Testing Times For Fire Safety Systems

Posted in The Industry on March 13, 2018


Facilities and building managers are under growing pressure to review their fire safety strategies in the wake of the Grenfell fire.

The ongoing review into the Grenfell Tower tragedy last year is subjecting the design and maintenance of fire safety systems to the full glare of publicity. The interim report published by the independent review panel chaired by Dame Judith Hackitt called for the industry to make major improvements to the way it assesses competence and to its training.

The committee, which is reviewing the role and effectiveness of the building regulations and fire safety in the wake of the tragedy and will publish its final report next month, highlighted "numerous examples" of lack of competence amongst engineers across all disciplines.

"The competence of those involved in the design, construction, ongoing operational management and maintenance of complex and high-risk buildings has been called into question. While there are many instances of competent people planning, building and maintaining buildings in a conscientious way, there is no consistent way to assess or verify their competence," the report said.

London Fire Brigade also attacked what it called a "general lack of competence" among building designers and construction companies and demanded formal qualifications and accreditation for anyone installing "life-saving systems like smoke ventilation". "There will be an increase in serious building fires unless the construction industry starts to take fire safety more seriously," the LFB said in its submission to the Hackitt inquiry. Its officers added that they regularly came across "significant construction defects" such as flawed compartmentation between flats, which can allow fire and smoke to spread throughout buildings. Critical They also saw "critical fire safety systems", such as mechanical smoke ventilation, that were either not installed as per the original design, poorly designed, or simply not working.

In the event of a fire, the dampers should close immediately to prevent the spread of fire and smoke through the ducting or open when needed to enable smoke extraction. The way they are controlled plays a vital role in keeping escape routes open and allowing access for fire-fighters. The systems need to be sophisticated, but also easy to use so that they do not slow down the emergency services when responding to a fire. Crucially, they must be regularly checked and properly maintained as part of routine planned maintenance programmes. It is increasingly clear that thousands of fire and smoke dampers in buildings up and down the country – including many in high rise residential blocks – are never checked. There is, therefore, no way of knowing if they will operate when called upon to reduce the risk of potentially deadly fire, smoke and fumes being spread throughout a building.

More obvious parts of the fire protection system, such as alarms; smoke detectors; extinguishers; and fire doors, are regularly checked and maintained because they are visible. Dampers are hidden away and often forgotten – even by fire officers carrying out risk assessments. Difficulty in gaining access to the ventilation ductwork; disruption to the operation of the building; cost; and the awkwardness of opening and closing the dampers by hand all combine to leave the many mechanical, spring-operated dampers 'out of sight out of mind'.

Motorised dampers are easier to test because they can be electrically linked to the fire alarm and ventilation systems. Testing can, therefore, be carried out remotely and automatically as part of a wider maintenance regime, ensuring reliable operation without disruption to the building occupants. These more sophisticated dampers are already used as standard in a number of European countries, but are still the exception rather than the rule in the UK.

Curtain fire dampers remain the most regularly specified type, by far, and have been used in UK buildings since the 1930s. They account for around 80% of all fire dampers fitted in new and existing buildings. They depend on a bi-metal, fusible link activating the damper mechanism when the temperature in the ductwork reaches 72°C, and have a spring mechanism that releases the damper blades to block the passage of the fire. These must be regularly maintained by someone who understands their operation.

Competent

The British Standard BS 9999 – the code of practice for Fire Safety in the Design, Management and Use of Buildings – covers routine inspection and maintenance of ventilation and air conditioning ductwork. It stipulates that all fire dampers be tested by a "competent person" at regular intervals "not exceeding two years" and should be replaced immediately if any fault is found. Spring-operated dampers should be tested every year, according to the standard, and even more frequently if they are installed in areas of heavy dust contamination. Unfortunately, pressure on maintenance budgets means this legal requirement is often overlooked, but this is all set to change in the wake of Grenfell.

The first task is to establish where each damper is; then the FM team must make sure they are all working properly and can be accessed for maintenance on a regular and ongoing basis. It makes sense to make this task part of the routine maintenance of the general ventilation system i.e. when ductwork is being cleaned and/or filters changed.

Fire risks are clearly in the spotlight following Grenfell, but building managers may need reminding that dampers, although out of sight, are part of their building's fire safety strategy and need just as much attention, if not more, than the elements they can see.

We don't know exactly what happened at Grenfell, but the fact that stairwells were full of smoke and so escape routes were compromised shows just how important it is to make sure fire safety equipment will do its job properly when called upon – and that means regular maintenance is a must.


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