How to tie subfloor vapor barrier into exterior walls
I am in the beginning of the process of finishing our basement and have almost completed the subfloor. What I've done is lay a 6mil vapor barrier on the concrete slab followed by 2x3 16OC and then Advantech OSB. With the vapor barrier, I followed many people's (and website's) advise in leaving and extra 4-5" along the perimeter, up the exterior walls. But now I find myself not knowing what to do with that extra 4-5 inches.
Many people and websites say to leave and extra 4-5" even if there is drywall. But nobody says what to do with them. I gather the idea was to tie it into the exterior walls vapor barrier. But my exterior walls are drywalled. There is no way for me to tie it into the vapor barrier in the wall. So what do I do now. Do I just cover it up later with baseboard moldings? If so, then what's the point of leaving the excess vapor barrier to begin with?