Coating application

Flame retardant additives for intumescent coatings work by charring and expanding in the presence of extreme heat. The increase in volume and subsequent decrease in density slows the heating of the substrate, increasing the time before the steel itself begins to melt. Flame retardants intumescents typically swell to 25 times their original thickness when engulfed in flames. This expansion allows them to provide a barrier between the flames and the steel that is exponentially larger than a coating that does not swell.

Adding thickness to an intumescent coating application increases the amount of swelling that will occur in the case of a fire incident. For example, if a 350 mil coating of a given intumescent has been determined to have a fire rating of 1.5 hours, 700 mils would theoretically be necessary to achieve a fire rating of 3 hours. In reality, though, added thickness is sometimes specified in certain areas such as curves and crevices, so something like a thickness of 750 mils may be required in order to achieve a 3-hour rating. This last is chancing and we see different coatings for different standards, depending the time rate which should be achieved.

Additionally, since they are applied directly to steel, no gap is created in which moisture can sit and incite corrosion. Fire retardant coatings fight corrosion in much the same way as traditional protective coatings, the difference being their ability to swell and the much greater thicknesses at which they are initially applied.

Whenever we can serve you with a flame retardant additive or intumescent coating for wood or steel, do not hesitate to contact us by phone or the contact request on the right.