How to Fix Bubbles Formed under Drywall Tape

By Mark J. Donovan

When taping and mudding drywalls it is important to apply a sufficient amount of mud (joint compound) over the drywall seam first before applying the paper tape. If you do not put a sufficient layer of mud on the seam first, you will end up with bubbles forming underneath the dried drywall tape.

To fix the bubbles formed under the drywall tape, you can cut out the section of tape and redo it, or you can peal back the tape and apply additional joint compound under it.

Applying Drywall Tape Correctly

There is a technique involved in taping and mudding drywall that involves experience and some artistry. Use a 4” drywall blade to first fill in the joint seams and to apply a 4” skim coat of joint compound around the seam area. Next lay your drywall tape into the seam and lightly flatten it down into the joint compound using your 4” blade. Then apply a layer of joint compound over the seam and let it dry.

After the first coat as dried, lightly sand, and apply two additional coats of joint compound. Again, between coats, lightly sand. Also use an 8-10” blade for the second and third coats and flare out the seam to about 12” in width.