Automist Smartscan Hydra

Using Automist to reduce risks identified by PAS 9980

PAS 9980 provides a methodology for the fire risk appraisal of external wall construction and cladding of existing multistorey and multi-occupied residential buildings. It is intended for use by competent fire engineers and other competent building professionals tasked with advising on the fire risk of external wall construction of existing blocks of flats. It is solely focused on assessing the risk to life and is not intended to be used as a method of proving compliance with building regulations, nor risk to property through fire damage. The EWS1 form is for valuation purposes and, therefore, concerned with the risk to the property. A Fire Risk Appraisal of the External Walls (FRAEW), as outlined in PAS 9980, may provide the evidence needed to complete an EWS1 form in many cases, as long as the investigation is intrusive, thorough and conducted by a suitably qualified professional.

This PAS applies predominantly to multistorey blocks of flats but also includes the following types of buildings if, from the perspective of general fire strategy and means of escape design, and specifically evacuation strategy, they are similar in nature to a purpose‑built block of flats:

  1. student accommodation;
  2. sheltered and other specialized housing; and
  3. buildings converted into flats.

Under the Fire Safety Act, it is a legal requirement for any building containing two or more sets of domestic premises to have a Fire Risk Assessment that takes into account the following:

The structure and external walls, including

  • Any attachments (for example, balconies)
  • Doors and windows within those walls
  • Any common parts
  • All doors between domestic premises and common parts

Useful quotes from PAS 9980 regarding fire suppression and detection

Some form of remediation works to the external façades might ultimately be necessary, but equally, in some circumstances, a more proportionate response might be improvements or alterations to the fire safety design and fire strategy in the building. For example, in some cases, this could be retrofitting sprinklers into the block, or, in some cases, albeit rarely, changing from a stay put strategy to an immediate, simultaneous evacuation strategy by introducing a fire detection and fire alarm system, although these approaches might have limitations (see also Annex G).

Examples of positive common factors influencing the ability of occupants to escape once fire occurs and spreads via the external wall construction to other parts of the building and the ability of the fire and rescue service to intervene effectively.

F.6 Fire detection and fire alarm system

System with automatic detection throughout the building, including within flats, capable of immediate full evacuation, configured as:

  • common area coverage, also with detectors at least inside flat entrance halls (local warning within flat from domestic smoke/heat alarms); or
  • common areas and throughout flats*; or
  • monitored by staff on a 24 h basis or by an alarm receiving centre (ARC)*

F.7 Fire suppression

Sprinkler system throughout building, conforming to BS EN 12845*

Domestic sprinkler/watermist system in each flat:

  • conforming to BS 9251 (sprinklers);
  • conforming to BS 8458 (watermist);

NOTE: The weight attached to the presence of any fire suppression system in the building needs to take into account whether the system extends into, for example, any car parking area below the flats such that the scope for a vehicle fire to ignite combustible material on the external walls of the flats is mitigated.

G.5.2.1 Probability reduction

As an example, where sprinklers are installed, they reduce the probability of fire spread via external walls by reducing the likelihood that combustible materials/ products in an external wall construction will be ignited by a fire in the building.

G. Sprinklers

Automatic sprinkler protection reduces the probability of ignition of external wall construction by suppressing or controlling fire within the building. However, sprinklers cannot control fires that might start externally, and they cannot be assumed to control fire spread via the external wall construction if it is ignited.

In consequence, although sprinklers can provide viable mitigation, consideration needs to be given to the likelihood of any fire scenarios that sprinklers would not control (e.g. fires involving combustible balconies, balcony storage or external fuel loads), and the potential consequences of fire spread in the event that the external wall construction is ignited.

Sprinklers within the flats would significantly reduce the likelihood of a flashover fire giving rise to window breakage and direct flame impingement on the rendered EPS. There would also be scope to monitor the operation of the sprinklers through flow switches and link the system to an alarm receiving centre to facilitate prompt attendance by the fire and rescue service.

However, in the event that the rendered EPS were to be involved, prompt evacuation of all occupants of the block might become necessary. Concerns that this would place over-reliance on the fire and rescue service would need to be recognized. Facilities to assist with evacuation, e.g. an evacuation alert system conforming to BS 8629, might be seen as beneficial in this regard, but an evacuation alert system would only be of assistance if used as part of the overall package of measures in conjunction with sprinklers and remote monitoring of alarm by an alarm receiving centre. Evacuation alert systems alone are not intended to be installed as a risk mitigation measure.

It would be likely that, before agreeing that such a solution could mitigate the risk sufficiently, the external wall assessor would need to be satisfied that the rendered EPS was not likely to give rise to the extremely rapid degree of fire spread equivalent to that of ACM with an unmodified polyethylene core. This would require further in‑depth technical assessment of the ETICS by a fire engineer with specialist knowledge in that form of cladding system.

Why is Automist a useful tool for addressing this risk?

Automist is an easy-to-retrofit alternative to a standard sprinkler. It conforms with BS8458 and can be installed in as little as 3 hours. It was designed with retrofit in mind with flexible hoses that don't need to go through the ceiling, low water demand, and no need for a no tank or water main upgrade. These attributes remove some of the challenges with traditional systems:

  • Water supply
    • There is often nowhere to house a large tank, or this is a high cost associated with the water supply upgrade.
      • Cat 3 – One tank of at least min 3000 litres (weighing 3 tonnes)
      • Cat 4 - Two tanks hold 6000-12000 litres (weighing 6 to 12 tonnes)
  • Power supply
    • Generator in the basement
  • Expensive Core drilling
    • Floor-to-floor for rising main with fire separation required between floors. The rising main will be in the corridor, and then a valve set going into each flat.
  • Asbestos
    • Asbestos was widely used in the construction industry from the 1930s and onwards. It can be found in ceilings with textured coatings (e.g. Artex, Marblecoat, Newtex, Pebblecoat). It is expensive to work around.
  • Leaseholders Support
    • There is often resistance from leaseholders. They may be worried about costs, privacy, ongoing maintenance, reliability (not wanting ‘accidental’ triggers), disruption and aesthetics. Retrofitting will often involve surface mounting on ceilings of unattractive trunking; in a recent judicial review application (unsuccessfully challenging the decision by Birmingham CC to budget for retrofitting sprinklers), one of the concerns raised by the claimant was ‘the disruption to tenants that would be caused during the fitting works and the unsightliness of surface-mounted retrofitted sprinklers and pipes’. In relation to the Oxford Tower Blocks, one resident interviewed by the local newspaper expressed dismay about the sprinkler system: ‘I don’t like it at all. Would you like that pipe going through your floor? The pipe looks like an industrial style of sprinkler and not for a home. I don’t like anything about it.
  • Life cycle costs
    • In 2006, the Building Division of the Office of the Deputy Prime Minister (ODPM) commissioned a detailed report (BRE report - No. 204505) on “The effectiveness of sprinklers in residential premises”, carried out by the Fire and Rescue Service.  It concluded that sprinklers are not necessarily the best solution for most housing due to their high installation cost and the water damage incurred when triggered. Read more about the lifetime case for Automist over fire sprinklers.


We work with many fire engineers who know how our technology can enhance safety and reduce specific risks. Fire engineering can be used alongside fire suppression case-by-case to address fire risks identified by a fire risk assessment.

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