Protection of vertical openings like shafts requires which approach?

• A. Leave penetrations open for ventilation.
• B. Enclose with fire-rated barriers and seal penetrations to prevent fire/smoke spread.
• C. Use non-rated partitions with minimal sealing.
• D. Protect only with dampers.

Answer: (B)

Vertical openings such as shafts act as highways for fire and smoke to move between floors, so they must be treated as part of the building’s fire barriers. The best approach is to enclose the shaft with a fire-rated barrier and seal every penetration through that barrier. This creates a continuous fire-resistance boundary that resists flame and smoke spread across levels, helping to keep adjacent spaces protected and allowing occupants more time to evacuate.

Dampers alone don’t provide a complete solution for shafts because, if gaps exist around penetrations or if the shaft walls are not properly rated, flames and smoke can bypass them. Similarly, non-rated partitions or leaving penetrations open completely undermine compartmentation. By using fire-rated enclosure for the shaft and applying proper fire-stopping at penetrations, you maintain the intended fire boundary and reduce cross-floor transfer of heat and smoke.