3 November 2026 · By Diego Gómez

Musty smell in the house but no visible mould? What it means

A damp, musty smell usually means hidden mould or high humidity somewhere. Where to look, how to measure it and how to get rid of the smell for good.

That earthy, stale smell when you come home is one of the first signs of damp, often before any black spots appear. The smell comes from compounds released by mould and bacteria growing where you can't see them.

Where to look

• Behind furniture on outside walls: wardrobes, beds and sofas pushed against cold walls.
• Inside wardrobes and cupboards, especially under the stairs or against an outside wall.
• Under the sink and around the bath: a slow leak or failed sealant.
• Carpets and underlay near the front door or in ground-floor rooms.
• Window reveals and trickle vents where condensation collects every morning.
• Washing machine seals and drawers, which are often the culprit in a small kitchen.

Measure the humidity

Put a hygrometer in the room that smells worst and check it in the morning. If it's regularly above 60%, the smell will keep coming back until you bring the humidity down, however much you clean or use air fresheners.

How to get rid of it

1. Find and fix any leak first: no dehumidifier can keep up with dripping water.
2. Clean what you find and wash fabrics that smell.
3. Dry the air: a 12L dehumidifier set to around 50–55% in the worst room, with doors closed, usually clears the smell within days. Check the size you need in what size dehumidifier.
4. Cupboards and wardrobes: a moisture absorber or a small dehumidifier helps in enclosed spaces.

If the smell is coming from a structural problem in a rented home, such as a leak or rising damp, it's your landlord's job to fix it: see damp and mould: your rights as a renter.

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