Gypsum board is supported with drywall clips (Photo 4).
We learned this with truss rise in the early 80s where we developed floating corners and drywall clips.
centers; two-stud corners; single member wood headers; elimination of unneeded trimmer (jack) and cripple studs in rough openings; elimination of headers in non-support walls, windows in alignment with regular studs, single top plate (trusses need to be stacked directly above the studs); drywall clips
(instead of wood backer components); and rigid insulation exterior sheathing (eliminates thermal bridging).
Instead, support those edges by attaching them to blocks nailed to the tops of the wall framing or to special drywall clips
attached to the walls.
Examples include drywall clips
that eradicate corner studs, engineered stair stringers which cuts down on lumber waste and concrete pigments that eliminate the need for conventional finish flooring.
Some builders consider the use of drywall clips
in corners a sign of poor quality.
To install the arches, use drywall screws to secure the sections to blocking and door framework, and to one another using the supplied drywall clips
If you're going to fish cables through joists, you'll need protector plates (10 for $2) and drywall clips
($10 for $3) as shown in Photo 4.