We must start by saying that both are different types of paints with their own characteristics and although most people tend to confuse Intumescent Paint with Fireproof Paint.
These are totally different since the latter is used to protect flammable materials (such as wood, for example), isolating them from the fire and preventing them from producing gases that contribute to the spread of fire. And on the other hand, Intumescent Paint is applied to materials that are heat conductors such as steel, preventing these materials from reaching such a temperature that it leads to collapse.
That is why, as we can see, both are paints whose qualities give passive protection against fire to the surfaces where they have been applied.
They are generally used on steel (bearing) beams and columns used in construction.
Next we will see what makes them different and their application.
Fire retardant paint:
The fireproof property means that it has the quality of not helping the propagation of the flame or the propagation of smoke by combustion.
Fireproof Paints, since they do not burn and do not spread the fire, are included in the term “Passive Protection against fires”, since their objective is to prevent the initiation of a fire, prevent its spread and promote extinction.
There are also fire retardant varnishes for wood that require fire retardant behaviour.
This type of paint reduces the flammability and combustion of the construction materials it covers, in addition to the fact that there are several types to cover specific materials, it can be applied on metal, wood, lacquered surfaces, etc. And it can be used for both indoor and outdoor surfaces.
Its application can be both with a gun and with a brush or roller.
Intumescent Paint is a passive protection system against fire and its function is that these products, when in contact with heat, transform by expanding their volume fifty times due to chemical reactions, thus creating a foamy thermo-insulating layer that prevents the transmission of heat to the element to be protected.
On the other hand, although they do not contribute to extinguishing the fire, Intumescent Paints do protect the structure that supports a building in the event of a fire, delaying its heating and thus giving people more time to leave in the event of an accident. If this were implemented in the greatest number of buildings, it would reduce material damage and save many human lives.
This type of paint is usually applied with a spray gun or brush and resists temperatures up to 600 degrees Celsius. Its properties are designed to control the fire instead of fueling it and so that the appropriate measures can be taken in order to extinguish it definitively.
Finally, as we can see, although both paints protect against fire, Intumescent Paints are the ones that offer the greatest protection since it has been proven that the estimated temperature for the collapse of steel is 500º C; therefore if the steel is protected from reaching this temperature, the structure will not lose its load-bearing capacity for a calculated time, which is very valuable during a fire since it could be the difference between living or dying, giving room to the emergency services or firefighters to do their job.