BS5839 makes reference to recommendations of maximum mounting heights for different types of detectors. This is to ensure that the detector is still effective when mounted at high levels. The recommendations of BS5839 split the mounting heights up into two categories. These categories are standard BS5839 systems and systems with a 5 minute fire service response time.
Below is a series of recommended mounting heights for fire alarm system equipment including different types of smoke detector (including Optical Beam Detectors) and Heat Detectors.
The table below also shows heights which detectors are permitted to be mounted at if 10% or less of the ceiling is the height shown.
Mounting Heights
Detector Type
Maximum Ceiling Height (m) Cat L/P
5 Minute Response (m) Cat P
Rate of Rise Heat Detector
9 Metres (10.5 metres for 10% of Ceiling)
13.5 Metres (15 metres for 10% of Ceiling)
Fixed Temperature Heat Detectors
7.5 Metres (10.5 metres for 10% of Ceiling)
12 Metres (15 metres for 10% of Ceiling)
Smoke Detectors
10.5 Metres (12.5 metres for 10% of Ceiling)
15 Metres (18 metres for 10% of Ceiling)
CO Point Detectors
10.5 Metres (12.5 metres for 10% of Ceiling)
15 Metres (18 metres for 10% of Ceiling)
Optical Beam Detectors
25 Metres (25 metres for 10% of Ceiling)
40 Metres (40 metres for 10% of Ceiling)
For More Information on Fire Alarm Products please click the following link:- Fire Alarm Systems
