Drywall Thickness Guide: 1/4, 3/8, 1/2 or 5/8 Inch?
Part of Interior & Finishes
Quick answer
1/2 inch is standard for interior walls. Use 5/8 inch for ceilings, garages and fire-rated walls; 3/8 inch for repairs and double-layering; and 1/4 inch for curved walls or skim-over work. The standard wall thickness is 1/2 inch.
Drywall comes in four common thicknesses. Picking the right one is about sag resistance (ceilings), fire rating (garages and shared walls), and whether the surface is flat or curved.
Thickness by application
| Thickness | Best for |
|---|---|
| 1/4 in | Curved walls, skim-over a bad surface, double-layer |
| 3/8 in | Repairs and patches, double-layer remodels |
| 1/2 in | Standard interior walls and ceilings (16" framing) |
| 5/8 in (Type X) | Ceilings (24" framing), garages, fire-rated walls |
Walls vs ceilings
- Walls: 1/2 inch is standard and plenty strong.
- Ceilings: use 5/8 inch (or 1/2 inch sag-resistant) so the panel doesn't bow between joists, especially at 24-inch spacing.
- Garages and shared walls: code usually requires 5/8 inch Type X for its fire rating.
- Bathrooms: match the thickness to the wall (usually 1/2 inch) but choose a moisture- or mold-resistant board.
Thicker board is heavier: a 4×8 sheet of 1/2 inch weighs about 50 lb, while 5/8 inch runs 70–80 lb.
FAQs
What thickness drywall for a ceiling?
5/8 inch is best for ceilings because it resists sagging, especially at 24-inch joist spacing. 1/2 inch sag-resistant board is an acceptable alternative at 16-inch spacing.
Is 1/2 or 5/8 drywall better?
1/2 inch is the standard for walls. 5/8 inch is stiffer and fire-rated, which is why it's used on ceilings, in garages, and on walls that need a fire rating.