The main visual difference on drywall is that the main visual difference on drywall is that mildew grows flat on the surface as a light gray, white, or yellowish powdery dusting, while mold is thick, raised, fuzzy, or slimy and appears in dark shades like black, deep green, or red.Because mildew stays strictly on the surface, it expands outward in a flat pattern. Mold, however, penetrates beneath the surface, eating into the drywall gypsum and paper lining, which often causes the paint to bubble, peel, or warp.
Because mildew stays strictly on the surface, it expands outward in a flat pattern. Mold, however, penetrates beneath the surface, eating into the drywall gypsum and paper lining, which often causes the paint to bubble, peel, or warp
If you cannot visually tell the difference here is a test you can do: (Wear Gloves)
The Bleach Test for Drywall
If you cannot definitively tell the difference by sight, you can perform a quick visual test:
- Dip a cotton swab into a diluted bleach solution (1 cup bleach per gallon of water).
- Dab it directly onto the stained spot on the wall.
- If the spot lightens or vanishes quickly, it is surface-level mildew.
- If the spot remains dark or the texture stays irregular, it is mold that has rooted itself deep within the sheetrock core.
Call an expert at DrywallPatch Pro to eliminate this dangerous problem.
