An intumescent coating is an expert paint that chemically reacts in a fire. The coating swells in size to create a burn, which protects the steel work for a particular period. As the intumescent doesn’t actively deal with a blaze it is known as passive fire protection.
Steel is an extremely physically powerful and adaptable building material, except at temperatures of 550ºC it begins to lose its structural integrity, which may lead to building cave in. The job of fire shielding coatings is to increase the time taken for the steel to reach its critical failure temperature and so permit inhabitant’s adequate time to escape and help enhance the safety of the rescue services.
Depending on the kind of building and its occupancy a fire ranking is awarded i.e. a length of time which a building be required to stay structurally sound in a fire situation. There are a range of solutions accessible from dynamic fire protection like sprinklers, as well as passive fire protection like intumescent.
How will it work?
Intumescent coatings are normally applied by airless spray to produce a smooth attractive finish that remains steady at ambient temperatures. These coating compositions are determined by organic resin binders, which are typically acrylate rubber or epoxy.
The resins are filled with active components that react in a fire at temperatures around 250°C to form a thermally insulating carbonaceous char or foam. The burn can be extended as much as 50 times the initial coating thickness.
The char reduces the rate of heating for this steel and therefore prolongs its load bearing capacity.