With the added difficulties of evacuating bed-bound or restricted mobility patients in the event of fire, those at Jutland’s largest hospital may rest secure in the knowledge that if it occurs, Hilti’s systems can contain and control fire spread
Hospitals present a significant challenge when designing for fire safety. They are complex buildings occupied by vulnerable people, some with restricted mobility or confined to bed, which means that should a fire occur, evacuation would be a major logistics exercise and a potentially dangerous one for some occupants.
The early involvement of Hilti fire specialists ensured that these concerns were addressed with the fire safety solution for the New University Hospital, Aalborg, Denmark.
Designed by the Indigo Consortium – schmidt hammer lassen architects, aarhus arkitekterne, Creo Arkitekter and engineering consultants NNE Pharmaplan, Brix & Kamp Rådgivende Ingeniører, Oluf Jørgensen Rådgivende Ingeniører and Royal Haskoning , the 134,500m2 hospital will be the biggest in Jutland and the backbone of the region’s healthcare system when it opens later this year.
To help prevent the spread of fire and smoke vertically between floors and laterally between rooms, the design for the hospital subdivides the building into fire compartments. These are separated from one another by compartment walls and floors made of fire-resisting construction. ‘Every floor is a compartment floor while in the wards, which have gypsum walls, every bedroom was treated as a fire compartment,’ explains Michelle Hornstrup, Hilti senior field engineer M&E.
Critically, to ensure integrity of compartmentation there must be no gaps in the construction of the element, which is why openings in compartment walls and floors for pipes, cables and conduits to pass through must be firestopped. Firestops for this type of application incorporate an intumescent element that will swell in the presence of heat to seal the opening around the combustible penetrants, such as plastic pipes or conduits to prevent fire or smoke travelling between compartments. To be effective, the firestop must be tested and third party-approved and have a fire resistance equivalent to that of the compartment wall or floor in which it is housed.
The early involvement of Hilti fire specialists was key to developing the safest and most cost effective fire stopping for the New University Hospital. The giant new facility features cast in-situ concrete floor slabs, rather then the more common Danish practice of using precast hollow-core elements to form the floor plates. Hilti exploited this feature by integrating its CFS-CID, cast-in firestop devices into the slab to enable plastic drainage pipework to pass safely between floors.
The CFS-CID features a firestop sleeve, complete with a lid, which is attached to the floor formwork, between rebar elements, before the concrete is poured. ‘It does makes demands on the user, because they must have decided the exact position of all pipework openings before the slab is cast,’ explains Hornstrup. ‘But this simply in line with design and construction best practice.’ Once the concrete is set and formwork dismantled, the device lid is removed to reveal the sleeve and its integrated fire and smoke seal. It is ready for pipes to be threaded through without the need for coring or drilling, while its integrated smoke gasket makes caulking unnecessary.
The contractor responsible for the construction of the floors appreciates the benefits the system delivers: ‘Hilti’s CID is a smart two-in-one solution as it creates the opening for the pipes to go through and at the same time offers an embedded fire stopping system,’ explains Nikolaj Pedersen, production manager. ‘The product is so efficient and easy to install that we’ve fitted 5000 pieces [on this project] and we’ve had zero failures,’ he adds.
Having used firestopping to ensure the integrity and insulation of the fire compartmentation, the challenge for the hospital is to maintain this integrity while accommodating changes to pipe and cabling installations from equipment upgrades and space reconfiguration. To futureproof the firestopping solution, Hilti’s CFS-SL Speed Sleeve has been used in compartment walls to enable cables to be removed and new ones added.
The speed sleeve is a firestop device with a twist mechanism that opens and closes an integral iris-like damper around the cables passing through the sleeve. This innovative device will help minimise air transfer between rooms and improve infection and dust control, and may even improve energy efficiency. ‘The Speed Sleeve means you don’t need a firestop professional each time a cable is added or removed, saving the FM team time and money and helping minimise the hospital’s running costs,’ explains Hornstrup.
Savings on both running and installation costs are major benefits of using Hilti’s pre-engineered firestop solutions on the New University Hospital. The real advantage, however, will be to the vulnerable people using the facility because it will improve patient safety by eliminating the danger from badly installed or poorly maintained fire stopping.