How to hang and finish drywall: materials and order of work

The materials list

Other sizes: how many sheets of drywall for a 10x12 room, and for a garage, how many sheets of drywall for a 2 car garage. For the weight you’ll be carrying, see how much does a bundle of drywall weigh.

Hanging the board

1. Ceiling first. Hang ceiling sheets across the joists, tight to each other. A 12 × 12 ceiling takes exactly three 4 × 12 sheets: how many sheets of drywall for a 12x12 ceiling.
2. Screws on the ceiling go 12 in apart along every joist (USG’s spacing), 3/8 in or more from the edges: 35 per 4 × 8 sheet on 16 in joists, as on how many drywall screws per sheet for a ceiling.
3. Walls next, top sheet first, pushed up against the ceiling sheets so they support the ceiling edges; then the bottom sheet, leaving a small gap at the floor that the baseboard covers.
4. Screws on walls go 16 in apart (USG), 28 per 4 × 8 sheet on 16 in studs.
5. Stagger butt joints so they don’t line up on the same stud, and keep joints away from the corners of doors and windows, where they crack.
6. Cut openings for outlets and switches with a jab saw or rotary tool; measure twice, because patches take more mud than any joint.

Set every screw just below the paper without tearing it. A depth-setting screw gun or a dimpler bit does this consistently; a screw that breaks the paper holds nothing and needs another beside it.

Basements and damp rooms

USG’s wallboard catalog says that where there is a risk of moisture exposure, you should choose panels with adequate resistance to mold growth: its moisture- and mold-resistant boards are labeled Mold Tough, and other makers have their own. Keep the bottom edge just off a concrete slab, because gypsum wicks moisture up (USG’s handling guide stores board on risers for the same reason), and let the baseboard cover the gap. Fix any water coming in before the board goes up; a moisture-resistant panel is not a waterproof one.

Finishing: three coats

1. Corner bead on every outside corner, fastened or bedded per its type.
2. Tape coat: a band of compound along each joint, paper tape pressed in and the excess squeezed out; creased tape in the inside corners; a first pass over the screws and the bead.
3. Fill coat: when dry, a wider coat over the joints, screws and bead with a 10 in knife.
4. Finish coat: a thin, feathered coat with a 12 in knife, wider again, followed by light sanding.

Each coat must dry before the next: ready-mixed compound dries overnight in normal conditions, longer in cold or damp rooms. Setting-type compound hardens in a set time printed on the bag, which speeds up the tape coat.

Levels of finish

The Gypsum Association’s levels run from 0 to 5. Level 4 (tape embedded, then further coats over the joints, fasteners and bead, sanded smooth) is the usual for walls getting flat or eggshell paint. Level 5 adds a skim coat over the entire surface, which USG recommends where gloss paints or harsh, raking light would show the difference between paper and mud. A skim coat is a much bigger mud order: see how much joint compound to skim coat a 12x12 room.

Sanding and dust

Sand lightly with a fine sponge or a pole sander, just enough to knock down ridges; over-sanding scuffs the paper. Sanding compound makes fine dust that irritates the airways: USG’s safety data sheet calls for minimizing dust and wearing a NIOSH-approved respirator where exposure isn’t controlled. Close off the room, cover vents, and use a vacuum sander or wet-sand where you can.

Prime, then paint

Prime the whole surface before painting so the paper and the joints absorb paint the same way; otherwise the joints show through as dull or shiny stripes. Then two finish coats: for this room, see how much paint for a 12x12 room.