Intumescent Coatings For Fire Protection: What Specifiers And Applicators Need To Know

Passive fire protection products are being required with increasing frequency for new and existing buildings. As a result, more contractors and specifiers than before need to understand the basics of such products. This article focuses on coatings that resist fire by intumescence that is, they expand when subjected to fire, thus increasing the barrier between the fire and the steel, increasing the time it takes the fire to reach and damage the steel, and allowing occupants in a burning building more tune to escape before structural collapse. There are two types of intumescent coatings that concern us: thin-film products (20 to 150 mils) and, thick film products (100 to 750 mils). The type of intumescent specified on any given project depends on all the properties needed in that coating in addition to fire resistance. Hence, properties such as weathering resistance, corrosion resistance, and appearance play a role in selecting the right type of intuinescent coating for a job. This article gives an overview of thin- and thick-film intuniescents, including relevant information about their testing, specification, and application.