Dryrot can be big trouble. It is sneaky, and makes itself at home in a structure long before you can visually detect it. For dryrot to thrive, it needs a combination of moisture, heat, and air. These amenities are in generous supply under kitchen sinks and in bathrooms, as well as in attics with poor ventilation and in basements. When rot is spotted, treat the affected area with a solution of 10 percent bleach and water. This kills the organisms and slows growth so a repair can be made.