Where To Install Smoke Detectors: The Definitive guide

Smoke detectors are essential tools for any home. They are early warning systems that are crucial for preventing house fires. Major accidents can be and have been prevented by the careful placement of these detectors. You can read more about the major causes of house fires and their prevention here.

 If you’re new to this and don’t know where to install smoke detectors then don’t worry. Our guide on smoke alarms placement will take you through all the steps that are required for a successful smoke detector installation. While also keeping in mind the safety precautions that need to be followed. So let’s start! 

We have a bunch of other helpful guides on a wide variety of topics so be sure to check them out at firefightertools.co

Types of detectors:

So to start off let’s first discuss the types of detectors you can get these days. There are two main types of fire alarms or detectors, heat and smoke detectors

Heat detectors:

smoke detector placement

These detectors have now been replaced by more modern smoke detectors. They were initially used to detect fires but due to their slow-acting mechanism, they were quickly replaced. 

Reports suggested that these types of alarms were sometimes activated after irreversible damage had been done. The best place for smoke detectors of these sorts were in small rooms where heat could be easily detected.

They operated by detecting a rapid change in temperature. Small changes were tolerated but if the temperature got above a specific point they would become active. 

The main problem with this was the fact that in house fires, heat is not the main cause of concern when it comes to the safety of the residents, it’s usually smoke. Smoke is deadly as it can choke the residents. Much like modern smoke detectors, the fire alarm placement for these was usually on the ceiling.

Smoke detectors:

smoke detector placement

Smoke detectors are the latest renditions to the fire alarms. As the name suggests they detect fires by detecting the levels of smoke in an area. They are usually very sensitive and fast-acting

Smoke detectors are widely used as the go-to fire alarms these days. Smoke alarms placements are determined by the size of the room and also the use. As we will discuss in just a moment, proper smoke detector placement is absolutely essential for the proper working of the detector.

These days two types of smoke alarms are being used, based on their working mechanism they are quite different from one another.

Photoelectric detector:

These types of smoke detectors work around the principle of the photoelectric effect. Without going into too much detail, it basically uses a light source and a photoelectric sensor. If the path of the light is disturbed by the smoke the alarm sounds. Proper placement of photoelectric smoke detectors is key in this type of detector.

Ionization detectors:

Ionization detectors are also very sensitive, they work by generating current between two electrodes if the current is disturbed then the alarm becomes active. The best place for smoke detectors of this sort is definitely the ceiling. So now we know the basic types of detectors lets answer the question “where to install smoke detectors”.

Where to install smoke detectors:

Finding out where to install smoke detectors can be a little tricky if you haven’t done it before, we’ll try to make this as easy as possible. Here is a location guide for determining exactly where to install smoke detectors. So let’s get started.

Smoke detector placement wall or ceiling: 

where should smoke detectors be placed

The best location for a smoke detector is definitely going to be the ceiling, wall-mounted fire alarms can be used but they should be placed with caution as placing one is a dead air space can render it useless. 

The main benefit of using a ceiling-mounted smoke detector is that it can be placed in a centralized position. In this way, it can detect smoke rising up from all corners of the room. So if you were wondering where the smoke alarm placement should be, wall or ceiling, you should definitely try to mount it to a ceiling, it is much better that way.

Be sure to centralize it and keep it away from any windows, also make sure that the fire alarm is less than 12 inches from the ceiling line.

Where to install smoke detectors in the Bedroom:

The smoke detector placement in your bedroom is an absolute necessity, it’s best that you install one smoke detector in each bedroom of your house. 

If you’re wondering where to install smoke detectors in your bedroom, then the short answer to that is that you need to place it exactly in the center of your room just like you would in a normal room.

Proper smoke alarm placement in the Hallway:

Hallway smoke detectors

Smoke alarms placement in the hallway of your house is also recommended. Depending on the length of your hallway you may need to place additional smoke detectors along the length of the ceiling. 

Generally, if you’re installing smoke detectors in a building that has hallways longer than approximately 30 feet then you need to place more than one smoke detector

The distance between two smoke detectors should be no more than 30 feet. A typical smoke detector setup should be equidistant from all corners of the room by about 21 feet. So when installing a detector make sure that the distance between the detector and the corner of the room is about 21 feet or less.

Which Floors should have smoke detectors:

smoke detector placement code

Each floor of your house or building should at least one smoke detector on each floor. 

Whether it’s the living room, the attic, or even the basement. Each floor should have one smoke detector. Also, if the floor has rooms in it then each room should have separate smoke detectors as we have mentioned previously. 

