How to Fix Bubbling in an Angle of Drywall

Slice the tape buried within the angle, using a sharp utility knife. Make two cuts, one on each side of the bubbling area. The tape was folded in half lengthwise, so slice the tape on both the ceiling and wall sides.

Pry the sliced portion out, using the edge of the blade. You might notice your cut wasn’t deep enough to reach the tape, especially if there have been multiple coats of paint or joint compound since the tape’s installation. In this case, make a deeper slice and pry out more material until all the drywall tape is removed.

Brush away loose material, such as crumbly drywall, small remnants of drywall tape and paint chips. Failing to remove loose material could lead to poor bonding and more bubbling.

Apply a generous amount of joint compound to the bare section, using a 6-inch drywall knife. The compound should extend roughly 3 inches from the interior of the angle along both the ceiling and wall sides of the angle.

Rip off a piece of paper drywall tape to match the bare section. Fold it in half lengthwise, and push it into the angle. If any area of the tape does not have joint compound underneath, push more compound under it with your drywall knife.

Wipe the tape flat with your drywall knife. Moistened tape rips easily, so use slow movements. If you rip the paper, pull it off, apply more joint compound and install a fresh piece of tape.

Allow the compound to dry for 24 hours or according to the manufacturer’s directions.

Cover the installed tape with a thin coat of joint compound. Hide the tape, but don’t apply so much compound that you leave the angle wavy and rough.

Smooth your work with 150-grit sandpaper. Fold the sandpaper in half to make it easier to access the innermost portion of the angle. Create a sharp, defined line.