The response of steel structures to fire is well understood, and extensive best-practice guidance is available. Where fire protection is needed, a range of cost-effective measures are available. Determining fire protection requirements for the structural steelwork of a building is a simple and straightforward process, consistent across all common building types.
All structural steel sections used in construction have some inherent fire resistance, but passive fire resistance methods increase their ability to withstand the effect of high temperatures.
These resistance methods are commonly split into reactive and non-reactive. Reactive forms are represented by intumescent paints that are inert at low temperatures, but which expand in heat to provide a charred layer of low conducting insultation. These can be applied on-site or off-site before construction.
Non-reactive forms include sprays and boards that surround and cover the steel work. Boards can cover unpainted steelwork, while sprays have the advantage of being able to easily cover complex designs through on-site application.
A combination of these methods and careful design allows for steel-built structures to offer high levels of fire protection.
An academic review by researchers from Johns Hopkins University found that the use of mass timber for high rise structures requires special consideration because of the combustible nature of the material. To read the full report, click here.