Intumescent fire resistant coatings are paint like coatings that are applied to structural steel members. Intumescent can take several forms; in general they are paint, though they may also be mastic or foam composite. The final thickness of these coatings typically ranges from 0.03 inches to 0.50 inches. The coatings are designed to provide insulation to the steel in the event of fire.
The intumescent coating is intended to provide an insulating barrier between fire and the structural steel. The insulating barrier is necessary to ensure the structural performance of the steel members at the temperatures anticipated during a fully developed fire. Intumescent coating can give up to 120 minutes fire protection.