Welcome changes to building regulations intensifies focus on performance of ‘fire-resistant’ cables, says Wrexham Mineral Cables

A leading manufacturer of Mineral Insulated Copper Cables is urging specifiers and designers to highly consider the stresses real-life fire scenarios have on ‘fire-resistant’ cables, so they can choose products that will truly withstand a critical situation.

As the focus on building safety intensifies, Wrexham Mineral Cables has approved of the amendments to Approved Document B (Fire Safety) of the Building Regulations – which means all new residential buildings over 11m tall must be fitted with sprinkler systems.

With the proposed Building Safety Act addressing the need for greater accountability at every stage of the construction process, Wrexham Mineral Cables’ Commercial Manager Steve Williams believes understanding the performance capabilities of different types of ‘fire-resistant’ cables is particularly important for specifiers and designers with whom the responsibility of product specification lies.

Currently, only ‘fire-resistant’ cables that are greater than 20mm in diameter must undergo testing for direct impacts and water testing with any significant pressure on a single test sample. For ‘fire-resistant’ cables under 20mm, different stages of the test are carried out on different samples of cable, whilst exposure to water is minimal. This means, most Fire Performance cables used to power fire alarms, emergency lighting, smoke detection systems and even smoke extraction systems in high-rise buildings, would not have undergone any true fire test to reflect the recommended changes.

He commented: ‘The tests which construction products are subjected to need to be relevant and relied upon, especially in tall buildings or anywhere that requires extended evacuation times. Regardless of size or construction, if a cable is required to function in the event of a fire, each single cable sample must have to pass a true fire scenario test.’ This is further reflected on the welcoming of sprinkler systems in high-rise buildings, providing the cables specified have undergone a true fire scenario test.

With the government set to review the certification system for testing construction products to examine how it can be strengthened, Mr Williams added this needs to be extended to ‘fire-resistant’ cables.

He added: ‘As a leading manufacturer of MICC cables (often referred to as the only true fire-survival cable) we have been calling for more stringent testing standards for “fire-resistant” cables that reflect real fire scenarios. We believe all “enhanced fire-resistant” cables should undergo a minimum of 3 hours’ fire testing, a water test that involves a fire hose or high-pressure jets, similar to a sprinkler system, and direct impact testing on the cable, not on the test rig supporting it. All three of these tests should be carried out on one single cable sample. Only then can a cable be classed as “enhanced fire-resistant” for use in critical circuits.’