When is fire protection not required for the bottom flange of certain structural elements?

Fire protection for structural elements is generally required to ensure safety and integrity during a fire. However, there are specific conditions under which fire protection may not be necessary. In this case, the criteria pertaining to the span of the structural elements play a crucial role.

When structural elements, such as beams or girders, span not more than 6 feet 4 inches, they are often considered to be of lower risk in terms of fire exposure and potential collapse. The reasoning is that smaller spans typically have less load and are less likely to contribute significantly to fire spread within a structure. Thus, they may not require the same level of fire protection as larger spans, which are more critical to overall structural stability during a fire event.

This understanding aligns with various building codes and fire safety recommendations that prioritize fire protection measures based on the potential impact on structural integrity and safety. Therefore, in scenarios where the spans are limited, the need for fire protection can be waived, allowing for cost savings and design flexibility in construction.