How can I finish a ceiling around a propane gas line to fireplace?
In a case like this you can cove the corner or use crown molding.
Both methods leave the corner open and different sizes are available pre made.
The toughest part with crown molding is the compound bevel cut at the corners. As there is always some waste I cut in my corners and the match things with simpler cuts. Check it out makes a nice upscale look and hides pipe really well.