What type of structural elements does fire protection not apply to if their span is not more than 6 feet 4 inches?

Fire protection requirements typically apply to structural elements to enhance safety in the event of a fire, ensuring that these elements maintain their load-carrying capacity for a certain period. In many building codes, specific elements are exempt from these requirements under certain conditions due to their size and limited potential for risk.

Lintels and shelf angles, when their span does not exceed 6 feet 4 inches, are often considered minor structural components that don't contribute significantly to the overall fire hazards in a building. Their smaller size and limited span mean that they are less likely to be exposed to conditions that would necessitate rigorous fire protection measures. Therefore, allowing exemptions for these elements is a practical approach in building regulations to focus resources on more critical structural components which have larger spans or greater implications for structural integrity in a fire scenario.

In contrast, load-bearing walls, reinforced slabs, and roof trusses are crucial structural components that typically require fire protection, regardless of their dimensions, due to the significant role they play in supporting the overall structure. These elements need to remain intact longer during a fire to ensure the safety and stability of the entire building.