Title is pretty much everything!
I have these high up windows that I'd like to clean and maybe in the future install curtains on. I guestimate the wall being 20ft (6m) tall.
For other rooms in the house I typically use an A-Frame, but it's impossible to find an A-Frame to reach that high where I am.
I plan on draping a towel over the top of the ladder to prevent scratches and scuffs on the wall, as well as getting a rubber mat or something if the floor seems slippery. I am just not sure if drywall would support a ladder? Especially near the frame of the windows. Maybe there's something else I'm not considering as well?
I have a major in structural engineering, and I’m commenting to say that you want to be very careful with reasoning that something will total less force because it caps out at your body weight.
Just to give an example, if you have a wire strung between two poles, and you hang your 100 lb self from the middle of that wire, the tension against the poles can easily be thousands of pounds.
It’s not going to play out that way with the ladder, unless the ladder is flexing. But if you have a ladder that bends, and it’s got a 10 degree bend in it, while the ladder is straightening it can be exerting far more force than your weight on the two ends.
Considering the static force diagram, a 100 lb downward force is going to be balanced by a set of opposing forces that sum to an upward 100 lb force.
Given that there are horizontal forces involved too, these individual force components can easily be greater than their sum.
Not saying for sure this ladder situation is one of those situations, but if you’re consistently applying a heuristic that a system of forces will be limited to the force input of an external stressor, you can be very rudely surprised by the actual system when it generates forces in the tons.