Fire safety in historic premises
03 February 2020
For its latest webinar, Fire Safety Matters partnered with Advanced and the National Trust to explore fire safety in historic premises
The Cutty Sark, Windsor Castle, Uppark, the Cuming Museum, Southwark, Eastbourne Pier and the Glasgow School of Arts are heritage buildings that have all caught fire in recent history.
“The likelihood of fires in heritage buildings is low, but the consequences are high if you do have one, and it normally results in quite significant property loss,” Bob Bantock, national fire safety specialist for the National Trust, explains.
In April 2015, a significant fire also broke out at National Trust property Clandon Park House. A fault occurred inside the electrical distribution board in the basement and, within a few hours, the fire had spread up to the roof through gaps in void spaces.
Fire risk assessment first and foremost
So how can we protect heritage buildings from fire? It must start with a fire risk assessment – a legal requirement under The Regulatory Reform (Fire Safety) Order 2005 for England and Wales. Under Article 9, the responsible person must make a suitable and sufficient assessment of the fire risks to people (life safety). The National Trust must also take into account property protection. The fire risk assessment document must be kept on site and reviewed on a regular basis and kept up to date.
Under Article 4, the responsible person has a duty to reduce the risk of fire and to stop it from spreading. This includes looking at the means of escape, making sure it’s safe for people and also taking measures for detecting fire through fire alarm systems.
The fire risk assessment helps to identify who the internal and external key stakeholders are that need to be consulted if you’re proposing any works, and it requires you to find out how the building is occupied and being used.
Bantock says: “From that, you need to understand who is responsible for what and that includes maintenance and repair. This process will help you understand what your significant findings are so you can apply the necessary passive and active fire safety systems to your building.”
The National Trust’s approach
Part of the National Trust’s fire risk assessment process is to identify water supplies, which can be scarce in heritage buildings, especially if it’s in a remote location.
For significant heritage properties, the National Trust uses L1/P1 fire alarm systems – L stands for life and P is property – with detection in every void space.
“Staff will respond first. They’re trained to use fire extinguishers, so if there’s a small fire we can make that initial attack,” Bantock says. “The P1 element of that fire system is linked to the alarm receiving centre so it can mobilise the fire brigade to assist with that process.”
To reduce the fire risk in its heritage properties, the National Trust tries to put in MICC cabled solutions.
“It’s costly but it’s less prone to rodent attack because of its mineral-insulated copper core. If you can get this into your walls, floors and ceilings it will last about 120 years – compared to ordinary cabling which might have to be replaced after 25 years.
“We also do five-year wiring tests. Thermographic surveys we do every two and a half years where we turn everything on and see if there are any hot spots – that’s one of the lessons learnt from the Clandon fire.”
The National Trust tries to get compartmentation – a solid wall in from the basement to the underside of the roof – into heritage buildings every 400 square metres.
“If there are any gaps and holes in that separation, then we look to fill that with a third-party-approved accredited product to be installed by third-party-approved accredited contractors,” Bantock says.
Dealing with large projects
An architect or design team working on a large heritage project will work to the RIBA plan of works.
“Post-Grenfell, they’re looking at revamping this and coming up with a different one called the Plan of Works for Fire Safety,” Bantock says. “We will employ where we can a chartered fire engineer to work on a very large project from the start, to look at the fire safety design, and help with the fire safety strategy. That sort of thing is always an afterthought when you work on a project. But the industry’s moving now to try to get that in at the beginning.”
Even if you don’t use a fire engineer, a fire risk assessor should be involved from the beginning to give advice. When engaging the external construction industry, it’s important to make sure they have got heritage experience and the same goes for fire engineers.
If the National Trust is working on a project, it must first make sure that the risk assessors and architects are working to the approved documents to comply with building regulations.
It’s a way of demonstrating that you’re meeting the functional requirements of those building regulations. The National Trust also makes sure it installs it fire alarm systems to the British Standard BS 5839-1 2017.
A question of balance
Amanda Hope, UK business development manager at Advanced, outlined some recent developments in fire alarm management.
Amanda explored how Advanced’s solutions can be implemented to reliably protect both lives and property, respect the value and authenticity of buildings and ensure compliance.
Amanda investigated methods of detection compatible with Advanced’s fire system, touching on:
• Aspirating Smoke Detectors (ASD), that draw air through a network of pipes to analyse the air for smoke contamination. If smoke is present, the fire system will trigger an alarm. They have a minimal aesthetic impact and extreme sensitivity.
• Wireless detectors, which require no cables as they are battery powered and operate via radio transmission. They are faster and cheaper to install than their counterparts yet also work alongside wired devices for seamless integration.
• Coloured smoke devices can be made to blend in more effectively with historic surroundings and are available in a range of bespoke colours.
• Beam detectors, comprising of an infrared transmitter and detector along with a reflector attached to the opposite wall. Beam detectors are suitable for spaces with high ceilings and can cover large distances of up to 100m. This means that fewer detectors are needed, thereby reducing the impact on the fabric of the building.
