Can Mildew Eat a Wall?

Types of Walls

Not all walls will succumb to the effects of mildew in the same way. In order for mildew to effectively eat away at a wall, the material must contain nutrients that can sustain mold and mildew growth. A brick wall and tile wall do not contain such nutrients, and therefore can only eat away at the nutrients provided by dirt and soil on those surfaces. On the other hand, ceiling tiles made of gypsum board, as well as plaster, drywall, wallpaper, wood and insulation material all contain nutrients (such as cellulose) for mold, according to the Centers for Disease Control and Prevention.

If you have a wall containing natural mold-sustaining nutrients, you must take care to keep these surfaces as dry as possible. In addition to their vulnerable physical properties, substances like wood and plaster also have a high level of porosity, meaning that they can trap moisture, creating even more of an ideal breeding ground for spores. You can prevent mildew by keeping them dry, and you can kill small areas of mildew by using dry heat (like a dehumidifier or heater).

When mold spores settle on a moist or wet surface, they begin to absorb the surrounding nutrients, which may include wood, plaster or paper. This absorption process requires corrosive chemical reactions, which release fumes called microbial volatile organic compounds. Over time, these chemical reactions can physically dissolve the material, causing decay and leaving holes in the wall. If the mildew has enough time to multiply into a mold colony, the damage can become widespread and affected walls will usually require replacement.

If you spot a small area mildew on a wall, you can remove it before it has the chance to colonize. As previously mentioned, you can neutralize the mildew using heat, but you can also disinfect it by spraying it with an acidic liquid like white vinegar or a chemical-based liquid like bleach. The CDC specifically recommends attacking mold and mildew with a mixture of 1 cup bleach to 1 gallon water. After disinfecting, dry the area again, and vacuum the surface to remove the dead spores.