Hearst Newspapers participates in various affiliate marketing programs, which means we may get paid commissions on editorially chosen products purchased through our links to retailer sites.

How to install a smoke alarm in your home

Don't forget to check your smoke alarms on a regular basis.

A smoke alarm is essential for any home, and for landlords, usually a legal requirement.

A smoke alarm is essential for any home, and for landlords, usually a legal requirement.

FotoDuets/Getty Images/iStockphoto

Smoke alarms are a necessary (and in most places legally required) fixture in your home. According to the, they must be installed inside every bedroom in a house, as well as outside every sleeping area and on each floor. If you rent, most state laws mandate that . If you're the building or home owner, you're responsible for the installation.

How to install a hardwired smoke alarm

Most smoke alarms these days, like this one from , are hardwired to your home’s electricity, as well as having a battery backup.

“If you know how to replace a light fixture, you can likely install a hardwired alarm yourself. If you’re not familiar with that process, consider hiring a pro. Besides the risk of getting electrocuted, installing an alarm incorrectly can lead to not only a noisy nuisance but also a serious risk for you and your home,” Bailey Carson, a home care expert at said via email.

Identify the breaker

If you’re installing a smoke alarm yourself, the first thing to do is locate the wall switch or breaker inside your home’s electrical box that controls the flow of electricity to that specific spot and turn it off. Your breaker box, usually made of grey metal, can be outside the house, in the basement, or in a closet.

If you’re not installing the alarm somewhere there's already an opening (i.e. a hole in the sheetrock) that leads to the innards of your house (and the wiring), hiring a professional electrician may be the way to go.

Where to cut the hole for your smoke alarm

But if you feel confident in cutting holes in your ceiling or walls, you’ll need a to determine where your wiring runs as well the locations of ceiling joists and wall studs.

Blue Polycarbonate Round New Work Ceiling Electrical Box
Carlon
homedepot.com
$1.54

Next, use an as a template to cut a hole. The electrical box will attach to the ceiling joist or wall stud and provide an enclosure for the wires at their connection points.

According to Carson, you should place your fire alarm on the ceiling or high on the wall (less than a foot from the ceiling), avoiding drafty areas like windows, ducts and doors. Also, try to keep them at least 10 feet from your stove to avoid regular false alarms.

How to wire your smoke alarm

Run wire from an existing power source, such as a wall outlet, switch, or circuit box. is stiff and you should be able to push it through the wall and/or ceiling to where you want it, though this sometimes requires more force than you suspect. Next, pull 2 to 3 inches of the newly run wire through one of the round openings in the electrical box and secure it in place with the provided clamp and screws. Then attach the box itself to the wood stud or ceiling joist.

Gray Solid CU UF-B W/G Wire
Southwire
homedepot.com
$17.88

If you’re replacing an old smoke alarm with a new one, you’ll obviously not have to do the whole running new wire and cutting a hole thing. You can jump right to rewiring a new alarm.

Smoke alarms (and light fixtures) will come with a mounting base and screws to attach the electrical box, as well as wires that will need to be attached to your house wiring. Pull the house wiring apart to separate the positive and negative wires and strip the outer coating from the ends using

Wire Nuts, Electrical Connectors
Bates Choice
amazon.com
$6.99

To create a proper connection, you need to wrap exposed wiring together. Twist the house wiring and the wiring from the smoke alarm together — one positive and one negative connection, or black to black and white to white if color coded. Don’t worry if you can’t tell which is positive or negative. If you wire it wrong, the fixture won’t work and you can just wire it the other way. I like to use both and to secure my wire joins. You want to avoid bare wire touching the electrical box, especially if it's metal.

Before you attach your new smoke alarm to the electrical box and twist on the cover, check to see if it works (if you wired correctly). If so, affix the base to the electrical box with the provided screws, install the batteries for its backup power source, and attach the cover.

“Add a fire alarm inside and outside each bedroom and sleeping area, as well as in your kitchen. There should be alarms on every level – including the basement. Consider interconnected alarms so they’re all activated once one is, making sure everyone in the home has time to get to safety,” Carson told us.

When to replace a smoke alarm

Don’t forget to on a regular basis. Replace the batteries as needed and the alarms themselves every 10 years.