Identifying mould · 1 min read
A musty smell with no visible mould: where to look
Smell without sight almost always means the growth is behind something. The six places it usually is in a commercial building.
The smell is a metabolic by-product of actively growing mould. If you can smell it and cannot see it, the growth is behind, above or beneath something.
Where it usually is
- Ceiling voids and plenums — roof leaks, sweating pipes, condensation above tiled ceilings.
- Wall cavities — slow plumbing leaks and failed waterproofing in wet areas.
- Under flooring — subfloor moisture, slab issues, water that ran under vinyl or carpet.
- Inside HVAC — drip trays, coils, insulated duct interiors.
- Behind joinery — cabinetry against cold external walls with no air movement.
- Storage and back-of-house — rooms that are closed, unventilated and rarely entered.
Confirming it without opening walls
Airborne sampling detects elevated spore counts even where nothing is visible, and moisture mapping narrows the source. Between them you can usually locate the problem without exploratory demolition.