Berger HomeShield Bio Wash is a ready-to-use, fast-acting anti-fungal pre-treatment solution designed for direct surface application. It effectively prevents the growth of mold, mildew, and other microbial or fungal activities on recommended surfaces such as plaster, brick and masonry. To apply the product, the surface must first be prepared by sanding with sand paper or by using a wire brush in severe cases, followed by a wash with potable water to clear all dust and foreign materials.