How to Do Tape and Float on Drywall

Inspect the wall and drive any protruding screws in with a screw gun. The heads should be just below the surface of the drywall. Locate any dimples or cracks created in the installation; mark those with a pencil for clear identification. Repair any serious damage; cut out bad sections and replace them with new drywall if necessary.

Put adhesive-backed fiberglass mesh drywall tape over all seams and any cracks. Press it firmly on the sides to make sure it sticks tightly. Install corner bead on both inside and outside corners; use fiberglass tape or nail on metal corner bead formed to fit the corner. Metal bead is better on outside corners, which are more subject to damage.

Spread drywall compound over all screwheads, all seams or other taped areas and all corners with a 5-inch drywall knife. Press the mud firmly into the gaps between panels. Spread it evenly over the screwheads and seams and smooth it with the knife, held at about a 45-degree angle. Feather the edges to the surface of the drywall.

Let that coat dry and sand it smooth with a power sander and fine sandpaper. Wipe the dust from the wall with a damp cloth. Spread another coat of mud over all areas, slightly wider than the first coat; use a wider knife if available. Feather those edges to smooth with the drywall. Let that coat dry and sand with extra fine sandpaper. Wipe off the dust and add a third coat if necessary to get the surface perfectly smooth.