MODERN METHODS used for the construction of timber-framed buildings are causing anguish among firefighters and insurers. So it was appropriate that this year’s RISCAuthority seminar was themed ‘New construction methods’ to seek to address and discuss these issues.
Insurance losses
The first speakers, Paul Woods, senior technical consultant at the Fire Protection Association (FPA), and Douglas Barnett, head of customer risk management at AXA insurance, provided a suitable link with last year’s event, which had the theme ‘Large losses’. Giving an update on the FPA’s statistics database for large fire losses in the UK, both speakers focussed on the importance of timely and accurate data gathering to indentify issues and trends relevant to insurance loss.
For a number of years, the FPA has published statistics in this area, but the decision was taken to create an online database, which launched in April 2009. To date, 328 loss adjusters have registered on the database, and for the year 2009-2010 some 345 reports were added, compared with 239 the previous year. The aim, said Mr Woods, is to align the database with insurers’ records, as well as those of the fire and rescue service’s FDR1 (fire damage) reports. By doing so, the database will provide a means by which insurers can benchmark their performance and provide the most representative data on large losses in the UK. This is seen as crucial for evidence-based lobbying and research.
Over the past year, the data entry form has been simplified to mirror the FDR1 form, explained Mr Woods. For example, it now requires less detailed information on sprinklers, where fitted, because the majority of loss adjusters will have a limited understanding of complex sprinkler system specification and , as such, the new format will reduce the risk of the form being filled in incorrectly. It is hoped that the database will soon have direct access to fire and rescue service statistics. As it stands, however, there is still much scope for increased input from insurers, and Paul Woods made a plea for such.
Douglas Barnett added that insurers should consider promoting the database and encourage loss adjusters to participate by, for example, making it a key performance indicator objective. If the database can become much more representative of the gamut of large fire losses, then the insurance industry will be better placed to view emerging issues and influence government with data that is pooled, urged Mr Barnett. For example, case studies over a number of years have shown that MMC timber-framed construction is problematic. However, all emerging insurance concerns resulting from the use of MMC building techniques must be presented to Communities and Local Government supported by quality and complete statistical evidence.
Operational risks
Picking up the theme of the risks posed by MMC timber-framed buildings, Geoff Harris (area manager, Fire Safety Enforcement) and Andy Brookes (head of operations) at Greater Manchester Fire and Rescue Service, offered a case study, highlighting the fire safety and operational issues which became apparent. Eighteen months ago, they explained, a three-storey, upmarket apartment block was destroyed by fire. It had a timber-framed construction using MMC.
When the first two fire appliances arrived at the scene, only smoke was visible and firefighters struggled to find the seat of the fire. More appliances arrived and it was discovered that the blaze had started in a wall cavity, but not before the fire had breached the roof. The fire had continued undetected in cavities for four days, and it was only when the building was demolished that the fire service was confident that the fire had been extinguished.
The cause of the fire was due to hot works being carried out by a plumber who was installing a condensate pipe from a domestic boiler through the exterior wall of the timber framed building. Whilst soldering the pipework he initiated a fire in the timber void and was probably unaware that the building was timber-framed.
Buildings are designed to deal with a fire in a compartment, not in a cavity, they said, and it was noted that in this particular building, which not untypically was clad with brickwork, one side of a cavity was flammable. Cavities in buildings like this often use a cavity barrier which is stapled in position, but the staples can melt in a fire. An alternative is to use ‘push-fit’ cavity barriers, but these are unpopular with builders, since they tend to push outside brick walls out of true when the mortar is wet. Another option is to drop barriers into the cavity, but clearly there is a lack of control with this method.
Other ongoing issues relate to works and alterations, which can breach fire protection systems. For example, many electricians do not realise that a new socket in a timber-framed MMC building needs to be fire protected when it is installed in a fire compartment wall. Another issue raised was whether timber-framed buildings should be restricted to certain uses, such as low-rise buildings and certain occupancies.
A problem for the fire service, they explained, was identifying the method of construction, which is often not obvious from the exterior. This can greatly affect operational decisions in the event of a fire. For example, the usual method of firefighting is with water, but water can fundamentally damage the structure of timber-framed buildings. The problem for the fire service, they asserted, is that current operational knowledge is based on traditional construction and, therefore, alternative approaches are needed for fighting fires in buildings using MMC.
