Chimney Options

[plastic_peanut]

wondered if you can offer some advice folks...
I recently posted about a stain on our bedroom wall which I found to be two nails imbedded in the wall which were corroding resulting in a bubbling almost foam like appearance to the plaster around them.
The wall appeared damp where the nails were installed but generally the wall feels cold not damp.but there is evidence of a tea coloured stain around 12” below where the nails were.
The position of the “damp” is around the chimney breast but it runs externally to the house and protrudes through the roof to the stack.

The house is a 60s house and from speaking to the next door neighbour they have had similar issues.
I have been given a quote to rebuild the chimney stack ( it is in poor shape) or remove it and retire the roof.

Ultimately I want to ensure the walls are dry but I have seen posts about hygroscopic salts.
Would anyone know what might be the best play here? I was initially thinking about removing the stack and ventilating where the fire currently sits but if I could guarantee rebuilding the stack would remove the damp I think that would be preferable.

Can anyone offer advice please? Thanks in advance

 

[^woody^]

You will need to post pictures of the damp, the chimney inside and out, so that the problem can be visualised in context.

Damp chimneys can be one or more of several potential causes

 

[plastic_peanut]

Thanks Woody, unfortunately there is a gas fire in place so I can’t take any pictures internally.
I have attached pictures of the wall, the two holes are where the nails were found below the wall. I dug around them to pull them out. I left the holes open for a week or two and then applied polyfilla. This set and then appears to be changing to a darker colour as a result of damp.

I have taken a picture of my neighbours chimney from our window for context ( sorry about the quality) but the other images are ours with the chimney running external to the house, passes through the tiles and then vents with a single stack. Flashing around the stack onto the tiles. There is also a section to the right hand side of he chimney( ground floor ceiling height that steps out from the wall and is tiled over for rain protection. Just visible in one of the images.

I have cleaned all the guttering to ensure this wasn’t a problem. The house backs on to woodland so there is a lot of moss etc

I hope this is of some help to assess my dilemma.

Thank you


Just to add, I have just measured the centre of the internal staining to the landing window. Then taken that measurement outside to see where it sits. Not easy in the dark but it is pretty much bang on to the centre of the chimney breast.