Where to install smoke detectors in the Kitchen:

ceiling mounted smoke detector

This is the most important smoke alarm placement. Most fire hazards start in the kitchen so it’s best to make sure that the smoke detector is placed correctly in the kitchen. 

One of the major causes of concern in placing smoke detectors in the kitchen, is the chance of a false alarm. It is quite possible that the smoke from your stove may cause the fire alarm to become active. To avoid this false alarm you will have to place the alarm at least 10 horizontal feet away from the kitchen stove. 

Vertical height doesn’t matter, horizontal length does, so keep that in mind. Smoke can easily rise to the top. Also, avoid smoke alarms placement near a window or anything of this sort like an exhaust fan.

Keeping a fire extinguisher in your kitchen is also great practice. According to some smoke detector placement codes you don’t need a smoke detector in the kitchen just an extinguisher, hence you can avoid the hassle of “where to install smoke detectors”. But it’s best practice to install one.

Smoke detector placement code:

The smoke detector placement code is actually dependent on the location of the building. Some areas have different regulations and policies for smoke detector placement than others. So be sure to check out your local placement code to find out exactly where to install smoke detectors in your building. 

The NFPA does have some general guidelines on this so be sure to check that out too.

What to do and what to avoid:

So let’s start off with the things that you should do. We have already told you about where to install smoke detectors, now it’s time to look at some general guidelines to follow:

  • It’s always best to get a detector that has both the photoelectric and ionization mechanism built inside of it. This increases reliability and also the sensitivity and at the same time decreases the rate of false alarms.
  • After you have dealt with where to install smoke detectors you now have to figure out how to install it. For this you have to consult the manual. So read the manual carefully and ensure that you have installed the alarm correctly
  • Most modern alarms these days have a button that you can use to test whether or not your alarm is active or not. It will make a beeping sound or flash a light. It’s absolutely essential that you do this after your first installation and also after each month. Smoke alarms are usually out of sight and reach. A fault can go unnoticed that is why you have to continually check to see if it’s working or not.
  • Always try to mount the alarm at the center of the room. As we have mentioned earlier this ensures that the smoke is easily detected. In the case of a wall mount place it at least 12 inches from the ceiling and make sure it isn’t in any dead air space. If you have a slanted ceiling then more than one detector may be required.

Where not to place your detectors:

  • For a proper smoke detector placement, it is essential that it is not placed in an area of dead air. Generally, the upper corners of the room are considered to be dead air spaces. So avoid that.
  • Smoke detectors should be placed at least 10 horizontal feet away from the kitchen appliances to ensure that a false alarm doesn’t happen.
  • Keep your smoke detector away from any humidity or ventilation system. This can negatively impact your smoke detector by damaging it or in some cases even causing false-positive results.
  • Your smoke detector placement should be such that it does not continuously interact with dust. This can also cause the same impacts as the ones caused by humidity.

Maintenance of your smoke alarm:

Now that you’ve learned where to install smoke detectors and also where to place your detector and where not to. It’s time to look into the maintenance of your device.

Check it monthly:

Testing smoke alarm

Once you have successfully installed your first fire alarm system you should not regularly check on it to ensure it’s proper working. A general rule of thumb is to check the working of your fire alarm once a month. You can do so by pressing the button on top of it.

Change the batteries annually:

changing the batteries of a smoke detector

If we’re talking about the battery then there are two types of fire alarms, one works on batteries while the other one works by connecting the alarm to the house power supply. We suggest the first one since it’s much easier. 

Even the one powered by the power supply has some batteries in it so that it works in case the power gets cut off. This battery needs to be replaced after each year. Even if it’s working fine replacing the battery is a good idea. 

Also cleaning it after a year is essential, as the time passes the detector gets stuffed with dust and dirt so it’s best to simply vacuum it or clean it with a piece of cloth.

Replace it after decade:

A good quality detector can last more than a decade but it’s best practice to change it after 3 to 4 years or at the maximum after a whole decade. Even if it’s super reliable at the end of the day it’s just a machine and is likely to degrade as the time passes.


Hopefully, this erased your confusion on where to install smoke detectors. Here is a short summary to conclude the proper placement of the smoke detectors. 

  • It should be placed in the center of the room, preferably ceiling mounted. 
  • The distance between the detectors and the corner of the room should be no more than 21 feet.
  • The location of the detectors depends on the layout of your house. In the kitchen, you should place a detector 10 horizontal feet away from the stove to avoid accidental alarms.
  • You should place at least one detector in each bedroom and hallway.
  • Check to see if it’s working properly after every month, replace the batteries at the end of the year, and replace the smoke detector after 3 to 4 years.

Now you know where to install smoke detectors. Hope this guide helps you to properly install your smoke detectors.

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