How to hang and finish drywall, and how to repair it
Check the framing, hang the ceiling before the walls with the joints staggered, screw each sheet off at the spacing in the board maker’s guide, then tape and finish the joints in three coats, letting each dry before the next.
A fire-rated wall or ceiling is built to a tested design: use the board type and layers it names, and repair it with the same materials.
Worked example
Example: a 12 × 10 ft room with 8 ft walls and no openings, walls only, one layer and 10% extra.
This example gives 13 drywall sheets by area.
- Surface area: 352 sq ft
- ceil(352 × (1 + 10/100) ÷ 32) = 13
Other calculators for this job
Every step of a paint and drywall project: measure, the list, what it costs and the quotes.
Check the framing first
Measure walls, ceilings, openings and changes in height. Add backing where cabinets, grab bars or a TV mount will hang, and mark pipes and wires so no screw finds them. Any wiring or plumbing inspection happens before the board covers it. Keep patches on a separate list from new walls; a small repair that has to match an old finish is its own job.
Pick the board
Most interior walls take 1/2-inch board. Ceilings often take a sag-resistant 1/2-inch board or a 5/8-inch one, bathrooms a moisture-resistant board and fire-rated walls Type X. USG’s Sheetrock Installation and Finishing Guide (J371) covers choosing, fitting and fastening panels. The drywall calculator counts whole sheets; a small window cut-out rarely saves one.
Hang it
Hang the ceiling first, then the walls from the top down, so the wall sheets hold up the ceiling edges. Run the sheets across the framing and stagger the end joints so they do not line up. Drive screws just below the surface without tearing the paper, about 12 inches apart on ceilings and 16 inches on walls; J371 gives the spacing for each case. Replace broken board and add support behind any loose edge before taping.
Buy the finishing materials
You need tape, joint compound (mud), corner bead for outside corners and screws. The drywall calculator starts tape, compound and screws from USG’s published figures; measure the joints and outside corners for a closer list. Use the tape and compound your finishing guide names. Agree on the finish level and who primes and paints, so “finished” means the same thing to you and the installer.
Tape and mud in three coats
Bed tape in compound over every joint and inside corner and cover the screw heads, then add a wider fill coat and a wider finish coat, feathering each edge. J371 says each coat must dry, or set for a setting-type compound, before the next, and cold or damp air slows it. Sand lightly, wipe off the dust and prime before painting.
Repair the cause, then the wall
For water damage, fix the leak and let the framing dry before new board goes up. For a large hole, cut the damaged board back to the framing on each side so the patch has support. USG’s Repair Drywall guidance says a fire-rated wall must be repaired with like materials and points to the Gypsum Association’s GA-225; leave rated-wall repairs to a qualified installer.