When using portable ladders for roof access, what is a requirement for the ladder?

For accessing roofs using portable ladders, the requirement that allows for safe and effective use is that the ladder should not be more than 20 feet long and must extend at least 3 rungs above the roof. This guideline ensures that workers can maintain a stable and secure three-point contact when transitioning from the ladder to the roof and vice versa.

Having the ladder at a reasonable height, like the 20-foot limit, reduces the risk of instability or accidents that can occur when using longer ladders, which may be more challenging to maneuver and secure. Extending the ladder at least 3 rungs above the roof edge provides an additional safety feature, as it allows users to grab onto the ladder while stepping onto or off the roof, enhancing their stability and reducing the risk of falls.

Other options do not align with the standard safety protocols for using ladders in this capacity. For instance, requiring a ladder to be 30 feet long could lead to complications with stability, while securing the ladder at the base, although a good safety practice, is not as specific as the requirement related to the height and rung extension, which directly pertains to safe access to roofs.