Lightweight modern façade systems are carefully designed to meet the performance needs of tall buildings, but people often misunderstand the complexity of passive fire protection requirements
While adequate fire safety systems must be specified as a life critical aspect of building design, the move towards façade-specific systems means that specification and installation should be straightforward. Paul Nash, fire stop manager at passive fire protection manufacturer FSi Promat, outlines a simplified approach to choosing the right system to provide passive fire protection in lightweight modern façades.
As with all aspects of a building, façades can see the rapid spread of fire around the building envelope if not adequately protected. This is why passive fire protection should be built into all lightweight façade systems as best practice.
While a strong focus is, rightly so, on the need to meet the non-combustibility requirements of high-risk buildings, wherever a façade is used, passive fire protection must be installed to limit the spread of fire. This remains an emotive subject and there is a very clear need to get this right first time, especially for projects that are classed as high risk.
The construction landscape has adapted and evolved in the wake of a stringent focus on building safety following the introduction of the Building Safety Act 2022. The recognition of the need for responsibility down the line, along with embedded traceability, has led to manufacturers stepping up to provide the solutions, data and training to make specification and installation as straightforward as possible.
This has included taking a holistic view of exactly what is needed to provide systems that address specific needs in the built environment. As a result, passive fire protection systems have evolved to provide easy fit solutions that are tested for use on specific façade systems to allow for easier specification and installation. These focus on three main applications.
Passive fire protection for rainscreen façades
Ventilated rainscreen façades feature an open cavity behind the cladding that allows air to circulate to help to manage moisture in the building. It is essential that this remains open to ensure ventilation.
Manufacturers have embraced the need for competency and collaboration to support the Building Safety Act, offering specification support and system training to ensure a full understanding of how the system needs to be specified and installed to work correctly.
However, in the event that a fire breaks out, this gap leaves space for heat and smoke to travel upwards if it is not protected in fire-resistant compartments. In a horizontal application, open state cavity barriers with an intumescent edge provide a solution that remains in its open state to allow air to continue to flow yet will expand to close the gap when exposed to heat. In a vertical application, the barrier should be closed state.
A dry fit solution, cavity barriers are easy to cut to size and are tested in line with industry guidance, with vertical, closed state barriers installed as a compression fit with appropriate support brackets. FSi Promat has created a range of cavity barriers that ensure a high level of protection where needed, with its Silverliner range providing fire protection from 30 minutes to 120 minutes (EI). Used to provide compartmentation, cavity barriers prevent the spread of fire from one floor to another.
Passive fire protection for curtain walling
Designed to support its own weight, the installation of curtain walling sees a gap left at the slab edge that allows for movement – and it is here that the fire risk exists. It is essential that this is sealed to prevent the spread of fire from one floor to another.
Slab edge fire stops have been developed to provide a tested solution to deliver the level of fire resistance required, providing between 60 minutes and 120 minutes depending on the product configuration or size. Systems such as FSi Promat’s Paraflam Ultra can provide fire resistance for up to 120 minutes, tested in line with EN 1364-4.
Passive fire protection for masonry
Passive fire protection must also be used in masonry façades despite the material being non-combustible as the cavity again provides a vulnerability that could see a fire spread.
Compartmentation must be maintained at compartment lines and around openings to resist the spread of fire in line with the requirements set out in the Building Regulations. Due to the make-up of masonry walls, closed state cavity barriers tested to EN 1366-4 (linear joint seals) should be installed to prevent the spread of fire within the cavity for a set period of time.
Clear data
With passive fire protection for façades broken down into distinct applications, systems are designed to work specifically with certain building fabrics to simplify specification.
In line with the need to demonstrate responsibility and competence, most passive fire protection manufacturers test their products extensively to show they meet the latest standard but also to demonstrate suitability in different applications, and when used against particular interfaces.
This gives specifiers and architects the information they need to demonstrate that a system will provide the required level of passive fire protection. The level of testing continues to evolve with manufacturers continually updating testing to widen the applications scope, including for interfaces as well as meeting incoming and updated test standards, such as the EN standard. Where test data does not exist for specialist or more complex applications, manufacturers such as FSi Promat provide expert technical support to find a compliant solution.
Training and information
Beyond this, manufacturers have embraced the need for competency and collaboration to support the Building Safety Act, offering specification support and system training to ensure a full understanding of how the system needs to be specified and installed to work correctly.
Specifiers can find support at every stage of the design, from early engagement and compliance data to expert advice for complex interfaces. Many manufacturers provide training in the specification and installation of systems, including CPD courses, in-depth training, toolbox talks and site visits to check compliant installation.
Through a belt and braces approach to responsibility and competence, manufacturers have simplified the process to specify and install passive fire protection in modern lightweight façades. This extends from comprehensive testing right through to specification support and system training to ensure the correct support is available to give architects and installers confidence in the accurate use of passive fire protection in modern lightweight façade systems.
*Please note, this is a commercial profile.
