Brad Parker, Owner and Managing Director at Charles Thomas, discusses a no compromise approach to heritage fire protection

Charles Thomas Heritage Fire Protection specialists has emerged as one of the leading installers of engineered fire protection solutions serving the heritage sector. Its clientele includes conservation building specialists, architects, consultants and owners of period property.

The company provides system consultancy, design and installation to historic and buildings of special interest, both commercial and residential estates.

Fittingly, the company has aligned the business with specialist products and services that are perfectly suited to safeguard yesterday’s treasures for future generations. One of these specialist products is Thermarestor: A predictive solution for electrical fires.

Electrical fires remain a prominent issue in heritage buildings. Though much of the mitigation solutions have understandably focused on post-ignition measures to prevent the spread of fire, Thermarestor is a device that aims to address the issue of pre-ignition at source.

Brad Parker, Owner and Managing Director at Charles Thomas, explains: “Fire is still the greatest single risk to our cultural heritage. Once established a fire has the potential to destroy the historic fabric completely, with the inevitable damage to valuable contents.

After a number of ‘headline’ fires, namely Windsor Castle, the Bailey report was commissioned to assess the adequacy of fire protection measures for the royal palaces and residencies that the Secretary of State had responsibility for.

“The investigation and subsequent report underpins the template for historic assets since its introduction in 1993. Sir Alan Bailey’s findings are well acknowledged and should be considered for all historic buildings.

“It concluded that the main lessons learnt from the fire were: the need for effective training of all staff in basic fire risk management and the actions to take in case of fire; the need for the earliest possible detection of fire by a reliable automatic fire warning system; and the need for fire separation or compartmentation to reduce the spread of fire.

“Recent large-scale fires could have been prevented or at least had the damage reduced if these protection measures were adopted.  In our case, ‘reliable automatic fire warning systems’ are at the forefront of our business vision.”

Helping to tackle the problems faced

The idea of Thermarestor emerged because there was not a low cost and accessible product on the market which could alert a third party to excessive, but pre-ignition heat in electrical locations.

Anything that uses electricity as a source of supply has the potential to cause a fire. In the UK alone there are approximately 25,000 fires of an electrical origin each year.

The major cause of fires involving fixed wire installations is localised resistive heating – loose, poorly made and oxidised electrical connections – generates excessive heat, often confined to a relatively small area.

If the heating process continues unnoticed over a period of time, Thermal Runaway can occur, whereby the heat generated cannot be dissipated, resulting in temperatures exceeding 1300˚C, hot enough to ignite any adjacent combustible materials. Prolonged electrical overload can have a similar effect, especially in relation to electrical intakes.

“The investigation to the devastating fire at Clandon Park in 2015, a Grade I National Trust property built in the 1720’s, reported the cause of fire to have started within a faulty distribution unit,” Parker tells. “The restoration project is reported to cost tens of millions of pounds.”

The importance of Heritage to our Economy shouldn’t be underestimated. Historic England’s study ‘Heritage and The Economy 2020’ value the heritage sector to an equivalent to approximately 2% of national gross value added (GVA) to the economy. In 2020 this was £36.6bn. The historic sector employs over 563,509 people.

Our Heritage attracts millions of domestic and international tourists each year. The number of visits to heritage sites in 2019 was 215m with these tourists spending £18.4bn. “These are large number with big consequences if we don’t protect our historic buildings,” Parker warns.

Unfortunately, existing circuit devices such as MCBs and RCDs offer no protection, as they are unable to detect heat generated at the points of connection.

Similarly, regularly inspecting and testing the electrical installation (an EICR in the UK) does not necessarily provide protection, because it is primarily concerned with determining if the installation is electrically safe for continued use, rather than focusing upon the risk of an electrical fire.

Given the recommended interval between inspections – and the fact that only a sample of the connected accessories, such as sockets, are routinely inspected – a resistive heating fault can easily develop unnoticed.

Thermal imaging using infrared cameras to detect ‘hotspots’ is another means of assessing the health of an electrical installation.

However, the usefulness of such a survey is dependent upon all electrical loads being present at the time of inspection, as the survey only records a snapshot at that moment in time when the camera passes over the connection point.

A case in point – Chester Cathedral

Charles Thomas has recently completed on a project installing Thermarestor in Chester Cathedral. “The vast majority of fire safety measures are post-ignition and seek to contain the effects of a fire,” says Parker.

“Thermarestor can possibly prevent such fires from happening in the first place. As a pre-ignition solution to the problem of fire, it represents a step change in fire safety.

“We have all read of devastating fires where the Fire Report carried out highlighted the ‘Resistance Heating Fault’ within a distribution board as the possible cause. Thermarestor sends a notification text to any number of ‘users’ when things are ‘warming up’ in the distribution board.

“As such Thermarestor will strengthen the fire prevention dynamic at Chester Cathedral, thereby reducing the fire risk to this important heritage structure.”

Key features of Thermarestor

As a pre-ignition solution to the problem, Thermarestor represents a step change in fire safety. The majority of fire safety measures are post-ignition and seek to contain the effects of a fire. Thermarestor prevents such fires from happening in the first place.

Key features of the system are as follows: continuous monitoring of the circuit for signs of excessive heat; if excessive heat is spotted, notifications can be sent to registered users as a maintenance issue warning which needs investigating – the fault causing overheating can then be rectified; notifications can be sent via an existing fire alarm or building management system, or as a standalone notification via text messages or email alerts; installation is straightforward and can be installed new or retro-fitted.

Predictive function

Thermarestor is important because it facilitates the sending of an alert to a third party prior to ignition, whereas most detection systems are post ignition.

That is not to say that post ignition measures lack credibility, but if there is an opportunity to turn a potential fire into a maintenance issue, then this must be a good path to tread.

The device thereby builds further fire safety into the whole dynamic by providing this predictive function.

“Our mission,” says Parker, “is to deliver fire protection solutions for the preservation of period buildings of special interest.

“As a society, with our country being home to some of the most outstanding and iconic historic architectural buildings of interest in the World, we believe it is all our responsibility and obligation to protect the very fabric of British heritage.

“We provide commercially graded consultancy system design and installation as we appreciate the importance of historic buildings and possess the knowledge and experience to overcome the modern-day fire engineering challenges they present. 

“Our company’s array of solutions includes the knowledge, qualifications and experience to assist in the design of fire protection requirements for any size project.

“As well as this, cost effective engineered installations will guarantee that new installation works or modifications to existing systems are certified in accordance with current regulatory standards.

“With Thermarestor in our armoury we believe we can provide a turnkey solution to any fire detection problem.”

This article was originally published in the January 2024 issue of International Fire & Safety Journal. To read your FREE digital copy, click here.