What must be installed in combustible concealed locations to cut off concealed draft openings?

Fireblocking is a critical safety feature required in combustible concealed locations to prevent the spread of flames and smoke through concealed spaces within walls, floors, and ceilings. This is important because such concealed areas can act as pathways for fire to travel quickly throughout a building, leading to rapid fire progression and increased risk to occupants.

Fireblocking is installed to cut off concealed draft openings, effectively creating barriers that limit the movement of fire through these areas. By doing so, fireblocking helps to contain fire within a specific area, providing additional time for occupants to evacuate and for emergency services to respond. This practice is essential in both new construction and renovations to ensure compliance with building codes and enhance the overall safety of structures.

The other options, while related to fire safety or insulation, do not specifically address the need to control and contain fire spread in the same way that fireblocking does. Draft-blocking, insulation blocking, and smoke-blocking pertain to different aspects of building safety and energy efficiency but do not fulfill the same role as fireblocking in combating the risk of fire in concealed spaces.