Howard Passey highlights several key fire safety factors to consider when refurbishing or renovating buildings.
When embarking on a building refurbishment, it is vital to consider fire risk at all stages of the process, from initial design through to the choice of materials and construction methods, to the effective management of the construction work. In the wake of the Grenfell Tower tragedy, there is an increased legislative focus on the roles and responsibilities of individuals in ensuring fire safety and recognition that only those with the appropriate and proven competencies are engaged in support of the design and construction work.
During the design phase of a refurbishment or renovation project, it is essential that construction teams factor in processes and systems that will minimise the risk of fire, as well as those that could prevent fire from spreading if an incident were to occur. If missed at this stage – when a building’s layout and specification is determined – retrofitting becomes far more challenging and can potentially compromise the future safety of the building. For example, non-combustible and non-flammable materials should be used wherever practicable, to reduce the fire load; materials and methods that avoid the need for hot work on site should be utilised; and applying design details that prevent the passage of smoke and flames up through a building during the construction phase. In addition access and egress routes must be effectively planned to retain safe evacuation routes during the construction phase; and firefighting and fire alarm systems designed to allow for their early use − possibly on a partial use basis.
Whist there are many key aspects of any refurbishment project that need detailed consideration, there are several as described below which are of particular importance.
Compartmentation
Compartmentation is a crucial measure in limiting the spread of fire and smoke by, for example, creating protected escape routes, surrounding areas of high fire risk and protecting critical infrastructure and/or materials. Essentially, compartmentation is the provision of fire resisting walls and floors – with measures to address any openings in the compartment lines such as doors, glazing, service penetrations and ductwork – to contain a fire for a designated length of time.
When approaching a renovation, it is important to be aware of an existing wall, floor or ceiling’s potential fire protection role and the compartmentation strategy within the new design. Even where minor retrospective works are carried out, such as the installation of data cabling or re-routing of other services, the integrity of compartmentation can be compromised, especially in areas generally hidden from view, such as above false ceilings, in service risers, or in loft spaces.
Sprinklers
While sprinklers are not a legal requirement in commercial buildings – and only in residential buildings over 11 metres tall – there is no doubt that they are incredibly effective at mitigating the spread of fire. The National Fire Chiefs Council found that, in incidents in both non-residential and residential buildings, sprinklers work as intended in 94% of cases and control or extinguish fires in 99% of cases.
When incorporating sprinklers into a renovation plan, it is important to remember that for a system to operate effectively, it must be correctly designed, installed, commissioned, serviced and maintained. The FPA’s LPC Rules for Automatic Sprinkler Installations incorporating BE EN 12845 is the most widely used and recognised installation standard in the UK, and is aimed at anyone involved in the specification, design, installation, service, and maintenance of sprinkler systems. The requirement for sprinklers must be assessed at the building design stage, so that they can be effectively integrated within the building and taken into account when considering its broader layout and intended use.
The right materials
Sustainability is now, quite correctly, a major consideration when choosing building materials. However, this increased focus on environmental responsibility should not detract from the need to ensure fire resilience at every step of the design and construction process.
It is vital that materials, products and processes that have the potential to impact on a building’s fire safety are properly validated for their intended use. While we are seeing a shift in favour of more natural materials, such as timber, the sizable impact of building with a combustible material cannot be ignored. The fact that timber will burn has a major impact on the potential fire safety of any building where it is used.
Dr Jim Glockling, technical director at the FPA, recently wrote that an example of how this comes into play is when considering compartmentation. In a building of timber construction, if the fire travels through a wall lining and into a service duct or cavity containing combustible materials, the fire is now inaccessible to both installed fire suppression systems and potentially fire fighters. It is in a space which communicates with other parts / floors of the building and in a configuration that promotes fire spread. If sprinkler protection was to be installed to protect such spaces, this may require sprinkler heads to be mounted on combustible ceilings, which would be contrary to the requirements of the Sprinkler Rules recommendations and, as a result, the wider use of suppression systems would also need to be reconsidered.
Hot works
Serious fires frequently occur during maintenance and construction operations, where work is proceeding on either machinery/plant/services or the fabric of buildings. Most of these are the result of carelessness and ineffective supervision during operations requiring the use of open flames or the local application of heat.
In order to prevent such an event, a formal risk assessment should always be carried out whenever any hot work is contemplated. Hot work activities may ignite adjacent or unseen material, heat may be conducted away from the working area by metal components and sparks, or hot metal may travel a long distance while retaining the potential to ignite combustible materials.
