Paint Bubbles on Newly Painted Walls

Moisture Problems

• Moisture can cause paint to become unattached from the wall surface and peel or bubble. If water is leaking somewhere inside the wall or a nearby source of water soaks into the front or back of the wall, the paint will often peel or bubble. Humidity from a dryer or bathroom vent and condensation from an unsealed outlet, attic or door can also cause paint bubbling.

Temperature Changes

• Temperature changes as new paint dries also cause bubbling. When new paint dries, its outermost surface dries before the inside of the paint layer completely dries. If the paint heats up when the outside is dry and the inside is wet, vapors from the interior layer of paint expand but cannot escape. The paint vapors then form bubbles in the paint, called "heat blisters."

Identification

• Determine whether moisture or a temperature change caused the bubbles. If the bubbles have water in them, they are moisture bubbles. If the bubbles have a collapsed appearance, are connected to peeling paint and have drywall or dry wood underneath, they are probably moisture bubbles that have dried up. If the bubbles have paint underneath and do not contain liquid or have a collapsed appearance, they are temperature blisters that formed when the paint heated up as it dried.

Prevention

• To prevent bubbles from happening again, repair causes of bubbling before touching up the paint. For example, caulk around leaky windows with waterproof caulking and insulate pipes that have condensation on them. Fill any open cracks in the walls with waterproof caulking. To prevent future temperature blisters, try to keep wet paint at a consistent temperature for at least a couple days as it dries. Avoid painting in the morning on a wall that has shade in the morning but sun during the rest of the day.

Remedy

• To fix bubbles in paint, scrape away the bubbles with a putty knife or razor. Sand the area to smooth it, and then touch up the bare areas with primer and new paint. If paint bubbled on a wooden wall because of a moisture problem, coat the bare wood with a water repellent before reapplying paint. As the paint dries, keep heaters in the walls off to avoid the temperature changes that cause heat blistering.