Guide
How much drywall for a garage
Sheets, mud and screws for walls and ceiling, and where fire-rated board is required.
Short answer
A two-car garage of 24 × 24 ft with 9 ft walls has about 1,307 sq ft to cover once the overhead and entry doors are taken off: 30 sheets of 4 × 12 ft or 45 of 4 × 8 ft with 10% waste. Code requires at least 1/2 in board on the wall shared with the house, and 5/8 in Type X on the ceiling if there is a room above.
Drywall for common garage sizes
| Garage | Area | 4 × 12 sheets | 4 × 8 sheets | Mud, Level 2 | Screws |
|---|---|---|---|---|---|
| One-car, 12 × 22 ft | 792 sq ft | 19 | 28 | 2 buckets | 639 |
| Two-car, 24 × 24 ft | 1,307 sq ft | 30 | 45 | 3 buckets | 1,008 |
| Three-car, 32 × 24 ft | 1,580 sq ft | 37 | 55 | 4 buckets | 1,244 |
The overhead doors are taken as 9 × 7, 16 × 7, 16 × 7 plus 9 × 7 ft. In the drywall calculator, which deducts openings as 21 sq ft doors, a 16 × 7 ft door is entered as 5 doors; the link above does that for you.
Use 4 × 12 sheets on garage walls
Garage walls are usually 9 or 10 ft high and long, which is exactly what 12 ft sheets are for: fewer butt joints, and every joint you avoid is tape and three coats of mud you do not apply. They are heavy and awkward, so the ceiling is easier with a rented panel lift.
Where the building code requires fire-rated board
Under the International Residential Code (Table R302.6), which most US towns adopt, an attached garage must be separated from the house by at least 1/2 in gypsum board on the garage side of the shared wall. If there is a bedroom or any habitable room above the garage, its ceiling needs 5/8 in Type X fire-rated board, and the walls holding up that ceiling need 1/2 in. The door into the house has its own rules. Local amendments vary, so check with the building department before you buy.
What finish level a garage needs
Level 2 is the usual garage finish: tape bedded in compound and one more coat over it. It is not meant to look like a living room under paint, and it takes about 75 percent of the mud a Level 3 finish does: the two-car garage above needs 3 buckets at Level 2 against 4 at Level 3. If the garage is becoming a workshop or a gym you will paint, Level 3 is worth it.