Is heave a risk?

[Erikarose]

Hi, sorry if this is posted in the wrong place! I was wondering if someone could offer me a little advice. My neighbour has agreed to do something about the 2 ash trees that are within 3ft - 5ft of my extension/house (house is 1930s, extension is around maybe 15-20years old - can’t remember). The ash trees were planted in round 2014-2015 so after the extension and are taller than a 1930s semi. I think around 8m now.  I know they run a risk of subsidence/issues to a property hence why I want something doing with them and also they hang over our extension roof/gutters etc. They are also directly over the shared sewer line for the street.. A friend mentioned heave could be a problem after I removed a smallish pear tree this year maybe 2-3m high from my garden. Is this something that I need to worry about wit the ash trees? I have had a couple quotes from tree surgeons for the ash trees and have said removal is best. I asked about heave and one asked me what heave was.. (wasn’t overly impressed with that answer) and one said while they are still small/young best to remove before they cause problems. Can anyone offer any advice? I’m in West Yorkshire if that helps. I think looking on the geology website my soil type is clay/sandstone (I could be wrong). House is low risk for natural subsidence. Any advice is welcome and thank you in advance. 

[Mark J]

3 hours ago, Erikarose said:

Hi, sorry if this is posted in the wrong place! I was wondering if someone could offer me a little advice. My neighbour has agreed to do something about the 2 ash trees that are within 3ft - 5ft of my extension/house (house is 1930s, extension is around maybe 15-20years old - can’t remember). The ash trees were planted in round 2014-2015 so after the extension and are taller than a 1930s semi. I think around 8m now.  I know they run a risk of subsidence/issues to a property hence why I want something doing with them and also they hang over our extension roof/gutters etc. They are also directly over the shared sewer line for the street.. A friend mentioned heave could be a problem after I removed a smallish pear tree this year maybe 2-3m high from my garden. Is this something that I need to worry about wit the ash trees? I have had a couple quotes from tree surgeons for the ash trees and have said removal is best. I asked about heave and one asked me what heave was.. (wasn’t overly impressed with that answer) and one said while they are still small/young best to remove before they cause problems. Can anyone offer any advice? I’m in West Yorkshire if that helps. I think looking on the geology website my soil type is clay/sandstone (I could be wrong). House is low risk for natural subsidence. Any advice is welcome and thank you in advance. 

Heave is only a potential issue if the trees predate the property. 

[daltontrees]

Heave is only a potential  issiue if there are shrinkable clays. Concentrate on that, before moving on to the other issues, like trees and fundations.

[Erikarose]

Okay, not sure if we are on shrinkable clay or not tbh. I no it’s low natural subsidence risk. The house was built where mining took place. 

[Dan Maynard]

Equally, we do know the trees are only 7 or 8 years old so (as said above) that rules out heave anyway. No chance they can have been drying the ground before the extension was built because they weren't there.

[Erikarose]

Before the extension there was a garage built on the ground in the same spot for a good 30 years before that. Good to know it should be okay then. Thank you.