2. HOW MANY ALARMS TO INSTALL
- CATEGORIES & GRADES -
The advice here follows the guidance in British Standard
BS 5839-Part 6: 2004 in general (for further information see
the BS standard itself).
The main reason for fitting Smoke & Heat Alarms in dwellings
is to ensure that when there is a fire, sufficient early warning
is given so that everybody can escape safely.
This means that the fire alarms should ideally be located near
all potential sources of fires and that the alarm should be
heard throughout the house – particularly in the bedrooms.
It is also important that nuisance/false alarms are minimised
to ensure the units are not disabled or ignored.
The BS standard gives guidance on:
- how many alarms to install
- what type of alarm to use
- where to position alarms
The above points will depend on the type of dwelling to be
protected and the level of fire risk.
Fire Risk Assessment
The ‘Grade’and ‘Category’ of system that should be installed
depends on the fire risk. The r isk assessment is based on a
combination of probabilities:
- fire occurring
- injury or death to occupant
- system operating correctly with a fire
- early detection and warning to occupants in the event of a fire.
The greater the risks, the more comprehensive and reliable
systems are needed.

2.1 Categories of System

There are three Categories of LD systems for Life protection
in Dwellings that can be installed, depending on the fire risk
and regulations.
Please see following pages for detailed information.
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