Last Updated on November 21, 2018 by Dave Farquhar
Smoke detectors save lives, so it’s important to have them. But how many you have and where you put them is also important. If you’re going to go to the effort to install smoke detectors, you might as well install them right. Here’s where to install smoke detectors.
First, a word about models
You can spend hundreds of dollars on a smoke detector, but you don’t need to. I buy the basic $5 models you can find at any home improvement store. I replace the battery every year and replace the whole detector every 10 years. Having fancy smoke detectors is a lot less important than having enough of them. Call me a curmudgeon, but I don’t want a wifi-enabled smoke detector.
For medical applications, battery brands do matter. Energizer and Duracell batteries to outlast Ray-o-vac and store-brand batteries in those applications. For smoke detectors, I don’t worry about brand as long as I replace them once a year. Get alkaline batteries, not heavy-duty.
Where to install smoke detectors in and around sleeping areas
The rule is at least one smoke detector on every level of the house, and on floors with bedrooms, you need one in each bedroom and one more near each sleeping area, which generally means in the hallway outside those bedrooms.
And yes, if you have a multi-story house with the master bedroom on a different floor than the rest, that’s two sleeping areas. You’ll need one in the bedroom and one in the hallway outside it.
My local inspector is picky about the placement in the hallway. He wants it no more than 15 feet away from any bedroom. So I try to find a place in the hallway as far from the bathroom as possible, yet no more than 15 feet from any bedroom. Keeping it away from the bathroom prevents steam from setting off the alarm in the morning.
You can mount them on the wall or on the ceiling, but if you mount them on the wall, they need to be within four inches of the ceiling to work properly.
Placement inside the bedroom can also make a difference. You want it near the door, for two reasons. First, it will give you an earlier warning if it’s near the door, since smoke’s most likely entry point is under the door. Second, if the smoke detector wakes you up at night and you’re disoriented, you can follow the sound out the door. Fire is black, so don’t expect to be able to see the door.
Where to install smoke detectors in non-sleeping areas
Floors that don’t have bedrooms still need one smoke detector. On those floors, I put them somewhere fairly central. Having it near the laundry room would make sense if you can do it, since dryers are one common source of household fires. I try to keep them away from bathrooms to prevent nuisance alarms.
I have mixed thoughts about kitchens. Kitchens are one of the more likely sources of fire, but it’s awfully easy to set off the alarm accidentally when cooking. You might try an alarm near the kitchen, and if you set it off several times a week and it drives you nuts, move it.
Proper and adequate placement saves lives.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.