What is intumescent paint for steel?

Intumescent paint for steel is a fire retardant paint which is used to protect the structural steel of a building.

Steel is commonly used for structural support in many kinds of buildings. It has many advantageous properties which make it an excellent choice compared with other materials.

One of these properties is that it is non combustable. In the event of a fire, however, it will eventually weaken in the extreme heat and the reduction in it’s load bearing capacity will result in the collapse of the building. An intumescent paint can prevent this from happening.

If an intumescent paint for steel has been applied a catalytic reaction occurs producing a layer of carbonaceous char up to 50 times the thickness of the paint keeping the steel below it’s critical temperature for much longer. Either one or two coats of the paint can be applied with two coats giving upto 2 hours protection.  This gives much longer for the fire to be dealt with and the building will stand a much better chance of to surviving the effects of the fire.

The demonstration below shows how these paints can protect steel structures from the heat of a fire. A strip of steel that has been protected with an intumescent coating is relatively unaffected after two minutes of being blasted with a blowtorch whilst an unprotected strip is quickly deformed.

Application of intumescent paint for steel

When treating steel with an intumescent coating the first step is to degrease the surface and remove any rust or mill scale. A primer should then be applied. The manufacturer of the intumescent paint will need to be consulted first to ensure compatability.

There are intumescent paints that are suitable for external or internal steel and the paints may be applied at the building site itself or before deliverery. An extensive range of finishes are available.

They may be water based or solvent based and there are specific solvent based paints for exterior use. They can be applied with a brush or roller or for larger areas with airless spraying equipment.

When applying intumescent paint for steel health and safety precautions should always be taken into consideration with protective clothing worn and ventilation masks used where necessary.

Video:
Pinturas Creizet
(We are not affiliated with this company)