Chalk Talk

Well, it could be grafitti, or your kid's special art project, but chances are, it is oxidation. This chalky residue is caused by the effect of UV rays from sunlight or a strong oxidizer like bleach (Sodium Hypochlorite). The exposed paint breaks down and the original color is lost, and you're left with a chalky residue. You tend to see oxidation on painted, aluminum-sided, and vinyl-sided homes. The good news it that this kind of residue can be removed with a power washer, so call your local power washer company and have them come over for a consultation.