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?
It's not a dumb question. Ladders are one of the most dangerous things people keep in their house, and making sure you're using one correctly is important. As to your situation, I think it would be fine to use an extension ladder. My only experience with extension ladder is using 28'-32' ladders to get into tree for trimming. I am not an expert on indoor use.
Yeah, I'd consider myself comfortable with ladders and with heights. I've climbed higher things than this. But you're right, they can be dangerous. I know how to respect them outside the house, but inside the house just feels more sketchy because I have to be aware of myself and any potential damage to the house. Don't want to make the wife mad ๐ .
Get a stabilizer bar for your extension ladder. It makes them much more stable and all the ones I've seen had padded feet on the ends which will also keep you from scratching up the wall.
I agree with everything said here and just want to ask, can you possibly have someone hold the bottom for you? At least that way youโll have an extra layer of safety.