5 Reasons Your Wall Paint Is Bubbling and How to Fix It for a Flawless Finish

Paint bubbling is a common but frustrating home improvement mishap that can occur for various reasons. The best-case scenario is that you made an easily fixable mistake while painting. The worst-case scenario is that your paint is bubbling because of a leak or hidden moisture. No matter the situation, fixing peeling or bubbling paint is essential for a flawless finish. Here's what renovation experts have to say about how to avoid paint bubbling and what to do if you're already staring at a peeling wall.

Common Reasons Your Paint Is Bubbling

Paint bubbling can happen for various reasons, but all of them are typically the result of a poorly prepped wall or moisture hiding where you can't see it. "Any sort of paint bubbling or blistering is usually due to poor preparation or moisture being trapped just beneath the paint," says Sabrina Phillips, owner, interior designer, and contractor at Designing Women of Orange County.

To understand how to fix your problem, you first need to understand the cause. Here are a few possibilities to look out for.

Lack of Proper Preparation

It's tempting to take a roller and start rolling away once you're ready to paint, but patience and preparation are key. "Bubbling could happen when the wall was first painted, and the surface was not fully cleaned or dried out before it was coated," says Phillips. "This leaves dirt and moisture trapped, and it bubbles up as it separates from the dirt or as the moisture tries to escape." A wall should be sanded, cleaned, and then primed before painting, ensuring it dries completely between each step.

Spackle That Hasn't Dried

Bubbling can also happen when you patch the wall with a joint compound or spackle and start painting over it before it fully dries, says Erik Harris, owner and general manager of CertaPro Painters Needham, Massachusetts. While patching is necessary for a smooth finish, let it completely dry before you continue prepping the wall. It's impossible for moisture to escape if the paint is applied when the spackle is still wet, causing bubbling. 

Painting in Humidity

Moisture in the air can get into your walls, meaning painting in the height of summer humidity can lead to bubbling. "In certain parts of the country where it gets very hot or humid, avoid painting in those extreme conditions as it can affect the quality of paint adhesion," says Phillips. "Wait for it to cool down, or try painting in the morning or evening."

Too Many Coats of Paint Too Quickly

Moisture can also come from the wet paint itself. If you slather too many coats of paint on a wall because you're eager to be done, you could find yourself staring at a bubbly, blistering wall. "A common issue is applying coats of paint too quickly and not allowing them to fully dry per the manufacturer's recommended dry time per coat," says Harris.

A Leak or Hidden Moisture

Of course, actual moisture hiding behind your walls can also cause bubbling. When moisture behind the substrate tries to escape and has nowhere to go, it expands the paint coating and causes bubbling, says Harris. This could come from a leak, a spill, or former flooding. Anything that could leave lingering moisture—or cause moisture in the future—could lead to bubbling paint.

How to Fix Bubbling Paint

There's no magic remedy to fix bubbling paint—you simply have to start over. But before starting over, it's critical to figure out why it happened in the first place. Whether it was due to a lack of prep, an over-eager approach to applying additional coats of paint, or a leak behind your wall, you need to understand the why before tackling the how.

Once you figure out what caused the bubbling paint, scrape and then sand the surface to remove all bubbling and flaking paint. Then, using a patching compound, repair any areas that were damaged. Sand it again once the patching compound dries. Prep the surface by cleaning it so it's free of dust and debris, letting it dry completely, then priming it. Once the primer is dry, use high-quality paint for a smooth finish.

How to Prevent Bubbling Paint

Preventing bubbling paint means covering all your bases before you start painting. Here are a few tips to stop the bubbling before it starts.

• Check for moisture: Ensure moisture is not hiding behind the wall before painting. Look for any visual clues like staining or warping. If you want to take it a step further, use a moisture meter, which registers any moisture in the wall.
• Prep the wall adequately: Sand it, clean it, and let it dry. There should not be a trace of dust or debris remaining on the walls.
• Prime the surface before painting: Not using a primer can lead to the paint not adhering as well to the wall or surface, causing bubbling over time, says Phillips. She advises using a high-quality primer, particularly on drywall.
• Pay attention to the paint you're using: Check the type of paint you're using and the type of paint you're painting over. "Clients or even contractors don’t know or check what type of paint was used before, and this will cause very poor adhesion to the surface with potential bubbling," says Phillips.