CROSS Safety Report
Testing of smoke control systems
A reporter is concerned about the way that smoke control systems in residential buildings are commissioned, installed, tested, and maintained.
Key Learning Outcomes
For facilities managers, fire risk assessors, system designers, and installers:
- There is a need for competent people at all stages of the design, installation, configuration, commissioning, and handover
- For those ultimately responsible for compliance with the Building Regulations at the build stage to be able to demonstrate how this has been achieved
For Responsible Persons:
- Be familiar with the requirements of Regulatory Reform (Fire Safety) Order 2005
- Ensure any smoke control system within their premises is configured correctly and check that this was carried out by someone who is competent to do so
- Ensure any smoke control system within their premises is tested and maintained correctly, this should be carried out by someone who is competent to do so
Find out more about the Full Report
The Full Report below has been submitted to CROSS and describes the reporter’s experience. The text has been edited for clarity and to ensure anonymity and confidentiality by removing any identifiable details. If you would like to know more about our secure reporting process or submit a report yourself, please visit the reporting to CROSS-UK page.
Smoke control systems are technical solutions to ensure the protection of life in case of fire. Their main function is to operate in case of an emergency so that no smoke will be present in access corridors and evacuation stairwells. Should a system fail to operate as designed, the consequences could be severe, which is why it's important that systems are identified as inadequate through regular checking and maintenance, before a fire occurs.
The issue reported came to light out of research conducted into the functionality of smoke control systems in existing residential apartment buildings. The programme included approximately 50 field tests, for the conduction of which the reporter requested the attendance of a smoke control or fire alarm engineer to test the cause and effect of the systems.
The presence of these professionals was requested because maintenance records offered by block managers were considered unreliable for the quality level and thoroughness of the research conducted. Similarly, the reporter is of the mind that risk assessors do not necessarily request or witness testing. Recent experience from real fires in Regents Quay in Leeds (where smoke vent shaft doors opened in additional floors and allowed the spread of smoke) and New Providence Wharf in London (where the smoke detectors failed to operate the Automatic Opening Vent) motivated the reporter to fully interrogate the systems in place.
Current technical guidance dictates that automatic opening vents (AOVs) are configured in such a way that only the vent in the fire affected floor should operate, with the rest in the remaining storeys staying closed. For example, this is articulated in BS 9991:2015 (paragraph 188.8.131.52) where:
“Only the AOV leading from the protected corridor or protected lobby where the smoke has been detected should be configured to open. This should open either to external air or into a smoke shaft; all other protected lobby vents should be configured to remain closed. Fire and rescue service override controls should not permit multiple lobby vents to be open simultaneously”.
Smoke control testing, like the one carried by the reporter, involves the exposure of automatic fire detection devices to artificial smoke or the activation of point detectors in ‘fire mode’, rather than an engineering override function. This way the system deals with the incident as with a real fire. A well configured system will ‘lock out’ once a detector is activated, so that if other point detectors in other floors are activated, the vents will remain closed. These additional vents should be able to be operated again after a system reset.
Even though the analysis is ongoing, the reporter’s initial estimation is that 60% - 80% of buildings have failed cause and effect testing. The failures have been attributed to many different reasons, examples of which are that vents are opening in the wrong direction, design critical vents are not opening at all, or that many systems are not 'locking out’ allowing the operation of vent doors beyond the fire floor.
Another concern originated with one mechanical depressurisation system not clearing smoke effectively, leading to smoke pooling in corridors due to the lack of airflow in the corridor. However, the system had passed the air flow readings at the stair door and shaft vent. Re-testing of this system is pending.
A survey for further insight from groups of professionals who are involved in testing and maintenance of smoke control systems indicated that there is a lack of competency and awareness of the proper operations of these systems. Additionally, smoke control installations are not being inspected, tested, and maintained correctly, according to these groups.
The underlying causes for this issue, according to the reporter, are the lack of competent contractors in the industry, which contributes to improper installation and commissioning, and the eventual ineffectual testing and maintenance of these systems. Finally, the reporter considers that any cause and effect testing is not being completed as specified, either by block managers, contractors, risk assessors, or fire service inspecting officers.
Finally, the reporter worries that these issues may be present in other buildings beyond the area that they surveyed.
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This is a highly pertinent report. I would add that it is critical that there is verification that the installed system accords with relevant design standards, and, if there are derogations, the installer should then be required to explain why, and be subject to scrutiny by the building control body, with full consultation with the FRS. The relevant associations might wish to consider amending their guidance to reflect this.
The Smoke Control Association (SCA) welcomes this CROSS UK report on the commissioning, installation, testing, and maintenance of smoke control systems.
For many years, the SCA has encouraged its members to raise the standard of the smoke control industry to ensure that buildings are safer environments for the occupants and for fire fighters.
This is reflected in the many standards and guidance documents that the SCA has produced or assisted to produce over recent years which have set new benchmarks for products and system design.
It recognises that while most installations are carried out by competent organisations using compliant products, there are other installations where for many reasons, the design, installation, commissioning and maintenance might not be completely as expected for a life safety system.
The issues found during some site inspections by our members reflect this report and some of the poorer installations encountered are usually a result of either inappropriate design, incomplete installation, non-certified components, incomplete commissioning or a lack of competent maintenance. Many of these issues are caused by using contractors who do not have the right level of competence, or by clients who source components from multiple sources and try to assimilate these into a system with no single entity having overall responsibility.
Another major challenge has been the ‘race to the bottom’ in the procurement process identified by Dame Judith Hackitt, where some buyers of smoke control installations, for example, have in the past, given price a higher priority over compliance, competence and quality.
