Neighbour refuses to cut down a tree which we know will causing subsidence

[Yellowstickerstalker]

Next door have a tree which is an ash, and our gardener told us that it would cause subsidence and it needs to be felled.
That was almost a year ago, since then we have an immensely frustrating backwards and forwards dialogue where he promises to do it, then changes his mind, then prunes it, says that is all he will do etc etc.
A few weeks ago we had the garden fences replaced and the intervening wall collapsed - it was obviously the tree had which had caused this.

After ringing me in a panic 👀on my advice my partner called next door round and showed him. He seemed to at least 'get it' and they shook hands on his promise to remove it. He has since cut it down significantly but not enough to stop growth. DP has just tackled him again and he said he is not doing anymore, my partner pointed out they'd agreed but that didn't land.

Annoyingly DP said 'yellow sticker' won't be happy, which I am annoyed about as I have deliberately tried to avoid getting involved. Next door is a total misogynist - I believe his initial stubbornness to do anything came from the fact our gardener is a woman. TBH, I have enough battles to fight, SEND kid who has been let down at school, EHCP review battles, it's constant and do not want to get involved.

So, my question is, does anyone know what we should do next please? We may move in the next few years, I don't want to be in dispute ideally. Can the council get involved if it only really poses subsidence issues for our properties? I have thought about getting an arborist round but I doubt we'll get access to the garden. The guy we are dealing with is the son of the owner, who is elderly and in her 90's and has also always been quite tricky to deal with so I have no faith in them seeing the light. Is there a quick and easy legal route which might only cost us a few hundred?
Thanks, for context they don't use the garden and have plenty of other trees, so I know it's not sentimental. That has never come up. They just don't seem to be taking it seriously even though a wall collapsed. They have also paid nothing towards removing the remnants of the bricks, which they also promised to do.
Thank you for reading!

Maybe speak to your house insurance, they will want to protect the property.
When a neighbours bad roof was damaging our garage and they refused to fix it our insurance sent a surveyor round. The neighbours had a roofer fixing the issue within a week, presumably our insurer contacted theirs and told them to sort it. We didn’t have to do anything.
Are they paying to sort the wall issue?

Has it actually caused subsidence? Nobody can categorically state it will as nobody can see into the future (even Nostrodamus wasn't 100%).

A few weeks ago we had the garden fences replaced and the intervening wall collapsed
Needs a diagram or photos because this reads that whoever did the replacing mostly likely caused the collapse. How old was the wall, how long and how much collapsed?

Edit - Annoyingly DP said 'yellow sticker' won't be happy,
What?

I would take the advice of a surveyor rather than a gardener. Sometimes when a tree is felled it causes more subsidence than before.

Keeping the tree pruned will help contain the roots. I certainly wouldn't go yelling about subsidence if you don't have it

...our gardener told us that it would cause subsidence and it needs to be felled.

You're listening to someone not qualified to make that statement and treating it as a fact.

Most professional gardeners are knowledgeable about trees (and quite a lot of them are qualified).

@Yellowstickerstalker I suggest you contact the tree officer at your local council. They can come out and assess the tree, and decide whether action needs to be taken and if so, what and by whom.

@BloodPressureHell
Edit - Annoyingly DP said 'yellow sticker' won't be happy,
What?

This makes sense in the context of OP's username. The DH told the neighbour that the missus wouldn't be happy with the non-resolution instead of standing up to the neighbour.

Are you totally sure about this? Isn’t there a line of thought that if you completely remove the tree, the roots, that will be big, will shrink away and cause subsidence due to a shift in the ground.
Also, if you want someone to do something for you that benefits you and will cost them money to have done professionally, the best route is to offer to pay the full cost.

We had a neighbour who bought and moved in next door and then sent us a formal letter saying that their house buyers survey told them that we had to cut down our tree.

We didn’t have the disposable income to cut down the tree, our survey from two years previously hadn’t flagged it at all and it was in our garden, they hadn’t asked whether we would be prepared to chop it down before they bought the house. I was so annoyed with them to be honest. We had nothing against taking it down and it was on our list but we had a new baby and didn’t have £2500 to spare because they decided it had to be taken out now now now.

Perhaps get a second opinion?

