The most effective means to keep mold in check include keeping the humidity level of your home at 40–60 percent, using an air conditioner and/or dehumidifier during humid months and in damp spaces like basements, and always utilizing exhaust fans in bathrooms and kitchens, along with dryer vents outside your home. Lastly, if there are leaks in your roof, walls or plumbing, it is important to repair them as soon as possible.