URGENT - Hide wall under ductwork

[shane]

Hi,

I'm using MEP2013 and for some reason I cannot get my ductwork to hide the walls below. Hide meaning show haloed lines. I've tried the ootb AECB templates and it still doesn't work. The duct elevation is 15'. Base height of wall is 10' so it should display dashed lines at crossing but it doesn't. Can anyone point me in the right direction?

Thanks

[Keith.Brown]

I believe that architectural items do not hatch underneath mvparts.  Only MEP objects will hatch under other MEP objects.  This is why alot of people will draw a slab as a mvpart so that they can get their ductwork and equipment to hatch correctly under the slab.