I have a pair of long 4x4 posts holding my chimney, and I'd like to build a ladder in to the posts for maintenance. In some ways this could be safer than using an extension ladder, as the posts are well-anchored.
I was thinking I could screw some short 2x4s on to posts as steps. A quick search on building a ladder says to notch the verticals, which seems nice and strong, but would be difficult to do in this setting.
As an experiment, I used a pair of 3 1/2"-long screws to attach a rung just above ground height. I jumped up and down on it and it held. Based on that data, I could use twice as many screws and be safe, right? Or not...