Intumescent Fire Protection
Paint supply companies have developed coating systems which, when correctly applied, provide fire protection to steel.
An intumescent coating is a specialist paint that chemically reacts in a fire. The coating swells in size to form a char, which protects the steelwork. As the intumescent doesn’t actively tackle a blaze it is known as passive fire protection.
The Role of Fire Protective Coatings
Steel is a very strong and versatile building material, but at temperatures of 550ºC it begins to loose its structural integrity, which may lead to building collapse. The role of fire protective coatings is to lengthen the time taken for the steel to reach its critical failure temperature and therefore allow the occupants sufficient time to escape, and enhancing the safety of the rescue services.
It is important that the full intumescent coating system is followed – most systems require surface preparation (blasting to SA2.5), a primer, the intumescent paint to a specific minimum coating thickness (dependant on the steel shape and thickness) and a protective top coat.
Testing is an important part of the process to ensure that the required fire resistance rating is achieved.