Where To Place Smoke Detectors? (2022 Code Placement)

If you want to learn about smoke detector code placement, you are in the right place!

In this guide, you will learn:

  • 9 common building codes for smoke alarm placement
  • Tips on smoke alarm installations
  • How to maintain them...
  • And more!
where to place smoke detectors

As a licensed home inspector, the last step of any home inspection is to test the home's smoke alarms. I usually use a specialized smoke can tester that simulates real smoke. And if a bedroom or home level is missing a smoke detector, I always call it out and put it in my report.

It is essential that smoke detectors are placed as high as possible and preferably on the ceilings. And smoke alarms need to avoid the extreme corners of a wall or the corner of a pitched ceiling.

And always avoid placing smoke detectors next to air vents, windows, or doors!

Keep reading to learn about the 9 common building codes for smoke alarm placement as well as some installation and maintenance tips!

Local Codes Have Final Authority On Where To Put Smoke Detectors

There aren't that many smoke alarm placement codes, but they are essential to keep home's safe. In fact, about half of fire fatalities happen when people are sleeping.

The 9 building codes in this article are based on the IRC or international residential code. The IRC is known as a 'model code' that many U.S. states and countries have fully adopted.

However, your local city or county may have additional codes or slightly modified codes than the 9 rules below. Here is an example of local codes from Washington D.C. on smoke alarms.

Always check your local area for the final word on smoke detector code placement!

9 Codes For Smoke Detector Placement

  1. Each Bedroom Requires A Smoke Alarm
  2. Hallway Outside Bedrooms
  3. Smoke Detector On Each Home Level
  4. Minimum Three Feet From Bathroom
  5. Minimum Distance From The Range Or Oven
  6. Connected To Electrical System AND Battery
  7. Smoke Alarms Must Be Connected To Each Other
  8. Distance From Ceiling When Installed On The Wall
  9. Distance From Wall When Installed On Ceiling

Code 1 - Each Bedroom Requires A Smoke Alarm

The code requires one smoke detector to be placed inside EACH bedroom.

This code is probably the most important requirement since the bedroom is the last place to be alerted before a possibly fatal smoke inhalation occurs while sleeping.

Code 2 - Hallway Outside Bedrooms

One smoke alarm will also need to be placed in the hallway outside of the bedrooms and as close as possible to them.

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Code 3 - Smoke Detector On Each Home Level

Every story that doesn't have bedrooms will also need at least one smoke detector including basements and habitable attics.

If you have a crawlspace or uninhabitable attic, a smoke alarm is NOT required.

Code 4 - Minimum Three Feet From Bathroom

A smoke alarm needs to be at least 3-feet from a bathroom door if the bathroom contains a bathtub or shower.

This code requirement is due to the fact that the moisture and humidity from taking a shower or bath can cause the smoke alarm to trip. Basically, keep the smoke detector as far from the bathroom as possible but still in close proximity to the bedrooms.

Code 5 - Minimum Distance From The Range Or Oven

An ionization smoke alarm shouldn't be installed within 20-feet of an oven, cooktop, range, or other cooking appliance. The distance can be reduced to 10-feet if it contains an alarm silencing switch.

If you have a photoelectric smoke alarm, this minimum distance can be reduced to 6-feet.

The reason for this code is to prevent the smoke alarm from constantly tripping. An ionization smoke detector is more sensitive than a typical photoelectric smoke alarm.

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Code 6 - Connected To Electrical System AND Battery

Smoke alarms need to be powered by the electrical system of the house.

The secondary power source will be the battery of the smoke detector.

This code increases the likelihood that the unit will always have power. If the home's power goes out, then the smoke alarms will still work with the battery. And if the battery goes out, it will still work with the electrical system.

Code 7 - Smoke Alarms Must Be Connected To Each Other

All of the smoke detectors in a home must be connected to each other.

If one smoke detector goes off, then all of the other detectors will beep. This is an important code that ensures you are alerted to a fire in a faraway part of the home.

An exception to this rule is with wireless smoke alarms that are configured to all go off at the same time. However, they still need to be connected primarily to the home's electrical system.

