Sign of damp
Musty smell
A stale, earthy smell that hits you when a closed flat is opened, or that lingers inside wardrobes, kitchen cabinets and bathrooms. There may be nothing to see. Air fresheners, incense or fresh paint during a viewing can mask it.
What it might mean in a flat
A damp, stale odour in a room or cupboard.
A musty smell is often the first sign of damp you cannot see yet. In a flat kept closed for a sale, the smell may be the only clue that cabinets or the wall behind a wardrobe are wet. It can also come from a dry floor trap, which is a plumbing issue rather than seepage.
Common causes
- Mould or mildew growing on damp plaster, behind furniture or inside wooden cabinets
- A slow leak inside a wall, under a floor tile or behind a kitchen cabinet that has not yet stained the surface
- Wet bathroom floors or floor traps that hold water, or dry traps letting drain air in
- High humidity in a flat that has been shut through the monsoon
- Damp in a plumbing shaft or duct next to the room
What an inspection checks
How we confirm it.
- Hygrometer readings of room humidity, compared room by room
- Meter and thermal scans behind and inside wardrobes, under the kitchen sink and along the shared walls with the bathroom and shaft, with every thermal anomaly confirmed by the meter
- Checks of floor traps and drains for water seals and smell
- Looking for hidden mould on the backs of cabinets, under sinks and behind panelling where access allows without removing anything
When to worry
Signals that it's active.
- The smell is strongest at one wall or cabinet and the meter reads high there
- It persists after the flat has been aired for an hour
- The flat was freshly painted and heavily scented for the viewing
Where it usually comes from
Questions buyers ask
The flat smells fine during the visit. Is it fine?
Maybe. A smell can be masked by open windows, fans and fragrance during a viewing. Instruments do not depend on smell, so the walls are still scanned.
Can a meter find a smell?
No. But a smell tells the inspector where to look harder, and the meter and thermal camera then show whether a wall, floor or cabinet is wet.
Could it just be the drain?
Yes. A dry floor trap or a broken seal can let drain air in. That is checked during the inspection and noted separately from damp.
Not ready to book? Walk the flat with our 10-minute self-check and get a snag list to take to the seller.
Start the Damp CheckFind the damp before you pay for it.
Book a moisture and thermal inspection. Report on WhatsApp within 24 hours.