Finishing my basement in my house , basement ceilings are a little shy of 8 ft. I have a wood stove down there that I would like to install in an alcove so I can mount a tv above it. Non combustible clearances for my stove end up with me needing a 4ft wide 4ft tall box. My question is can I lower the height of the box by leaving the ceiling inside the alcove open ? Entire alcove construction will consist of metal studs and Durock with stone covering. Just looking for insight or ideas on how to pull this off. Thank you