used in homes. Some actually detect heat and actual fire, some detect smoke, and some do both jobs.

Heat Detectors

Heat detectors feature a detecting component inside the unit that activates an alarm when it reaches a predetermined temperature. Heat detectors are sufficient for places where the speed of detection isn't critical, or in small, confined spaces. They have a lower false alarm rate, but they are somewhat slower at detecting fires. In many household fires, smoke kills victims before fire.

Smoke Alarms

Smoke alarms will detect most fires more quickly than heat detectors. They use a different technology entirely to sense a fire, and there are three types of smoke alarms currently sold:

  • Ionization smoke alarms sound an alarm when smoke of any amount enters the internal chamber and the current flow is interrupted. This type of alarm works best for very fast, fierce fires.
  • Photoelectric smoke alarms operate using a light source and a photoelectric sensor. This type of alarm works best for slow, smoldering fires.
  • Combination smoke alarms use both ionization and photoelectric technologies. The NFPA recommends using smoke alarms that combine both technologies for the best protection.

Carbon Monoxide Detectors

There are many combination detectors sold that combine smoke detection with carbon monoxide detection, and these pose some complications for positioning in the home. While smoke from fires tends to rise to near ceiling level, carbon monoxide mixes with air and is often found in the greatest concentrations near the floor. Most experts recommend positioning CO detectors outside each sleeping area and on every level of the home.

For these reasons, it is best to keep smoke detection and CO detection systems separate and not rely on combination devices. If you do have combination detectors, mount them at the recommended smoke detection height, then install backup CO-only detectors at knee level on each floor of your home.

Tip

While you may prefer a hardwired smoke detector, it's important to remember that a battery-operated smoke detector is safer than no smoke detector at all.

Where to Place Smoke Detectors and CO Alarms

The proper positioning of smoke alarms may be dictated by your local building code, but there are also standard recommendations from the National Fire Protection Association. These recommendations are the basis for many local code requirements:

Placement

  • Smoke alarms installed in the basement should be installed on the ceiling at the bottom of the stairs leading to the next level.
  • Smoke alarms should be installed at least 10 feet (three meters) from a cooking appliance to minimize false alarms when cooking.
  • Mount smoke alarms high on walls or ceilings (remember, smoke rises). Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm).
  • If you have ceilings that are pitched, install the alarm within three feet of the peak but not within the apex of the peak (four inches down from the peak).
  • Don't install smoke alarms near windows, doors, or ducts where drafts might interfere with their operation.
  • Many experts point out that smoke alarms should be placed on the ceiling, or high up on the walls. By positioning the detectors at roughly 12 inches below the ceiling, you can ensure that they will detect smoke at the earliest opportunity.

Rooms

  • Install smoke alarms inside each bedroom, outside each sleeping area, and on every level of the home, including the basement.
  • On levels without bedrooms, install alarms in the living room (or den or family room) or near the stairway to the upper level, or in both locations.
  • It is important that every floor of your home have at least one smoke detector. Garages are a very common source of fires, so make sure yours is equipped with a smoke detector. Don't forget basements, sunrooms, and swimming pool or spa areas of the home, and be sure to include furnace rooms, laundry rooms, and other utility spaces in your alarm plan.

Smoke Alarm Installation Tips


Never paint smoke alarms. Paint, stickers, or other decorations could keep the alarms from working. For the best protection, interconnect all smoke alarms. When one smoke alarm sounds, they all sound. Interconnection can be done using hard-wiring or wireless technology. When interconnected smoke alarms are installed, it is important that all of the alarms are from the same manufacturer. If the alarms are not compatible, they may not sound.

Power Sources

Smoke and fire alarms can be powered by household circuit current (hardwired), or they can be powered by batteries. These hardwired smoke alarms usually have an internal battery backup system that allows them to keep operating should the home's electrical service be interrupted.

Although the battery-operated smoke alarms, which usually use 9-volt batteries, are very popular due to their low costs and ease of installation, they only provide good protection if the batteries are checked and replaced on a regular basis.

Hardwired, interconnected smoke detectors are the best option and are now often required in new construction. Even where building codes allow older homes to rely on battery-operated detectors, it is a good idea to have a hardwired system installed. If you must rely on battery-operated detectors, make sure to replace the batteries twice a year. The habit of changing the batteries at each change from daylight saving time to standard time is good practice to get into.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Home Structure Fires report. National Fire Protection Association.

  2. Smoke Alarms in U.S. House Fires. National Fire Protection Association.

  3. Home Fires. Ready.gov, United States Government.

  4. Talking Points. National Fire Protection Association.

  5. Carbon Monoxide AlarmsNational Fire Protection Association.

  6. Installing And Maintaining Smoke Alarms. National Fire Protection Association.