Being told to rip out privet hedges cos they are causing subsidence?! What!?

[Shortysoso]

We live in London, clay soil, on a hill, big 1900 houses split into flats.

Upstairs neighbour’s insurer (lovely neighbour, no issues with her)says hedges in their front garden and shrubs in their back garden are causing subsidence in her flat.

This is from expert reports which shows they drilled holes and found some roots. No holes drilled in the front and no roots identified.

Seems lame to me but they are insisting it’s quite common and hedges need to come out.

Has anyone heard of this or similar?

Only hedge we really care about is the shared one along boundary between our front paths so not the end of the world - but I just don’t like being threatened into this (if we don’t remove hedges we risk liability for all past and future costs of subsidence) and it seems a bit unlikely. Surely if privet caused subsidence half of England would be in a ditch?!

Any advice or experience or expertise very welcome!

I would be interested to see what the report actually says.

I have dug out old privets and the roots only go down about a foot.

That sounds absolutely crazy.

Reminds me of a time when my grandparents insurance company claimed the subsidence on the corner of their house (built 1898) was definitely and unequivocally caused by the plum tree at the side. Builder was there when they made this statement and both he and my dad gleefully recall the insurance man's face when the builder lifted the plum tree out of the ground with one hand to show roots of about 6" deep and dead. . Insurance firm didn't want it to be the towering oak trees in the nearby copse at fault ...................

Shortysoso can you dig down under one of the privets and check the roots yourself? It does sound bonkers that they could cause the problems

Total cobblers. How can you get subsidence in an upstairs flat if there isn't any downstairs?

Unfortunately we have had similar. The neighbours huge trees were identified as the main cause, but a small tree of ours (meant to have shallow roots and no roots seen crossing boundary when their house is a metre lower than ours) was listed as a contributing factor. Their house is already underpinned too.

I'd say - utter rubbish! Have you searched online the maximum root depth of privet? I just looked, top of the search was this: Privet hedges do not have the same root structure as trees and are generally, shallow rooted. It is unlikely that a privet hedge would cause subsidence. The other main factor is drying out of the ground, especially in clay footing areas - the clay dries out in long, hot & dry spells and shrinks. Also, privet roots are generally in the top 6-8 inches of soil. As I thought. Much more likely that the very dry summers has caused the clay to shrink and all the rain we've had has resulted in heave. Not forgetting gravity, being on a hill. Why not ask a tree officer (from the council) if they could visit and give their opinion on source of subsidence? Good luck

Who has written this report about the subsidence in an upstairs fiat? The insurance company? Or someone with Structural engineering qualifications who might actually know something? You should ask to see the report. Who owns the hedges? It’s also unlikely subsidence is just evident on the first floor. It’s a failure of foundations so look around the ground floor too.

My feeling is the insurance company has sent a cowboy round and their view isn’t to be trusted. What evidence can you see of cracking? You would definitely see cracks on the outside of the building.

What is the position regarding the freeholder and their insurance? I wouldn’t grub up anything until the facts are established. Also where hedges have drunk water, and are then removed, the water stays in the soil. On clay this can cause the ground to swell and this isn’t great either.

Absolute tosh. Ask to see the report but dont be bullied, this is actual bloody bullshit

Reminds me of my old ground floor maisonette that had an oak tree at the bottom of the garden. My upstairs nrighbour was a professional moaner and complained incessantly about the leaves blowing into her garden.
I was in the garden with my two young children, when there was a sudden downpour. We dashed inside and I hadn't even shut my back door when her balcony collapsed and fell onto my back step with bits bouncing into my kitchen.
I knocked on her door and she hadnt even heard the crash, and she just started ranting that it was my tree that had done it.