I am working on a bathroom renovation. As part of it I am trying to determine if a wall is load bearing. Wall in question runs parallel to floor and ceiling joists. A small window of drywall is removed at floor level. bottom plate of wall is 2x4 and so are studs. In the attic I moved insulation aside and found the top plate...which is a 2x6. Anyway the top plate runs past the wall and ends over the hallway bordering the bathroom. So, is does a top and bottom plate od different sizes make sense?
If its parallel to the joist, you can be pretty sure its not holding anything up other than the 2x6. I'd guess the purpose of the 2x6 is probably there for the edges of the ceiling to be nailed to.