Damp and mould alerts for rental properties

Why this matters for landlords

• UK home insurance typically excludes damp and mould as wear-and-tear, not an insurable event. The exposure here is regulatory and duty-of-care.
• Awaab's Law only applies to social landlords today. Private-sector timeframes are coming once secondary legislation is published, and getting a documented monitoring history in place now is cheaper than scrambling once it does.
• Damp and mould disputes with tenants usually come down to an argument about cause: a leak, or condensation from poor ventilation. A dated, independent weather record is useful supporting context in that conversation.
• Vacant properties between tenancies are especially exposed — nobody's airing rooms or running heating, and nobody notices until the next viewing.

How we detect it

We read sustained outdoor humidity for the property's location, anchored to BS 5250, the UK's own code of practice for condensation control. It documents that sustained high humidity pushes external wall surfaces into the range that supports mould growth. This is an outdoor proxy, not an indoor reading — there's no hardware installed at the property.

Full methodology, including the backtesting and where the evidence is strongest and weakest, is on the how it works page.

What to do when you get this alert

• This is a weather-conditions alert, not a mould detector. It flags conditions that favour mould — it doesn't mean mould is there. Go and look, especially in rooms with poor ventilation.
• Check any tenant reports against the alert timing, and check ventilation (trickle vents, extractor fans, any recently blocked airbricks) if the property is vacant.
• If you do find damp or mould, photograph it and note the alert date — useful for your own file, and for Awaab's Law timeframes if they end up applying to you.
• Use the Property Risk Report as one dated input in a tenant dispute, alongside your own inspection — not as a standalone diagnosis.