How to Make a Room Corner Round

Spread protective floor tarps over the area under the wall corner to catch excess adhesive or drywall compound.

Measure the entire height of the corner using a tape measure to determine how long to make the rounded corner bead.

Lay the plastic corner bead on the floor or on a table, and measure it from one end until you reach the proper cutting length. Mark the location with a marker, tracing all the way around the perimeter, including the rounded portion.

Cut through the marked location using a pair of tin snips. You may need to make smaller cuts along the rounded side to maintain an even cut.

Remove the lid from a tub of joint compound, and scoop up 1/2 to 1 cup using a drywall knife. Smooth the compound over both sides of the wall corner until it is 1/8 inch thick.

Spray the paper facing on the corner bead lightly with water. Pick up the corner bead, and press it into place at the very edge of the corner.

Apply more joint compound over the corner bead until no portion of it is visible. Blend the edges of the compound back toward each wall.

Wait until the compound dries, and then sand it down using a piece of fine-grit sandpaper until both sides of the corner are smooth. Then, pick up a sanding sponge, which is flexible, and run it up and down the rounded corner to smooth out any imperfections.

Prime and paint the rounded corner as desired.