When attempting to treat black mold growth in a basement the first key to success is to eliminate moisture. This can be very difficult as basements often have openings under a house that can allow moisture in. It is also very difficult to dispel dampness in the basements, as they often stay cooler than the rest of the house. Sealing off an openings, and making sure that rainwater does not come in along the base of the house is the first step in treating basement black mold growth.
Once you have sealed the basement off to the outside, and dried the moisture through use of fans, or dehumidifiers you can began treating the actual mold itself. If you have a very large, or finished basement use plastic sheets to separate the basement into smaller regions. As you clean you will be sending mold spores into the air, and these can began a regrowth in an already treated area if you do not isolate the sections.
Begin with a basic mixture of borax and water. Spray the affected area and scrub away the mold as you would when treating any other part of the house. Side aside any loose materials that has mold on it in a plastic bag for removal. After you have initially treated the area go back over it with a solution of bleach water to kill any surface mold that may have escaped.
Once you have treated the mold remember to dry the entire basement are again, as any residual moisture can restart mold growth. Remove all material that may contain mold from the basement Keep checking the basement in the following weeks so any new mold growth can be eliminated before it can spread. When you make your check ups remember to look for sources of moisture you may have missed, on your first initial inspection of the basement. Due to the enclosed nature of a basement painters masks, and goggles are highly recommended as the mold spores can make you ill.