Heave / subsidence from oak on clay soil

[joepatr]

Hi all

 

I’m based in North West London (an area with shrinkable clay subsoil) and currently have an oak tree in my garden, approx 6/7 metres tall. 

 

I’d like to have this taken down eventually but am obviously concerned about the risk of not only subsidence but also heave. 

 

Could anyone recommend the best way to manage this to ensure ensure the safety of my property? I was thinking the best way would be to have the tree slowly reduced over a period of time before having the stump totally removed. 

 

Would this be the way forward, if so, how much and over what period? I was thinking taking it down in quarters over the next few years but one of the local tree surgeons suggested thirds every couple of months. 

 

I’d be grateful for any suggestions and also any companies in the Hillingdon area who could help. 

[benedmonds]

6 hours ago, Khriss said:

Will reiterate, get structural engineers report on yr house / foundations / soil type and drainage, the Arb report on tree and it's future . Without information, it's just as long as this thread. 

 

But what use is this information?  

The reports are NOT going to be conclusive, they should identify the level of risk of subsidence if the tree is remains. 

My guess is there would be a moderate or high risk depending how far from the house it is.. But that doesn't help much and they want the tree out because of light anyway.... 

 

If the structural engineer states there is a high risk of heave if the tree is felled, your only option is to retain the tree and hope it never dies..  There is nothing practical (that I am aware of) you can do to prevent any heave and I think we have agreed that staged reductions are pointless.

[Mick Dempsey]

 

53 minutes ago, Mark J said:

I get where you're coming from. I'm of the opinion that well executed reductions don't lead to panic flushing.

It’s not really about opinion is it? It’s more about species.

 

Plus ‘panic’ is a perjorative (human emotion) adjective to describe regrowth, does a lime/plane tree panic after its cyclical trim? Is that so bad?

 

 

[Mark J]

3 minutes ago, Mick Dempsey said:

 

It’s not really about opinion is it? It’s more about species.

 

Plus ‘panic’ is a perjorative (human emotion) adjective to describe regrowth, does a lime/plane tree panic after its cyclical trim? Is that so bad?

 

 

This is the homeowners forum. I was trying to use terms that may make sense to people without a background in plant science.

Perhaps I should have said "I'm of the opinion that well executed reductions don't necessarily lead to panic flushing."  Of course the reaction to pruning is species and tree dependent.

[Boo Who?]

 
It’s not really about opinion is it? It’s more about species.
 
Plus ‘panic’ is a perjorative (human emotion) adjective to describe regrowth, does a lime/plane tree panic after its cyclical trim? Is that so bad?
 
 

So it would have to be a hefty reduction to reduce water uptake and desication rate- beyond that of recommendations.
It then does come down to a different question of opinion - can you live with that not very authentic looking oak tree at the bottom of the garden because it has ecological/habitat value but on going cost implications, or do you just be rid of it?

[Mark J]

11 minutes ago, Boo Who? said:

So it would have to be a hefty reduction to reduce water uptake and desication rate- beyond that of recommendations.
It then does come down to a different question of opinion - can you live with that not very authentic looking oak tree at the bottom of the garden because it has ecological/habitat value but on going cost implications, or do you just be rid of it?

This particular tree isn't apparently causing any trouble while it's the size that it currently is. Hence my suggestion to make it a bit smaller, let it get back to nearly its current size and repeat.

[Mick Dempsey]

2 minutes ago, Boo Who? said:

So it would have to be a hefty reduction to reduce water uptake and desication rate- beyond that of recommendations.
It then does come down to a different question of opinion - can you live with that not very authentic looking oak tree at the bottom of the garden because it has ecological/habitat value but on going cost implications, or do you just be rid of it?

Fair questions, and, before I have another glass, I’ll punt an answer.

 

Too much emphasis is placed on trying to retain trees that were there before houses were built, in a kind of revenge, pro nature gesture.

 

This is actually a decent tree, be a shame to lose it for no reason, I know that sounds like I’m contradicting myself.

 

So in summary, I have no answers except it’s Arsenal v Man.U now, and I’m going to have that glass...

 

 

 

 

[Mark J]

Salut!

[Khriss]

To reiterate that structural engineers report will include foundation depths and condition and soil types, you can find radically different  soil around London, sand lenses and gravel drifts which would determine how much heave or slump or what ever ever. The Arb report will give you an idea of tree health and likely management - if any. Plus if you have bought a badly built house-that tree is the least of yr worries. ( Persimon homes are facing outrage on many of their recent developments ) K

[Mark2]

Assuming the photo was taken from the house, the view from your window will be similar ! Personaly I’d rather look out my window at a hundred year old oak tree, than look out at a ‘stump’ and a bleak treeless view of hard de-natured distopia! Was the tree there when you moved in!

get it pruned occasionally ! Max and min hight, it will never cause a problem in your lifetime. Enjoy long summer evenings sipping wine in good company soft music and much laughter! Dont huddle around in what would look like a prison yard with out that tree.

and remember most people giving advice have there own personal agenda ! Good luck 

[tree-fancier123]

each big old tree near a house should come with a pipe sticking out the ground with a cap on, and instructions to water x number of litres per day in a hot dry summer