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.
Drywall repairs: the method and what to buy
Each repair from USG’s instructions for its Sheetrock repair kits and patch pack. Every one ends the same way: sand when dry, then prime before painting, with Sheetrock First Coat or a flat latex wall paint high in solids. A wet sponge sands without dust. Ready-mixed patching compound takes about 24 hours a coat at 75 °F; a setting-type compound such as Easy Sand 90 hardens in about 85 to 130 minutes.
| Damage | How USG repairs it | What to buy |
|---|---|---|
| Dent, small hole or hairline crack | Fill it with compound and let it dry, then a second coat if it still shows. | Patching compound, a taping knife, a sanding sponge, primer |
| Popped nail | Drive a new nail 1 1/2 in from the popped one, then drive the popped nail back in. Leave both heads in a shallow dimple and cover them with compound. | Drywall nails, patching compound, primer |
| Crack about 1/8 in wide | Press compound into the crack, bed one strip of paper tape over it, then cover the tape with a second coat. | Paper joint tape, compound, a taping knife, primer |
| Hole up to about 2 in | Coat the edges of the hole, lay two or three strips of paper tape across it in a criss-cross, bed them in compound, then two more coats. | Paper joint tape, compound, primer |
| Hole over 2 in, or water damage | Cut the damaged board out back to the studs: a utility knife along the studs and a keyhole saw between them. Slip repair clips onto the edges and screw them on, screw in a new piece of board the same thickness and snap off the tabs. Tape all four sides without overlapping the tape, then a second and a third coat. Fix any leak before the new piece goes in. | A piece of drywall the same thickness, drywall repair clips, drywall screws, paper joint tape, compound, a keyhole saw, primer |
| Torn face paper | Peel off the loose paper and skim a thin coat of compound over the area, feathered out, then a second coat if needed. | Setting-type or patching compound, primer |
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 hole over 2 inches, cut the damaged board out and hold the new piece on the framing or on drywall repair clips; the repair table above gives each repair and what it takes. 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.