Bubbles resulting from localized loss of adhesion, and lifting of the paint
film from the underlying surface.
Possible Causes of Blistering paint
Painting a warm surface in direct sunlight.
Application of oil-based or alkyd paint over a damp or wet surface.
Moisture escaping through the exterior walls (less likely with latex paint
than with oil-based or alkiloyd paint).
Exposure of latex paint film to dew, high humidity or rain shortly after paint has dried, especially if there
was inadequate surface preparation.
Solution Blistering paint
If blister go down to the substrate: try to remove the source of moisture. Repair loose caulking; consider
installing vents or exhaust fans. Remove blisters (see Below).
If blisters do not go all the way down to the substrate: remove them by scraping, then sanding, prime bare
wood and repaint with a quality latex exterior paint.