In article ,
wrote:
1) The builder wants access to the roof to inspect the coping stones at
the top of the parapet as he feels that could be the source of water
ingress. Ok, if that is true, how come the damp is not experienced by
the top floor flats? I have asked the occupants of the top floor flats -
I have only established contact with one flat owner at the moment - if
they experience damp, and they say no. I have left my phone number at
all flats asking for any information on symptoms of damp. Those I have
spoken to say the have temporary condensation issues fixed by opening
windows.

If water is getting inside a cavity wall, it could appear almost anywhere.
Although it would seem odd that it travelled several floors before
becoming noticeable.

Why not use a decent drone and camera to inspect the top of the wall?

--
*If at first you don't succeed, destroy all evidence that you tried *

Dave Plowman London SW
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