Hang a Pre-Hung Door
Setting a factory-hung door plumb with an even reveal — the standard prehung sequence, the split-jamb variant, and the long-screw trick that stops heavy doors sagging.
Score and Break Out Proud Drywall So Door Casing Sits Tight to the Jamb
When drywall stands proud of the door jamb, casing rocks and gaps. Mark the casing's footprint, score inside that line with a knife, and break out the drywall behind it with a hammer — the casing lands flat on the jamb, and the crushed zone stays hidden.
sheetrock sticks out past the door frame, trim won't sit flat, molding gap at the door, door trim won't lay flat
The Problem
Drywall that finishes slightly proud of the door jamb is everywhere — a heavy coat of mud at the corner, a jamb set a hair deep, and now the casing teeters on the high drywall instead of sitting flat. Nail it anyway and you get a rocked casing with a gap at the jamb line, right at eye level on every door.
The Technique
Make room behind the casing where nobody will ever see it.
- Hold the casing (pre-assembled, in this carpenter's shop) in position and mark where it will sit on the drywall.
- Mark a second line inside that footprint, then score along it with a utility knife. The score is the fence — it stops the drywall from breaking out any further than you want.
- Crush and break out the drywall face between the score line and the jamb with a hammer, removing material until the casing drops in tight against the jamb.
- Nail it off: 18-gauge brads into the jamb, 16-gauge nails through into the framing.
The relieved zone sits entirely behind the casing — the trim covers its own surgery, and the joint at the jamb closes up tight.
Pro tip: The score line is the step that makes this safe to do on finished walls — drywall face paper tears in whatever direction it pleases unless a knife cut tells it where to stop. Score deliberately, crush confidently.
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