Hey guys, I had some issues with the paint/caulk cracking where the quarter-round molding was sitting on top of the stringers of my staircase. The movement in the stairs broke the caulk and paint joint.

I removed the quarter-round molding, scraped the wall and top of the stringer clean, then installed new quarter-round. I attached the quarter round very well and I also drove strews thru the stringer into the studs on the adjacent wall to limit movement in the staircase. Everything came together well, it's solid as a rock and ready to be finished.

The wall is fully painted and the quarter-round is primed, now I am ready for caulk. I want to caulk this well so I don't have the same problem happen again after all this work.

In some areas there is a gap between the quarter-round and the wall, that will be easy to fill with caulk. However, in other areas (such as where the quarter-round meets the top of the stringer) the joint it very tight, no gap at all. Because of this, I won't be able to get any caulk in there. I will be able to get a thin film of caulk over the top of the gap, but that won't really help if there is any movement and the gap opens up, right?

What do professional painters so in this instance?

Thanks!