Building safety a “ticking time bomb” if fire cable testing isn’t strengthened

Under current standards, only ‘fire-resistant’ cables greater than 20 mm in diameter undergo testing for direct impact to reflect falling debris and water jet testing on a single test sample. For ‘enhanced fire-resistant’ cables under 20 mm, no direct impact test takes place. The water test is just a spray test, while different stages of each test are conducted on different samples of cable.

Wrexham Mineral Cables believes this situation is putting lives at risk.

The company’s assertion emerges at a time when London’s Fire Commissioner Andy Roe has called for urgent change in the building industry as the number of blocks of flats in London with fire safety failings is now more than 1,000. While a majority of the issues involved are due to cladding, the remainder centre on other fire safety defects. In all of these buildings, the London Fire Brigade has suspended its ‘Stay Put’ strategy.

Testing “needs to be strengthened”

Wrexham Mineral Cables’ commercial manager Steve Williams suggests that testing needs to be strengthened for all fire-resistant cables as part of the construction industry’s wider drive to improve building safety.

Williams commented: “‘Enhanced fire-resistant’ cables play a fundamental role in ensuring that emergency and building-critical systems are supported in the event of a fire. They provide early indication of a fire and keep systems safe, while providing extended time for the Emergency Services to evacuate occupants and ensure critical circuits remain functional for longer periods. This is particularly crucial in high-rise buildings where evacuation times can be extensive or otherwise hindered due to the sheer size of the building.”

He continued: “The tests to which construction products are subjected need to be relevant and relied upon. It’s extremely concerning that ‘enhanced fire-resistant’ cables most commonly being used in fire alarms, emergency lighting, extraction systems, monitoring systems or even back-up generators may not survive fire, water ingress and direct impact. If this is the case, then it follows that building safety will remain a ticking time bomb.”

Raising industry standards

Williams informed Fire Safety Matters that Mineral Insulated Copper Cable is the only fire performance cable that, in historical testing, has survived in temperatures of over 1000˚C, while also being subjected to direct hammer blows and a full water pressure test using a fire hose.

Samples tested have been measured at just 5.7 mm in diameter and maintained their circuit integrity for over three hours.

Further, Williams noted: “We remain committed to raising industry standards. The only way to achieve this is by introducing a higher classification for such products. The Government’s review of current systems for testing construction products is a step in the right direction, but more needs to be done to ensure the safety of buildings.”

If a cable is required to function in the event of a fire, Williams asserts that each single cable sample must have to pass a true fire scenario test, helping to identify those which can survive, rather than simply resist fire.

“Ensuring that the tests which construction products are subjected to are relevant and can be relied upon is the only way in which we can make buildings truly safe,” concluded Williams.