Who is responsible for pointing damage to shared wall?

ThisIsWeird

Did you know that allowing Ivy to grow up walls could damage them? If you didn't, then you cannot assume the neighbour did. Even if you did know, this, you cannot assume the neighbour should be as well informed as you.

It comes under a legal/civil area where it has to be determined whether someone should know that they are causing damage - how obvious is it? Is it considered general knowledge? Should the person have been aware of the consequences?

In this sort of case, the answer is? No idea.

It would have been a different situation had you been aware that Ivy was growing against that wall, and you had informed the neighb to remove it before damage was caused. If they then took no action, they would - theoretically - be liable.

Mud and soil build up - if they are allowing this to build up higher than the level that was there when the extension was built, and this breached the DPC level and caused damp, then they'd be liable, I'm pretty sure. However, if the ground level has not changed, then the 'fault' would have been down to the builder of your extension.

Have you asked for legal guidance on this?

At the moment, it looks to me as tho' you can try and get some recompense from the neighbour, but without proper legal advice - which, if 'positive' can then be enforced - I suspect you won't get very far. I mean, how far will a 'threat' from you go to making the owner jump?

What you can do, after you have carried out the repairs, is make it clear in a recordable way that they mustn't allow anything in their garden to grow up that wall from that moment onwards.

propertyrental

If you can prove that the actions of the neighbour (or his tenants) caused damage, you can claim. To succeed in courtyou'dneed to prove negligence ie they knowingly did (or didn't)  do something to cause the damage.

It sounds like they did cause the damage , but proving that, and proving they knew, will be hard and risky.

Cut your losses. Make the damage good. But to protect yourself in future, send a letter outlining the do's and don'ts for the future so that if, for example, they allow the ivy to re-grow and that causes further damage, you have evidence that they knew not to allow it to happen.