Encapsulation. Environix pioneered the technique in Seattle and now the method is widely used. First, it involves applying a chemical treatment to kill any active spores. Second, an encapsulating layer is applied to cover the remaining staining. Of course, no treatment is ever performed without first addressing the underlying moisture issue.
Physical removal. Occasionally contractors will attempt to physicallyremove not only the surface mold growth but also the remaining staining. Popular techniques include dry-ice blasting and hand sanding. Both methods are extremely costly and leave behind a vulnerable surface. Because of these negatives, these approaches have fallen out of favor.