Code 8 - Distance From Ceiling When Installed On The Wall

where to put smoke detectors (1)

A smoke detector on the wall should be at least 4-inches from the ceiling with a maximum distance of 12-inches when it is installed vertically on the wall.

Remember, smoke rises so that is why it should be installed as high as possible. However, the extreme corner of a room is a dead zone (it will have less smoke) which is why it should be at least 4-inches from the ceiling.

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Code 9 - Distance From Wall When Installed On Ceiling

If the smoke detector is installed on the ceiling, then it shouldn't be within 4-inches of the wall.

The reason for this code as mentioned above in Code 7 is that the extreme corner of a room will have less smoke.

How To Install Smoke Alarms?

The basics of installing smoke alarms require one in each bedroom and at least one on each home level.

It is essential to only install UL listed smoke detectors and preferably a combination of ionization and photosensitive units. Ionization alarms respond faster to visible flames and photoelectric units beep faster when there is a lot of smoke.

Here are a few installation tips:

  • Install them on the ceiling and in a central location. Smoke rises so a central ceiling install spot is best.
  • Avoid the extreme corners of a room or a pitched ceiling. The corners tend to have less smoke.
  • Avoid doors, windows, and vents. Try to avoid installing a smoke alarm where a draft may occur.
  • Don't paint over them. Paint, stickers, or other objects will impede the functioning of smoke detectors.
  • Link all smoke alarms together. When one smoke alarm goes off, all the other units should beep as well. This can be done through a wireless or wired connection.

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How To Test Smoke Detector Locations?

Smoke alarms should be tested at least once a month by pressing the test button or using a tester can.

As a home inspector, I always used a smoke tester spray can because it shoots aerosolized particles which simulate smoke. And using a tester spray can allows you to test smoke alarms from 6-feet away.

When you test a smoke alarm, you should verify that all of the smoke detectors go off at the same time. After the alarms go off, you will need to hit the reset button for them to stop. If you use a tester spray can, you can simply fan the smoke alarm with a notebook or magazine to get it to stop beeping.

It is also a good idea to make sure everyone in your household knows how to respond to a smoke alarm. In the case of a real fire, your home's occupants may only have a few minutes to leave the house safely.

How To Maintain Smoke Alarm Installations?

Believe it or not, there are some basic maintenance tasks for smoke detectors to keep them in tiptop shape. Here are a few things you need to do:

  • Clean the smoke alarms periodically. Follow the manufacturer's instructions or use a vacuum cleaner attachment to remove dust.
  • Replace the batteries. If your smoke alarm makes a chirping sound, this means the battery needs to be changed. Make sure to use a battery that is approved by the manufacturer.
  • Install new smoke detectors. It is recommended to install new smoke alarms every 10-years.

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Frequently Asked Questions

Should smoke detectors be on the ceiling or wall?

Smoke detectors are permitted to be installed on the ceiling OR wall. However, it is usually preferred to be installed on the ceiling so it can be in the center of the room. If it is installed on the wall, it needs to be at least 4-inches from the ceiling and with a maximum distance of 12-inches.

How many smoke detectors should be in a house?

There needs to be at least one smoke detector in each bedroom of the home. Every home level also needs at least one smoke detector including the basement.

Do I need a smoke alarm in every room?

Every bedroom needs a smoke alarm. Besides the bedrooms, there needs to be at least one smoke detector on each home level outside of the bedrooms. If you have a 3-story house (including basement) and 4-bedrooms, then this house will need at least 7 smoke alarms.

What is the best location for a smoke detector in a bedroom?

The best places to put smoke detectors are on the ceiling towards the center. Smoke rises and the ceiling is usually the most effective location.

Final Thoughts On Smoke Detector Code Placement

Having properly placed smoke alarms is crucial to your safety in case of a fire.

With modern homes and all of the synthetic materials, you may have just a few minutes to exit your home. It is essential to have at least one smoke detector in each bedroom and on each home level. If you have a large home, you may need more than 1 per level.

I hope you enjoyed this guide from Home Inspector Secrets, and stay safe!

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