A steel column encased in 3 inches of concrete has a fire rating of what duration?

In construction and fire protection, the fire rating of a structural element, such as a steel column, is determined by the thickness of the fire-resistive material encasing it. A steel column that is encased in 3 inches of concrete can achieve a fire rating of 4 hours under certain conditions.

Concrete is a highly effective fire-resistive material due to its thermal mass and the fact that it does not burn. The thickness of the concrete around the steel plays a crucial role in insulating the steel from elevated temperatures during a fire, allowing it to maintain its structural integrity longer.

Generally, a concrete thickness of 3 inches provides sufficient insulation to extend the fire rating to 4 hours, which is suitable for high-rise buildings and structures where longer fire-resistance ratings are required to ensure safety and compliance with building codes.