Mold & moisture
Musty Smell After a Leak: What It Means and What to Do
Updated · Copperline editorial
Common hiding places
- Carpet pad under a dried-looking carpet
- Bottom of drywall behind baseboards
- Sink base and toe-kick cavities
- Insulation above a ceiling stain
- Under laminate or vinyl plank flooring
Is it mold?
Often, but not always — wet materials can smell before growth is visible. If the odor persists more than a few days after drying, have moisture readings taken.
How it's fixed
Find the moisture with meters, remove materials that can't be dried, clean and treat affected surfaces, and dry to a verified standard. Sealing over a smell traps the problem.
What a professional check involves
A technician takes moisture readings around the original leak area, checks under cabinets and behind baseboards, and may use thermal imaging. If mold growth is found beyond a small area, remediation follows containment practices such as those described in IICRC S520.
Musty Smell After a Leak: What It Means and What to Do: follow-up questions
Will an air purifier fix a musty smell?
It may reduce odor temporarily, but the smell returns if damp materials remain.
Is a musty smell always mold?
Not always, but it usually means something stayed damp long enough for microbial growth to start.
Every home differs; editorial standards.