What is the minimum thickness typically required for spray-applied fireproofing on structural steel?

The minimum thickness required for spray-applied fireproofing on structural steel is influenced by various factors, including the type of fireproofing material used and the required fire-resistance rating. Typically, the range of 1/2 inch to 3 inches is consistent with many building code requirements and industry standards, recognizing that the thickness needed can vary depending on the specific fire rating intended and the exposed steel configuration.

Adequate thickness is crucial because it directly affects the fire-resistance performance of the structural steel. A thickness of 1/2 inch is often aligned with lower fire-resistance ratings, while achieving a fire-resistance rating of several hours may require thicknesses towards the higher end of the scale, approaching 3 inches. It's important for fireproofing to not only provide protection to structural steel during a fire but also to maintain the integrity and lifespan of the building materials under extreme conditions. This range considers these critical safety factors in design and construction practices.