Bubbles and blisters happen when paint loses adhesion in small spots and lifts away from the surface. They can appear within hours of painting or months later. The fix depends on the cause, so the first step is figuring out which kind of blister you're dealing with.
Heat Blisters
When paint is applied to a hot surface, often in direct sun, the top of the paint film dries quickly while the paint underneath is still wet. As the trapped water or solvent tries to escape, it pushes up bubbles.
How to identify: Blisters appear soon after painting, usually on sunny walls or dark colors. If you cut one open, you'll see paint underneath instead of bare wood.
Moisture Blisters
Moisture blisters form when water gets behind the paint. It can come from outside through failed caulk, gutters, or flashing, or from inside the home through walls in bathrooms, kitchens, and laundry rooms. As the water tries to escape, it lifts the paint.
How to identify: Blisters show bare wood or the substrate when cut open, and they often contain water. They tend to appear near moisture sources and may come and go with weather.
Other Common Causes
- Painting over dirt, grease, or chalk prevents paint from bonding, so it lifts in spots
- Painting damp surfaces traps moisture right away
- Latex over oil-based paint without a bonding primer can cause blistering and peeling
- Interior walls painted while humid, like in a bathroom that's used before the paint dries, can blister
- Applying a second coat too soon can trap moisture in the first coat
How to Fix Blistering Paint
1. Identify and correct the cause. For moisture blisters, that means fixing the leak, caulk, gutter, or ventilation problem first. 2. Scrape the blisters off and remove any loose surrounding paint. 3. Sand the edges smooth so the repair blends. 4. Let the surface dry completely, especially if moisture was the issue. 5. Prime bare areas with the right primer for the surface. 6. Repaint in suitable conditions, out of direct sun and with enough time between coats.
How to Prevent It
Paint clean, dry surfaces. Avoid painting in direct sun or on hot surfaces. Follow recoat times, and fix moisture problems before painting. In bathrooms, run the fan and keep the room dry for a day or two after painting.
The STRIPES Takeaway
Blisters are a sign that something went wrong underneath: heat, moisture, or poor adhesion. Painting over them only hides the problem temporarily. Find the cause, remove the damaged paint, and repaint correctly so the repair lasts.
Planning a Painting Project in Atlanta?
STRIPES PAINTING CO. handles interior and exterior painting throughout the Atlanta area, with a focus on prep, quality products, and clear communication. Contact us to schedule a free estimate.
STRIPES PAINTING CO. - Built on Detail.
Planning a painting project in Atlanta?
Get a free estimate from STRIPES PAINTING CO. and put this tip to work.
Get a Free Estimate