How many rungs must a ladder extend above the roof line once extended?

The correct answer is that a ladder must extend one to two rungs above the roof line once extended. This standard is set to ensure that firefighters have a secure handhold when exiting or entering a roof. The additional height allows for safe and stable contact with the roof edge, minimizing the risk of slipping or falling.

Having the ladder extend above the roof provides both a physical guide for where the firefighters can safely step off onto the roof and helps establish a visual reference for team members who may be on the ground or engaged in other firefighting operations. This practice is crucial for maintaining safety in high-risk scenarios commonly encountered at fire scenes where access to roofs may be necessary for ventilation or rescue operations.

Other options such as extending two to three rungs or three to four rungs may provide additional height, but they are not standardized requirements and can increase the risk of instability if the ladder is not properly secured. Moreover, the suggestion of no specific requirement would undermine established safety protocols designed to protect personnel during operations.