Most homeowners think mildew only grows in damp corners or shaded areas, but it actually travels across the home in ways that are easy to overlook. Once it starts on one surface, it slowly spreads to nearby areas and creates bigger problems if it is not cleaned early. Moisture Moves Down the Home Water does not stay where it lands. Rain runs across shingles, drops into gutters, and moves down siding before reaching concrete. Any mildew that starts on the roof or gutters can be carried with...