Why Does Indoor Latex Paint Bubble?

Wet Surfaces

• If the surface beneath the latex paint is wet, even only slightly, this will disturb the adhesion process of the paint, which will cause small bubbles to form where the paint cannot adhere. If you wash a wall before you paint it, you must allow the surface more than enough time to dry thoroughly. Even if it appears dry, touch the surface. If it feels damp, keep waiting. You can speed up the drying process by aiming fans at the wall.

Mixing Paint Types

• Mixing paint types as well as the kind of finish of the paint also will cause small bubbles to appear. For example, if you previously used an oil-based paint on the wall, and now are trying to use a water-based paint without primer in between, it will not adhere properly. Likewise, if you used a semi-gloss paint before, and you are using a semi-gloss paint again without preparing the surface, the paint simply cannot stick to the wall.

High Humidity Levels

• High humidity levels within your home also can affect how well paint adheres to the wall. Never paint on a rainy day, or when there is excess moisture in the air. A few days before you plan to paint a room, install a portable dehumidifier and let it take the moisture out of the air. Place a hygrometer in the room. If the levels are above 40 to 50%, do not paint on that day.

Application Techniques

• How well you apply the paint is another reason that bubbles can occur in the surface. Rolling on paint too quickly or going in opposite directions with a roller will cause bubbling. Always work slowly and skim the roller over the wall. Properly loading the roller also will help prevent bubbles. Put latex paint in a bucket and use a paint screen to help you squeeze excess paint off of the roller before using it on the wall.