Roof water leaks have damaged a 3x3 ft section of painted drywall ceiling -- it's a bit crumbly & I don't think it will ever recover, even after it dries out.
So I intend to cut out the crumbling section & insert a new drywall piece, tape, mud, etc.
One edge of *bad* drywall is on the butt edge of the adjacent *good* panel. If I cut directly on this butt seam, the adjacent good panel will have some thickness of tape & mud on its edge.
One edge of the new 3x3 drywall patch would therefore be next to the already-built-up, butt edge, of the adjacent drywall panel.
Is this a bad idea?
Will it be difficult to blend & feather the new drywall patch with the adjacent, built-up butt edge?
Are there better ways to do this?