When it's wet and cold, the same corner of the bedroom always gets damp. You can see the paint is a darker colour and it's wet to the touch and attracts mould. This dark patch rises up the corner.

If you get a little portable heater in the corner and heat it up, you can get rid of the patch.

Is this just condensation on an outside corner, or rising damp? Are there any telltale signs to look for?

Many thanks.
Andrew

If it's in a upstairs room it is unlikely to be rising damp, as that rises up from the ground

It could be condensation or penetrating damp.

This is a downstairs flat.

Also, the same flat had a chemical DPC put in around the downstairs shower room, but we have real problems in there. You open the windows for a few hours and the walls (with a horrible wallpaper) are dry, but close the windows and the walls become literally wet.

We're getting the people who did it back to see what they say, but would like to become knowledgable first. I'll be fitting a fan into this room when I do it up, but at the moment we just open the two windows when showering.

That's two damp-related problems for the price of one (thread)!

Many thanks again for all your help.

You could do with a damp meter really to ascertain just how damp the walls are.

The shower room sounds like condensation to be honest.

totally agree..
if you close the windows in one room and it litterally gets wet even if the shower isnt running then the chances are thats the cause of your other problem too..
simply running a washing machine for a couple of hours will put a good few litres of moisture into the air, if opening a window lets this moisture out then the solution is more ventilation...
you dont tend to find mildew on penetrationg damp, its usually condensation (basically distilled water)
penetrating damp or rising damp will usually bring with it salts found within the masonary, mildew doesnt like that at all..

Thanks for your responses.

Going to borrow a dehumidifier and see what happens. I assume that if it was rising damp then that wouldn't cure it, so it does then i guess it was just real bad condensation.

Ta.