The arrival of the Regulatory Reform (Fire Safety) Order in October 2006 represented one of the most significant pieces of fire legislation in recent decades. Its aim was to reduce death, injury and damage caused by fire, and it heralds a new proactive approach to managing risk.
The main effect of the Order is to place greater emphasis on fire prevention in non-domestic premises. Fire certificates have been abolished and the responsibility for compliance with the Fire Safety Order will rest with the ‘Responsible Person’. This is generally the person in control of the premises, or in a workplace, the employer and any other person who might have control of the premises, such as the occupier or owner.
The responsible person must carry out a fire risk assessment, the focus of which is the safety in case of fire of all ‘relevant persons’. This task may be passed to some other competent person, but the responsible person still holds responsibility for meeting the Order. The fire risk assessment will help the responsible person to identify risks that can be removed or reduced and to decide the extent of the general precautions that should be taken to protect people against the fire risks that remain.
Responsibility for enforcement of the new rules lies with the Local Fire and Rescue Service Authority who will carry out regular inspections, especially of premises that present most risk to the community. These inspections will be carried out within the context of the new Integrated Risk Management Planning (IRMP) agenda for the FRS.
Because responsibility now falls on the shoulders of a much wider and largely inexperienced group of people, the role played by those competent people undertaking the fire risk assessments or inspecting the building is of vital importance, together with the quality of the guidance that is available.
The Department for Communities and Local Government (DCLG) has issued “A Short Guide to making your premises safe from fire” together with a series of 13 guides on how to carry out Risk Assessments for identified building premises. The guides provide information about what to look for in order to minimise the risk from fire. Any fire risk assessment naturally needs to cover a wide range of aspects, from sprinkler systems to possible sources of ignition, escape routes to the combustibility of the fabric of the building, and it is this last aspect that has raised some concern in the construction industry.
Suitable and Sufficient Assessment of the Building Fabric
Under the section ‘identifying a fire hazard’ the DCLG guides list ‘insulated core panels’ as a potential source of fuel to be considered in a. However, by not distinguishing sufficiently between the many different types of panel, insulant and application there is a danger that the ‘responsible person’ will be led to believe that their building represents a risk where it does not, or will be unable to identify where the real risks are. Managing risk involves having adequate and accurate information. Without clear guidance, mistakes could be made that are costly either in financial terms or in terms of human life.
Even though the building fabric and Insulated Panels only form a small part of the fire risk assessment, it is crucial to base it on the right information and not on a generalised view about the behaviour of insulated panels in a fire. In recognition of the need for clearer guidance, EPIC (Engineered Panels in Construction) has produced a comprehensive guide to the main points that concern Insulated Panels when conducting a Fire Risk Assessment under the RRFSO, making it easy for those carrying out the assessment to identify whether or not they have a potential risk. These include:
- Insulated Panels and where they are found in construction
- Their performance in fire
- How to identify panels and other systems
The first step is to ascertain whether or not the building is constructed using insulated panels. Certain insulated lining systems such as Insulation boards with thin facings on either side e.g. aluminium foil or bituminous felts are often wrongly described as ‘panels’. Great care should be taken to check that a wall or wall lining is a panel and not a board when conducting a fire risk assessment
Insulated panels normally consist of two metal facings either side of an insulating core. The core is either bonded to the facings using a polyurethane adhesive in the case of mineral fibre panels or by autoadhesion in the case of polyurethane and phenolic cores. There is no air gap between the core and the facings. The panels are manufactured in a factory and delivered to the construction site as a single piece unit.
Insulated panels are generally regarded as non-structural although they are strong rigid units that act compositely when under load. This strength allows loads such as wind or static forces to be transmitted to the supporting structure and it is this property that distinguishes panels from other types of insulated lining systems It is important to make this distinction because the mechanical and fire properties of panels compared to alternative forms of construction can be totally different.
Having looked at the nature of the construction, the second stage is to consider other aspects such as the materials used. For example, the central core can be made of any one of a variety of insulating materials, each with different characteristics. The choice of insulation has a direct bearing on the performance of a panel in fire and therefore the fire risk assessment.