US lessons
One delegate asked whether there was anything to be learnt from the USA, where the majority of buildings are timber-framed. In response, Jim Glockling, technical director at the FPA, said that according to the US National Fire Protection Association, cavity fires in timber-framed buildings, without sprinklers, is a significant problem.
Next, Niall Rowan, technical officer with the Association for Specialist Fire Protection, explained that of all the MMCs, timber-framed buildings have shown the most growth – in terms of popularity on a construction method – for many good reasons: sustainability, energy efficiency, construction speed, light weight, and the quality of manufacture of pre-fabricated elements. When fire strikes, however, it is characterised by rapid spread and destruction. Most fires in MMC timber-framed buildings, said Mr Rowan, occur to incomplete structures; after completion, tests have shown they are comparable with traditionally constructed buildings. But, he added, the tests assume they have been built properly.
What emerges is that passive fire protection features were often poorly installed. In timber-framed buildings, this is especially a problem, said Mr Rowan. While timber-framed buildings are not the problem per se, the issues that need to be addressed are poor specification, installation and enforcement. For example, said Mr Rowan, there are hundreds of tower blocks in London with no fire risk assessment. Are fire and rescue services checking that risk assessments are being done? Better specification supported by enforcement would go a long way to improving the situation, he urged.
UK perspective
Geoff Arnold, chairman of the UK Timber Frame Association (UKTFA) and managing director of Pinewood Structures, outlined the UKTFA’s proposals for addressing the issue of the vulnerability of timber-framed structures during the building phase. Responsibility for all construction site activities ultimately lies with the principal contractor, yet accountability lies with the timber-frame manufacturer. In an effort to rationalise these two factors, UKTFA came up with an initiative called SiteSafe.
The initiative is mandatory for UKTFA members, which are estimated to account for 80% of the UK timber frame construction industry, but only for large projects (four-storey-plus and/or 2,500m2 aggregate). Mr Arnold described SiteSafe as: ‘An accredited process to ensure manufacturing members provide clear and concise information and assistance to principal contractors regarding fire safety on large timber-frame construction sites’ (also see p.xx). It is a three-stage process involving pre-construction planning, on-site visits during construction, and off-site policing after construction is complete. Over the next three months, SiteSafe will be appraised with a view to generating further recommendations, and research and development project work.
Taking a small step away from the core themes addressed by the first speakers, Peter Wilkinson, associate director of Fire and Risk Services with the FPA, explored the historical development of fire engineering in the UK. Since 1666, prescriptive rules have been formulated in an effort to cope with the problem of unwanted fires. A landmark in this reactionary process occurred after the Second World War with the introduction of the Building Regulations. It was not until the expansion of Stansted Airport in Essex in the late 1980s that engineering firm, Arup, considered how the practice of ‘fire engineering’ could aid in the design of uncompartmented large spaces. Today, fire engineering is seen as the door to innovative design and architectural freedom.
Recently, however, concerns are being voiced. A number of interviews around the topic of fire engineering conducted by Mr Wilkinson have elicited some worrying thoughts. ‘The first phase of failures is now being seen’, said one interviewee. Another said, ‘there will be a serious fire in a fire engineered building’. Is fire engineering too often seen as simply a cost-reducing process or a way of ‘legitimising’ deviations? Are there too many gaps in data, application over buildings’ life cycle, and education? Is it the case that practitioners now have ever more sophisticated tools, but lack the experience to correctly use them? Mr Wilkinson is currently undertaking a doctorate degree on the subject, and hopes to develop his ideas.
The final speaker was chief executive of the Security Systems and Alarms Inspection Board, Geoff Tate, who provided an assessment of the relationship between the insurance and security industries, and the scope for collaboration towards better understanding and smarter standards.
Mr Tate highly recommended the recently published RISCAuthority document S9: Intrusion and hold-up alarm systems: considerations for installers and other stakeholders. While he said this was ‘an excellent publication’, its existence was an indication of a lack of influence by insurers among practitioners in the security industry. This was a challenge to which he hoped both industries would rise.