Smokeproof enclosures that are protected from fire and smoke in the building they serve are?

Smokeproof enclosures that are protected from fire and smoke in the building they serve are?

• A. Exterior stairs
• B. Interior stairs
• C. Exit stairs
• D. Attic stairs

Answer: (C)

Smokeproof enclosures refer to protected interior egress routes that stay tenable during a fire, allowing occupants to escape. These are the exit stairs—interior stairways enclosed and fire-resistance rated, often with smoke-sealed doors or stairwell pressurization to keep smoke out. Exterior stairs aren’t within the building’s protected path and can be exposed to smoke and weather, so they don’t meet the smokeproof enclosure concept. Attic stairs aren’t used as the primary protected exit route inside the building.

Smokeproof enclosures refer to protected interior egress routes that stay tenable during a fire, allowing occupants to escape. These are the exit stairs—interior stairways enclosed and fire-resistance rated, often with smoke-sealed doors or stairwell pressurization to keep smoke out. Exterior stairs aren’t within the building’s protected path and can be exposed to smoke and weather, so they don’t meet the smokeproof enclosure concept. Attic stairs aren’t used as the primary protected exit route inside the building.