Deep, irregular cracks resembling dried mud in dry paint film.
Possible Causes:
Paint applied too thickly, usually over a porous surface.
Paint applied too thickly, to improve inherent poor hiding (coverage) of a lower quality paint.
Paint is allowed to build up in corners upon application.
Solution:
Remove coating by scraping and sanding. Prime and repaint, using a top quality latex paint. Mud-cracked areas can also be repaired by sanding the surface smooth before repainting with a top quality latex paint. This type of paint is likely to prevent recurrence of mud cracking, because it is relatively more flexible than alkyd paint, oil-based paint and ordinary latex paint. Quality paints have a higher solids content, which reduces the tendency to mud crack. They also have very good application and hiding properties, which minimize the tendency to apply too thick a coat of paint.