Following Grenfell, the SCA implemented wide ranging membership criteria to which every member is required to adhere, based around using compliant products, carrying an appropriate level of Professional Indemnity Insurance and signing up to the IFCC 3rd party certification scheme SDI 19 – a system of independent auditing and assessment of installations: https://www.ifccertification.com/certification/installer-certification.html
All members of the SCA who carry out installation of smoke control systems are required to carry this certification.
The audit process follows the guidance of BS 7346-8, which is the Code of Practice for the Planning, Design, Installation, Commissioning and Maintenance of smoke control systems.
Notwithstanding this all smoke control installations should follow a clear path at the commissioning stage, which includes:
1. Verification of the compliance of installed components
2. Verification of conformity to the design
3. Verification of the electrical installation in accordance with IET Regs
4. Electrical performance tests of equipment
5. Mechanical performance tests
6. Cause and effect testing of all operating modes
7. Integrated system tests with other building systems, e.g. fire alarms, generators, etc.
The issue of multiple levels opening at once has been identified for many years now and the installation should only activate on the first signal received, subsequent signals should be ignored unless part of the strategy – this should be checked during step 6 of the process described above.
A thorough commissioning process should identify and eliminate all the issues identified by the report when the building is complete. Product compliance and competence of key individuals is fundamental to this process.
However, all these efforts can simply be undone by a lack of maintenance once the building is occupied – all building systems need to be maintained over the life of the building, to keep them in full working order.
Once the building is occupied, the Regulatory Reform (Fire Safety) Order takes over, which requires an appropriate system of record keeping, testing and maintenance to be put in place. This should include, but not be limited to:
• Daily inspections for faults and notifications by owner/operator
• Weekly zone tests by owner/operator
• Quarterly full tests (all zones) by owner/operator
• Annual maintenance by competent specialists
The annual maintenance visit should include a process of checking the equipment is still in full working order, cleaning, where applicable and verification of performance which is similar to the commissioning process including as a minimum steps 4 to 6, making sure that the installation is still operating at the same level as the original design. The SCA is currently drafting a detailed maintenance guide for smoke control installations.
Following this guidance, using competent operators for the maintenance process along with using compliant components for replacement parts should ensure that the installation operates in the correct manner for the duration of the building’s occupation. Membership of the SCA ensures that its members receive regular updates on standards, guidance and recommendations relating to smoke control installation. As stated earlier, all members are required to sign up to a membership criteria, a code of conduct which includes, for example, using compliant products, carrying an appropriate level of Professional Indemnity Insurance and signing up to the IFCC 3rd party certification scheme SDI 19. Furthermore, the SCA has introduced a complaints process, that allows whistle-blowing should a member be found to be acting inappropriately.
While the issues observed by CROSS UK may be typical of the historical shortcomings of the construction industry as a whole, the SCA believes that the steps put in place by its membership will go a long way towards eliminating the issues found at the project completion stage. It is the duty of the owners of smoke control installations to ensure that a robust maintenance plan is put in place and that all outstanding actions and repairs are resolved in good time.
We strongly recommend therefore, that membership of the SCA is specified for all installation and maintenance of smoke control installations – a list of members can be found at https://www.smokecontrol.org.uk/.
Conor Logan CEng FIMechE FCIBSE
Expert Panel Comments
Expert Panels comment on the reports we receive. They use their experience to help you understand what can be learned from the reports. If you would like to know more, please visit the CROSS-UK Expert Panels page.
This is a significant concern and a recent London Fire Brigade thematic report included research into smoke ventilation systems in existing buildings and came to similar conclusions. These issues are being identified more and more by FRSs and obviously, unfortunately, normally 'during/post fire' but some being found during audit activity.
The report does not give the reasons for the non-functioning systems but these are likely to be poor design, poor installation, poor maintenance or a combination of all three. In addition, there can be a gap in understanding between those designing such systems and those testing and maintaining them. System design can be complex.
The report highlights two approaches to testing and maintenance of systems. One is based on simple cause and effect testing of the design. The other mentions testing the effectiveness of the system (i.e. a mechanical depressurisation system), with reference to 'smoke pooling', which infers that smoke from a fire was simulated in some way. These are different approaches to the testing of systems, and cause and effect testing in 'cold' conditions is typically done, rather than any simulation of smoke movement for practical reasons.
The report confirms the importance of an appropriate method for testing and maintenance of these systems, as the nature of testing with smoke, to assess system effectiveness, can influence the outcome of the testing (e.g. if 'cold' smoke is used, this behaves differently to 'hot' smoke, and may not necessarily be appropriate). Therefore, careful consideration needs to be made for appropriate testing and maintenance of these systems.
The real issues are those of competence and understanding. A UKAS accredited 3rd party certification scheme for installers of smoke ventilation systems in residential buildings is in operation, but not all installers are members of that scheme and in addition the scheme has only been in existence in recent years so there are plenty of existing systems that would have been installed by companies that are outside the scheme.
There are no schemes available for checks on the competence of companies that carry out maintenance of smoke ventilation systems, so there is no way for facilities managers to ensure that their systems are being maintained by a competent engineer. Facilities managers and fire risk assessors must be encouraged to ensure that they do what they can to ensure that systems are fully functioning. This may require investment but as they are safety critical fire safety systems that is necessary.
It is of vital importance that any smoke control system performs as required and intended to support the fire strategy of the premises. Failure to ensure this is the case may not only lead to formal enforcement action by the relevant authority having jurisdiction but may also place persons at risk of death or serious injury in event of fire.
There are documents that can be cited in ADB (both volumes), BS 9991/9999 as well as various documents on the Smoke Control Associations website Smoke Control Association, particularly SCA Guidance on Smoke Control to Common Escape Routes in Apartment Buildings.