Symptoms
- Small raised bubble or ripple in the tape after applying joint compound
- Bubble appears while the compound is still wet or shortly after
- Area feels hollow when lightly pressed
Likely causes
- CommonAir trapped under the tape during applicationNot pressing the tape firmly enough into wet compound leaves air pockets.
- CommonNot enough compound applied underneath the tapeTape needs a bed of wet compound to adhere properly; too little leaves gaps.
- PossibleTape applied over a dusty or dry surfaceTape won't bond well if the surface underneath wasn't properly prepped.
What to do
- If compound is still wet, lift the bubbled section of tape carefully.
- Add more joint compound underneath if it looks thin or dry.
- Re-press the tape firmly with a taping knife, working out excess compound and air from the center outward.
- Let dry fully before applying finishing coats.
- If already dry, cut out the bubbled section with a utility knife.
- Reapply new tape with adequate compound underneath.
- Finish with additional coats, sanding smooth once fully cured.
Tools and parts
- Taping knife
- Utility knife
Drywall tapeSearch: “paper or mesh drywall tape”
Joint compoundSearch: “joint compound for drywall repair”
When to call a pro
Call a drywall finisher if bubbling keeps happening, since technique adjustments can fix it quickly with the right tools.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.