Definition: Lifting of the paint film from the underlying surface, which appears as bubbles or blisters in the paint, usually caused by heat, moisture or a combination of both. This condition can eventually lead to peeling of the paint if not corrected. This is called Paint Blistering.
- Painting in direct sunlight or on a surface that is too hot
- Application of an oil-based or alkyd paint over a damp, wet surface
- Exposing a fresh paint film to dew, high humidity or rain
- Moisture passing through interior walls from common household sources such as bathrooms, kitchens and laundry rooms causes paint blistering.
- Determine if blisters were caused by heat or moisture. Break open and examine the substrate and back side of blistered paint.
- If only the newest coat of paint is blistered, the blister was probably caused by heat.
- If the peeled blister contains several coats of paint and the bare surface is exposed, the blister was probably caused by moisture.
For paint blistering caused by heat
- Remove blisters by scraping, sanding or pressure-washing down to underlying coats of paint or primer.
- Repaint the surface with a high-quality interior/exterior paint (make sure the surface temperature is below 90º F).
- Find the best paints suited for your project to prevent paint blistering.
For paint blistering caused by moisture
- Repair loose caulking and improve ventilation of the building to prevent a recurring problem.
- Remove the blisters by scraping or sanding down to the bare surface.
- Prime all bare areas with a high-quality primer.
- Repaint the surface with a high-quality paint in the desired finish.
For More Information: Paint Blistering