What is the general safety rule for the distance from the base of a ladder to the building relative to its working length?

• A. One-tenth its working length
• B. One-half its working length
• C. One-third its working length
• D. One-quarter its working length

Answer: (D)

The safe way to lean a ladder is to place the base about one-quarter of the ladder’s working length away from the wall. That 4:1 rule sets the ladder at roughly a 75-degree angle, which puts the weight of you and the ladder over a solid base and distributes forces in a stable way.

If you tuck the base in too close, the ladder becomes too steep and can tip backward when you push off or shift. If you push the base out too far, the angle flattens, the top can slide down the wall, and the feet may slip, making the climb unsafe. Using a distance equal to a quarter of the working length hits a balance that reduces tipping risk while still letting you reach the intended height. For example, a 16-foot ladder should have its base about 4 feet from the wall.