Case Study: Fire Sprinklers Retrofit in Tower Block
As a result of the tragic events which occurred at Grenfell Tower in June 2017, a decision was taken to retrofit a full fire sprinkler system into the 12 storey block, Cumberland Towers, the only tower block in Ipswich of its’ type. Ipswich Borough Executive Committee agreed that despite it having a high level of existing fire safety it would be prudent to accept recommendations that a fire sprinkler solution would improve the safety of the residents to the highest level.
In August 2017, Nationwide Fire Sprinklers were selected as the council’s preferred contractor, tasked to both design and install the retro-fitted sprinkler system . Work on site was scheduled to commence by late October allowing 10 weeks for the completion and client acceptance of the design. An installation and project management team was allocated at an early stage to ensure that the client’s preferred programme schedule would be met.
Property: 12 storey, 63 flats & communal areas
Client: Ipswich Borough Council
Project Value: £180k
Time to complete: 10 weeks
Cumberland Towers was constructed during the 1960’s as a block for all ages but since the late 1990’s has been converted into sheltered housing. Comprising of 63 flats and 12 storey tall, it also has on-site communal areas, a shared kitchen and a hairdressers salon. Each flat consists of a bedroom, kitchen, bathroom and living room.
Ipswich Council Housing spokesman Neil Macdonald said:
“This is important both to improve the safety of the building and to provide reassurance to our tenants. This is their home and they need to be able to feel secure here.”
Alongside the fire sprinkler installation, the property was also undergoing a major refurbishment project comprising of energy efficient windows and balcony screens are being installed with open balconies being enclosed. In addition, the Council was also carrying out external thermal insulation cladding and putting in new doors and windows.
On many large scale retrofit projects* a pre-start and design site visit is often recommended. This is one of the most effective ways to fully understand the project and get an early view of any potential challenges that may be faced. From the outset the project was designed and installed to the BS9251:2014 standard. This resulted in a dual designation of a Category 2 (Blocks of flats greater than 18m high) system for the flats and a Category 3 for the communal areas.
As the property has 2 large water tanks on the top floor it was decided to use this as a shared water supply on to which a pump would be fitted. The existing tanks are now shared with domestic demand and upon sprinkler activation the supply is all diverted to suppression. This approach helps to reduce costs and also minimises disruption and prevents the added work of creating dedicated space for water storage and pump facilities. Utilising the existing riser spaces within the building the design allows for main water feed down the building that then supplies each level, with a valve set installed in each riser cupboard.
From the valve set, the floor is then fed by 1” pipe and each flat has 4 sidewall heads offering protection to the bedroom, living room, kitchen and main corridor.
Importantly the valve set is wired directly to main building fire panel which will display a “Fire” alert in the event of activation allowing Fire and Rescue Services to clearly see which floor level the activation is occurring on.
A section example of a flat design showing pipe runs and sprinkler head types. All designs are hydraulically calculated to ensure delivery requirements are met
Communication and coordination are very important when undertaking a project that requires the co-operation of residents. Ipswich Borough Council recognised this and from the offset organised pre-start residents meetings where there is an opportunity to show and explain exactly what would be happening and also to help address any issues the residents may have had.
When working in someone’s home, it is important to respect that fact. All our engineers are fully house trained!
A dedicated Tenant Liaison Officer was employed by Ipswich Borough Council throughout the project giving a single point of contact to address concerns too, co- ordinate flat availability and kept all involved parties up to date. Nationwide Fire Sprinklers do strongly recommend this within any project; experience shows the value of this on larger installations.
The following comments were taken directly from an email sent by a resident to the project team at Ipswich Borough Council.
“After our conversation on the sprinkler installation, I’m very pleased to let you know of my experience with the Company.
The engineers arrived a minute early of the agreed time of 8am. As usual they were scrupulously polite and respectful and said I had prepared my rooms perfectly and with that I went into my sitting room and with the door ajar in case they would need something, and carried on with my work on the computer.
