When there is a fire, there are two systems which help combat the devastation: Active and Passive fire protection.
Active systems (such as fire doors, suppression systems and alarms) work to contain the fire and smoke it causes.
Passive fire protection materials by comparison, come into their own during a fire, by insulating steel structures from the intense heat of the flame.
They are set apart from active systems in that there is no mechanical activity used to combat the flame. Rather, they look to preserve the steel and the structure so that fire crews can safely enter to extinguish the fire whilst occupants can safely get out.
But Passive Fire Rating is more than just the protection of steel beams. It can include penetrations, barriers, walls and more.
Passive Fire Protection (PFP) in Detail
While we have touched on the subject of passive fire protection in some of our older blog posts, it is something that we haven’t really probed deeply into yet. Alongside active fire protection systems like sprinklers and fire extinguishers, PFP solutions help effectively control the spread of fire in a structure.
But first a recap – why are they called passive? PFP systems are so labelled because the manner by which they exhibit their fire-resisting capability is without overt activity. Generally speaking, most passive fire protection materials only work when the environment around them reaches certain levels (temperature being a key one). They are built and/or sprayed into many different parts of the structure during construction so the building is protected until such time as they are needed. Because they are often concealed, they are nearly forgotten. By comparison, an active system can be manually engaged (such as a sprinkler, or smoke screen).
While active fire protection devices are used to detect and suppress the actual occurrence of a fire, passive fire protection systems help prevent a fire from affecting the structure for a certain amount of time, thus giving building occupants sufficient time to evacuate before the structure loses its integrity making passage difficult and/or deadly.
Among its many benefits, PFP is advantageous because it is used to:
- Control the spread of smoke, heat, and fire by containing it in a single compartment;
- Ensure sufficient evacuation time for building occupants and protecting their exit routes;
- Help structural steel maintain its strength and integrity when exposed to heat; and
- Prevent damage to assets and the structure, in general.
Different Types of Passive Fire Protection Materials
Passive Fire Barriers
These are fire-rated barriers installed on the ceiling, the walls, and the floor of a building. They are usually made of masonry, concrete, gypsum, or combination wood. The most common use is to compartmentalise fire, including the protection of evacuation routes to safeguard occupants’ escape.
Opening protection materials include doors, fire-rated glazing or fire-rated glass and framing that are installed at openings like doors and other similar gaps where contained fire can escape. In the case of heating, ventilation, and air conditioning ducts, fire and smoke dampers are used as opening protection of the duct system.
These are products like sealants and sprays used to protect what’s within the wall, door, or ceiling when a fire-induced penetration occurs and affects the cables, electrical circuit, and the like. If they are not installed and the fire barrier has been penetrated, overall fire protection will be rendered less efficient and the probability of fire spreading up will increase.
Structural Fire Protection
This is where intumescent coatings (our favourite topic and products!) belong—thin-film fire-resistant paints (and older technologies such as vermiculite) that are applied over structural steel to prevent steelwork from heating up and losing its integrity at extreme temperatures for a specific period of time, usually between 60 to 120 minutes.
Other solutions that protect steel members from fire include board encasement and vermiculite spray, which we have discussed in another blog post – Fire Retardant Coatings – A Comparison.
Do you still need passive fire protection when you have other fire protection systems installed on your premises?
Absolutely! Remember, when it comes to protecting your assets, your building, and the people working in and occupying the space, there is no such thing as redundancy.
Aside from that, you are required by the National Construction Code (NCC) and the BCA to use passive fire protection regardless of the building type.
Class 9c buildings, for instance, which cover aged care buildings or residential accommodation for elderly people, have a distinctive fire protection requirement under the 2019 NCC Guide. If we take a look at this classification specifically you will see just how important fire rating is.
According to the code, “Residents of Class 9c buildings are often unable to evacuate without assistance. They may be incapable of walking or bedridden. It is therefore important to make sure that fire and smoke only affects small areas of the building, hence allowing residents sufficient time should evacuation be necessary.”
Because of this challenge, NCC required Class 9C buildings must be subdivided into areas with a maximum area of 500 square metres by smoke walls complying with Specification C2.5. The smoke walls must comply with the following:
(a) The wall may be lined on one side only.
(b) Linings on the wall must be non-combustible and extend to the underside of—
(i) the floor above; or
(ii) a non-combustible roof covering; or
(iii) a flush plasterboard ceiling lined with 13 mm standard grade plasterboard or a fire-protective covering, with all penetrations sealed against the free passage of smoke.
(c) If plasterboard is used in the lining on a wall, it must be a minimum of 13 mm standard grade plasterboard.
(d) Not incorporate any glazed areas unless the glass is safety glass as defined in AS 1288.
(e) Only have doorways which are fitted with smoke doors complying with Specification C3.4.
(f) Have all openings around penetrations and the junctions of the smoke-proof wall and the remainder of the building stopped with non-combustible material to prevent the free passage of smoke.
(g) Incorporate smoke dampers where air-handling ducts penetrate the wall unless the duct forms part of a smoke hazard management system required to continue air movement through the duct during a fire.
In Item (e), the smoke door referred must have two solid-core 33mm leaves that are side-hung to swing in the direction of egress; or in both directions so that aged residents can easily pass through them and they won’t have to push heavy doors. The NCC also requires the smoke door leaves be able to resist smoke at 200°C for 30 minutes.
Related: You can take a look at one of our passive fire protection project for a Class 9C building called Jeta Gardens Retirement Village, where we helped strengthened the building’s fire protection measures through different passive fire protection materials.
Who to Call for Your Passive Fire Protection Needs?
When it comes to the fire safety of your building, it is important to only work with experienced professionals who are compliant with different state and territory legislations, the BCA, NCC, and relevant Australian Standards. Understanding the regulations of the BCA at the best of times can be tough, but when it comes to fire rating, these interpretations can be even harder. That’s where we can help.
If you need help identifying the right and legal passive fire protection materials for your building, it’s time we had a chat – give one of the Permax team a call or drop us an email today.
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