The genre around buildings and construction or building maintenance are hardly “sexy” topics. So, it’s no wonder that when it comes to building protection, fire rating hardly rates a mention (no pun intended). When you see scenes in a movie where a building is on fire, you see images of fire suppression systems (extinguishers, drenching systems, smoke alarms). These can be dramatised so they have appeal. But you never see a closeup of the steel stressing under heat. It is just not that exciting.
However, the truth is, passive fire rating is essential which is why it is prescribed for high rise buildings, commercial and industrial buildings, and complexes.
In this piece, we discuss why passive fire protection is important and the different types of protection.
- Structural fire protection
- “Fire proofing”
- Opening protection
Structural fire protection
Fires can cause horrific damage to all building types irrespective of whether they are commercial, residential, or community-based buildings. How a fire spreads in these structures depends on the type of materials used in their construction, but beyond these factors you may not have considered such asthe placement of windows could affect the propagation of a fire. That’s why it’s important to consider fire safety from the very beginning and in fact, in newbuild commercial, multi-swelling residential and industrial buildingsthe designs need to incorporate the appropriate passive fire protection system. In Australia this can take many forms which we will look at through this piece.
Concrete and fire-resistant coated steel are often considered the ideal options when constructing high-rise commercial or residential buildings – albeit Cross Laminated Timber projects are growing in prominence. Because these materials do not spread fire, the behaviour of the fire can be restricted and eventually controlled, which works to help safeguard a building’s occupants. Conversely, where more combustible materials are in-situ (such as timber desks, carpet, and other furniture) the fire has more fuel to burn, and can generate flames that would cause greater structural damage and lead to potentially catastrophic outcomes.
Window placement also matters in structural fire protection. Its distance from a fire source as well as its condition (whether it’s open or closed) can play a role in the spread of flames. If a building is not properly constructed and windows are placed without a thought to their positioning, there could be a significant wind flow that travels through the structure which may considerably propagate a fire.
Ultimately, the materials used in a building as well as the intended use (thus considering include the presence of combustible materials like wood furniture, oil, clothing, and gas) must be taken into account when developing a building design that aims to lessen the risks of fire damage to both the property and its residents.
Compartmentalisation is one of the fundamental aspects of a passive fire protection system. The general idea is to divide a building into several small sections in order to better limit the propagation of fire, smoke, and gases. This can be achieved through the use of fire-resistant floors and walls. Separating the building into multiple fire compartments will also give occupants more time to evacuate while firefighters attempt to control the blaze.
To make sure that a building is properly compartmentalised, the walls and floors must have the appropriate fire-resistance ratings as mandated by regulations. It’s also important that each compartment is equipped with the right elements for fire protection. These elements can include hatches, doors, metal tubes, partitions, etc.
Once a fire breaks out, all these systems should work together to create a space where the flames can be contained long enough to give time for more active fire protection measures to kick in.
Another important measure in passive fire protection in Australia is fireproofing. Defined simply, fire proofing (albeit it is not a scientifically correct term) is rendering a material incombustible or resistant to fire. It is often applied to steel structural elements so that critical aspects of the building can continue to stand until a fire is brought under control. It’s also crucial for ensuring that vital support systems will continue to operate during a conflagration.
Asbestos was commonly used for fireproofing until its harmful effects on human health were discovered. These days, intumescents are the fire-proofing materials of choice. Intumescent coatings protect structures by forming a resistant char that swells to several times their original thickness in order to insulate objects when these are exposed to heat.
Fire proofing, though, is not a magic solution that solves everything. Eventually, any fire proof coating will also degrade by continuous exposure to heat. That’s why you need to check the ratings of products to see how long they can withstand a fire before making your selections to ensure they meet the requirements of the BCCA. The density of the coating should also be considered since it can contribute to the overall weight of a structure. In many instances the best choice is to select water-based intumescents, which are more eco-friendly options (they have a very low presence of harmful volatile organic compounds (VOCs)) and which are quite light when applied..
As much as it may seem more functional to have a door or opening where you need it, when it comes to fire barriers, all openings need to be designed to ensure the highest integrity of the barrier so that it can function properly. For example, if a door has been installed in a wall with a two-hour resistance rating, the door must also have the same resistance to fire. This ensures that the entire compartmentalised system will work when the situation calls for it.
When it becomes necessary to punch through a fire-rated barrier so that important building services such as wires, cables, and pipes can be installed, the point of penetration must also be protected by a firestop system. The firestop device should have a rating that corresponds to the barrier’s rating as well. Furthermore, the effectiveness of a firestop can be impacted by its installation. So, it’s recommended to hire a specialist who can ensure that the right products are used and installed correctly.
If you’ve ever wondered what a passive fire protection system in Australia may look like (figuratively speaking that is), well now, know a little bit more. ultimately, the most important thing you need to understand is that fire protection measures must all work together in order to be effective. This means that you need to incorporate active fire protection components as well so that you can adequately safeguard a building.
Active fire protection includes the manual suppression of fire through the use of fire blankets and extinguishers. It also utilises automatic fire suppression systems like water sprinklers and foam. All these must be properly integrated within a building along with passive fire protection elements so that you will have a comprehensive fire safety strategy that can address multiple scenarios.
Without the proper fire-resistant construction and the required protections, a structure may not be able to withstand it when a fire breaks out. The flames are likely to spread quickly and overwhelm active fire protection components like sprinkler systems and fire extinguishers. So, both active and passive fire protection systems must work in tandem to prevent the loss of lives and property.
A complete fire safety plan takes all these different factors into consideration and makes use of a multi-pronged approach in formulating the appropriate strategies. So, take your time to develop your plan and consult with experts to ensure success.
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