Mud cracking: 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 in corners upon application Remedy: Remove coating by scrapping and sanding. Prime and repaint, using a top quality water-based paint. Mud-cracked areas can also be repaired by sanding the surface smooth before repainting with a top quality water-based paint. This type of paint is likely to prevent recurrence of mud cracking, because it is relatively more flexible than solvent-based paint, and ordinary water-based 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 minimizes the tendency to apply too thick a coat of paint.