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RCI March 2018

Project1_Layout 1 07/05/2013 CLADDING & SHEETING Firestops: a passive route to safety is on the rise Tall buildings continue to play a significant role in meeting our housing and workspace needs with high-rise curtain wall systems being one of the most recognisable components of today’s buildings. But along with this has come the increasing importance of passive fire protection solutions playing a vital role in these buildings. Chris Hall, commercial development officer at SIDERISE, feels that passive fire protection solutions, such as firestops, are crucial to prevent the passage of flames and noxious gases from one compartment floor or room to the next Fires in high-rise buildings can generate large quantities of smoke that tend to spread vertically throughout the building, even if the fire is contained to one room. Smoke travels up to 130 metres every minute, and whilst most people can easily move at this rate in normal circumstances, the majority of survivors of fires stated that smoke restricted their ability to see to no more than four metres. When the gap/cavity at the perimeter edge between the floor and curtain wall is not properly sealed, flames and smoke can spread vertically to higher floors, and horizontally from one room to the next. Addressing these gaps/cavities by properly installing firestops maintains the floor’s fire compartmentation of the building. This delays vertical smoke-spread and reduces the risk of smoke-related injury in the upper floors of the building and adjacent rooms. Safe solution The perimeter barrier firestops seal the gap between the edge of the compartment floor slab and external curtain wall. Due to project designs and site tolerances, this linear gap can be variable, so the firestop system used needs to have a degree of ‘dynamic’ movement capability – compression and recovery – in order to accommodate serviceability movement, and more significant movement under fire load. It’s critical the firestop system does this in combination with the primary functional requirement, which is to maintain continuity of fire resistance between the compartment floor and the external wall. The installed firestop system needs to match the same period of fire resistance as the compartment floor. All firestop systems need to be tested to two criteria: integrity and insulation (EI). Integrity (E) refers to the ability of the system to prevent the passage of flame, smoke and combustible gases either through, and around the material or through joints in an assembly; while Insulation (I) refers to a measure of the increase in conducted heat transferred from the exposed to unexposed surfaces of 180°C rises above ambient. These two criterias are critical in the development of curtain wall perimeter firestop products. The most effective products combine a number of material features – density, thickness, resin content, fibre structure and controlled compression – which together determine the 050 MARCH 2018 RCIMAG.COM “Products used for fire safety installation should carry an independent third-party certification, in order to ensure that the product supplied is the same as that tested” resistance properties. When looking at the integrity (E) criteria, the material chosen must be impervious to the transfer of flame and gases, easy to install with minimal site management, and accommodate all real-world requirements at interfaces, joints and details. In order to meet the fire and smoke stop requirements in all external façade applications, Certifire Approved perimeter barrier and firestop systems offer an unrivalled combination of fullyqualified performance, practical installation and service benefits. The principal function of these systems is to maintain continuity of fire resistance by sealing the gap between the compartment floors or walls, and external curtain walls horizontally and vertically. These systems can offer fire rating options ranging from 30 minutes to five hours, and can accommodate void widths up to 1,200mm. In addition to providing an effective seal against the passage of smoke and fire, the products can also function as an effective acoustic barrier and plenum lining. Key design considerations The firestop should have test evidence to show that it is capable of accommodating movement of a façade. It is imperative that the installed seal is able to function effectively with due regard to all


RCI March 2018
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