What is the maximum vertical spacing for fireblocking?

What is the maximum vertical spacing for fireblocking?

• A. floor and ceiling
• B. 10 feet
• C. 15 feet
• D. 5 feet

Answer: (A)

Fireblocking is meant to stop vertical spread of fire through concealed wall spaces by dividing the cavity at each story boundary. The best way to ensure that vertical passages are contained is to place blocking where the wall cavity meets a floor or a ceiling—the floor and the ceiling lines. This creates a barrier at each story level, so the maximum vertical spacing is effectively the distance between floor and ceiling. That’s why the correct choice is floor and ceiling. The other options suggest a fixed numeric interval inside a story, which isn’t how fireblocking placement is specified.

Fireblocking is meant to stop vertical spread of fire through concealed wall spaces by dividing the cavity at each story boundary. The best way to ensure that vertical passages are contained is to place blocking where the wall cavity meets a floor or a ceiling—the floor and the ceiling lines. This creates a barrier at each story level, so the maximum vertical spacing is effectively the distance between floor and ceiling. That’s why the correct choice is floor and ceiling. The other options suggest a fixed numeric interval inside a story, which isn’t how fireblocking placement is specified.