The most commonly used core material for insulated panels is polyurethane (PUR) or polyisocyanurate (PIR). From the mid 1990s the insulating panel industry gradually moved from PUR to all panels being manufactured using PIR by 2004. Mineral wool (MW) cores are used in a variety of panels for walls, ceilings and internal compartment walls. Polystyrene (PS) has been used as a core material for over 30 years mainly for panels used internally and for Cold Store panels.
Understanding the performance of panels in fire
Fire Safety Assessment under the Regulatory Reform Fire Safety Order is primarily concerned with life safety and the prevention of fire. This is very different from assessing a building from the viewpoint of property protection or that of the Fire Services where the fire is likely to be fully developed rather than a developing fire.
It is therefore important to take full account of the fact that at the critical personnel evacuation phase of a fire in buildings clad in PUR, PIR and mineral fibre panels the vast majority of heat, smoke and toxic hazard is created by the materials involved in the initial fire. It is these hazards that are likely to be critical in terms of life safety.
In a developing fire, the fire will generally be localised and the temperatures lower. At this stage the core of the Insulated Panels is protected by the metal facings unless the temperature causes the facing or panel to collapse, for example with some freestanding Polystyrene (EPS) cored panels where the core is seriously affected at temperatures below 180°C.
For this reason it is important to distinguish between panels used for the external envelope that are securely fixed to the building framework and that would remain in place thereby protecting the core, and internal panels that are often freestanding or supported on other panels and that are more vulnerable to collapse. PUR, PIR and mineral fibre panels are normally mechanically fixed through to the structural steelwork of the building and case studies have shown that these panels will not collapse until the building collapses.
Over the last 10 years considerable advances have been made in understanding how panels behave in fires, both through case history analyses and test, and the information has been made available to designers and building owners. Extensive large scale fire tests on a range of insulated panels have been carried out by EPIC in conjunction with the major test laboratories. For more information is available on the EPIC web site.
The results, backed by case history information, indicate that:
- Insulated Panels fixed to the building structure, in particular the roofs and external walls of buildings, remain secure without collapse even when the fire changes from a developing to developed stage
- Contribution of a combustible core to the fire i.e. as a source of fuel, is limited and gradual in the developing stage of a fire
- The contribution in terms of smoke and gases is minimal for MW, PIR and PF but slightly greater for PUR
- The contribution from PS cores is greater at an earlier stage due to the low melting point (120°C) and can result in the generation of black smoke. The bond of the facing is also compromised at an earlier stage increasing the possibility of collapse.
These results demonstrate how important it is to understand the nature of the insulated panels under scrutiny. The dilemma facing many of the people who have responsibility for fire risk assessment thrust upon them by the RRFSO is lack of information about the construction of the buildings they are responsible for. How can they tell whether insulated panels have been used, and what type they are?
Identifying different panels
The EPIC RR(FS)O guide carries unique information to help anybody involved in fire risk assessments or in the inspection process to identify whether the construction is insulated panel, what the insulating core material is and how the panels are fixed. These three elements are crucial in determining whether or not there is a risk.
The guide contains background information, simple diagrams and practical checks to enable identification of the different panels and any particular areas of risk arising from application or use. The guide will not only be of interest to the responsible person, it is intended to be an invaluable tool for competent persons undertaking the fire risk assessment, the Fire and Rescue Service and Insurance Surveyors alike.
In the meantime it is the responsibility of all those with a background in fire safety to ensure that the right information is made as widely available as possible in order to assist the process and avoid misconception and misrepresentation of perfectly safe construction materials and methods. The fact remains that insulated panels are increasingly specified in higher risk applications such as schools and hospitals because they can perform well in case of fire as well as delivering on thermal efficiency requirements.
The RRFSO is a major step forward in managing the risk of fire. It has the potential to save lives as well as reduce damage to property. As an initiative it deserves the backing of everybody in the construction industry. Let’s make sure, therefore, that it doesn’t cause a different kind of damage through misinformation.