Mould in bedroom advice please

[stefficles]

I have a one bedroom flat in south west London built in the 1960s. At Christmas time my brother dried clothes in his room with the windows closed and his heater wasn’t switched on right (it has now been switched on correctly). This resulted in mould on the bedroom walls. We now open the windows and never dry clothes in there.

He developed a cough and runny nose/sneezing when the mould came (he has asthma). We used vinegar on the walls but the cough didn’t go so we used commercial anti mould spray. The cough is a lot better but it’s still not fully gone. There is some staining of the walls but my family think there isn’t active mould any more. I’m concerned mould might have got into the plasterwork and that’s why he’s still coughing.

I want to get the staining painted with anti mould paint but not sure if I should get a damp surveyor or a plasterer to see it first, before asking painters for quotes? I would be very grateful for any advice. Thanks.

How long have you been in the flat ? I moved in my current flat in summer, all looked fine, when t went bellow 8c , the mould and damp appeared. Dehumidifiers, repainting, ventilation , clothes in open storage formats like hanging or open shelving

Has he actually had treatment? I know DH had aspergillus after sleeping in a mouldy room and had to have voriconazole before he improved. The mould may have actually gone from the room but he may still be suffering if he’s not had any treatment.

You’ve done a lot of the right things already—ventilation, stopping clothes drying, and treating the mould. But if your brother’s still coughing and there’s staining left, it’s worth digging a bit deeper before painting over it.

Mould can sometimes penetrate into plaster, especially if the wall stayed damp for a while. Painting over it with anti-mould paint might mask the issue short-term, but if there’s still moisture or spores underneath, it could come back.
I’d recommend getting a damp surveyor rather than a plasterer first. They’ll check for hidden moisture, condensation risk, and whether the mould was surface-level or deeper. If they give the all-clear, then a painter can prep and seal the wall properly.

I’ve been using a free visual scoring tool to assess mould risk from photos—happy to share it if you want to double-check the area before booking anyone. Hope your brother feels better soon, asthma and mould are a horrible combo.