Meeting the minimum standard for fire resistance

Robert Cridford is technical manager at materials supplier Siniat

In the wake of the 2017 Grenfell Tower tragedy and the subsequent identification of failings within industry regulations, codes, practices and approval processes, there’s been a major tightening-up of fire-safety legislation over the past few years – and rightly so.

The publication of the Hackitt report in 2018 played a major role in this and, in 2019, Approved Document B was updated to incorporate more rigorous fire-safety standards. The changes outlined that the industry should move away from testing systems for fire resistance to British (BS) standards and instead ensure that systems are both tested and classified to the latest European (EN) standards.

“Although it may start with the manufacturer, it does not end there. We need the whole supply chain on board”

The simplest way to look at the amendments to Approved Document B is that any fire-resisting element should be proven using EN standards, following the process of ‘test’, then ‘extend’, and then ‘classify’.

First, testing must use the appropriate EN fire-testing standard. Next, extension of test data to similar applications can be done, but only by qualified and approved third-party bodies using the test standard or extended application (EXAP) – and, critically, only where the standards explicitly allow it. Finally, this evidence must be validated and summarised in an official third-party classification report.

Following this chain means that you are meeting Approved Document B and that everyone involved knows that the evidence is to a minimum standard of quality and verification.

The challenge is that the updated guidelines in Approved Document B can be more onerous than previous testing standards. They demand extensive additional testing, extension and classification of a manufacturer’s entire portfolio of systems, which is a laborious and expensive task. This process takes time – even years – to complete. So it is understandable that since 2019 the industry has been in a transitionary period.

However, three years down the line, legacy recognition of the old BS standards should no longer be acceptable. Manufacturers of systems for fire resistance should, by now, have invested in any additional testing and classification. In the very near future, all manufacturers must be able to supply classification reports for their most commonly used systems – at least.

But although it may start with the manufacturer, it does not end there. We need the whole supply chain on board if the industry is to adopt a robust and consistent approach to fire-safety testing, assessing and classification. When human life is at risk, we’ve got to work collaboratively to tighten our practice.

Confidence to design and build

Many designers and contractors are increasingly concerned about liability for poor design and construction, with difficulties in securing insurance and long extensions to defect liability periods. But if we want to sleep at night knowing that we are building safely, ensuring that we meet Approved Document B is the simplest way to mitigate these risks.

The building-safety regulations will soon stipulate a ‘golden thread’ of building-performance evidence, particularly around fire safety, stimulating a need for an up-to-date, easily accessible and unbroken thread of information. EN and (EXAP) evidence ensures that fire-safety information is not only more robust, but is supplied in a clear and consistent format, enabling the golden thread to be achieved more easily across the industry.

So, demanding classification reports is crucial for ensuring that fire-safety standards are taken seriously. If contractors, architects and building control aren’t requesting adequate fire-resistance information, it won’t become part of the project requirements and inevitably won’t be supplied, potentially exposing the client, designers and contractors to future issues.

We know that the industry is serious about preventing the loss of property and life. So we need to put that concern into action. Meeting the most up-to-date, robust, legislation is the best – and easiest – way to improve the safety of our buildings and give our partners and, more importantly, the people who will live and work in the buildings we construct, the peace of mind they need.

The minimum standard

The strict extension rules in an EXAP standard mean tough criteria must be met to increase height or change components, and old conventions may no longer be valid. This will inevitably cause some challenges and lead to some changes in practice for many different parts of the construction industry. But if we truly care about compliance, then it is completely necessary for the industry to familiarise itself with the right standards, adapt, and design and build accordingly. This isn’t about going above and beyond – this is the minimum standard that we should all be adhering to.

Like many things, supply and demand plays a role in this. While manufacturers need to invest in the provision of third-party classifications, main contractors, architects and building control need to be aware that these standards exist and that manufacturers are now able to meet them. Otherwise, as an industry, we are not building safely.

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