I have a wall that I need to build to make a defined space for a laundry room. I am running into 2 problems with my project:

1. I have a slanted ceiling, and
2. The wall will be going parallel to the joists.

I have read that I need to add nailing block to the ceiling; however (admittedly, looking for a short cut here), I was hoping maybe I could avoid cutting into the ceiling by accessing the attic above, installing the blocking, and then attaching the top plate (hopefully that is the right terminology) to the ceiling? I think I can mud the wall, but the ceiling is textured, and I want to avoid having to re-texture as much as possible.