NFPA 13 requires clamps to support the weight of a standpipe at every other level.

NFPA 13 requires clamps to support the weight of a standpipe at every other level.

• A. At Every Level
• B. At Every Other Level
• C. At No More Than Two Levels
• D. Only At The Base

Answer: (B)

The main idea here is that a vertical standpipe must be restrained so its weight and any movement don’t cause sag or misalignment as it runs through multiple floors. Clamps or hangers provide fixed points that hold up the pipe, keeping the alignment of the system and reducing the risk of damage or leakage from movement. Placing supports at every other level creates end points for each span of pipe between supports. That means each section of standpipe is effectively held up at both ends, which helps resist gravity, vibration, and any dynamic forces when water is flowing. This level of support is enough to keep the pipe stable over the height of a building without adding unnecessary clamps on every single floor. It’s a practical balance between safety and installation efficiency, aligning with the idea that the pipe’s weight is carried along its length with periodic, robust supports. Choosing to support at every level would be more than necessary in many installations, and relying on supports only at the base would leave long unsupported spans that could sag or shift. The every-other-level approach provides the required restraint without overdoing the hardware.

The main idea here is that a vertical standpipe must be restrained so its weight and any movement don’t cause sag or misalignment as it runs through multiple floors. Clamps or hangers provide fixed points that hold up the pipe, keeping the alignment of the system and reducing the risk of damage or leakage from movement.

Placing supports at every other level creates end points for each span of pipe between supports. That means each section of standpipe is effectively held up at both ends, which helps resist gravity, vibration, and any dynamic forces when water is flowing. This level of support is enough to keep the pipe stable over the height of a building without adding unnecessary clamps on every single floor. It’s a practical balance between safety and installation efficiency, aligning with the idea that the pipe’s weight is carried along its length with periodic, robust supports.

Choosing to support at every level would be more than necessary in many installations, and relying on supports only at the base would leave long unsupported spans that could sag or shift. The every-other-level approach provides the required restraint without overdoing the hardware.