Plasterboard (known also as drywall) comes in 4-by-8-foot sections and is 5/8-inch thick for ceilings, or 1/2-inch thick for walls. Screws are used to attach ceiling drywall to joists, where nails hold wall drywall to the studs. As ceiling drywall sheets weigh 34kg, two people should install each piece in place. When drywalling a garage, if the ceiling is sloped and not horizontal, use 5/8-inch drywall on the sloped roof sections, and install it first before applying drywall to the walls.
Hold the first sheet of drywall up against the garage roof starting in one corner. Insert one 5/8-inch drywall screw through the drywall and into the roof joists eight inches apart. Do not break the drywall surface paper with the screw head, only indent it.
Mark the second section of ceiling drywall using a chalk line for larger pieces. Run the edge of a utility knife along the line and bend the drywall on the opposite side to the line to break the drywall along the line. Run the edge of the knife along the inside bend of the break to separate the drywall. Screw the piece of drywall into place. Cut to size and install all other pieces of ceiling drywall.
Hold the first sheet of wall drywall against the wall starting in one corner. Use one 5/8-inch drywall nail to secure it to the wall studs (one nail every eight inches). Merely indent the drywall surface with the nail heads. Cut to size and install all wall drywall pieces.
Unroll and cut to length a section of drywall mesh tape. Apply the tape the a drywall joint (sticky side down) so that the joint runs down the centre of the tape. Cover all drywall joints with the tape following the same process. Cut to length and apply corner beading to all exterior corners (that is, corners sticking out). Secure the beading to the wall with drywall nails.
Fill a drywall tray half full with drywall compound. Take a six-inch drywall knife and smear the compound over all tape and beading. Feather out the drywall by smearing the compound past the edge of the tape/beading onto the wall, decreasing the thickness of the compound. Also, cover all screw and nail heads with compound. Wait 24 hours (or more) for the compound to completely dry.
Sand all compounded areas first with medium, then fine, sandpaper (wear a dust mask). If any screw/nail heads or tape/beading can still be seen, apply more compound and sand again when dry.
Use a six-inch drywall saw to cut out any receptacle or light switch boxes. Measure and cut out these boxes before the drywall is installed into place against the wall.