For 1/2" gypsum board (drywall) installed on wood studs 16" on center with no adhesive, follow the International Residential Code (IRC) R702.3.5 and Gypsum Association GA-216-22 standards:
- Walls (vertical studs): Screws must be spaced maximum 8 inches on center along each stud. → Place screws every 8" vertically along the stud, starting within 3/8" of the top and bottom edges, and no more than 16" from the end of the board.
- Ceiling (joists or furring strips): Screws must be spaced maximum 7 inches on center due to gravity load and reduced holding strength overhead. → Place screws every 7" along each joist/furring strip, starting within 3/8" of the edge and no more than 12" from the end of the board.
Additional requirements:
- Use #6 x 1-1/4" Type S or W drywall screws (coarse thread for wood studs).
- Drive screws just below the paper surface — do not break the paper face.
- Stagger joints; avoid aligning vertical seams over the same stud on adjacent sheets.
- For ceilings, consider using 5/8" Type X if sagging is a concern (though 1/2" is code-minimum for 16" oc joists).
Note: If using metal studs, spacing changes — but you specified wood studs, so above applies. Always check local amendments — some jurisdictions may have stricter rules. If unsure about structural integrity or ceiling load (e.g., insulation, texture, or fixtures), consult a licensed contractor or inspector. Never skip screws — adhesive alone is not permitted for structural attachment per IRC.