Fire Detection & Alarm Systems

Whilst the main focus of a fire protection strategy should be to prevent fire there is always the possibility that a fire situation may occur and therefore automatic fire detection is essential. Every second saved through early warning facilities could make the difference to a company or site recovering from a fire without too much disruption.

We can offer full design, installation, commission, handover and maintenance packages in accordance with current BS5839-1 standards for an extensive range of wired & wireless fire alarm systems, giving you the earliest possible warning in the event of a fire situation facilitating swift and safe evacuation of people from your premises.

Under BS5839-1: 2017 we can offer a full design, installation, commission, handover and maintenance packages for an extensive range of wired & wireless fire alarm systems. 


We can help you provide the earliest possible warning in the event of a fire situation which in turn facilitates swift and safe evacuation of people from your premises.

Categories of Fire Alarm Systems:

Manual fire alarm systems

These are the least sophisticated of systems, which rely on the building’s occupants to detect a fire and provide a warning to others. When a fire is discovered, employees must activate the alarm manually, in order to alert everybody else in the building to the danger.

A typical example of a manual fire alarm system is a series of break glass units, which are installed at each point of exit in a building. This allows those escaping a fire to raise the alarm as they leave the danger zone.

Manual fire alarm systems can be effective but due to reliance on individuals, it means that there can be an increased risk of employee and visitor safety, especially if the site is not highly populated with few people to raise an alarm. 

Automatic fire alarm systems for the protection of life

Fire alarm systems that fall into the L category are those deemed most suitable for protecting life within a building. Systems designed for this purpose are divided into five sub-categories, depending on their level of effectiveness.

Category L1 – Maximum life protection

This is the most comprehensive fire alarm system, which features detectors in all areas of a building where a fire could feasibly start. Detectors are linked up to a centralised alarm system which alerts the whole building should a fire break out. 

The objective of this setup is to ensure that inhabitants are given the earliest possible warning, should an emergency occur. It is therefore the ideal standard for premises such as large hotels and care homes, where early detection of a fire is crucial to the chances of escape.

Category L2 – Additional life protection

Fire alarm systems that fall into this category feature smoke detectors in all rooms that form part of an escape route, including corridors. Detectors also need to be installed in all high-risk rooms, such as kitchens, boiler rooms and areas with heavy plant machinery.

L2 systems are effective at providing an early warning to occupants beyond the source of the fire and those working in high risk areas. Examples of properties that typically employ this system include factories or medium sized residential premises.

Category L4 – Modest life protection

An L4 category fire alarm system consists of detectors within escape route areas only, such as in corridors and stairways. Any circulation areas that make up part of the escape passage should also be fitted with a detector when the site is classed within this fire alarm category.

Commercial properties that generally adopt this category of system are those that have a lower level of risk. For example, an office that consists of ground floor rooms only would require less warning time to evacuate all personnel.

Category L5 – Localised life protection

L5 fire alarm category systems are those that are installed to tackle a specific fire risk in a certain area of a building. For example, if there is a room in a building that poses an exceptional hazard because of the items stored there or business activities carried out there.

An L4 category system may be appropriate for the building in general but an L5 system is also required, in order to recognise the level of risk this particular room presents.

Automatic fire alarm systems for the protection of property

P category fire alarm systems are those that are designed to protect property. It is appropriate to label a system under this category, when considering how a business and its operations will be protected from the risk of fire.

Category P1

A P1 fire alarm system involves installing detectors in all areas of the building. The objective of a system like this is to protect buildings that are critical to the operations of a business.


Category P2

In a category P2 fire alarm system, fire detectors are installed in high risk areas only. Whilst a system like this does not provide the same level of cover as a P1 solution, it does provide early detection for the most likely sources of a fire.

This early detection will decrease the time it takes for the fire services to arrive on the scene and will help to minimise any damage to the property and losses to the business.

By implementing maximum protection across a whole site, those in charge of fire safety can ensure that any fire that breaks out is detected and neutralised as quickly as possible. This lowers the risk of damage and disruption and in turn, the financial impact that a fire could inflict on a company.    

Revised system grading for fire detection and fire alarm systems:

Whilst BS 5839-6 has previously been split into six varying Grades, each outlining the level of protection appropriate for certain properties and their corresponding levels of risk, the new update has altered the six sections, removing Grade B and Grade E, whilst Grade D and Grade F have been split into Grade D1 / Grade D2 and Grade F1 / Grade F2 respectively. Grade C has been revised and its recommendations expanded.

The new grading system is as follows:

Professionals should adhere to the above grades when designing, constructing and managing fire detection and fire alarm systems in domestic properties. They should also be aware of the revisions made to Table 1 of The Standard, which outlines the minimum grade and category of system that should be installed to provide protection of life in typical premises. The updates have been made to reflect current living conditions.

In conjunction with Table 1, a new table has also been created, which outlines the recommended testing and servicing by grade to prevent the blocking or delaying of fire alarm signals transmitted via social alarm systems in sheltered housing to an alarm receiving centre.

Categories for fire detection and fire alarm systems (as per BS 5839-6-:2019):

With regard to categories, the standard of protection in sheltered housing flats has been increased from Category LD2 to Category LD1, positioning it as a higher potential risk. To meet LD1 requirements, the installation of a fire detection system is required throughout the premises – this includes all rooms (and circulation areas that form part of the escape routes) except toilets, bathrooms and shower rooms.

The three categories for fire detection and fire alarm systems are listed below and outline where fire detection systems should be installed:

LD1 Maximum Protection

LD2 Additional Protection

LD3 Minimum Protection

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