Kilz offers paint primers containing a mildewcide that helps prevent mold and mildew growth on the primer layer. The primer is designed for areas prone to mold and mildew to prevent future problems.
The special Kilz primer is not designed to go directly over existing mold and mildew. The manufacturer recommends first killing and removing any existing mold and mildew problems. A solution of bleach and water or special mold-killing cleaner works to remove the mold. The surface needs to dry completely before painting on the Kilz primer.
Water-based primers that help prevent mold include Kilz 2, Kilz Max and Kilz Premium. Kilz Complete is an oil-based primer with mildew-fighting properties.