sweeps not cutting wall

[kgatzke]

Why isn't the membrane sweep cutting the wall?  It was cutting fine at -6" but it fails every time I move it to -4-1/8".

Why isn't the void sweep cutting the wall?

The origins of ALL the sweeps are well within the wall.  

I'm disappointed with how sweeps work in general but it doesn't seem like I'm breaking any of the rules in this instance so I want some explanations.

[Alfredo_Medina]

I think you should consider all the elements of this detail as elements to be added at the top of the wall, not subtracted. The top of the wall is at a certain height, and then you put the cap elements. But It seems like your doing the opposite logic: stopping the wall at a higher elevation, and trying to cut the wall with these elements.

[kgatzke]

Because I know two heights, the base of the wall, a roof slab in the case of curbs, and the underside of the mechanical equipment.  At least I can set all the layers of the wall to extend the thickness of the coping assembly, but now I have to remember that number and remember to set the extension for the walls and instruct the junior staff members who may or may not change coped walls.

Why can't the sweeps just cut the wall the way they're supposed to?