Q: I have noticed a white powder around the edges of my concrete walkway. Should I be concerned? A: The white powder is the result of efflorescence, which occurs when a soluble salt, such as earth, ...

On cool and damp days, many homeowners worry about mold. When it pours and storms outside, windows often remain closed to avoid letting in moisture. Anxious eyes scan every visible spot on the wall.

1.The floor of my basement is spotted with efflorescence. What is causing this, and how can it be removed? There has never been water on the floor. I run a dehumidifier in the summer when the basement ...