How Do You Distinguish Mold From Mildew on Walls?

Color is your first clue. Mildew typically shows up as white, gray, or light yellow patches with a powdery, flat texture. It sits on the surface of the wall, like a dusting of flour. Mold, in contrast, tends to be darker: black, green, brown, or even blue, and it often looks fuzzy, slimy, or velvety.

Texture matters too. Run your finger lightly over the spot (wear a glove). Mildew feels dry and chalky, and it may come off easily. Mold feels softer, sometimes wet, and it clings to the surface. If the spot has raised, irregular edges or looks like it is growing into the paint, it is more likely mold.

Both mold and mildew produce a musty odor, but the smell is often stronger with mold. If the wall smells earthy or like rotting wood, mold is likely. Mildew has a milder, dusty scent. Also, look for signs of moisture behind the discoloration, such as peeling paint, bubbling wallpaper, or soft spots.

Mold needs a consistent source of water to thrive. Check for leaks from pipes, roofs, or windows, and for condensation on cold walls. In a humid climate like Port St. Lucie, indoor humidity can stay high, so use exhaust fans and a dehumidifier to keep walls dry. Address any leak right away to stop growth.

For small mildew spots, you can clean them yourself. Wear gloves, goggles, and a mask. Mix a solution of water and mild detergent, or use a vinegar and water mix. Scrub gently, then dry the area completely. Avoid bleach on porous surfaces like drywall, as it can damage the material and may not reach mold roots.

For mold, cleaning is trickier. If you decide to tackle a small patch, use a commercial mold cleaner and follow the label instructions. After cleaning, monitor the spot for regrowth. If it returns, or if the area is large, call a pro. Remember, the key is to fix the moisture problem, or the growth will come back.