Thanks everyone, these replies are really useful. I’ve become a bit one tracked minded about it (am ND) and it’s really useful to hear other opinions, especially if they contradict my thought process as sometimes I need shaking out of my mindset! I’m also seeing the other side of it and am also reassured that maybe the subsidence is not as imminent as I feared.
Will look into all your suggestions, thanks so much

Ask the neighbour if you can get it crowned so it won’t grow any taller.

Reducing the height/spread is actually a really good way to manage any subsidence/heave potential. Unless it's very close to your house it's almost certainly what an arborist would suggest as it's the least disruptive all round.

Right. I am not mrs knows everything about trees but I live with and among them and have done for some 30 years so have learned a bit. Point one is that @Gardendiary is right. Not to terrify you but a house in the middle of the estate that I live on had a tree removed when the estate was newly built. The loss of the tree ended up with the house needing to be underpinned. Thats an unusual worst case but it happens. Another issue with tree removal, but, at least round here, less of an issue than it used to be is that in areas where there is a high ground water table, the existing trees can be helping to keep this in balance.

Even with a good gardener I wouldn't be taking their word on trees as anything but an opinion. As people have said, I'd be talking to someone with proper expertise. Our local council tree advisors won't come out unless the tree has a protection order on it but you can ask and also find out if the tree is protected. A local decent arboricultural firm might be a good bet but not Fred Bloggs chop it and chip it.

Can i suggest you try and start from the beginning again with the neighbour? You have been under a lot of strees and I know from personal experience how that can magnify stuff. Whose wall fell down and how do you know it was the tree that caused it? It sounds possible (forgive me) that the neighbour is in the position that they will say anything to keep you off their back? Anyone you get in for advice will probably ask to enter the neighbour's garden or enquire if you have their permission to get an assessment because they don't want to step into a neighbour dispute any more than anyone else does.

I knwo I have rambled on and hope this is helpful and hasn't offended you.

I have some Qs:

1- what is your soil like?
Not the topsoil, the stuff underneath - say a foot deep or more.
Is is clayey (plasticine type consistency)? Or dry and sandy? Could you roll it into sausages?

2- how far is the tree from the house?

3- how old is the tree?

4-how old is the house?

OP, How far is the tree from your house?

What type of soil are you on, eg. London clay?

Incidentally, if the tree is on his land, you have no right to insist he remove it. Presumably the tree was there when you bought the house.

Your gardener is not a structural engineer.

You need to get a proper, qualified Arboriculturalist to come and have a look and give their opinion.

I doubt very much the Council will get involved in a private matter unless the tree is TPOd.

If the tree isn’t causing subsidence then what is the actual issue? A gardener is not qualified to tell you categorically that it will cause subsidence.

if I were your neighbour I’d tell you to jog on to be honest.

Agree with this

As a gardener I think what your neighbour has done is the right thing to do.

Your dh has thrown you under the bus which I would explain is exactly what a misogynist loves which is maybe why he felt compelled to do it.

If you are thinking of moving soonish, please don't worry about it further. Try to put it out of your mind, a significant prune will help and subsidence would be unlikely to occur before you move unless you have signs now.

You need a structural engineer not an arborist and you can have a visit for a couple hundred quid to ease your mind.

I really think you need to calm down about the tree. First of all, trees don't necessarily cause subsidence, and only a surveyor/expert can tell you if they do, not a gardener, not a tree surgeon.
Secondly - removing a tree can cause subsidence, as can a big reduction in the crown.
Thirdly - your neighbour is under absolutely no obligation to fell a mature tree because your gardener told you something.
The collapse of the wall is more likely to be caused by all the buggering around.

I wouldn’t be felling a tree unless there was really strong justification including evidence of movement. And I certainly wouldn’t do it because a gardener said it will cause subsidence. 😂

An ash tree is a moderate (not high) demand species. There are many factors to consider including the shrinkability of the soil, the depths of the foundations and the construction. For example, so you know if your floors are solid or suspended?

Without this technical context, making a judgment to remove the tree is completely unjustified and premature.

Felling a tree can actually create more harm with ground heave as the soil rehydrates and swells in the absence of the tree’s moisture uptake. This can lead to more structural damage than the original concern.

I’d be politely telling you to sod off.

No to insurers. They’ll do nothing as no damage. As this is in your interest have you offered to split the cost?

We have been advised to remove a tree but this was by a structural engineer not a gardener

About £400 incl vat.

If it's an ash, it'll die and fall over soon anyway when it succumbs to ash dieback.

Can you post a photo of it? I'll probably be able to tell you if it's already got the disease.