Intumescent coatings, also called fire retardant paints or intumescent sprays, are a type of fire protection that protects steel and other metal structures from thermal attack by swelling and forming an insulating layer. These protective coatings are easy to apply and look like ordinary paint, but when exposed to high temperatures, they expand into a thick insulating material that protects the structure from further thermal attack. The expansion is a result of chemical reactions that take place within the coating, and it can provide up to 120 minutes of fire resistance.
This is the same kind of coating that was used during the World Trade Center attacks, and it provides the same level of safety for those inside buildings. In fact, all new construction projects should use intumescent coatings for the safety of those inside as well as to prevent any structural damage caused by the heat generated during a fire.
Essentially, intumescent coatings are made of a complex mix of chemicals suspended in an ordinary binder. When the coating is exposed to heat, it begins to soften and release the suspended chemicals, which then reacts with the steel or other material that it is covering. The reaction causes the paint to expand, and this creates a thick insulating material that is commonly known as char. The char helps to protect the structural steel from high levels of thermal stress, and it allows the structure to continue to support itself for a long period of time.
This prevents the building from collapsing and offers more time for people to evacuate buildings and firefighters to arrive and put out fires. Intumescent paint is also an effective way to protect wood structural members. This type of fireproofing paint is not as common as the other kinds, but it can still be an effective option in a variety of situations and applications.
There are many different brands of intumescent paint, and each product will vary slightly in terms of the types of fire ratings that it offers. Some provide 30 or 60 minutes of protection, while others can offer up to 120 minutes. Most are designed to be applied using airless spray equipment for the best results, but they can also be applied with brushes or rollers as well.
When deciding what to buy, it is important to choose a quality product. This means selecting a brand that is approved in standardized fire testing, and that it has a proven track record for performance in real-world conditions. It is also a good idea to choose a fire rating that matches the specifications of the project, and that will provide the required protection in an acceptable amount of time.
Intumescent paints are available as either solvent-based or water-based formulations, with the latter generally requiring less drying times. The most popular options include vinyl toluene acrylics, styrene acrylics and silicone acrylics for use against steel structures, while those for protecting against hydrocarbon fires tend to be based on epoxies.