Ongoing subsidence issue

Tracyd2861

Hi

Any advice would be much appreciated.

9 years ago we had subsidence on the extension of our house. We had injection by GeoBear but this did not work and the house has been monitored since 2023 and is still moving.

We have a large oak tree at the end of our front garden and the insurance company now want to apply to remove the tree - we do not want the tree removed and have requested that they underpin the property - they have replied saying they are applying to the local council to remove the tree. I have asked why they cannot do the underpinning but goes on deaf ears.

Suggestions needed

jaybeetoo

It sounds like the insurance company will refuse to do the underpinning until the source of the problem is removed (i.e. the tree roots). If they do the underpinning and the roots continue to cause damage then you’re on your own as the insurance company won’t pay twice for the same problem and you could end up with a big bill further down the line. You could employ a surveyor, at your own expense, to get another view.

Bigphil1474

I'd let them take the tree out and get the problem fixed. When we had subsidence in 2010, the cause was a damaged water company drain, and the insurer wouldn't do anything until that was fixed, and they monitored for a year. While we were waiting, we removed every bush from the area just in case it wasn't just the drain.

silvercar

I’d do some research on ‘heave’. If you take out an old oak tree in one go, there is a lot of water that was once being fed into the tree that will now be sitting in the ground. This can cause the surrounding land to heave, the opposite to subside. It is much harder to correct. The correct way to remove an old oak tree is to reduce it over a number of years.

We had a big oak tree in our back garden in our old house. Cracks would appear throughout the garden in the Summer months. I bumped into the new owners recently who said that they had removed the tree to brighten up the garden and now the ground was permanently soggy.

Slinky

My brother's neighbour removed all the fruit trees in the old orchard at the bottom of the garden, and built an enormous extension which was just feeding rainwater into existing the old soakaway. The new neighbour behind complained about the fruit trees in my brother's garden saying they were causing damp in his property…… completely refusing to believe the source was my brother's neighbours property changes. The gardens slope down towards the complaining neighbour. They harrassed my brother via solicitors and in the end he gave way and had his trees reduced in size. I very much doubt this improved anything.

Annemos

https://forums.moneysavingexpert.com/discussion/comment/81981034#Comment_81981034

Just spotted this Post. So sorry for late response.

Yes, I agree, silvercar. A Heave assessment definitely would need to be done.

As far as I am aware, Heave is more of a potential problem if

1 The Tree is older than the building and

2 The house and Tree are on Clay Soil.

(I am no expert on Resin Injection. But I have wondered to myself…. can Resin Injection be a sure remedy, if the clay is still expanding and contracting with the seasons? I mean, I can understand it might work, if a leaky drain had washed away sandy soil and you are then filling up stable void areas. But if a Large Tree is still there on Clay Soil and droughts, aren't the void areas potentially still unstable… I cannot see how this works.)

If you need to go to the Financial Ombudsman to dispute this, you would need to get a Structural Survey and Tree Survey done yourself. If your own analysis of a suitable remedy differs with that of the Insurance Company and the FOS says yours should be implemented, then there is a chance the FOS would rule that your Survey expenses should be paid back to you by the Insurance Company.

Just to stress, that the FOS are not technical experts and so they rely on the weight of actual technical evidence provided by both parties. They do not take much notice of a Homeowner who has no technical evidence.

I do wish you all the best getting this sorted out.

Just to note, too: As far as I am aware, an Underpinning is done to put deeper concrete foundations under the damaged area, so that the new foundation extends BELOW the influence of the Tree Roots. So Underpinning is sometimes used when there is a Protected Oak Tree, for example. Or if there is a big Heave risk if a Tree is removed.

Here is an FOS case I came across. The Insurance Company had not tried Resin Injection, but instead it was a Piling Method that had failed. I am attaching this, so you can see how the FOS approaches this sort of thing.

https://www.financial-ombudsman.org.uk/decision/DRN-4661837.pdf

One other thing that I remember seeing discussions on. That is the subject of whether a large Tree can be removed in stages and not cause Heave. Or does that actually only have the same impact as removing it in one go, anyway. Several Tree Experts were arguing on both sides.