Since this place is a veritable font of knowledge.

I have a wisteria growing in my garden, it’s on a free standing frame next to my neighbors garage. Conveniently it prevents him from looking down into my garden from his terrace/balcony. He hates it with a passion.

Yesterday he turned up on my doorstep demanding that I remove it as it was damaging the foundations of his house/causing damp/putting his insurance up. Does anyone know of wisteria causing problems, as most of the information that I’ve found points to it being fine root-wise but it can damage roofs if it gets under them, which is why I cut it back.

On closer inspection it turns out that his drains are broken and leaking water under his property/onto mine, which is more likely to be the cause of his sinking. I think he may have alluded to this as to why he wants to change his insurance provider to one that covers for ‘wear and tear’ so that he can get the drains fixed as an insurance job, he can’t change without his premium going up as the wisteria is ‘too close’.

Am I right in telling him to poke it?

the only plant i’ve heard of that can attack concrete etc is japanese knotweed, yet i’m ready to be enlightened. however, with you being a reasonable neighbor, if he came up with a engineers survey that said it was causing a problem, and not his crappy drains, then you’d move it. and then plant some ivy.

The roots: The wisteria roots spread so strongly and abundantly that if planted near walls or pavements they can easily grow into them causing serious damage .

From http://www.wisteria.it/informa-e.htm

But from the Daily Wail

Wisteria will only grow where there is soil. It will not, therefore, stray under the house

http://www.dailymail.co.uk/home/gardening/article-1247100/ASK-MONTY-Can-roots-Chinese-wisteria-damage-house.html

In the case of walls and pavements made with cement this problem does not exist.

from the first link above as well.