Why is Steel Protection important?

Patrícia Gabriel / 30 September 2022

Structural steel is one of the most common materials used in building construction! Despite its high strength and ductility, structural steel is also noncombustible, which means that its integrity can be compromised at high temperatures.

Fire protection of structural steel is attained by painting the steel structures with a special protective paint – an intumescent coating. The intumescent coating expands at high temperatures and forms a protective, insulating layer on the surface of the steel. Therefore, in a fire, the steel structure will be protected for a given period of time while the people are safely evacuated and the fire fighters can extinguish the blaze.

Why do we need fire protection for structural steel?

If it’s not there, there is a big risk that the building will collapse in a fire.

Steel will not burn, but if it gets exposed to heat, it loses its strength very quickly.  Loss of strength of steel begins at about 300ºC and increases rapidly after 400ºC. Failure temperature of the steel core is about 550°C, depending on the orientation and type of structure. When steel looses its’ strength building can and most likely, will collapse.

In a cellulosic fire for example, when it is fueled by wood, paper and/or plastics, an average piece of unprotected steel hits 550 °C in as little as 15 minutes.

Nullifire offers Intumescent Coatings that protects the steel from reaching structural failure temperatures in fire. Protected steel will maintain structural stability for times up to 120 minutes, which gives the emergency services time to evacuate people and stop the fire.

How do intumescent coatings work?

When the coating is exposed to temperatures of ~200°C, the coating starts to react and rapidly swell, or intumesce, providing an insulating char much greater in thickness than the original coating. This thermally insulating char barrier reduces the rate of heat conducted to the metallic element.

How thick do intumescent coatings need to be applied?

Film thickness of the coatings, depending on the product and the project vary from 0.2 to 4 mm typically. Coatings can be applied using conventional spray equipment or by brush.

Which systems does Nullifire offer?

For decades Nullifire has been one of the leading innovators of steel protection and intumescent coatings. With steel protection from Nullifire steel will maintain structural stability for up to 120 minutes, giving the emergency services time to evacuate people from the structure and stop the fire.

With products approved to a range of local and international standards, Nullifire systems have the ability to match a number of requirements. Nullifire offers patented hybrid technology systems, waterbased and solvent based systems that are suitable for different environments and applications.

Take a look at the table below to understand the differences between the systems:

Please consult our technical service for choosing the right system for your project.