Paint blistering on surfaces like walls or ceilings looks like bubbles and uneven texture. It’s caused by loss of adhesion and lifting of the paint film from the underlying surface.

• Heat blistering is caused by painting in direct sunlight on a surface that is too warm.
• Moisture blistering can be caused by the migration of water through an interior wall to the exterior, thus pushing the paint off of the surface.
• Moisture seeping into the home through the exterior walls is also a culprit.
• Application of oil-based or alkyd paint over a damp or wet surface will also cause blistering.
• Exposure to dew, high humidity, moisture or rain shortly after paint has dried, especially if there was inadequate surface preparation or poor ventilation in areas like kitchens and bathrooms.
• Damp basements.
• Insufficient surface preparation such as painting over a contaminant that the coating cannot adhere to.
  

• If blisters go all the way down to the surface layer under the paint, the cause is likely to be moisture escaping from the surface. Remove all loose paint by scraping or other method, then sand the surface to smooth out any rough edges. Be sure to remedy the cause of excess moisture before repainting. You may need to repair old or damaged caulking, install new caulking, or install vents, exhaust fans or siding wedges to allow the moisture to escape instead of seeping through the paint.
• If blisters go down to a previous coat, remove all loose paint and sand. If the surface is glossy, sand until dull and allow sufficient drying time after cleaning.
  

You've solved your paint blistering issues and are ready to repaint. Start with Premium Wall & Wood Primer. Once dry, apply paint. If you're working on a wall or trim we recommend ProClassic^® Waterborne Interior Acrylic Enamel. Add finishing touches with PowerHouse^™ Siliconized Acrylic Latex Sealant.

When you're ready to repaint an exterior wood surface, start with Exterior Oil-Based Wood Primer. You could also start with a long-lasting paint and primer in one like Duration^® Exterior Acrylic Latex. Seal joints and edges with SherMax^™ Urethanized Elastomeric Sealant.