Intumescent Paint For Passive Fire Protection - Buildings come in all shapes and sizes. From boxy warehouses purpose built with wide open areas, high stud ceilings and plain concrete walls to complex architecturally designed facilities filled with intricacies, hallways, offices, boardrooms, nooks and crannies. There really are endless possibilities for what is considered a building. However, there is one major commonality between all these buildings - once you’ve stripped all the concrete, timber, plaster, glass and other building materials you’re left with one thing, a frame made out of structural steel.
Your building’s structural steel is arguably the most crucial feature of it. Because we don’t see it, it is often overlooked. Once structural steel is in place during the construction of a building, there’s little more that needs to be done to it. Building owners know that they can rely on the strong materials to stand tall for decades to come, and even in the instance of renovating a building the structural steel is more than likely untouched. Being the building's main form of stability, you don’t want to tinker with it, rather choosing to set it and forget it.
Structural steel is strong and able to withstand extremely heavy loads. It is flexible enough to withstand any minor ground movements, while being stable enough to stand erect. It is almost perfect.
However, there is a caveat to the material make-up of structural steel. While it provides strength in all the right places, it also can be quite efficient at transporting heat. This can be disastrous, as the structural steel can act like an electrical wire during the event of a fire, conducting heat through itself and spreading it around your building. While the heat is spreading through the building, the steel also softens and the structural integrity of a building is severely compromised. Even if a fire is put out in time, if the structural steel has softened and warped, the building is no longer safe for habitation.
So how do we protect structural steel from a potentially catastrophic fire? The answer is intumescent paint.
What is Intumescent Paint?
There is a common misconception that intumescent paint is the same as “fire rated paint”. This undermines the technology hiding beneath the paints surface, intumescent paints application is far more impressive than simply being fire resistant. First off, it is more of a coating than a paint. When heat is applied to the coating it reacts by swelling in a controlled manner. It is able to do this because the coat reacts with heat to produce a carbonaceous char. This char is formed by a large number of bubbles that expands to create an insulating layer around the structural steel. This insulating layer prevents the transfer of heat into the steel beams and significantly reduces the chance of a local fire spreading to the rest of the building while simultaneously protecting the steel from heating to the point that it begins to soften and loses its structural integrity.
To prevent the structural collapse of a building, intumescent paint is designed to prevent steel from reaching critical temperatures at which point its load bearing capacity becomes equal to the effect of the applied loads. The critical temperature of steel varies between 360-750 degrees Celsius (depending on the loading scheme) but the most common critical temperature range is between 500-620 degrees Celsius.
Intumescent coatings do not modify the intrinsic properties of the materials they are applied to and different types of intumescent paint can be used on a variety of materials. While steel is the most common, it can also be applied to timber, concrete and other composite materials.
How is Intumescent Paint Applied?
The preferred means of applying an intumescent coating is by spraying it onto the steel using airless paint equipment. This ensures a quick and high quality finish. While it is possible to apply intumescent paint using a brush and roller, it takes much greater care to ensure that the finish is adequately distributed at the correct consistency.
For intumescent paint to be effective, it needs enough space to expand, it needs to be considered in the initial design stage of a building. If it is placed too close to any fixtures or timber such as door frames, it’s ability to create its insulating layer will be compromised, meaning that heat will still be able to potentially soften the structural steel and make its way into other parts of the building. While it is possible to retrofit intumescent paint, the process is complex, difficult, and would come at a substantial financial cost.
We stock a range of intumescent paints for Steel: https://passivefireproducts.com/category/23-steel-intumescent
Timber: https://passivefireproducts.com/category/25-timber-protection
or Plasterboard: https://passivefireproducts.com/category/35-wall-and-ceiling-coating
You can also purchase from specialist suppliers such as FireRatedPaint.com
Call our technical team on 0333 043 0018
or Contact us for Sales or Technical Enquiries
