Installing your alarms

How many smoke alarms do you need?

The more suitable and routinely tested alarms you have installed the more confident you can be about the early detection of a developing fire and about hearing an alarm when this happens. If you have more than one alarm consider linking alarms.

No areas of the boat to be protected should be further than 5m from an alarm. In the case of large vessels, such as some narrow boats, the dimensions of the vessel may mean a slower reaction time for a single alarm and so you may need to install multiple units for maximum protection.

Where to fit smoke alarms

The ideal place is along the centreline of the boat in the same cabin space where a heater or cooker is in use, but not too close to any appliance.

It also needs to be mounted on a well-insulated part of the ceiling avoiding cold spots.

If you can, try to avoid putting it any closer than 300mm to any vertical surface.

If headroom is a problem and you really have no choice, mount it on a wall between 150mm – 300mm below the ceiling height, but not directly above a ventilator or opening window.

Make sure it is easy to reach so you can test it routinely and so that you can press the hush button with ease.

Always put smoke alarms where you will be able to hear them, particularly when you’re asleep or when doors are closed. Try testing the alarm in place before you fix it in position.

Where not to put a smoke alarm

Don’t fix a smoke alarm:

  • in the galley or bathroom, where it could be accidentally triggered by cooking fumes or steam; or,
  • where you can’t hear it while you’re asleep; or,
  • too close to a cooker or heater where the alarm will produce false alerts; or,
  • flush to the ceiling and try to avoid positioning the alarm close to any roof ventilator.


avoid steam Hear Alarms in Bed