Hydroscopic Salts on Chimney breast

[JakeB]

Hi.
I have a leak which is showing at the top of an upstairs chimney breast and across the ceiling.
The chimney breast is no longer used and the fire place is plastered over.
The chimney has been lowered by previous owner, and I'm not sure if the chimney has been capped or not.
I assumed the leak to be coming via the roof. But a roofer I had out to look, upon seeing the paint work, said that the problem was hydroscopic salt deposits rather the a major problem with the roof.

Having not heard of this before I looked into it but still aren't sure if it's is the case, or if it is just something I'm being told to avoid the roofer carrying out the repair. He was happy to quote for a full new roof, but less inclined to quote for a much smaller repaor job.

Any advice welcome on diagnosis and repair.
Thanks

 

[bobasd]

is there a chimney breast behind the wall we can see?
or has a chimney breast been removed from off that wall?

can you show pics of any remains of the chimney stack, and c/stack flashing?
and pics from inside the loft above the suspect area?
and a pic of any chimney breast and fireplace on the floor below?

 

[JakeB]

Hi there.
That wall has the chimney behind it. The fireplace has been boarded over at ground floor.
Roofer told me the stack has been lowered as it is straight rather than steps out at the top.
Photo attached of chimney but doesn't quite show the top, I'll take another in daylight.
Likewise the loft, though in the loft you can just see the exposed chimney brick. There appears to be a white powder like substance formed in the vmvrick in the loft.

 

[bobasd]

OP,
i asked for various pics for specific reasons?

the new stack pic shows the stack to be internal but no loft pic?
has the stack in the pic been lowered?
the brickwork & pointing & flashing look to be in good condition.
pics of the flaunching/capping and back gutter would help?

given that you have a min. of two flues in the stack it's necessary to open the fireplaces & have both flues swept and vents installed where the fireplaces have been blocked off - flues need through ventilation from bottom to terminal top or you will get hygroscopic contamination seeping through.

 

[JakeB]

Hi.
I managed to get some photos from in the loft as below.
Loft itself feels damp I'd say. I also now have a small wet patch showing on the other chimney breast in the house which is on the front. Again this is damp patch in the upstairs bedroom and the paint has started to flake off.

I'm just trying to establish if water ingress through the roof or chimney stacks is the main issue or if the salts issue could be present or both.

Thanks again.

 

[bobasd]

i'm surprised that there's not more damage showing in the roof bedroom.
there's too much damp, and now another stack and the purlins to consider, to give you much sensible advice.
you really need a pro roofer on the roof examining the stack, and below investigating the very damp loft.

to answer your question: it could be that moisture is coming both from the stack and flues - and from the roof area.

why not read up on the Related Threads below, and roof leaks in the roofing forum?

fwiw: the white salt like efflorescence is harmless.