Help! My house is going mouldy.

[Kentlassie]

I noticed black mould this morning. It must have come up really quickly because I’ve never noticed it before. Usually I would think poor ventilation etc but it’s right next to the back door, which is opened multiple times a day. Could damp come through the walls and cause this? It’s two external walls…

Any other tips to stop it spreading?

do you heat your house/this room?
is that a particular cold corner?

external walls can be cold and attract condensation which mould loves.
and ina corner there might be less ventilation. plus the rain and high humidity in winter won't help.

Is there a down pipe on the outside of the wall? This happened to us and there was a leak in the pipe that took the rainwater from the roof.

HG mould remover to get rid of it brilliant stuff

Get a dehumidifier definitely, it won't fix that particular bit of mould but stop the damp

Penetrating damp soaks through brickwork. £20 container of wall sealer from Wickes. White vinegar kills mould.