Research shaping the future of fire safety design and management was outlined to a packed auditorium at the second annual BRE Fire Research Conference which took place recently (June 2016).
Experts discussed newly published and current BRE research related to both passive and active fire protection, ranging from roof void compartmentation and fire safety in open plan flats, to sprinkler systems in housing and the problem of false fire alarms.
More than 150 delegates from across the UK and overseas, including the Middle-East, attended the day event held at BRE’s headquarters and science park in Garston, near Watford.
Reflecting BRE’s standing in the field of fire behaviour research and fire performance testing, the diverse programme of ten speakers attracted a wide range of stakeholders. Among attendees were architects, engineers, building control officers, local authorities, housing associations, manufacturers, fire safety consultants, and representatives from the NHS, fire services, academia and insurance industry.
This year’s keynote lecture was given by Professor Colin Bailey, Deputy President and Deputy Vice-Chancellor of the University of Manchester and an international authority in structural fire engineering. As well as writing a series of seminal fire design guides, he was lead expert in reviewing the structural fire design of London landmarks The Shard, The Pinnacle and Heron Tower, among others.
Professor Bailey discussed the legacy of large-scale fire testing at BRE Cardington which yielded critical data on structural fire behaviour that continues to inform safer, more robust and more cost effective design solutions.
Together with real fire data and the development of codified performance-based approaches, the work has delivered tools to better predict a building’s performance during a fire and more accurately assess risks.
Professor Bailey argued that performance-based design employing advanced models can better respond as we push the limits of structural engineering with the use of longer, thinner sections and new materials. A prescriptive approach dictated by building standards and system fire testing is less adaptable to the impacts of new technology and materials.
Referring to fire data on multi-storey structures, he explained that while any visible degree of vertical displacement in the beams will typically necessitate replacement, it does not lead to building collapse – a point that has been acknowledged by insurers. Hence, performance gains do not necessarily follow from an increase in beam fire protection, with evidence showing that between 40-55% of beams in multi-storey steel structures can be left unprotected. A performance-based approach therefore provides the confidence to target fire protection where it is required.
Landmark research
The remaining nine papers, presented by experts from across BRE’s certification, structural and fire safety teams, gave an insight into other landmark research and opinion-leading projects.
Tom Lennon outlined DCLG commissioned research and experimentation into the fire resistance and fire safety of compartmentation in roof voids. It forms Workstream 3 of a number of linked projects to review the efficacy of fire safety provisions in Part B of the Building Regulations.
Findings confirm that, when applied correctly, current guidance on roof void compartments, cavity barriers and fire-related dampeners does achieve requisite performance. But a number of issues compromising compliance have been highlighted. These include lack of inspection during installation and poor workmanship, notably gaps being left in compartmentation due to gaps around the cavity barriers, as well as site techniques affecting the assumed level of compression of the barrier. DCLG guidance regarding compartmentation in roof voids is expected in the near future.
Dr Corinne Williams reported on a current project for the Welsh Government to monitor the success of residential sprinkler installations at a number of pilot schemes. Sprinklers became mandatory for new and converted houses and flats in Wales on 1 January 2016. Involving feedback from residents, builders, water companies and other stakeholders, the study covers 177 dwellings at 12 different locations, comprising social housing and one private housing development.
Initial observations highlight the need for early planning of installation to avoid costly rework. For example, cut-outs need to be correctly sized for sprinkler pipework. Care is needed in locating pump control equipment, especially in kitchens, to minimise inconvenience to occupier lifestyle. Water supply – whether it should be mains fed, or from a dedicated or boosted supply – should also be considered early to ensure adequate pressure to the sprinkler system.
Costing Britain around £1 billion a year, Raman Chagger talked about BRE research into the significant problem of false fire alarms on commercial premises. Statistics on call-outs attended by the fire services during 2013/2014 across Great Britain show that 58% (293,000) were false alarms. Building on previous BRE Trust work in this area, a six-month programme of live investigation of false alarms was undertaken by BRE in conjunction with the Scottish Fire and Rescue Service and a specialist fire alarm investigator.
Detailed analysis of 65 false alarms indicated that 20% resulted from testing, underlining the need to take systems offline for this activity. Manual call points accounted for 16.7%, indicating a need for greater use of protective covers. The project has led to 35 recommendations for reducing false alarms. These were discussed at a stakeholder workshop in February to see how they can be taken forward by the industry. Research by King’s College London suggests that the use of multi-sensor detectors could significantly reduce false alarms. BRE together with partners is currently working on a standard test method for assessing multi-sensor detectors with optical and heat functions.
