Damage to Boundary wall

[HappyDays80]

Hi there

Would be grateful for some advice. I share a boundary wall with my neighbour which acts as a partition between the public pavement and our properties. We both live in a detached house with this wall spanning across as the front border. There are 3 pillars and 2 walls and 2 railings. The middle pillar divides the boundary (with end pillars on either side). My neighbour had decided to grow a California Lilac right up against their wall which has resulted in the central pillar developing 3 cracks ( 2 of the cracks are at the base and match from front to back which indicates the pillar is not supporting the wall but is now being supported by the two walls either side). I raised this issue with my neighbour amicably – they removed the hedge but now refuse to repair the central pillar –They are disputing that the hedge had any cause for this damage - Legally where do I stand? What is reasonable? Communication has gone down hill and want to understand what is the probability that the hedge was responsible.

Apologies for loading one photo - i could not upload any others as the files were too big - hope you can get the jist of things from this photo

[des8]

If you are really responsible for the wall (what do your deeds actually state) and you are concerned about the safety factor you cannot afford to let the matter stand.
IF you are jointly liable for the whole wall (and I'm not sure you are) and not just the part on your land, and your neighbour disputes your view of the condition, you either need to get down and repair it yourself, or have it surveyed.
If the surveyor deems it unsafe (and agrees it has been damaged by your neighbours plant) you are in a stronger position to negotiate with your neighbour (or even to obtain a court order) regarding its repair.