Recommended foundation method for Clay soil nr trees

[patp]

19 hours ago, George said:

 

Strange, they're usually not mandated until foundations are 1.5m deep.

 

Heave can cause issues as the ground reuptakes moisture.Ideally you'd have a good idea f the full soil strata and site history. But as that would mean a huge expense, only a very blunt 'worst case' tool is available. 

 

Because I'm an SE my BCO just left me to it on the structural things. He pointed towards a nearby tree but due to the local geography I assured him it wouldn't cause issues. 

That's 1.2 from memory :). We could not find heave boards anywhere. All local builders merchants had never heard of them! Once I started searching merchants a bit closer to London I found them. Just goes to show that they don't get used much around here (Norfolk).

[George]

Ah well... Norfolk tends to lag behind a few decades...

 

 

[Mr Punter]

NHBC have the foundation depth tables where you have trees. https://nhbc-standards.co.uk/4-foundations/4-2-building-near-trees/4-2-13-foundation-depth-tables/

 

They used to have a calculator as well but not sure if they still do.  Bear in mind it makes no difference the current size of the tree (unless being removed).  The calculation is based on the full mature tree, so if you have a small willow or oak nearby I suggest you remove it before BC are invited to site.

[patp]

On 14/06/2021 at 11:25, George said:

Ah well... Norfolk tends to lag behind a few decades...

 

 

Or because we are sub tropical with lots of sand