Posts in category: Passive

Charles Devenish, Managing Director at Adexon Fire and Smoke, explores the transformative journey of fire curtain technology in the face of modern challenges

Adexon Fire and Smoke specialises in designing and manufacturing fire and smoke curtains.

Our history dates back to 2005 as part of the Cubex Group, which I established in that year.

Adexon is the business in the group that is dedicated to fire curtains, the other group businesses being Virtek (gates) and Cosmos (metal doors).

Around the time of the Grenfell tragedy, we recognised significant potential in the fire curtain market and decided to prioritise and invest heavily in this area.

Six years on, Adexon now boasts the UK’s most comprehensive range of legally compliant, third-party certified fire curtains.

We have achieved a considerable advancement in fire curtain design, positioning us as leaders in this field.

Historically, fire curtains faced recurring issues. These included fabric tears, curtains jamming in guides, and gaps between the fabric and guides.

These issues primarily stem from the conventional design of retaining the fabric in the side guides by inserting a bolt or popper through the fabric every e.g. 200mm.

Since the bolt’s size exceeds the guide’s gap, it effectively prevented the fabric from pulling out.

Issues to overcome

The primary issues with traditional fire curtain designs is the old method of retaining the fabric in the side guides using bolt and nuts, or poppers.

The penetration of the fabric together with what becomes a point load leads to frequent tearing and ripping of the fabric over time.

The inherent weakness is at each of the points where the fabric is fastened.

Over time, these fastening points become susceptible to wear and tear, akin to what might happen if you put a fastener through a shirt or jacket and then pulled on it regularly.

Regular movement exacerbates this vulnerability, leading to eventual tearing.

Additionally, because these bolts or poppers are typically placed every 200mm, there are significant gaps between each fastening point.

When these fasteners tear loose, the gap between points of retention widens, compounding the problem.

A third concern, and perhaps most common, is the jamming of the fabric or the curtain in the guides.

The bolts, originally intended as fasteners rather than as a travelling component, can ‘run’ into the narrow aperture and jam, metal-on-metal.

Whilst in a laboratory the curtain can be installed perfectly square and hence this is less likely to happen, on construction sites and in the real world, if the curtain is installed only millimetres out of square, or if the fabric unravels only millimetres out of square it will likely jam in the guides before full deployment.

In real-world conditions, which are far-removed from laboratory precision, variables and tolerances can cause the fabric to descend unevenly.

Consequently, the fabric may ‘run’ into the guide’s gap, leading to jamming.

Not only is this a life-safety issue in the event of a fire but the specific load on the popper or nut and bolt that is jammed accelerates ripping and tearing.

To address these challenges, we developed a new design 3-4 years ago featuring a continuous pole within the guide, around which the fabric is looped and then stitched.

This design has been extensively third-party tested and comes with current valid third-party certification.

This above design provides continuous retention of fabric, eliminating gaps, and with no travelling fasteners, point loads, or penetrations of the fabric it reduces the likelihood of fabric catching or tearing.

While the solution seems simple, it represents a significant advancement in design and greatly benefits the fire and safety industry.

We anticipate other companies will adopt variations of this design, which ultimately serves to enhance user safety in fire situations.

Changing the game

Fire curtains in the UK have largely remained unchanged for decades.

Until now, there have only been minor tweaks but no substantial advancements addressing the major, day-to-day issues – what one might call the ‘elephant in the room’.

Examples of these issues and the pains they cause the end-user was evident when talking with visitors at FIREX and the Fire Safety Event last year, where prominent figures like heads of facilities at universities, facilities management professionals, and estate managers, who have these curtains in their properties or portfolios, expressed a strong dislike for fire curtains per se.

Their frustrations stemmed from recurring problems such as jamming and tearing.

These are serious issues for life safety and their legal obligations under the Regulatory Reform (Fire Safety) Order 2005 which stipulates they have to maintain life safety equipment such as fire and smoke curtains in good state of use.

These issues have made fire curtains more of a headache for them rather than a safety solution.

It was clear from the reaction to our design that it is a welcome step-change, more than one describing it as ‘genius’.

Fire curtain applications

Fire curtains are not essential in every context; for instance, one could simply install a wall instead.

However, they are crucial in certain applications. It’s important not to overstate their necessity by claiming they are indispensable in all scenarios.

Rather, fire curtains are extremely effective when there’s a need for fire compartmentation combined with a desire for design flexibility, such as in spaces where installing walls, doors, windows, or glazing for compartmentation is not preferred.

For architects and designers tasked with dividing a space in the event of a fire or providing a protected means of escape, like an escape route, fire curtains are an excellent solution.

When retracted, they are virtually invisible, concealed within ceilings, and guides can be built into the walls.

They can be seamlessly integrated into the architectural design to be practically invisible, yet they deploy automatically upon activation of an alarm.

This feature allows them to close off a space, thereby protecting the building and occupants from fire and smoke spread, and also providing escape routes where required.

They are not only relatively inexpensive but also offer architects and designers significant flexibility that wouldn’t be possible without them.

We’ve further improved traditional fire curtain design by addressing the traditional use of cold smoke seals, which are commonly made from polypropylene filament, melting at 170 degrees Celsius.

