Bubbling Paint Will Ruin Your Walls—Here's How Experts Prevent It

Painting is one of those home improvement tasks that people either love or despise. It’s the easiest (and most affordable) way to make a space look brand new, making it the perfect winter remodeling project as you put away some of your budget for gifts. However, as with all DIY projects, it's not always as easy as it seems, and some problems may not appear until after the paint has dried. Bubbling paint is one of them, and it's a perfectionist's nightmare.

Bubbling paint, or blistering, is one of those pesky, unforeseen issues that can, ahem, pop up a few hours after you put down your brush or even years later, depending on the cause. The fix might be as simple as scraping the blister off, patching the area, sanding it smooth, and repainting. Most likely, though, you'll need to do some investigating to figure out what happened and ensure there isn't a bigger problem lurking, like water damage or a faulty foundation.

“Paint bubbling is usually caused by moisture, bad prep, or cheap paint,” says Erica Anenberg, general contractor and CEO of Girl Flip, a Los Angeles–based construction and remodeling company. “In my experience, moisture's the biggest culprit.” Excess moisture causes paint to lose its adhesion, pull away from the drywall, and create uneven air pockets. That's why bubbling paint is most commonly seen in kitchens and bathrooms, where condensation builds up rapidly. If you see it in another room, it could be an indicator of a leak coming from the plumbing, air-conditioning system, or the roof. “You'd be surprised how many people don't realize they've got a leak somewhere,” Anenberg says.

Prepping your walls inadequately or using the wrong paint or primer can cause cosmetic paint bubbling too—this usually looks like a crop of smaller bubbles.

You need to address the root cause of bubbling paint to prevent further damage to your home. Once you've done that, it's usually pretty easy to patch up your wall and make the paint look smooth again. Below, we'll walk you through various scenarios and solutions for solving unsightly bubbles in your paintwork—and explain how to prevent them next time.

Bubbling Paint Causes

From insufficient prep work to poor conditions, there are a few common reasons why you might have paint bubbles on your home's interior or exterior walls.

The Walls Are (or Were) Damp

The most common reason for bubbling paint, as mentioned above, is too much moisture exposure, resulting in a loss of adhesion. When moisture gets trapped in between paint layers, air pockets form where the paint releases from the wall. Moisture could be coming from humidity in the room, through poorly constructed drywall, from a leak, or through an external crack in the wall. You need to fix any leaks or moisture issues before you start, advises Anenberg. “It's worth the extra effort.”

You Painted When It Was Too Hot

Temperatures over 85 degrees Fahrenheit can cause paint to dry unevenly, and that can lead to bubbling paint. It's ideal to paint when it's between 50 and 85 degrees.

You Didn't Clean the Walls First

If you didn't wipe down the walls properly before painting, grease and dirt could be the cause of bubbling. Paint can't fully adhere to a wall that's greasy, resulting in a bubbled appearance.

You Didn't Prime the Walls

Primer is important whether you're starting with new walls or covering existing paint. It ensures the paint can grip the surface evenly and consistently.

You Used the Wrong Kind of Paint

Bubbling paint can happen when you use a different type of paint than what's already on the wall. Oil- and latex-based paints can't go on top of each other; the compounds don't bind, which means you'll get air bubbles in the top layer of paint.

You Painted Over Wet Paint or Primer

Not waiting long enough in between coats can also result in bubbling paint. Again, moisture is the enemy here. Wait until your primed and painted walls are fully dry before applying the next coat.

You Stirred the Paint Too Long or Too Fast

This is a little like baking—you don't want to overmix paint. It introduces air bubbles into the paint that can show up on your walls. Mix it slowly and keep it brief.

You Used the Wrong Roller Cover

Not all paintbrushes and roller covers are the same. They're designed to apply paint evenly to textured surfaces, from the smoothest to the roughest. It's important to choose the correct material and nap size for your walls so you don't end up with problems later.

For roller cover material, there are a couple options to choose from:

• Woven fabrics: Materials such as mohair and microfiber help prevent lint from being left behind in the paint, providing an extremely smooth surface.
• Knit fabrics: Materials like polyester and lambswool hold more paint in them, allowing you to cover more surface area faster. They do, however, tend to leave behind some marks or stippling.

You should also choose a roller cover nap size that's best suited to the paint and surface you're working with:

• Shorter nap roller covers: These covers don’t pick up as much paint as longer nap roller covers, making them ideal for painting on smooth or semi-smooth surfaces. They range between ¼ to ⅜ of an inch in length, and you should typically use these when you’re painting metal doors, cabinets, and smooth walls and ceilings.
• Medium nap roller covers: For semi-smooth to rough textures, you should probably use medium nap roller covers. These typically range in length from ½ to ¾ of an inch, and they do best painting over textured walls, stucco, and concrete to name a few.
• Longer nap roller covers: Ranging between 1 to 1 ¼ of an inch, longer nap roller covers are best used for rough to extra rough surfaces, like brick and roughly textured concrete. They hold in more paint than the shorter options, allowing you to cover more space in one roll.

How to Fix Bubbling Paint

If the cause is surface-level—not the result of a crack in the wall and drywall—begin by scraping off the bubbled paint. Sand it down to create a smooth surface for primer, then fill any holes or cracks with a patching compound. Let the compound dry overnight, then sand again gently with fine-grit sandpaper. Clean the area after sanding, apply a primer, and allow it to dry completely before repainting.

“You'll likely need to repaint the whole wall or a large section for it to blend well,” says Anenberg. “Old and new paint side-by-side can be noticeable. Plus, if you don't have the exact paint you used before, you'll run into matching issues. Best bet? Repaint the entire wall for a seamless finish. It's more work upfront but saves headaches in the long run.”

Here's what to know to avoid bubbling in your paintwork and get smooth results next time.

• Look for cracks: Cracks near windows and doorframes could be letting moisture in and wreaking havoc inside the wall. This is a common cause of damage to drywall and framing.
• Watch the weather: Try not to paint on an extremely hot day because the heat can cause paint to dry unevenly, resulting in bubbling. Similarly, avoid painting in high humidity so that moisture doesn't get trapped in between paint layers. If you're painting a bathroom, finish painting the room and allow the paint to dry completely before showering or running a bath.
• Check the humidity: If excess moisture is a constant problem where you live, you may need to run a dehumidifier in the space you're painting as you work and while the paint dries to prevent bubbling in your paintwork.
• Prep the walls before painting: Remove dirt, dust, and grease with a rag and soapy water. Let the walls dry completely before applying primer and between every coat.
• Use primer: Primer lays the perfect foundation for paint. It works as a sealant to help the paint bind better to the wall and creates a smooth surface for you to apply it to. Anenberg recommends using a high-quality primer and paint.
• Allow ample time for drying in between coats: If you live in a humid climate, you may have to wait a few days for primer and paint to dry fully before you lay down the next coat. Be patient! It'll pay off in the long run.