Loss of paint due to poor adhesion. Where there is a primer and top coat, or multiple coats of paint, peeling may involve some or all coats.
Possible Causes:
Seepage of moisture through un-caulked joints, worn caulk or leaks in roof or walls.
Excess moisture escaping through the exterior walls (more likely if paint is oil-based).
Inadequate surface preparation.
Use of lower quality paint.
Applying an oil-based paint over a wet surface.
Earlier blistering of paint (see Blistering).
Solution:
Try to identify and eliminate source of moisture. Prepare surface by removing all loose paint with scraper or stiff wire brush, sand rough edges, and apply appropriate primer. Repaint with a top quality acrylic latex exterior paint for best adhesion and water resistance.