Experience has shown that a satisfactory standard of care and supervision is far more likely to be achieved where a formalised written permit to work system is in force, under a competent supervisor with the authority to ensure compliance with the procedures. Such procedures are simple and straightforward and when applied will significantly reduce the risk of fire. They include:
- consideration of whether the work can be undertaken in a different way that does not require hot work, or if not practicable undertaking the work in a dedicated area suitably arranged and with appropriate precautions where fire risks can be more safely controlled
- where neither of the above options are practicable a risk assessment of the area and work to be undertaken should be completed
- the work area should be cleared of all combustible materials and those that cannot be moved (including fixtures and fittings) protected with a suitable non-combustible material
- the potential for sparks and such like to travel through openings in wall or floor construction should be considered and protected against
- appropriate fire extinguishers should be provided and staff competent in their use
- a continuous fire watch should be maintained by a dedicated individual throughout the works and for at least 60 minutes after work is completed, followed by further checks being made at regular intervals, of no more than 20 minutes, up to 120 minutes after cessation of hot work, before the permit is signed off
Further guidance, available free of charge, can be found in the RISCAuthority risk control guidance RC7 Recommendations for Hot Work. In addition, the RISCAuthority Hot Works Site Induction is a software-based toolkit is designed to ensure best practice risk control processes are understood by all entering a site. Located on a pc with printer and camera at reception, the software elicits information from those entering a site to conduct hot works and takes them through a hot works safety video, before asking them to complete a series of questions to demonstrate they have watched and understood what is required of them. If they answer enough questions correctly, then a photo ID, time limited certificate is issued to them which also contains important emergency site contact details.
Individual responsibility
The Grenfell Tower tragedy highlighted major skills and knowledge gaps among those responsible for the design, construction, maintenance and day-to-day operation of buildings. The Building Safety Bill has taken steps to address this by introducing a new regulatory regime that holds to account those participating in the design and construction of buildings, including refurbishment of existing buildings.
The Bill calls for the identification of ‘appointed persons’, each of whom will carry responsibility for certain aspects of the design, construction and maintenance of buildings. These individuals will need to be able to demonstrate their understanding of fire risks, alongside recognising the importance of using appropriate materials to positively impact building safety and minimise the threat to life.
Commentary within the Bill suggests that the principal designer, principal contractor and anyone involved in the appointment or management of third parties must have ‘appropriate skills, knowledge, experience and behaviours’ to carry out their duties in line with building regulation requirements.
It is certainly a challenge for those involved in the design and construction process to demonstrate a thorough understanding of fire risk. It is important for individuals to recognise the limitations of their own competence and seek support from certified professionals with demonstrable experience where necessary. For example, an architect embarking on a complex refurbishment project should engage a fire consultant or, where necessary, a fire engineer to ensure that fire safety is prioritised within their designs. Similarly, engaging with competent specifiers will ensure that product and material choices will meet the design criteria for fire safety performance.
Formal risk assessments
All non-domestic premises, and the common areas of some residential premises, are required to be the subject of a fire risk assessment, including during the construction and refurbishment works. For these assessments to be as effective as possible, the assessor must have access to all the information they need and those responsible must act on their recommendations. A particular consideration of the assessment will be ensuring the safety of those with access to parts of the premises that remain occupied during refurbishment or renovation of discrete parts which will require, alongside the other relevant fire safety matters, consideration by a suitably experienced and competent person. The best way to ensure competency is through third party certification schemes covering individuals, organisations, systems and products, especially given the ambiguity over the ‘appointed persons’ who will be charged with managing fire risk.
The need to balance the priorities of sustainability and safety, while keeping up with the latest legislation and regulations governing the construction industry, can make any approach to ensuring fire safety feel like a daunting task. But with support in gaining the right knowledge and understanding, you can ensure your renovation projects are fire safe, protecting the building and its future occupants from considerable risk.
Howard Passey is director of operations and principal consultant at the FPA
Fire Prevention on Construction Sites. The Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation, published jointly by FPA and Construction Industry Publications, introduced in 1992 and now in its 9th Edition has recently been made available for free download.
Please be aware that considerable efforts have been made to ensure the accuracy of the information contained within this article at the time of publication, however any legislative (or other) changes that come into effect after this may render the information out of date until it is reviewed and updated as part of the FPA’s content review cycle.