Installing a smoke detector: where and how to place it

Since 2016, every French dwelling must have at least one smoke alarm (DAAF). Positioning it well is as important as buying it: a badly placed detector can sound at the slightest kitchen vapor or, on the contrary, fail to react to the start of a fire. This guide explains how many detectors to install, where to fix them and how to check they work properly.

How many detectors to install

• At least one detector per dwelling, installed on a landing or in the hallway serving the bedrooms
• An additional detector for each level of the dwelling
• An installation recommended in the bedrooms, especially if the door stays closed at night
• Avoid placing a detector in the kitchen or bathroom, where false alarms are frequent

The landing is the strategic point of the house: it is the obligatory passage between the bedrooms and the rest of the home. If your home has several floors, one detector per landing is recommended so the alarm triggers early, whatever level the fire starts on.

Where exactly to fix the detector

1. Fix the detector on the ceiling, in the center of the room or the hallway if possible.
2. Respect a distance of at least 30 cm from the walls and corners, where the air stagnates.
3. Maintain a distance of at least 50 cm from light fixtures and electrical appliances.
4. Keep the detector more than one meter away from air vents and windows.
5. Place it at a minimum height of 60 cm from the floors and tall furniture if you fix it on the wall.

Smoke naturally rises toward the ceiling: that is why ceiling installation offers the fastest detection. If the ceiling is sloped, install the detector between 50 and 150 cm from the highest point. In a room where the ceiling exceeds 4 meters high, bring the detector closer to the area to protect rather than leaving it far up high.

Fixing the detector to the wall or ceiling

1. Mark the location of the holes using the supplied fixing plate.
2. Drill with a bit suited to the support (concrete, drywall or wood).
3. Insert the anchors then screw the plate.
4. Clip or screw the detector onto the plate.
5. Insert the batteries and do a first test by pressing the dedicated button.

The places to absolutely avoid

• The kitchen and bathroom, where vapor and cooking fumes trigger false alarms
• Near a window or a ventilation grille, where drafts carry the smoke away
• Less than 50 cm from a light fixture or a radiator that heats the sensor
• In a closet or behind furniture, where smoke never reaches the detector

Maintaining and testing the detector

A smoke detector is not just installed: it is checked regularly. Press the test button once a month to confirm the alarm sounds. Dust the device twice a year with a soft cloth or the breath of a low-power vacuum. When the detector emits an intermittent beep, replace the batteries immediately and run a full test again.

A well-installed smoke detector doubles the chances of evacuating a home in the event of a fire. By taking the time to place it in the right spot, test it every month and replace the batteries at the first beep, you turn a simple device into real protection for your family.