Plaster not drying

Morventoad99

Hi, I’m looking for some advice. About a year ago a damp patch appeared on a bedroom wall, which then became three separate patches on the same wall. 

I had a roofer come to look at the roof as it is the original 1950’s roof. He said dry as a bone, no problem. 

He said maybe ingress from the chimney and pulled out some foliage growing in it and capped it off as it doesn’t come down into the house anymore. 

I used a humidifier for several months and no improvement. 

I then had the outside walls rendered/roughcasted as the old render was “boss”
No improvement, so a plasterer took away the plaster at the 3 patches, put in a damp proof coating and re plastered. 

After 3 months, the plaster was still showing damp at 50% plus. 

The plasterer then suggested having the full wall done, which I did 6 weeks ago. Now still showing 50% damp! 

I am at my wits end as it is my wee girls room! What is the problem? Can anyone advise?
thanks in advance

stuart45

Have you got solid or cavity walls?

kazwookie

Is the guttering dripping down the wall?

grumpy_codger

Morventoad99 said:

...

I used a humidifier for several months and no improvement. 

...

Hardly a surprise... You should have used a DEhumidifier

jonnydeppiwish!

Are you sure it’s just not marking coming through? We had that but has disappeared after 3 costs of paint and not reappeared after a year.
Also, are you using a damp meter? If so, they’re not the most reliable pieces of equipment