Q: I am planning to change the staircase from carpet to wood. I have one side boxed and the other side open with rails. I read in the Q&A that the extra nosing needs to be cut flush with the riser face. How about the extra tread width from the open side that extends beyond the riser width and overhangs beyond the drywall, do I need to cut stair overhand there as well?
If yes, up to what surface?
A: Yes, you need to cut the overhang on the open side also, up to the outside edge of the stringer. You can buy new tread slabs that are finished on one or both sides or that are just meant to be encased with a stringer on both sides. You would have to glue veneer, or use some sort of cove mold on the outside of the stringer to cover the tread edge you cut off. Not bad if the stringers are painted. This could be difficult if they are not.