Help Identifying Water Penetration or Condensation Causing Damp Spots on Walls

[CarryOnScreaming]

Hi there

I have a flat on 3rd floor of a 1930's brick built ex-council block with tennants in at the moment. Small spots of damp have started appearing on the window wall, mostly low down, either side of the radiator, though a couple are above the sill beside the window on one side as well.

Main area of damp

I suspect they are from condensation, though the tennants assure me they keep the room well ventilated. Is it possible this kind of damp can appear through water penetrating the wall (solid brick, which looks good from distance outside)? I have no experience in this area so any information advice or opinions much appreciated.

Close up of patch

- there has been no similar problem in the past ten years that I and other tennants have lived in the flat.

More patches

[welsh brickie]

no its condensation, usually from drying clothes on a radiator that's on an outside wall,
Neat bleach applied with a sponge will stop it.

[CarryOnScreaming]

Thanks for your reply

- yes, this seems to be the unanimous concensus from every angle, I shall be wise to this from now on!