If every part of the roof construction is at least how many feet above any floor immediately below, fire protection of structural members is not required?

The correct position regarding the required height above floors for roof construction pertains to the need for fire protection of structural members. When every part of the roof construction is at least 20 feet above any floor below, it is generally considered that the risk of fire spreading to the structural components from the lower floors is significantly minimized. This height creates enough separation that elevates the roof assembly above typical fire exposure from the floor level, effectively reducing the necessity for fire-resistant treatments on the structural members.

This regulation is primarily rooted in fire safety practices as outlined in building codes, which aim to ensure that buildings maintain structural integrity during a fire event and allow for safe evacuation. The 20-foot threshold is designed to provide ample distance to prevent heat, flames, or smoke from compromising the roof structure, thereby supporting overall safety.

The other height options do not provide the same level of assurance and are, therefore, not sufficient to classify the roof structure as exempt from fire protection requirements. The standards set forth by building codes prioritize safety and the potential for fire incidents, making the 20-foot measurement a vital guideline for inspectors and builders alike.