Commercial Building Inspector B2General Administration, Permits, and PlansMedium
A commercial building inspector is performing a final inspection for a new 4-story Group A-3 assembly building. The building has a standpipe system. Which type of standpipe system is typically required for buildings exceeding 3 stories in height?
- AClass IV
- BClass II
- CClass III
- DClass I
Show answer & explanationAnswer & explanation
Correct answer: C. Class III
IBC Section 905.3.1 requires Class III standpipe systems in buildings where any floor is located more than 30 feet above the lowest level of fire department vehicle access, or more than 3 stories in height. A 4-story building falls into this category.
Why the other options are wrong
- A. Class IV is not a recognized standpipe classification in the IBC.
- B. Class II standpipes are for occupant use, with 1.5-inch hose stations, generally in lower-hazard or smaller buildings.
- D. Class I standpipes are for fire department use only, with 2.5-inch hose connections, typically in higher hazard or multi-story buildings, but Class III encompasses both 1.5-inch and 2.5-inch connections.
Class III Standpipe System
A Class III standpipe system is a combination system designed for both fire department and occupant use. It provides both 1.5-inch hose connections (for occupants) and 2.5-inch hose connections (for fire department) at each story, offering maximum flexibility for fire suppression.
- Combines Class I and Class II features.
- Required for buildings over 3 stories or 30 feet high.
- Provides both 1.5-inch and 2.5-inch hose connections.
Memory trick: The 'Three Classes of Standpipes' protect different heights and users.