When cleaning any mold, basic personal protection equipment such as rubber gloves, eye protection and a high-quality pollen or dusk mask should be worn. The molds seen on lumber are largely a collection of fungal spores on the surface of the wood. Wet wiping and scrubbing the lumber will remove the mold. But simply wiping the wood can release spores into the surrounding air. A better approach is to gently spray or wet down the mold prior to removal.
There are a number of products on the market, ranging from common bleach to commercial mildewcides, which are promoted for cleaning mold from wood. However, the U.S. Environmental Protection Agency suggests using a mild detergent and water for most mold clean up. The EPA recommends wet vacuuming the area, wiping or scrubbing the mold with detergent and water and, after drying, vacuuming with a high-efficiency particulate air (HEPA) vacuum.
Common bleach and water can be used for cleaning mold. Cleaning Commercial Recommendations The U.S. Centers for Disease Control (CDC) recommends using a solution of 10 parts water to one part bleach to clean mold from surfaces. Stronger formulations of bleach and water may be used, particularly to remove the discoloration caused by the mold fungi. The Wood Handbook, published by the U.S. Forest Products Laboratory, recommends a solution of one part household detergent, 10 parts bleach and 20 parts warm water. The solution should be applied using a bristle brush or sponge to scrub the surface of the wood. When using bleach indoors, make sure there is adequate ventilation and wear personal protection equipment. Never mix bleach with ammonia or any detergent or cleansers that contain ammonia. If commercial products are used for cleaning mold, be sure to follow the manufacturer’s instructions for use
The WWPA is a great resource for more information