We are preparing to start phase one of our basement finishing... the bathroom and guest room. Our house is 1 1/2 years old and the bath was roughed in during construction. The issue is the bathroom ceiling. There are considerable ductwork (main trunk lines) running below the floor joists in half the room and we want to install a flat ceilling below that, preserving any ceiling height we can. How best to frame the ceiling? I can post pics if it will help. I would rather over engineer than cut it close.