You've given a room or your home an updated look with a fresh coat of paint, but then your newly painted surface began to bubble. The bubbles could appear in one small area or cover a large portion of the wall. Either way, it's not good, and now you must fix the problem. Luckily, the reason for bubbling paint and the solutions are simple. Plus, once you know the cause, you can prevent future bubbling.
Why Did the Paint Bubble?
Paint bubbling is caused by the paint film lifting away from the surface. There are several reasons for paint bubbling, and it's important to determine the exact cause before you can remedy the situation.
If you didn't properly prepare your wall prior to painting, the paint may bubble. You may have painted over a contaminant that the paint is unable to stick to. Painting on a dirty surface, such as one covered with oil or grease, could result in the paint not properly sticking to the wall – and therefore bubbling. Not taking the necessary steps to prime your walls correctly is another reason bubbling may occur. Your paint may also blister is if you applied an oil-based or alkyd paint over a latex paint, or if you applied either of those paints to a damp or wet surface.
Heat and moisture can also lead to bubbling. If you painted a wall in direct sunlight, then the wall may have been too warm for the paint to adhere properly. Damp basements or walls where water has traveled from the interior to the exterior wall may result in the paint being pushed off the surface and bubbling. Additionally, latex paint that is exposed to humidity, moisture, rain or even dew shortly after it has dried may bubble. And poor ventilation, which is common in kitchens and bathrooms, may also cause latex paint to blister.
The best way to handle bubbling is to prevent it. Before you paint any surface, make sure that it is both clean and dry. Depending on what is on your wall, you may need to dust, wash with a household cleaner or even use a grease remover to thoroughly cleanse the surface. Once all dirt has been removed, wipe your wall with a clean, dry towel and wait until it is fully dry before proceeding. Next, apply the primer so that your new paint can strongly adhere to your wall, and wait for it to dry. Paint only in dry, cool conditions – humidity or heat can result in bubbling. Once you've painted your surface, make sure it is completely dry before exposing it to moisture. If you are painting an area that is poorly ventilated or humid, consider using a fan.
Fixing Paint Bubbles
To fix paint bubbles, you'll need several tools: A putty knife or paint scraper, sand paper, cleaner, several rags, joint compound, primer and your paint. Begin by scraping the bubbles off of the wall with your knife or scraper, and then sand that area until it is smooth. If the paint has blistered because of moisture, then remove the source of the moisture, if possible. If the paint has also bubbled in a previous coat, remove those bubbles as well. Next, clean the area to remove any dust from sanding, dirt or grease on the wall. Once the wall is dry, fill in any pits in the wall with joint compound, then sand it to create a smooth surface. Clean the area again, let it dry, and then apply primer. Once the primer is dry, repaint that area.
There are two less traditional solutions to removing bubbles. The first one is to simply do nothing. Sometimes, paint bubbles will vanish as the paint cures. The other solution is to iron out the bubbles. To do this, heat your iron, but do not fill it with water as that will add additional moisture to your surface. Place your hot iron directly on the bubble and hold it in place for 30 seconds to one minute. Once the surface is cool enough to touch, press the bubbles out with your fingers.