Preventing Basement Fuzz

Q: How can I stop white fluffy stuff from forming on my basement floor? I’ve tried acrylic basement floor paint, but it doesn’t help.

A: The white stuff you see is called efflorescence, and it's caused by minerals that migrate up through the concrete floor, carried in solution by moisture. As this moisture evaporates, it leaves the minerals behind in a kind of continuous cycle. As the process of moisture migration and drying continues, it can cause quite a build-up over a period of months. Many people mistake efflorescence for mold growth. And although the minerals involved are harmless, efflorescence does indicate enough inward moisture movement to cause problems if you decide to finish your basement in conventional ways. The best way to solve your problem is with a truly waterproof basement coating like Drylok or Xypex. Trouble is, both these products must be applied over bare masonry surfaces to be effective. If removing the old paint is a problem in your case, consider covering the basement floor with a dimpled sub floor tile product like Dricore or Subflor. These are made from squares of oriented strand board (OSB) factory-bonded on top of a dimpled plastic layer. Once assembled, this plastic seals out moisture, while creating a foot-friendly surface on which you can install many kinds of engineered wood, laminates or vinyl flooring.