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Additional Smoke Alarms in Houses

Additional Smoke Alarms in Houses

Additional Smoke Alarms in Houses

On 16th March, Dick Roche, TD, Minister for the Environment, Heritage and Local Government announced the making of new Fire Safety Building Regulations and the publication of a new edition of Technical Guidance Document B (TGD B). TGD B itself covers all areas of Fire Safety, including the subject of smoke alarm selection and installation with the requirements based on the latest edition of BS5839: Part 6: 2004.

Background to BS5839 Changes

BS5839: Part 6 was revised in 2004 to advocate the use of additional smoke and heat alarms in high fire risk areas in dwelling houses in order to give higher levels of protection to the inhabitants of such dwellings. Research had discovered that the majority of dwelling fires started in the kitchen and main living areas of dwelling houses. By locating alarms in these areas such fires would be detected as early as possible, giving the inhabitants of the dwelling as much time as possible to vacate the building. In particular, the research found that some 40% of all fire deaths were caused by fires started in living rooms, and so by placing an alarm in such a location the desired effect was to specifically target such high risk areas. The important point to note is that dwelling fires can escalate incredibly quickly and therefore giving an early warning of fire conditions can make all the difference of escaping safely from a burning building.

BS5839 also addresses the issue of false alarm reduction with smoke alarms, and therefore advocates the use of heat alarms in kitchen areas because normal cooking fumes would cause a smoke alarm to be activated unnecessarily. A heat alarm responds to excessive heat rather than smoke and therefore will not false alarm in kitchen areas. In a similar manner, BS5839 advocates the use of heat alarms in living rooms if smoke alarms would give rise to false alarms. However, the use of optical smoke alarms in preference to the more highly] sensitive ionisation smoke alarms would normally be sufficient to overcome any issues with false alarms in living areas.

BS5839 defines Grades and Categories of smoke alarms, with Grades A-F defining the different types of fire alarm systems, and Categories LD1, LD2 and LD3 defining where smoke and heat alarms should be fitted in different dwellings.

Technical Guidance Document B (Fire Safety) of the new Irish Building Regulations takes the requirements of BS5839: Part 6: 2004 and makes the following statements:

Fire Detection and Alarm Systems for Dwelling Houses

1.5.5.1 Grades of fire detection and alarm systems (page 55 TGD B)
"The grade of the system should be at least Grade D as described above (Grade D systems are based on the provision of one or more mains powered smoke alarms each provided with an integral power supply. They may also incorporate one or more mains powered heat alarms with an integral power supply). Note: Grade E and F systems which are based only on battery or mains powered smoke and heat alarms, are not acceptable for new houses"

1.5.5.2 Fire detection and alarm system types (page 55 TGD B)
"Dwelling houses should be provided with an LD1 or an LD2 fire detection and alarm system in accordance with BS5839: Part 6: 2004 designed for the protection of life".

"An LD2 system incorporates suitably located and interconnected detectors in all circulation areas that form part of the escape route and in all rooms or areas, such as kitchens and living rooms, that present a high fire risk. Heat detectors should be provided in kitchens"

"Dwelling houses with up to three storeys above ground level should have at least an LD2 system"

What Does This Mean?

What this effectively means is that under the new requirements of TGD B, at least two additional smoke or heat detectors must be installed in dwelling houses, with a heat detector in the kitchen and a smoke or heat detector in the main living room. Under the previous TGD B, the minimum requirement was for smoke detectors to be installed only in the circulation areas of a dwelling house (Category LD3).

In addition, these four alarms must be Grade D (mains powered with battery back up) and interconnected to each other.

Therefore, under the new requirements of TGD B this now means that four interconnected Grade D smoke or heat alarms must now be installed in an average dwelling house, compared to two under the previous TGD B.

The new requirements of TGD B will be required in new dwellings commencing on or after 1 June 2006. However, as is the case with all new Building Regulation requirements the operative date is subject to the transitional arrangements to allow the industry time to adjust to the new regime. In this case there is an exemption from the 1 June deadline for new buildings for which planning permission is applied for on or before 31 May 2006 and which are substantially complete by 31 May 2009.

This transitional arrangement is designed to avoid delays in the commencement of work on new buildings, at an advanced stage of design and planning.

Contractors should certify their installations using the model certificate form on page 67 of BS5839 Part 6.

NSAI - I.S. 3218:2013 Fire Detection and Fire Alarm Systems for Buildings.

For full details, please refer to section 10 of IS 3218:2013 Fire Detection and Fire Alarm for Buildings. To date the Building Regulations, Technical Guidance Document B, have not be amended to cover the additional smoke/heat requirements in IS 3218, but this new requirement would be very good practice and should be applied where possible.