I prefer to use non-toxic and eco-friendly methods to get rid of mold in my home. Mold spores are dangerous enough, so I don't want to add unnecessary respiratory irritants to my crawl space. Tea tree oil is the perfect choice, as it is a broad spectrum fungicide and kills every type of mold it comes into contact with. Tea tree oil is sold at most health food stores and some discount superstores like Walmart. Although it can be a little pricey, you only need 2 teaspoons of tea tree oil per 2 cups of water to effectively kill mold. Add the mixture to a spray bottle, spray on moldy areas and let air dry. It's an easy, simple and effective mold killer.