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Fire Doors: Routes to Enhanced Performance

07 November 2022

THE TRAGIC fire at Grenfell Tower in June 2017 has led to much examination of the escape protocols for high-rise buildings and the materials and products used within the build process. In parallel with Fire Door Safety Week 2022, which ran from Monday 31 October until Friday 4 November, Alfie Hosker discusses the overriding requirement for the enhanced security and fire performance of door sets.

Post-Grenfell, the Government quite rightly called for further investigations and Secured by Design took an active part in that process as a member of the Grenfell Tower Technical Group, which was set up in March 2018 to provide technical advice specifically on entrance door sets to individual flats. Those door sets include the door, the associated frame and all component parts, such as the glazing and door hardware.

The Grenfell Tower Technical Group’s members, which included representatives from other not-for-profit organisations – among them the Fire Industry Association (FIA) and the Door and Hardware Federation (DHF) – met frequently throughout the rest of that year. Our comprehensive technical findings were duly reported to central Government via the Grenfell Independent Expert Panel.

Building on the collective expertise and experience within Secured by Design, the FIA and the DHF, these three organisations took the unprecedented step of collaborating on a document entitled ‘Guide for Selecting Flat Entrance Door Sets’, which was subsequently published in March 2019.

Aimed squarely at housing associations, landlords, building owners, developers and local authorities in England (with the caveat that much of the advice is equally applicable to other nations comprising the UK, even though Building Regulations may differ slightly), the publication brings together the best collaborative advice available from the industry in one straightforward document in a bid to highlight the fundamental issues of fire safety and security for those selecting such door sets.

Importantly, the publication makes the point that there is no conflict between fire and security with Building Regulations Approved Document B (fire) and Approved Document Q (security) carrying equal weight and neither taking precedence over the other.

The publication also covers why only factory produced door sets can meet both Approved Documents B and Q, what to look for in terms of performance for fire, third party certification for fire and also security issues and other performance affecting flat entrance door sets, glazing considerations, what to be aware of in terms of assessments, installation, maintenance, multi-occupancy buildings and Government advice to Building Control.

Certification to include smoke control

Last year, it came to the attention of Jon Cole (chief operating officer at Secured by Design) that smoke test evidence was not being included in certification schemes as it was for fire resistance and security. We have subsequently revisited the possible life-threatening characteristics of fire-rated door sets given that asphyxiation caused by smoke inhalation is the most common cause of deaths in flats when a fire occurs.

Currently, door set thresholds can legitimately be tested to BS 476-31.1 or BS EN 1634-3 with the threshold taped up and be assigned an ‘S’ designation (according to the guidance within Approved Document B) or an ‘Sa’ classification (when classified according to EN 13501-2) as the threshold gap is effectively discounted in both instances.

It's also possible to maintain designated smoke performances (ie S or Sa) when following the guidance outlined in BS 8214, which allows for a 3 mm gap at the threshold in situations where fitting a threshold seal is not practicable.

It’s the firm opinion of Secured by Design that neither are acceptable in a ‘real world’ fire scenario. The former (ie taping up the threshold) proves nothing when the door set is exposed to smoke in an apartment block and could therefore lead to smoke unnecessarily entering an area that’s designed to be a safe haven. The latter (ie the 3 mm gap allowance) has been independently proven to allow smoke leakage of up to 10.5 m3/h/m (ie three times the allowance of 3 m3/h/m in the current Building Regulations).

Find out more about a series of tests commissioned by the Intumescent Fire Seals Association by visiting the website at https://www.ifsa.org.uk/wp-content/uploads/2021/04/IFSA-Fact-Sheet-02-v0321.pdf

As soon as we realised that smoke was at risk of not being treated in the same way as fire and security evidence, it was critical we sought to resolve this issue specifically for all Secured by Design developments and in relation to all door manufacturers recognised by us through our Secured by Design membership scheme. In early 2021, we secured agreement from all of the UK certification bodies working in this area to incorporate smoke control into their fire and security schemes for flat/apartment entrance door sets.

Confirmed requirements

With the safety and security of residents very much in mind, we have confirmed our requirements for all fire, security and smoke-rated door sets carrying Secured by Design approval to the UK test and certification organisations. All smoke control tests should be conducted with the door set threshold un-taped. Further, the allowance of a 3 mm gap under the door is also unacceptable.

Therefore, Secured by Design will require all member companies with door sets listed on Secured by Design schedules that are fire-rated and required by the UK Building Regulations (England, Scotland, Wales and Northern Ireland) to have smoke control properties for the intended installation (eg  flat entrance door sets) to be certificated for the following attributes: security, fire and smoke control. On that basis, all Secured by Design fire, security and smoke-rated door sets will require a detail that enables the door set to comply with the Building Regulations’ maximum requirement for smoke leakage of 3 m3/h/m.

Secured by Design has committed to both promoting our requirements and to support other organisations lobbying for change in this important area. We are adamant that any door set carrying Secured by Design accreditation should be fit for purpose in all declared characteristics, but especially so those that are life-critical such as fire, security and smoke control.

Ultimately, we are wholly committed to saving lives and making homes safer places in which to live, work and play.

The ‘Guide for Selecting Flat Entrance Door Sets’ is currently being updated to include these new Secured by Design requirements. The readers of Fire Safety Matters can have full confidence in using this publication as an authoritative source of information, which will guide practitioners through the complexities of what is an extremely important area of the Building Regulations.

Alfie Hosker is Technical Manager at Secured by Design (www.securedbydesign.com)

*Copies of the ‘Guide for Selecting Flat Entrance Door Sets’ can be downloaded for free at https://www.securedbydesign.com/images/downloads/DOORSET_BROCHURE_update_25.3.19.pdf