• Manifestations
  1. Blistering appears as bubbles on the painted surface.
  2. It occurs because of aadhesion being lost, which results in the paint film lifting from the underlying surface.
• Causes
  1. Applying the paint to an area that is warmed by direct sunlight.
  2. Applying the paint to an area that is warmed by direct sunlight.
  3. When moisture escapes through an exterior wall.
  4. NOTE: Occurs more frequently on surfaces painted with alkyd or oil-based paint. Occurs less frequently on surfaced painted with latex.
  5. When a film of latex paint is exposed to morning dew, excessive humidity or any amount of rain falling within a short time period after it has dried.
  6. If the surface was prepared inadequately, blistering is more likely to occur.
• Solutions
  1. Repair caulking where it is allowing moisture to enter. Install a ventilation system such as exhaust fans.
  2. When blisters penetrate the substrate, they must be removed by scraping and then sanding the surface.
  3. Finally, prime the wood, allow sufficient drying time and apply high-quality latex paint manufactured for exterior use.
  4. If blisters have not reached the substrate, scrape them off and sand the surface.
  5. Next, apply a primer to the bare wood.
  6. After it has dried, repaint the surface using a high quality latex paint.