High-rise buildings have unique challenges related to fire protection such as longer egress times and distance, evacuation strategies, fire department accessibility, smoke movement and fire control.
The numbers of persons living on high-rise buildings are high compared to low-rise buildings, and only evacuation method in case of fire is the staircase. So, the fire protections of high rise buildings have gained significant attention worldwide.
The Role of Passive Fire Protection in Tall Buildings
It is hard to over-emphasize the importance of a passive fire protection (PFP) strategy and its subsequent governance in building design. Ideally you need a strategy comprising an assessment of the likely fire risks, an evacuation plan, and the means to deal with both, the absence of a robust strategy has long been a problem, only now properly appreciated.
Checkmate Fire offer the complete range of passive fire protection installation services for both new builds and existing constructions to maintain compartmentation and fire stopping – which is installed to 3rd party accredited standards nationwide.
Its disparate parts function as a whole and cannot simply be installed in isolation from each other or the many other critical systems that govern the design of buildings
Getting it Right First Time
Since many aspects of PFP are hidden from view, retrospective fixes for poorly installed designs are disproportionately difficult and expensive. No wonder that projects are increasingly insisting on certified qualifications and accreditations from their specialist contractors.
PFP in buildings affects almost every aspect of the design. The objective is to restrict the fire to a fire and smoke-resistant compartment long enough to allow people to escape safely and for the emergency services to attend. Checkmate Fire offer compliance and survey solutions to identify your issues.
Best practice also aims to minimize other kinds of damage. Combustion will destroy the building fabric but again, the effects of smoke – even cold smoke – are much more damaging.
Checkmate work with you to ensure these principles are applied to the following elements of the building, each a specialist field by itself:
Passive Fire Protection
Passive Fire Protection is best thought of as a critical system rather than a mere technical solution. Its disparate parts function as a whole and cannot simply be installed in isolation from each other or the many other critical systems that govern the design of buildings
Steel frames are particularly vulnerable. Steel loses strength quickly under quite low heat loads and so must be protected in board materials, or sprayed with intumescent paints or cementitious applications. Timber frames are combustible; they are usually protected by plasterboard. Concrete frames generally do not need protecting, although spalling can be a problem, particularly if it exposes steel reinforcement.
As well as preventing fires from spreading internally, it is desirable to stop them spread to neighbouring buildings and other assets too. There are many solutions, all of which of course must be thoughtfully designed.
Doors or shutters only need to be fire-rated if set in fire-rated walls, in which case their ratings must match in most circumstances. How they are intended to be used and by how many people will affect the choice of door-closer and other elements of door furniture. Correctly installed third-party certificated complete fire doorsets are the preferred route to peace of mind.
Compartment walls should run continuously to join the floor above to form an uninterrupted fire barrier, even through ceiling voids and roof spaces. Doors and glazing in them need equal fire-resistance in most circumstances. Any service holes through compartment walls should be kept as small as practicable and must be appropriately fire-stopped. The same is true for shafts running through floors or ceilings. And since these are hidden from view, contractual responsibilities for getting them right must be clearly stated.
These are barriers that preserve escape routes and areas of especially high fire risk, such as cooking machines in food factories or fuel storage spaces. Doors, glazing and service penetrations need equal fire resistance in most circumstances.
Resistance depends on the material they are made from. Timber chars and is consumed at a predictable rate. Superheated concrete is prone to explosive spalling, which might expose steel reinforcement. Steel deforms and weakens catastrophically when exposed to heat. Proprietary fire protection products must be selected with care to suit the particular on-site conditions.
Ceiling or wall cavities are protected from flames and smoke with barriers. Because they are hidden from view in the finished building, they must be designed and installed correctly, making it particularly important to clarify responsibilities in the contractual arrangements.
Often left in the hands of a specialist sub-contractor, fire protection in the air distribution system needs careful attention. Methods include installing fire dampers where it passes through the compartment wall or floor, using fire-resisting ducts or enclosing the systems in fire-resisting shafts.
Ducts and shafts containing fuel lines and other building services can obviously help to spread fire and smoke and must be adequately fire-stopped wherever they penetrate compartments and other fire barriers.
Where these penetrate fire barriers, they must be appropriately fire-stopped. The exact method will depend on what is penetrating the barrier and how the barrier is fire-rated. Large penetrations have the added problem of potentially weakening the structure, and so any seals will have to be capable of reinstating the structural integrity of the fabric as well as stopping any fire.
Glazing in fire barriers such as compartment walls or ceilings must match their fire-rating. There are many products that maintain their integrity. Specifiers are increasingly selecting glazing that insulates against radiant heat as well, which is important along escape routes. Note that their frame and method of fixing is critical. For more information, go to Alufire