Fire alarm control panels:
A recurring challenge is to make the system as unobtrusive as possible without impacting performance. Thanks to repeater panels, the larger fire panel can be hidden from view. Some new repeater panels such as Advanced’s TouchControl touchscreen are designed to suit many locations, to flush fit and can add new performance features such as TouchControl’s digital zone plans and active maps showing fire status throughout a site. An alternative is bespoke cabinets and housings, which can be tailored to fit seamlessly into almost any decorative scheme or hard-to-access space.
Prioritised protection and notification
Another key to effective fire safety is to ensure that critical or high-risk areas are specified for a higher level of detection.
Fires can spread very quickly in historic structures, so measures to allow quick extinguishing via sprinklers, water mist or, for high priority areas, suppressant gas or foam should be considered.
For example, high value items such as the Magna Carta at Lincoln Castle required the installation of ASD in conjunction with gas extinguishant systems, Hope says.
“When the ASD detects smoke, it deactivates the air conditioning, providing a more stable environment, which then allows the devices on the gas extinguishing system to do their job. With the gas extinguishant system, a double knock activation provides confirmation of a genuine alarm causing the gas to release.”
BS 5839-1:2017 is the latest revision of British Standards code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises.
The EN 54 series of standards deal with fire detection and alarm systems. Advanced’s MxPro 5 fire alarm control panels are approved to EN 54 parts 2, 4 and 13.
The fire risk assessment needs to consider all the users of the building. As such, requirements for the Equality Act 2010 need to be considered.
“In scenarios where a deaf alert and radio paging solution is required by law, Advanced offer LifeLine. LifeLine delivers clear and instant transmission of fire alarm alerts, information and emergency communications via personal pagers to help ensure compliance," Hope says. "We can also provide SleepCom units which can be placed discreetly under the pillow to alert the occupant via vibration in the event of a fire situation.”
Eliminating unwanted alarms
False alarms remain one of the fire industry’s biggest issues, costing time, money and a lot of inconvenience. To address this, Advanced has developed AlarmCalm. Comprising of comprehensive configuration software for Advanced’s fire systems, the solution is a more complete false alarm management (FAM) technique, that will suit almost any building or site strategy, promising to radically reduce false alarms.
It allows a site to be divided into FAM zones called building areas (up to 200 per panel or 40,000 per network). These are virtual areas used for FAM programming that by default match fire zones but can be set independently to cover multiple zones and points or individual points. The use of building areas makes even complicated cause-and-effect easy to set up.
Once configured as part of a site’s cause and effect programming, AlarmCalm enables verification of a genuine alarm prior to entering a fire condition.
“These features come as standard as part of our false alarm management suite, built in to the MxPro 5 panel,” Hope concludes.
For Amanda Hope:
Can a pager system be installed anywhere?
Prior to any pager system installation, it is best practice to undertake a survey of the premises. Some sites can prove trickier than others however, on the whole, yes it can be done anywhere.
Are there any other practical alternatives to the pager when there are many people with hearing impairments in the building?
Alternatives include strategically placed strobes and flashing beacons.
Are the strobes mandatory?
It’s all down to the design. In a lot of public buildings, you will have strobes and it will be down to the design as to where to put those strobes. The main priority will be to cater for the hearing impaired under the Equality Act.
When adding panels to networks, do you need to program all the panels?
Not with Advanced. Once a panel has been installed on an existing network and given a network address it will become visible and able to communicate with all other panels without reprogramming of any of the existing panels.
Would wireless protection systems work effectively across multiple buildings or structures, e.g. caravans, lodges, or campsites?
They can work effectively. The most important thing to consider with a wireless system is conducting a radio survey to ensure the transmission paths are clear.
For Bob Bantock:
What is the National Trust’s position on the installation of sprinklers in heritage premises?
We’ve recently installed a sprinkler system at Quarry Bank Mill (a preserved textile mill). Every time we’re doing a project, part of the thinking and the strategy is to consider sprinklers in heritage buildings.
What’s your view on sprinklers compared to water misters in historic premises?
From a heritage perspective, both are the same. One produces more water, one produces less water. If you go down the mist system route, a lot depends on the type of room because if you’ve got big open spaces and big open windows, that can affect the mist system; if you get a broken window or cross-ventilation it could remove your mist cloud. So we would consider either.
How does the National Trust train staff and third-party tenants to deal with potential responses to fire alarm systems?
Under Article 22 of the Fire Safety Order, you’ve got that duty to coordinate and cooperate. If we’ve got multi-occupied buildings or a donor family or holiday cottage lets, we make sure that there are fire drills at least once a year to test evacuation procedures. If you’ve got third-party occupiers in your property, they do a fire risk assessment for their areas of responsibility and then we sit down and discuss how the system works across both, and have joined-up fire drills.
You can listen to the full webinar via http://tiny.cc/809ijz