Tree Roots - Foundation calculations

[Field_of_Dreams]

I have been reading the NHBC standards, in particular the bit about foundations and trees and it mentions about the calculations needed when there are trees nearby but also trees that are going to get removed.

 

I can't actually tell what they mean by "trees to be removed" and was hoping someone may be able to offer more insight.

I have several stumps that will be dug out and whilst that means some roots may still exist in the ground, the bulk of them will be pulled along with the stump.

Does this count as a "tree removed" or should it be dealt with as though it never existed?

 

I realise that leaving a stump or grinding one still means all the roots are still there and as such gets factored in but the guide does not clearly state, from what I can see, about trees/stumps that get removed completely.

 

The trees that got removed were within 2M of the foundation and were fully mature sycamores (medium thirst).

I am hoping to get an insulated raft.

 

The more I look at foundations, the more questions I have ?

[PeterW]

when were the trees cut down..?

 

what is the ground composition..? Sand..? Clay..?

[Field_of_Dreams]

@PeterW

Ground is medium clay. Still waiting on a GI report.

Trees got cut between 6-18 months ago...I did it at various stages.

[nod]

I’ve got our tree report somewhere 

We are surrounded by trees 

The SE did remark that trees removed can be more problematic than those remaining 

Something to do with the roots still sucking the water up 
He asked me to mark those to be removed and recommended using clay board to help combat the heave 

[PeterW]

SE has got that a bit wrong - the issue on clay is when trees are removed, the water content on the clay goes out of balance and the clay expands to reach equilibrium which can take 9-12 months. The roots stop taking water the point at which the canopy is removed.

[Field_of_Dreams]

just checked and they got removed 12 months ago.

 

 

[Mr Punter]

Just do not tell NHBC.  The soil will have done all the heave it needed to over the wet winter.

[Field_of_Dreams]

@Mr Punter Not getting any NHBC on this build.

I was looking at their docs just to see about standards and hoping to further my knowledge.