Damp patches on bedroom wall

[blackbirdxx]

Hi,
I have 2 internal damp patches on the walls near the ceiling in my small bedroom. The largest patch is on the chimney stack with the other on the opposite wall. My house is an 1890 semi with solid brick construction. I’ve been on the roof and there is no obvious place of where damp is getting in but the chimney stack faces the prevailing weather and experiences driving rain. I appreciate that its difficult for anyone to diagnose the problem not seeing the house but I’m after any advice I can get. My idea of a solution is to repoint the flashing on the stack and apply Thompsons or similar to all the chimney brickwork. Is there anything else I should be considering?? Any ideas welcomed.

 

[ree]

First you will have to find the cause of the damp patches.

To possibly find the cause, or causes, why not take pics of the c/stack, and the surrounding roof slate or tile.

Then go into the loft space and take pics of the chimney breast and the underside of the roof.

Then take pics of the patches in the bedroom.

Are any of the fireplaces in that chimney breast blocked off?

The patch on "the opposite wall" - is that wall an outside wall?

 

[^woody^]

Is the damp brown/yellow stain, or black mould? If the former and at the wal/ceiling junction, it's more likely a flashing problem. I can't see any value in applying Thompsons.

Is the chimney in use or capped and vented