Short Answer: Why Is My Drywall Tape Bubbling or Cracking?
Drywall tape usually bubbles or cracks because:
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There was not enough mud under the tape
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The mud started drying before the tape was embedded
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The wrong compound was used
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Coats were applied too thick
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The drywall moved
Most tape failures are installation mistakes, not material defects.
Now let’s break down exactly what is happening and how to fix it.
What Causes Drywall Tape to Bubble?
Bubbling usually happens during the bedding stage.
When you embed paper tape, there must be a solid layer of wet compound underneath it.
If there are dry spots, air pockets form.
As the mud dries and shrinks, the tape lifts and creates bubbles.
The Most Common Cause
Not enough mud under the tape.
People try to keep things neat and apply too thin of a base coat.
Then they press the tape in and accidentally squeeze out too much compound.
The tape ends up partially dry underneath.
If you are new to taping and mudding, read this first:
[INTERNAL LINK]
What Causes Drywall Tape to Crack?
Cracking is different from bubbling.
Cracking usually happens later and often means movement.
Common causes:
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Thick mud layers that shrink
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Using lightweight compound to bed tape
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Framing movement
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Poor screw placement
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Not enough screws
When compound shrinks, especially if applied too thick, it can pull and crack along the seam.
If framing shifts even slightly, the seam shows it.
Did I Use the Wrong Type of Joint Compound?
Possibly.
If you used lightweight compound to embed tape, that can cause issues.
Lightweight mud is easier to sand, but it does not bond as strongly.
For bedding tape, I use All Purpose compound.
For finish coats, I switch to lightweight.
If you are unsure which compound to use, read:
[INTERNAL LINK]
Using the correct mud at the correct stage matters more than brand.
How Do I Fix Bubbling Drywall Tape?
It depends on the severity.
Small Bubble
If it is small and solid around the edges:
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Cut out the bubbled section with a utility knife.
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Apply fresh compound.
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Re-tape that section.
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Feather wide.
Do not just mud over a bubble. It will not fix the problem.
Large Bubble or Loose Tape
If the tape is lifting over a long seam:
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Remove the affected tape completely.
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Scrape the area flat.
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Re-bed new tape properly.
Trying to patch over failed tape rarely works long term.
How Do I Fix Cracked Drywall Tape?
First, determine if it is surface cracking or structural movement.
Surface Shrinkage Cracks
If the crack is hairline:
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Scrape the seam lightly
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Apply a thin new coat
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Feather wider than before
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Sand lightly
Often this is just shrinkage from thick mud.
Movement Cracks
If the seam opens back up after repair, something is moving.
Check:
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Screw spacing
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Framing
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Loose panels
You may need to re-secure the drywall before retaping.
If you are unsure whether to repair or replace the section, read:
[INTERNAL LINK]
Why Did My Tape Bubble After Painting?
This usually means moisture got trapped.
Common reasons:
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The mud was not fully dry before priming
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High humidity slowed dry time
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Primer reactivated partially dry compound
In Cleveland humidity, especially in basements, dry times can stretch.
Let mud dry completely before priming.
If you are unsure about dry times, read:
[INTERNAL LINK]
Should I Use Mesh Tape Instead of Paper Tape?
Mesh tape has its place.
It works well for small patches.
But for flat seams, paper tape is stronger and less prone to cracking when properly embedded.
Mesh tape also requires setting compound for best performance.
Paper tape embedded in All Purpose compound is still the most reliable method for standard seams.
How Do I Prevent Tape From Bubbling in the Future?
Follow this process:
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Apply a proper base layer of compound
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Press tape in firmly
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Ensure full contact underneath
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Remove excess mud but do not starve the seam
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Let it dry completely
Thin coats.
Full dry time.
Correct compound.
Those three things prevent most tape failures.
Are Tape Bubbles a Big Deal?
Small ones are fixable.
Long failed seams are more work.
The sooner you fix bubbling tape, the easier it is.
If you paint over bubbling tape, the repair becomes more complicated later.
When Is It Better to Call It?
If:
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Multiple seams are failing
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Ceiling seams are cracking
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Movement keeps reopening cracks
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You are unsure about structural stability
Sometimes the issue is bigger than mud.
Drywall finishing is forgiving. Structural movement is not.
If you are in Northeast Ohio and your drywall seams are failing repeatedly, Colin Can Help handles drywall repair and finishing professionally.
Final Advice
If your drywall tape is bubbling or cracking, the cause is almost always:
Not enough mud under the tape.
Too much mud on top.
Or movement underneath.
Slow down. Use the right compound. Apply thin coats. Let it dry fully.
That solves most drywall tape problems.