bloody hell that damp wall!!!!!!!!
its under his patio too - notice the wet patch so it's not just encroaching on their walls.
the next door extension looks to me like it's over the boundary as well.
I didnt see any soak away or drains in that garden. I suspect there are big issues with the neighbours property, gutters at least but given that wall is not damp it's wet concrete i suspect there's damaged and covered water pipe or drain.
I dont think he could have got the pricier survey or otherwise hw would know more than he does. If that's penetrated indoors there's no way it can be painted over he's got big problems. I can see the patio will need digging up
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It looks like the neighbours have pulled the fence down, built their extension and then joined the fence to it, which is not good. I am not sure i understand in a victorian terrace how that wet wall is further back into the garden their kitchen extension which looks like it's the legal size.
I didnt see any soak away or mains drains in that garden. I suspect there are big issues with the neighbours property, gutters at least but given that wall is not damp it's wet concrete i suspect there's damaged and covered water pipe or drain. I strongly suspect this given his neighbours extension is so big compared to theirs.
If the problem is under the neighbours house EEK. And the neighbours garden looked untidy and there's no way they wouldn't know that wall is wet, so i suspect its a rental property. Even so negotiating the work with the neighbour - not easy and a possible dispute.