Solvent-Based Thin Film Intumescent Coating
This information reflects our best understanding of product composition in 2022.
Intumescent coatings swell during a fire to encase a substrate in a thick bark of char, which protects the substrate from burning. In the case of structural steel, the concern is that the steel will weaken in the high heat of a fire, rather than...
Intumescent coatings swell during a fire to encase a substrate in a thick bark of char, which protects the substrate from burning. In the case of structural steel, the concern is that the steel will weaken in the high heat of a fire, rather than burning. The intumescent component of the coating is commonly composed of a carbon donor, phosphorous donor, and a nitrogen source. It is also important to note that the intumescent additives can perform ancillary functions as well, such as stabilization, fire resistance, or filling. This CP describes solvent-based intumescent coatings that are site applied to structural steel and intended for non-corrosive/non-humid environments. This Common Product describes a standard formulation for a solvent-based thin film intumescent coating. Products with low-VOC formulations are also available, but were found to be less common.
The Historical version of this CP can be found here Historical Factory-Applied Thin Film Intumescent Coating - 2015. Note that this CP did not include solvents because it was meant to capture a factory-applied coating as delivered to the job site.