Nobody likes to see bubbles in their drywall mud. They prevent the wall from being completely smooth and leave an uneven surface for the first coat of paint.

Fortunately, these bubbles are easy to fix as long as you can identify the cause.

The most common cause of bubbles in drywall mud comes from incorrectly taping the joints. Fixing this problem requires removing the tape, adding more joint compound, and applying new tape.

Here’s what you need to know.

How Do You Fix Bubbles in Drywall Mud?

fixing air bubbles in joint compound

If you have bubbles in your drywall mud underneath your paper tape, take the following steps to fix it:

  • Use a utility knife to cut above and below the bubbles, and then remove that section of tape.
  • Apply a layer of drywall mud to the drywall joint where you removed the tape. (This layer should be slightly wider than the width of the tape.)
  • Tear a piece of tape to fit the section.
  • Place the tape over the freshly applied joint compound.
  • Now, starting at the top, run your drywall knife over the tape using even strokes. 
  • Do this until you’ve embedded the paper in the joint compound and all trapped air is released.

After you’ve fixed the bubbles in your drywall mud, you can finish the job by applying a 1/16th inch layer of joint compound over the drywall tape. You’ll then need to allow the mud to fully dry, which will take about 24 hours.

Next, add a second coat of joint compound that’s about 1/16th thick, let it dry, and then sand until smooth.

What Tools Will You Need to Fix the Bubbles in Drywall Mud?

If you have bubbles in your drywall mud due to air trapped in the paper tape, you don’t need many tools to fix the issues. You probably already have most of these on-site.

Here are the tools you’ll need:

  • Joint compound
  • Paper tape
  • Drywall knife
  • Utility Knife
  • Trowel

Why Does My Drywall Mud Have Bubbles in It?

There are two main reasons your drywall mud might have bubbles in it.

The first is because there’s air trapped underneath the paper tape you’ve used. 

This is a common problem for those who don’t have a lot of experience with drywalling. It results from not putting enough joint compound in the drywall seams before applying the tape, and then not pressing firmly enough to release the trapped air after applying the tape.

When this happens; air gets trapped under the tape. As the compound dries, the air bubbles or blisters, which becomes pretty noticeable.

The second most common reason for air bubbles involves the texture of the wall you’re applying the mud too.

As drywall compound dries, its moisture content does two things – evaporates and absorbs. This means some of the moisture gets absorbed into the sheetrock while the rest evaporates into the air.

If a barrier (like a painted surface) blocks the first coat of joint compound, the drywall cannot absorb the moisture, and tiny bubbles form as the moisture passes outward.

To fix this, you can try sanding down the bubbles and then adding a product like No Pock Pro to the joint compound before reapplying. Alternatively, you can add a little bit of dish soap to your drywall mud.

How Do You Prevent Bubbles in Drywall Mud?

There are a few steps you can take to prevent bubbles in drywall mud, as long as it didn’t go bad. First, make sure you’ve thoroughly mixed your drywall compound to the right consistency – it should have the texture of frosting. This is very important if you’re not using a premixed compound.

Secondly, when you tape the gypsum drywall seams, make sure you use an adequate amount for your first coat of compound before applying your tape. Then, run your drywall knife over the paper tape to embed it in the mud and release the air bubbles. This will prevent the mud from having blisters.

Finally, if you’ll be adding compound over a painted drywall surface, add a product No Pock Pro to your drywall mud before applying it to the wall.

Conclusion

Drywall bubbles are easy to avoid and are mostly fixable. It’s not uncommon to see bubbles in drywall mud, especially in joints with paper tape. If this is happening to you, try removing the tape and applying a thicker, even layer of joint compound before putting a new layer of tape back down. Then, remove trapped air with your drywall knife.