Hi,
Hoping you can shed some light on a damp problem! I own a Victorian (1880s) basement flat that is part of a semi-detached house. There are damp patches along the interior wall I share with my neighbours. Some are quite low but some rise up to 1.5m or so.
There is a bit of a concentration around the chimney breast but the chimney has been checked and seems to be fine (and there are patches in other areas anyway). Oddly next door don't have damp on this wall (though some issues elsewhere in their flat).
There was damp proofing treatment by one of the big companies before I bought the flat. I've had a couple builders in and they suggest tank and render with Sika and inject some damp proofing stuff. However as that seems to have been done previously and none of them can explain where the damp is coming from I haven't gone down this route. Happy to spend money to fix the problem but I'd like to know where the water is coming from/what the problem is - all the info I can find is generally about exterior walls.
If anyone has experienced this or has any advice as to how to fix it I'd be very grateful!