Dr Jim Glockling, Consultant and the former Technical Director of the Fire Protection Association and RISCAuthority discusses the residential sprinkler system installer scheme in development at BAFE.
In association with a building’s built-in passive fire resisting features, residential sprinkler systems have been demonstrated to be very effective at protecting lives from fire, both of the occupants and those attending. Their use has typically been prevalent where normal safety measures might be considered insufficient to assure the safety of occupants either due to their own special needs, or due to the specific challenges of the building such as its height, layout, or remoteness from Fire Service support. Post-Grenfell, and with new specific legislation for their inclusion in new in some UK nations, there has been a proliferation in demand for residential sprinkler systems and the market has often struggled to keep up. This is of course a recipe that can lead to challenges of quality in terms of:
- whether the sprinkler system design is appropriate for supporting the overall fire safety plan of the building
- quality of correct specification, installation, and use of all products and materials.
All of which may impact upon the system’s ability to operate and perform when needed, and not operate inadvertently and result in water damage. To highlight and address these issues, the Association of British Insurers commissioned TGN Residential Sprinkler Systems to BS9251 Guidance and recommendations for the implementation of Residential Sprinkler Systems, which has since been built upon by RISCAuthority to produce an insurer augmented version of Approved Document G that covers household water systems: ADG Insurer Requirements for Enhanced Escape of Water Protection and Safety in Building Plumbing and Water-based Fire Suppression Systems, based on The Building Regulations 2010 Sanitation, hot water safety, water efficiency.
When we talk about sprinklers it is important to note that there are some key differences between residential and commercial sprinkler standards. Residential installations are designed for life safety – to assist the occupant reach a place of safety in the event of fire. Commercial systems are designed for property protection. This difference results in standards that are very different in terms of size and complexity, and how they are deployed. Commercial standards must cater for a myriad of diverse environments from office blocks and shopping centres, to warehouses. They must be adaptable to the challenges presented by the many different stored commodities they protect in association with the full range of storage methods used. With every recommendation seeking to provide a resilient solution, based upon full-scale testing, and to be suitable for insurance underwriting purposes, the most crucial feature is that their use is entirely prescriptive. Every similar commercial protection scenario should result in the specification of the same system, with the same water delivery rates, and duration. Simply put, the ‘engineering’ has all been done prior to the authorship of the ruleset.
Compare this now to residential sprinkler standards. Although standards provide design solutions for some basic situations, any situation where occupancy, circumstance, or building challenges warrant special consideration - which will be the majority of situations - the user is directed to seek the services of a risk expert. Whilst these ‘Special Considerations’ are referenced in the sprinkler installation standard, it is the responsibility of the client, or their appointed representative, to consider these, and communicate the results of their deliberations to the sprinkler designer/installer so that these can be accounted for within the design. Residential standards therefore have a large ‘fire engineering’ component to them, and procedurally demands an exchange of information between key stakeholders to ensure the resulting system will do its part in meeting the requirement of the overall fire safety plan for the building. To proceed without this, the sprinkler designer/installer inadvertently risks taking on liabilities which are not theirs to take, and breaks the ‘golden thread’ of information exchange specified post-Grenfell in the Hackitt Review.
Residential sprinkler systems are also characterised by a reliance on plastic pipe for water distribution which can present a significant escape-of-water challenge if poorly implemented. The chemical compatibility of plastic pipe to other materials that they may transport, or externally come into contact with, is complex but requires very careful consideration during design, installation, and through-life maintenance if network failure and the associated escape of water is to be avoided. The route to failure is usually two-part; a weakening at the molecular level by environmental contaminants, which in turn reduces the strength of the pipe to below the mechanical forces it is being asked to handle. As such the contributing factors can include:
- mechanical stressing of the pipe or fitting from poor installation
- abrasion/pitting of the surface that encourages contaminant ingress and cause structural weakening
- contact with incompatible materials and poor bonding.
The potential impact that contact withcommon materials can have on the longevity of the system must not be underestimated and as such requires considerable research and expertise on the part of those installing and maintaining the system. It is imperative that those installing plastic pipe networks are OEM trained in the design, installation, and maintenance of the specific products used within the system.
For some plastic pipe types the list of materials that they are sensitive to might even seem counterintuitive, and include many very common associated construction products such as: caulks and fire stopping materials; leak detection fluids; mould inhibitors; pipe clamps; pipe tapes; thread sealants; paints; and insulating materials.
To address these, and many other potential issues with quality of supply, BAFE are developing a new scheme, DS302 For the Design, Installation, Commissioning, Maintenance & Verification of Sprinkler Systems in Domestic and Residential Premises, based upon a requirement:
- to clarify the roles and responsibilities of all participants in the specification, design, and installation process
- to ensure the correct information exchange happens to deliver the required system
- to insist upon third party certification of people and equipment for the delivery of an effective system that will function against fire, and not contribute to escape of water losses.
There has never been a more important time to address this, given that the proliferation of sprinkler systems will be a key component of preventing future terrible fire events in the multi-storey situation.
The proposed scheme will differentiate BAFE registered organisations from nonregistered organisations by assuring:
- structural compliance with CDM and RRO
- sprinkler system designers/installers do not accept unacceptable liabilities for the installation
- proper demarcation between active and passive protection responsibilities
- the system meets the requirements of the fire safety strategy
- all equipment, people, and methods are third-party certificated
- that there is compatibility between sprinkler pipe components and any materials they contact that will prevent escape of water including fire stopping of pipe penetrations through fire resisting elements of structure
- that where BS 9251 systems are extended to include (small) areas of Ordinary Hazard commercial protection (now permitted within BS 9251:2021), that the designer is fully conversant with BS EN 12845 and therefore has the required deep understanding of commercial sprinkler protection systems to identify best practice and system selection.
And will be meaningful to:
- property owners taking the Hackitt approach of doing ‘what needs to be done,’ rather than ‘doing the minimum you can legally get away with’
- design/installing organisations who want to differentiate themselves on the grounds of quality
- insurers who seek systems more likely to perform and less likely to leak.
It is hoped that this valuable initiative will protect the hard-earned reputation that sprinklers have for being the most reliable form of fire suppression.
For more information on the proposed competency scheme, (DS302) For the Design, Installation, Commissioning, Maintenance & Verification of Sprinkler Systems in Domestic and Residential Premises, please contact the BAFE office via info@bafe.org.uk.
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Dr Jim Glockling is a Consultant and the former Technical Director of the Fire Protection Association and RISCAuthority.