Place the ladder on a solid, dry flat surface to prevent accidental movement. The feet of the ladder should be level. If the surface is not level, use ladder leg levels to adjust for slight variations.
If the ladder legs are not enough to level the feet, it may be necessary to use a wide stable platform such as a large board as the base. Do not try to level the base or make a ladder reach higher by setting it on boxes, bricks or other unstable bases.
Avoid placing a ladder on a slippery surface such as liquid, ice or snow. If you must work in these conditions, use ladders with slip resistant shoes. For ice and snow, use spike or spur type safety shoes.
When positioning a portable ladder that will access a platform or the roof, the ladder must extend four rungs, or at least three feet above the surface. That way you can safely get on and off the ladder.
Improper placement of ladders causes injuries. Never:
Use a ladder as a horizontal platform, scaffold or to lift anything
Lean stepladders against a wall for use.
Use a ladder on a scaffold platform.