If you’re a builder, an architect, a property developer or even a property owner, there’s one burning question you should know the answer to. Does structural steel need to be fireproofed?
On the surface, it might seem like a silly question. After all, you know that steel is incredibly tough and durable. Why would it need to be fireproofed?
Fair question, so let’s provide a fair and informed answer in this blog.
You may be surprised by the simple answer. Does structural steel need to be fireproofed? In some projects, it’s an absolute must!
First things first: Is structural steel fireproof?
Before we contemplate whether structural steel requires fireproofing, let’s first look at whether it’s fireproof.
Structural steel is certainly highly fire-resistant, but that doesn’t make it fireproof.
Steel is a non-combustible material, which means it won’t ignite or contribute to the spread of flames. However, when exposed to extremely high temperatures in a fire, structural steel can lose its strength and integrity.
You only need to remember what happened in New York on 9/11 to see a perfect example of this. More on this tragic incident at the end of this blog.
Getting a little technical, as steel heats up, it expands and once it reaches around 550°C, its ability to carry loads diminishes rapidly. This means that while steel itself won’t catch fire, it could still fail structurally if exposed to prolonged heat without fire protection.
That’s where fireproofing comes in.
When is structural steel fireproofed?
Now, you might be wondering, “If steel won’t catch fire, do I really need to fireproof it?” The answer depends on the type of project, local building codes and other factors.
In many cases, structural steel must be fireproofed as part of a building’s fire safety requirements. Particularly for commercial buildings, high-rise structures and critical infrastructure. Regulations often demand that steel must withstand fire for a certain period of time, allowing people to evacuate safely and preventing building collapse.
Here are a few examples of when fireproofing is commonly required in structural steel:
- Steel framing used in skyscrapers or tall buildings often requires fireproofing to maintain the integrity of the structure in case of a fire. This is crucial for buildings where evacuation might take time.
- Shopping centres, schools, stadiums and government buildings also often require structural steel fireproofing to protect large crowds in the event of a fire.
- Fireproofing is often applied to structural steel in underground car parks, subway systems and basements to provide added protection in spaces that can be difficult to evacuate.
That said, not every project will require fireproofing.
For example, outdoor structures like bridges or towers may not need fireproofing unless local codes or the specifics of the environment demand it. Some low-rise or residential buildings may also be exempt from stringent fireproofing requirements, depending on their size and function.
How is structural steel fireproofed?
So, how do you go about fireproofing structural steel?
There are several methods that steel fabricators use to protect steel from fire. The right one depends on the project, the environment and regulatory requirements.
Here are some of the most common methods of fireproofing structural steel:
- One of the most popular methods is intumescent coatings, that are applied as a spray or paint to the steel surface. In the event of a fire, these coatings expand and form a thick, insulating layer that helps protect the steel from heat. Intumescent coatings are often chosen for their aesthetic flexibility, as they can be applied in thin layers that preserve the look of the steel.
- Spray-applied fire resistive materials or SFRM involves spraying a thick, fire-resistant material (like cementitious or fibrous compounds) onto steel components. This creates an insulating barrier that slows heat transfer and extends the amount of time before the steel reaches a critical temperature. While effective, this method may not offer the same sleek appearance as intumescent coatings, making it more suitable for areas where the steel is not exposed.
- In some cases, structural steel can be encased in concrete to provide fire resistance. The concrete acts as a shield, preventing heat from reaching the steel quickly. This method is more traditional and may be used in combination with other fireproofing materials for added protection.
- Another method involves wrapping steel in fire-resistant boards or panels. These boards provide a physical barrier against heat and can be installed directly onto the steel components. Fireproof boarding is particularly useful in environments where a robust, multi-layered protection is necessary.
Each of these methods comes with its own advantages. The choice of which to use depends on factors such as cost, appearance and the specific fire-resistance rating required for the project.
Why fireproofing matters
When it comes to the safety of a building, fireproofing structural steel is about more than just meeting regulations – it’s about protecting people, property and the long-term integrity of the structure. Without proper fireproofing, even the toughest steel could fail in a fire, leading to catastrophic consequences.
At Kelly Steel, we take safety very seriously. Every structural steel and fabrication project we undertake is carefully planned and executed to ensure it meets the highest safety and fire rating standards. We understand that fire protection is a critical component of construction and we work diligently to ensure that the steel we supply is up to the task, no matter the environment or building type.
While structural steel is inherently fire-resistant, fireproofing is often a necessary step in ensuring that it maintains its strength in high-heat situations. Whether you’re building a high-rise in the city or a large commercial complex, fireproofing ensures that the structure remains safe, resilient and compliant with fire safety regulations. Note: Fireproofing failures, not just the impact of the planes, likely caused the rapid collapse of the World Trade Center towers on 9/11. That’s according to architects and engineers who spoke to a federal panel several months after the tragic event. Analysis found that neither tower had enough fireproofing to withstand the intense heat for the minimum of two hours needed for occupants on upper floors to escape.
