CSLB General Building (B)Finishes and Building EnvelopeEasy
A drywall installer is hanging 1/2-inch gypsum board on wood-framed ceilings and walls in a standard living room with no fire rating requirement, using screws only (no adhesive). Per typical fastening schedules, how should screw spacing generally compare between the ceiling and the wall applications?
- AScrew spacing is not regulated for ceilings, only for walls
- BCeiling screws should be spaced closer together than wall screws
- CCeiling screws should be spaced farther apart than wall screws
- DCeiling and wall screw spacing must always be identical
Show answer & explanationAnswer & explanation
Correct answer: B. Ceiling screws should be spaced closer together than wall screws
Ceiling applications typically require closer fastener spacing (commonly 12 inches on center) than wall applications (commonly 16 inches on center) because ceilings are more prone to sagging under gravity, requiring tighter fastening to prevent board deflection at panel edges and in the field.
Why the other options are wrong
- A. Ceiling fastening is regulated by gypsum board installation standards, just like walls.
- C. This reverses the actual relationship; ceilings need tighter spacing, not looser.
- D. Fastening schedules differentiate between ceiling and wall applications; they are not identical.
Drywall Fastener Spacing
Gypsum board fastener spacing differs by application, with ceilings typically requiring closer spacing than walls to resist sagging.
- Common screw spacing: 12 inches o.c. on ceilings, 16 inches o.c. on walls
- Closer spacing needed where gravity load on the board is greater
- Adhesive application can allow wider fastener spacing
Memory trick: Ceilings sag, so screws stay snug and close together.