British Standard BS 5839-6:2013 (also known as BS 5839: Pt.6) is a set of specific recommendations for fire alarm systems for all dwellings (new build and existing properties). The standard contains detailed points on all aspects relating to the design and installation of fire alarm systems. The standard details codes of practice and recommendations to meet regulation, legislation and best practice around fire alarm systems. A focus of BS 5839-6:2013 is guidance on the type of alarm to install and the areas of the property to protect. This is sectioned by the standard into levels and grades as described below.
There are six grades of system ranging from Grade A to F, whereby a higher grade generally represents a greater risk of fire in the premises, so a higher level of fire safety system is needed to be installed. However, the nature of the premises and the characteristics of the occupant are also important factors.
The majority of standard housing in the UK fall within the D-F category -whereby mains or battery powered alarms are installed. This progresses in complexity until a grade A is reached, in which a full fire detection system with control and indicating equipment is installed (in accordance with BS 5839: Part 1).
BS 5839: Pt.6 System Categories relate to the level of protection afforded to occupants. The Category of System that is appropriate depends primarily on the fire risk.
The three main categories for implementing a fire safety system are as follows:
Although Building Regulations in England and Wales only specify a Category LD3 system as the basic requirement in domestic new builds, this only offers a minimum level of protection in circulation spaces, so it is best practice to install to Category LD2. This is as BS 5839-6 states that “a Category LD3 system cannot be expected, with any degree of reliability, to protect people who might be involved with the fire at ignition or in its early stages.” In fact, the equivalent Building Regulations in Scotland and Northern Ireland require Category LD2 as a minimum level of protection. Building Regulations in England and Wales are therefore expected to follow suit when they are next revised.
However if the risk to occupants from fire in any part of the premises is deemed to be high, a Category LD1 system would be appropriate. For example, a LD1 system needs to be considered if the occupants suffer from any disability (mental or physical) that could delay their escape from fire. This is relative to the longer time it may take these tenants to escape.
The British Standard BS 5839-6:2013 recommends the use of multi-sensor alarms in all rooms expect the kitchen. Multi-Sensor alarms contain two separate sensing elements – optical and heat detection. As the unit monitors two different by-products of fires (smoke and temperature), its response to all types of fire is vastly improved over traditional single sensor alarms. They are also less prone to false alarms associated with the ionisation and the optical type alarms. FireAngel smoke alarm have a Thermoptek Muti-Sensor which is the technology choice for the UK Fire and Rescue Service.
The BS 5839-6:2013 standard also states that alarms should be interconnected within a property to ensure audibility. In the case of Grade D systems (typical for standard domestic properties), this can be done by either hardwiring the alarms or using Wi-Safe 2 wireless interlinking (such as on the WSM-SN-1). BS 5839-6:2013 also references the ability to test the alarm system from floor height. This can be achieved using an Alarm Control Unit (such as the WTSL Control Unit) which is a wall mounted unit designed to offer simple testing and control of the alarm system.