In fire doors, this is not an issue as the intumescent strip, activated at 180 degrees, ‘takes over’ the sealing after the melting of the cold smoke seals.

However, on a fire curtain there are no intumescent strips due to them potentially blocking deployment.

In a fire, especially in multi-storey buildings with fire curtains over lift shafts, temperatures can vary dramatically, often reaching 1000 degrees Celsius.

At these temperatures, a cold smoke seal on a fire curtain becomes ineffective within seconds, failing to provide smoke control.

Other manufacturers use rubber draught excluders, but these too melt.

We’ve addressed this by using fire-resistant fabrics for sealing, and are advocating for hot smoke tests as the new standard in BS EN 1634-3.

Our approach uses fire-resistant components for effective smoke sealing, challenging the adequacy of current standards that allow using only cold smoke seals.

Certification

Without valid third-party certification, the responsibility falls on you, either as a buyer or specifier to ensure the product being manufactured is the same as the product originally tested, sometimes years ago. Or you can just take the manufacturers word for it.

Independent third-party certification entails a Notified Body, accredited by UKAS or equivalent, conducting regular independent and thorough inspections at the manufacturing site.

This involves factory production control inspections and audits of processes and documentation.

This level of oversight, executed by the Notified Body, represents the gold standard in quality control, ensuring that the product delivered to site is the same to the one tested.

In the absence of such certification, it is your responsibility as a buyer or specifier to conduct your own checks.

This might mean visiting production facilities to inspect manufacturing and production lines, checking through the design drawings and checking the components being used are identical to the ones originally tested.

This is impractical for most buyers and specifiers as well as being beyond the experience of most, especially compared to what a Notified Body will do.

Being realistic, could you invest the time to scrutinise their processes or verify if the components used in the products are consistent? In reality the valid third-party certification provides a level of risk mitigation that is crucial for life safety products and for which there is no substitute.

The difference could be life or death: a non-certified product might not perform as expected, potentially leading to catastrophic outcomes.

Regulatory changes

The process of regulatory changes are often gradual, with ample notice provided.

Manufacturers are given notice to align their operations accordingly, as the saying goes, ‘getting their ducks in a row’.

An example for the fire curtain market followed the inclusion of EN 16034 in the Official Journal of the European Union in 2016.

This signalled a three-year notice period before it became a harmonised standard. This time is also called the coexistence period.

For all countries under the Construction Products Regulations, the foreword of the harmonised standard applies, “This European standard shall be given the status of a national standard… and conflicting national standards shall be withdrawn at the latest by October 2019.”

In the UK it is prefixed with ‘BS’ giving it the title BS EN 16034, being the harmonised standard plus BSI’s guidance.

The harmonised standard is what is legally mandatory under the Construction Product Regulations since 1^st November 2019, specifically covering vertical fire curtains.

The key criterion for determining whether a product requires CE marking under the Construction Products Regulations is whether it is ‘covered’ by a harmonised standard.

You can read more about this topic in our white paper, Fire curtain regulations in the UK.

In the case of fire curtains, BS EN 16034 is such a standard since being harmonised on 1^st Nov 2019.

There remains a lack of awareness about this in the UK, possibly due to the existence of the older British Standard BS 8524 that some have historically favoured.

BS 8524-1 was the first dedicated fire curtain standard globally when it was published in 2013 but has now been superseded by BS EN 16034 for vertical fire curtains.

Prior to BS EN 16034 becoming harmonised, some in the UK pushed back against it so as to keep BS 8524-1 alive in the UK.

The Group of Notified Bodies for the Construction Product Regulations Steering Group 06, GNB-CPR-SG06, reviewed this resistance and concluded that BS EN 16034 does cover vertical fire curtains, making it a legal requirement to CE mark vertical fire curtains to it from 1^st November 2019.

The consequences for breaching these regulations are severe, including potential imprisonment and fines.

While there may not be many prosecutions under the CPR, the risk of legal repercussions is still a significant concern.

Another critical aspect is the insurance implications. Insurers can look for reasons of non-compliance to potentially deny coverage, even if the policy has been paid.

For instance, if a non-compliant fire curtain fails in an event of a fire, insurers could refuse to pay out, arguing that compliant products were not used.

This could lead to substantial legacy issues if people fail to install or replace their fire curtains with ones that are legally compliant.

Future of fire curtains

Fire curtains are increasingly recognised as a growth market with potential far exceeding the current market size.

Their applicability spans a diverse range of sectors, including manufacturing, storage, commercial, public buildings, and housing, where compartmentation in the event of a fire is crucial.

For example, in scenarios where charged items are stored, fire curtains can effectively isolate a fire, preventing it from spreading.

In the general construction industry, fire curtains have often been considered a last resort due to prevailing issues and perceptions.

However, as we continue to communicate their benefits and demonstrate their improved functionality, the industry is beginning to recognise their value.

People are noticing the elimination of previous pain points and headaches associated with fire curtains.

As these negatives are addressed, there’s a growing preference for using fire curtains over avoiding them, acknowledging their effectiveness and practicality in fire safety and prevention.

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