Closets are a haven for mold and mildew because the lack of air movement means that humidity levels can rise quickly. Eliminating condensation and increasing air circulation are the keys to transforming a damp closet into a dry one that is safe for storing clothes without danger of mold and mildew damage.
Empty the closet and examine the walls, ceiling and floor for signs of mold and mildew. These include brown, black or green stains or fungus-like growths on the surface. The overall pattern is random, but mold and mildew often appear as a cluster of circles.
Remove any mold or mildew by spraying with a bleach mixture of 2 tablespoons bleach in 1 liter of water, then wiping it away with a rag.
Place moisture-absorbing materials in the closet, such as silica gel, anhydrous calcium sulfate or activated alumina. These powders should be placed in open containers anywhere in the closet; however, it's important to keep them out of the reach of children and pets.
Run a dehumidifier as necessary in the closet to keep humidity levels below 50 percent.
Install louvered doors and wire shelving to encourage air circulation. Remove existing closet doors by lifting them up off the hinges and placing louvered doors of the same size on the existing hinges. Remove solid shelves by lifting them off the supports or unscrewing them from the brackets, and put wire shelving in their place.
Feel the walls to determine if one is cold or damp, especially walls facing the exterior. Also check the floor if the closet is directly above the basement. The combination of cold air from the outside and warm air from the inside may be causing condensation in the closet. Add insulation to any outside walls causing moisture condensation, or to the ceiling of the basement below the closet, to stabilize temperatures and prevent additional condensation. A foam board can be placed directly against the wall or ceiling to act as insulation, or fiberglass insulation can be placed between the wall and a foam board.
Put in a vent that allows air to circulate in and out of the closet. This can be placed anywhere, but is usually added above the closet doors where it is inconspicuous and doesn't detract from the room. Find the studs and cut a hole in the drywall between them the same size as the vent -- then slide it into the opening.
Launder clothes and other fabric items before replacing them in the closet, since mold feeds on soil. Wipe down all other items with a damp rag.
Leave space between clothes, boxes and other items for air to circulate. Ideally, there should be about 6 inches between stacks of boxes, and clothes should not touch each other or be packed together when hanging. Pay special attention to areas near outside walls; leave extra room for air to move in those places.