Intumescent Coating & Paint for Steel Structures

Intumescent fireproofing is key for reinforcing steel structures within a passive fire protection strategy. By adding a protective layer to structural steel, intumescent paint extends the length of time a building can withstand high temperatures.

This not only reduces damage to steel, but it could also make the difference between fully evacuating a building and putting the lives of occupants and firefighters at risk.

How does intumescent paint protect steel?

Intumescent paint protects structural steel by lengthening the time it takes for steel to reach its ‘critical temperature’. Critical temperature can vary based on the building design.
While it has been known to range between 350° – 750° in Ireland it is commonly 550°. Once steel reaches its critical temperature, it will begin to lose its nominal integrity and load-bearing capacity, increasing the likelihood of structural collapse.

In the event of a fire, the chemical properties of intumescent paints undergo an endothermic process. This means that when temperatures reach around 250°, the paint will expand into a carbonaceous char layer. Once solidified, this forms a protective coating for steel beams, columns and other building elements, without affecting their mechanical properties or basic functionalities.

This increases the steel’s fire resistance time whilst the building is evacuated. The exact performance of intumescent products can vary, offering 30, 60, 90 and 120 minutes of fire resistance depending on the specific type of coating and structural requirements.