Steve Manchester discussed BRE’s expert appraisal of the benefits and limitations of wireless fire detection for prisons. BRE has previously assessed wireless technology for Sodexo Justice Systems. Traditional wired point detection is typically installed in cell ventilation ducts to prevent tampering. Capable of supporting up to 250 sensors from one control panel, wireless systems are much quicker and less disruptive to install. This is a huge advantage in overcoming access in the tightly controlled space of the prison environment. However, signal blockages, ‘dead spots’ and interference from other radio sources are among the drawbacks.
Nigel Firkins outlined how BRE’s latest Loss Prevention Standards are setting the benchmark in performance for local area fire suppression systems. They include LPS 1223 for Catering Equipment Suppression Systems, and LPS 1655 for Personal Protection Water Mist Systems which addresses the greater risk from fire of vulnerable people, often living alone. Also new is LPS 1656 for Condensed Aerosol Extinguishing Generators. Allied to this, BRE is currently developing an LPS for Direct Local Application in Small Enclosures.
A common feature of all four standards is that they are geared to a limited amount of fire suppression agent being discharged close to the seat of the fire and at an early stage of fire development. This early detection/annunciation/actuation principle uses relatively small quantities of extinguishant in the most effective and cost-beneficial way, advancing fire protection and the sustainability of technology at the same time.
Dr David Crowder highlighted BRE’s work with real fire incident data from the past 12 months signposting future developments and trends in fire protection and fire risk strategies. This has included experiments on fire spread via spandrel panels to assess the potential need for changes to regulations. Other research has focused on the growing incident of fire development through soffits. Experiments on aluminium, plywood and uPVC soffits have shown they do not promote lateral spread, so work continues to identify the contributing factors.
Worryingly, yet consistent with the findings of the compartmentation in roof voids project and by no means a new phenomenon, he warned that workmanship is the biggest problem affecting fire safety at the moment. He said that there is a pressing need for non-fire trades to understand the aspects of their site work that can compromise fire protection in buildings.
Dr Chris Salter highlighted fire safety considerations for open-plan flats, as the modern trend for ever larger open living space outgrows the parameters of current UK guidance. Previous work by BRE for NHBC determined various flat layouts considered to offer a level of fire safety equivalent to an ADB compliant layout. The use of fire engineering and modelling still offers robust scope to demonstrate how open plan flats can comply with regulations.
Martin Shipp discussed the importance of fire risk assessment under current fire regulations governing non-domestic premises. The Fire Safety Order places a legal duty to safeguard people from fire risks on the ‘responsible person’ who may have little experience in this discipline. Mr Shipp underlined the need to seek professional support in ensuring that fire protection measures and management systems are based on competent fire risk assessment.
BRE’s expertise in managing industrial hazards was the subject of the concluding presentation by Rob Lucas. While modern health and safety is vastly improved, the potential for catastrophic incidents remains. Mr Lucas cited the 2008 sugar dust explosion at Imperial Sugar Refinery (USA) which claimed 14 lives and injured 38, and the Buncefield oil storage explosion in 2005, Britain’s most costly industrial disaster.
He outlined BRE’s leading profile in the field of DSEAR (Dangerous Substances and Explosive Atmospheres Regulations) assessments for process, manufacturing and food industries as well as biomass and energy. This involves screening hazardous areas in relation to ignition risks and advising on improved safety, mitigation procedures and designing out hazards.
Strong demand and a positive reception from all sectors for the conference, which launched last year, is set to make it a firm fixture of BRE’s annual events and CPD programme.
BRE Global managing director, Debbie Smith, who hosted proceedings, said: “We are delighted at the number of attendees and enthusiastic feedback. It reflects the diversity and influence of BRE’s fire research activities, working with government and major stakeholders on pressing areas for investigation and improvement in fire protection and fire risk management.”
Afterwards, a number of visitors took the opportunity to observe a live fire test in BRE’s Burn Hall, one of Europe’s largest dedicated research and test facilities for fire performance and fire suppression. Many also toured BRE’s world class Innovation Park which is at the forefront of cutting edge thinking in eco- and sustainable building materials and methods.
For more information, go to www.bre.co.uk/frcpresentations
