Mold in built in cupboard (duplicate threads merged)

[dontbelieveawordofit]

maybe they’re not aired enough before you put them away.

 

[Stringy]

Is the room next door heated/used?
Is the chimney used?

The room next door is used as a bedroom and the chimey is no longer used as the gas fire was removed and an electic fire put in to replace it.

 

[fillyboy]

It is a rental property and the tenants have just told me of the issue, i am not in the area but will be travelling there soon so i can check.

Bingo. There's the problem, 'tenants'. One landlord I did a lot of work for had 6 houses, all of similar construction on an estate. In two of them there was so much mould it looked like they'd painted the walls and ceilings black, I'm really not exaggerating, the tenants of course complained and when we pulled up to inspect them, you couldn't see in the windows for condensation.
Fortunately the other 4 houses had tenants who on occasion would open windows.
If it is only in the cupboard, fair enough, probably not their fault, the side adjoining the chimney is probably a cold spot.

 

[foxhole]

Does sound like dumb tenants failing to vent the rooms and probably drying clothes indoors etc.