Which component is designed to seal penetrations for plumbing or electrical installations to prevent fire spread?

• A. Fire Door
• B. Fire Stop
• C. Cockloft
• D. Fire Resistance rating

Answer: (B)

Sealing penetrations through fire‑resistance rated walls, floors, or ceilings to stop fire spread is the job of a fire stop. It fills gaps around plumbing, electrical conduits, or ducts so flames and hot gases can’t quickly pass from one compartment to another, helping maintain the integrity of the fire barrier. Fire stops can be caulks, mortars, mineral wool, intumescent materials, or other rated sealants that expand or harden under heat. By contrast, a fire door is a protective door, a cockloft is a space above ceilings, and a fire resistance rating is the barrier’s performance level—not a physical seal. So the component designed to seal penetrations is the fire stop.