Apart from a very brief visit to check the drill hole, I saw nothing of them and heard a couple of brief drill noises which were so brief as to me barely noticed. Then, quite suddenly, one of them appeared with a Hoover and started cleaning my carpet. I must have looked surprised because it was just after 9.30. He said, with a smile, all done.
I thanked them warmly as they left and my hall looked cleaner than before. I told them I would mention this so I hope you might pass these comments on to the Company because I had heard so much nonsense going around about the noise and dirt and 6 or 7 hours to complete.”
George De Stratton, Resident, Cumberland Towers
Residents are actively encouraged to ask questions and their feedback is vital in ensuring a smooth running project. We’re first to listen and help to ensure tenants are happy with the works done.
Sidewall sprinklers are either concealed in bespoke surface fitted boxing or cored through the flat walls, showing only a flush fitting cover-plate.
Surface fixing in projects of this nature overcome a variety of issues; installation time is decreased, no risk of compromised fire stopping as a result of excessive drilling/coring, white boxing is unobtrusive and importantly for projects with tenants in residency – disruption is minimised.
In other retro projects undertaken by Nationwide Fire Sprinklers the use of sidewall sprinklers fitted into custom fitted boxing also overcame another common issue on older properties – asbestos.
Many have traces of the substance in Artex ceilings which can be expensive and problematic to professionally remove.
Additionally there is the inherent danger posed when working around asbestos. Hence working off walls provides another advantage.
“The project has gone really well from start to finish. Working closely to understand the needs of our client and residents has helped up to achieve a near-perfect installation.”
Mark Fowler, Project Lead
To maintain compartmentalisation and retain fire resistant integrity it is vital that any service holes are thoroughly filled using correct fire stopping materials.
Unprotected horizontal and vertical penetrations in fire-resistance rated wall or floor assemblies diminish the fire-resistance ratings of these structures and are the leading cause of rapid and erratic spreading of smoke and fire.
In older buildings, it is not uncommon that over years of continued refurbishment projects that had original designed fire containment features have been compromised due to remedial work which has failed to patch service holes and voids created. As the principals of any fire and evacuation “Stay Put” policy are underpinned by the assumption that the building will retain its’ original fire containment design – it is vital that any contractors working to create or perforate walls, voids or ceilings then duly apply suitable and sufficient fire stopping materials to maintain this.
This is temporary stuffing during installation to provide continued fire protection during the ongoing works. The final fire stopping was added once the riser was completed.
Components & Compliance
Each floor has a valve set located within the existing Riser cupboard.
The set comprises of pressure gauge and a flow switch and the flow switch carries a relay down to the main fire panel to report in the event of activation.
Additionally, as per the British Standard, in this case, BS9251:2014 the system has a dedicated testing and control device attached to the pump.
Nationwide Fire Sprinklers have developed a fully BS9251 compliant product known as ATACS [Automated Testing And Control System] which ensures the whole fire sprinkler system complies with the requirement to auto-test on a 28-day cycle.
The ATACS unit is fitted next to the pump and will test it on a regular basis reporting any fault via a hard-wired relay to the fire panel.
The ATACS unit is capable of displaying both Fault and Fire conditions to the fire panel/alarm system allowing site management staff to investigate in the event of a fault.
ATACS ensures compliance with the extract taken from BS9251 below and offers more assurance to the client that Nationwide Fire Sprinklers provide the best in class in terms of design, installation and products.
5.9.3 Dedicated sprinkler pump
Where a dedicated pump is used, in addition to the recommendation in 5.9.1 it should be:
a) designed to include an automatic test cycle where the pump is activated at least monthly;
b) operated automatically on demand but requiring manual shut down.
Extract: BS9251:2014 Fire sprinkler systems for domestic and residential occupancies – Code of Practice
“Your installer Matt was excellent. He is certainly a very good tradesman, works very hard and efficiently and has done a great job. Very pleased with him, he was very friendly and worked really well against the odds.”