Foundations verses trees.

[Willa]

Help / advice please.
How close can one dig foundations next to mature trees?
Foundation will be 600 wide x 1100 deep. Tree is an oak with a TPO.

Thanks in advance.

 

[Richard C]

If it's closer than 5m, don’t underestimate what may be required & you may want to get the JCB ready; all you can do is consult your local BC. I don’t know much about different tree root characteristics etc. & there are undoubtedly others on here more knowledgeable but I personally know of a couple of cases where 3m has been forced! The source of my information now "loses" any nearby trees before it become an issue but that's obviously difficult if you have a TPO!

 

[noseall]

soil type has a huge bearing on determining suitable foundations.

particularly clay substrate.

 

[Shytalkz]

There are two issues: protecting the tree roots from the building and protecting the building from moisture extraction by the roots.

The former comes into play in whatever soils there are on site; many local authorities publish info sheets on avoiding damaging tree roots when building close by. This can often require shallow reinforced foundations spanning between bases, so as to avoid the need to cut out/damage radial roots.

The latter is only a consideration in clay soils.