Function

Drywall corner beads do not require the installation of paper drywall tape. Instead, attach corner beads with drywall nails or screws. Cut the corner to the size that matches the length of the exterior corner you wish to cover. Hold the corner bead so that it forms a straight line and lies flush against the exterior corner. Install drywall nails or screws every few inches along the length of each side of the corner bead.

Paper Tape

Drywall finishers use paper drywall tape to cover cracks. They first cover the cracks with a generous coat of joint compound and then use a drywall knife to install paper drywall tape over the crack. After the initial installation dries, drywall finishers then apply multiple coats of joint compound to hide the paper drywall tape. But taping the seams of exterior corners isn't necessary because a corner bead covers the gap between two boards of drywall.

Considerations

Lifting edges are a typical problem that occurs when installing corner bead. If this happens, do not install paper tape over the lifting edges in an attempt to disguise them. Eventually, the lifting edges will shift the tape and create air bubbles. The only effective solution is to install more nails or screws to push the lifting edges down.

Alternative

If you can't use nails or screws to install corner bead due to framing issues, don't attempt to secure the corner bead by installing paper tape along its edges. While the corner bead may seem secure at first, eventually it will fall off. Instead, install plastic corner beads, which require only joint compound for installation. Essentially, you lay a thick coat of joint compound over the exterior corner and press the plastic corner bead into place. After several coats of joint compound, the plastic corner bead is secure and stable.