Signs of Damp in a House: What to Look For

By HUBB Group  ·  Updated September 2026  ·  5 min read

Damp rarely arrives as an obvious, unmissable patch. Usually it's smaller than that: a smell that wasn't there before, a corner that always feels cold, paint that's started to lift for no clear reason. Catching it early is the difference between a straightforward fix and a much bigger job later. Here's what to actually look for, and how to tell it apart from ordinary condensation.

The early signs

• A musty smell - often the very first sign, sometimes weeks before anything is visible. Strongest in cupboards, behind furniture, or in rooms that aren't used often.
• Discoloured or bubbling paint and wallpaper - a sign moisture is sitting behind the surface rather than on it.
• A cold, slightly damp-feeling patch on a wall - even when the rest of the wall feels normal.
• Mould in corners, behind furniture, or around window frames - especially if it keeps coming back after cleaning.
• Skirting boards or door frames that feel soft, or timber that's started to warp - a later-stage sign that moisture has been present for a while.
• Salts or a white, powdery residue on brickwork or plaster - a classic sign of rising or penetrating damp, caused by water carrying dissolved salts through the material as it evaporates.

Damp or condensation? They're not the same problem

Both look similar on a wall but the causes, and the fixes, are completely different. True damp involves water actually getting into the building fabric, either rising up from the ground (rising damp) or getting in through the walls or roof (penetrating damp). Condensation is different: it's moisture already inside the property, from cooking, showers, drying laundry, settling on cold surfaces like external walls or single-glazed windows.

Treating condensation as if it were rising damp, or the other way round, is the most common mistake homeowners and landlords make, and it's usually the reason a mould problem keeps returning even after it's been cleaned off. The two need genuinely different treatments, so getting the diagnosis right first matters more than the treatment itself.

Why landlords in particular need to take this seriously

Awaab's Law requires landlords, initially social housing providers, to investigate and remedy damp and mould hazards within strict statutory timeframes. That means a "we'll get to it eventually" approach isn't good enough any more. Reporting needs to be structured and auditable, showing what was found, what was done, and when.

What to do if you spot the signs

Don't paint over it and hope. Painting or wallpapering over an active damp problem just hides the symptom while the underlying cause keeps working. The right first step is a proper survey to establish whether it's damp or condensation, and if it's damp, where it's actually coming from.

Frequently asked questions

What's the difference between damp and condensation?

Both look similar on a wall but the causes, and the fixes, are completely different. True damp involves water ingress into the building fabric (rising or penetrating). Condensation is moisture from inside the property settling on cold surfaces. Treating one as if it were the other is the most common mistake, and the reason mould keeps coming back.

Will damp come back after treatment?

Not if it's treated properly. Mould and damp return when the underlying cause is left unfixed, which is why treatment always starts with diagnosing the cause rather than just cleaning the surface.

How much does a damp survey cost?

We charge a fixed survey fee and provide a written, fixed-price quotation for any treatment needed, so there are no surprises once the cause is confirmed.