How Many Smoke & Carbon Monoxide Detectors Do I Need?

There are lots of things that you can do to ensure that your home and your family are as safe as possible from fires.

You can put together a fire plan so your family knows the safest way to evacuate the home in the event of a fire.

You can keep a fire blanket or domestic fire extinguisher in the kitchen. You can check your electrical appliances for faulty wires and cables.

But one of the best things you can do is install a series of smoke alarms and carbon monoxide detectors in your home.

Smoke detectors are a legal requirement, and carbon monoxide detectors are also a legal requirement in certain states.

They are both extremely important for keeping your home safe. Having a smoke detector or carbon monoxide detector can save lives and prevent serious injury. 

How Many Smoke & Carbon Monoxide Detectors Do I Need?

But how many smoke and carbon monoxide detectors do you need in your home? Where should you put them?

If you want to know more about how to use these devices to protect your home then keep reading. We have put together this guide to tell you everything you need to know. 

Why Are Smoke Detectors Important 

If a fire starts in your home, it could spread far and become quite powerful before you are aware of it.

This is especially true if the fire starts at night when you are in bed. Having a smoke detector will notify you of the fire much faster, giving you a chance to try and extinguish the flames.

If you cannot put the fire out safely then you will still have more time to evacuate your home and call the fire department. 

The sooner the fire department can arrive at the scene, the faster they can extinguish the fire and the more chance they have of saving the lives of anyone trapped inside.

In more than half of the house fires that result in a fatality there was no smoke detector present in the home. 

Why Are Carbon Monoxide Detectors Important 

Carbon monoxide is an odorless and colorless gas, so if you had a carbon monoxide leak somewhere in your home you would not be able to notice it without a detector.

Carbon monoxide poisoning can cause serious health issues, and if you breathe in enough carbon monoxide in a short space of time then it can kill you. 

Carbon monoxide leaks can occur if your gas appliances are faulty or they have not been installed properly. The leaks can happen at any time. 

How Many Smoke Detectors Do You Need?

Now you understand why it is so important to install smoke detectors in your home, how do you know how many you will need? 

At a bare minimum, you should have a smoke detector installed on each floor of the house. However, the more you have the safer your home will be.

The National Fire Protection Association recommends that you install one in each bedroom, outside sleeping areas such as on the landing at the top of the stairs, and in hallways.

You should also install one in the kitchen and in the living room. 

There should be no more than 30 feet between each smoke detector to give you the best chance of being notified of a fire as soon as possible. Smoke rises quickly, which is why smoke detectors tend to be installed on the ceiling. 

How Many Carbon Monoxide Detectors Do You Need?

How Many Carbon Monoxide Detectors Do You Need

You should have a minimum of one carbon monoxide detector on each floor, but the amount that you have will depend on the size of your house and the placement of your gas furnace and other gas appliances. 

It is important to install a carbon monoxide detector outside of sleeping areas, in the kitchen, and in the living room or dining room.

If you have a gas furnace then you should make sure that there is a carbon monoxide alarm installed nearby. It is also a good idea to install one in your garage. 

Carbon monoxide doesn’t rise like smoke. It mixes in the air and is a fairly dense gas, which means it collects around knee height.

Carbon monoxide detectors should therefore be installed at knee height in order to have the most benefit.

If you are worried about pets or animals knocking them off the wall or interfering with them, you can install them at chest height instead. 

Dual Function Detectors 

Instead of installing smoke detectors and carbon monoxide detectors, some people use dual detectors. They will detect smoke and carbon monoxide. However, the placement can be a bit of an issue. 

The dual detector will need to be installed on the ceiling in order to detect the smoke, but this means it will not detect the presence of carbon monoxide as easily. 

How To Maintain Smoke And Carbon Monoxide Detectors

For the detectors to work properly you need to make sure that they are unobstructed. This means that you cannot block them off or place furniture in front of them. 

You should test the detectors at least twice a year but preferably once a month to make sure that they are still working properly.

Remember to replace the batteries. Some detectors will beep to let you know that the battery is dying and needs replacing. 

You will need to replace your smoke detectors every 8 to 10 years depending on their condition, and carbon monoxide detectors every 5 to 7 years.

If you are moving into a different property, don’t forget to ask how old the smoke and carbon monoxide detectors are so you know when to replace them. 


Smoke detectors and carbon monoxide detectors are very important for keeping your home and your family safe from house fires and gas leaks.

They give you more time to react to the threat and to evacuate the home safely. It also gives the emergency services a better chance at containing the fire and extinguishing it quickly without it spreading.