Help! Any damp detectives here?

[Zandathepanda]

Student flat. Ground floor. Old terrace house probably 1900-1920. Damp appeared after sleeping in room for one night so, with other problems with the house, Dd came back home.

Landlord says it’s condensation - she didn’t cook and there’s no shower nearby. However it had been raining a lot and was raining that day. He says open the window and don’t put furniture against the walls.
I am concerned it’s rising damp.
There are several walls that have similar patterns in the corner. But this is her bedroom wall, the other side is another ground floor flat.
Patches in corners in living room and other bedrooms.
Can anyone say from the photos?
I am concerned about her getting ill but also the water is round an electric socket she’ll need. She’s not that happy about having a ground floor window open (onto yard) at night.

It may well be condensation, however nothing to do with the students. Given the amount of salts on the outside wall, probably the historical dampness evaporating from the wall and possible chimney have left a lot of salts on the inside as well.
Those salts absorb water from the air really well (in the same way your salt pot in the kitchen and miraclegro get wet when sitting around open) making it damp.
Even assuming the original problem with dampness is solved, the next solution isn't too keep the humidity at ridiculously low level, it's to strip off the wall and plaster with non gypsum based plaster.

The last time I saw 'tide marks' like that was my house.

Turns out I had a water main leak and it took months to dry out.

There is definitely something leaking (mains or drains).

The outside wall is shocking.

The source of the water has to be found and stopped before this problem goes away.

Dehumidifiers won't help.

A call to the council is in order, as this property is not fit.

Thanks everyone for your advice. I am in an awkward situation as my daughter just wants to move in with her friends and there’s zero other housing options available.

So if she's moving in then try not to use that socket. If she has to then ensure an extension lead with cut out is used and try not to leave anything plugged in when she's not there.
If there are dehumidifiers in property can she keep one?
Are there window limiters on her window so it cannot be opened easily by people from outside.
Don't put furniture against walls if at all possible leave a circulation gap.
What's the heating and does she pay for electricity or is it included in rent? If its a radiator and included then leave it on all the time for background if it's an electric heater and she has to pay then it's more difficult.
She can still contact council if things get difficult later on,it's unlikely to get better during the winter

Also take photos of room now included furniture walls and floor coverings so at end of tenancy she can show condition so she can get back any deposit.
It's recommended that all new tenants do this in their rooms and common areas.
E mail copy to landlord so it's dated

Star thank you. She has been really good and done all this - good life lessons learnt! She kept it factual, no emotion, explained everything in terms of health and safety. Lots of photos (he complained were edited) so she corrected him on that! She cc’d the letting agent who are not impressed by his tone on the email - I think they have spoken to him which he didn’t like. He has also responded by email so everything is on him. There’s a very clear email trail.

Rising damp is definitely a thing and most often affects older buildings that don't have a proper damp proof course. It can make you ill as well, the mould is definitely linked with respiratory illnesses. It doesn't look very healthy place to live. Is there any chance she can find somewhere else? I would consider reporting this to environmental health, although in my experience they don't always respond very quickly or very helpfully.

The dehumidifier will have to be going 24/7.

Nothing can be put near the damp walls, check the floor under the carpet regularly - you may have to roll the carpet back and mop the floor as well.

If she can try to negotiate a reduction in rent because of the cost of running, renewing the filter and emptying the dehumidifier, fair play.