Straight ladders may only be ascended up to the fourth step / rung from the top.
The elbow method is used to easily determine the correct contact angle.
Double-sided ladders that can be accessed from both sides may only be ascended up to the third step / rung from the top.
Multi-purpose ladders in the position of use: "Double-sided ladders with attached push-up extension ladder" may only be ascended up to the fifth rung from the top.
Double-sided ladders with a platform and platform ladders must be chosen so that the user can reach the maximum required working height from the platform without having to stretch.