Roots of Holm Oak

Hi,

I am trying to decide whether to use Holm Oak as a clear stem hedge in my garden.  I have a newly built stone wall with lime pointing that I wish to  add a hedge above the level of the wall to give added privacy.  I am concerned about the root system of the Holm Oak and any potential issues with the wall.

Can anyone give adivise on this or any other suitable evergreen clear stem hedgin otions, it is quite an exposed windy site with clay soil.

Thanks