CSLB General Building (B)SafetyMedium
A contractor is preparing to use a portable ladder. What is the MINIMUM distance that the base of a portable ladder should be placed from the vertical plane of its support, relative to the working length of the ladder, to ensure stability?
- A1/5 of its working length
- B1/3 of its working length
- C1/2 of its working length
- D1/4 of its working length
Show answer & explanationAnswer & explanation
Correct answer: D. 1/4 of its working length
Cal/OSHA and general safety standards recommend that the base of a portable ladder be placed so that the horizontal distance from the base to the vertical plane of its support is approximately 1/4 of the ladder's working length (the 4:1 ratio rule).
Why the other options are wrong
- A. This angle is too shallow, making the ladder prone to tipping backward or bending.
- B. This angle is too steep and would make the ladder unstable and prone to sliding out.
- C. This angle is too steep and would make the ladder unstable and prone to sliding out.
Cal/OSHA Portable Ladder Angle
The base of a portable ladder should be set at a horizontal distance from its support equal to 1/4 of the ladder's working length (4:1 ratio).
- Applies to portable ladders
- Horizontal distance: 1/4 of working length
- Ensures stability and prevents sliding/tipping
Memory trick: Four to one, safe ladder fun!