mould risk humidity
Compare estimated surface relative humidity with the conventional 80% threshold in EN ISO 13788.
You want an estimate of whether a cold surface favours mould.
Dew point
13.2 °C
Estimated surface RH
95 %
Risk band
High (ISO 13788 threshold)
Estimated surface RH is above the conventional 80 % threshold in EN ISO 13788. A climate that favours growth if it lasts — not a finding.
Estimate from the ISO 13788 threshold (80 % surface RH). Not a survey and not a finding of existing mould.
ISO 13788 is a design threshold, not a medical test and not a legal finding.
Useful next step
If risk is high, log T/RH for a week and read the mould guide. Do not paint over it without lowering moisture.
No affiliate link is live. Products below are categories, not model reviews.
10–25 €
Without a relative-humidity number, every tip is guesswork. A €10–25 hygrometer is the first useful purchase — before any dehumidifier.
When: Always, as the first diagnostic step.
Not when: It does not replace a moisture meter or a rising-damp survey.
Affiliate link not connected — a category, not a model review.
25–90 €
Helps tell “damp air” from “damp wall”. Absolute readings are rough: compare zones.
When: Suspected rising damp or a leak.
Not when: It is not a professional survey instrument.
Affiliate link not connected — a category, not a model review.
8–25 €
Existing mould has to be removed. Anti-mould paint alone, if moisture stays high, is a delay.
When: After you understand the cause, while RH is being lowered.
Not when: Large areas, strong odour, vulnerable occupants: consider a professional.
Affiliate link not connected — a category, not a model review.
No. It means the surface climate favours growth if it lasts. Without visible growth there is no infestation to “certify”.
It is a design standard, used here as a conventional threshold. It is not an enforcement notice.
en