[Fine Edge]

Bidding on a new patio where existing Birch roots have grown under existing brick pavers.
Once I remove all pavers, is there anything ( granular or liquid ) that would stunt the root growth or prohibit the root growth in the proposed new patio area.
This Birch looks close to full grown ( 45' tall ) so I'm wondering if these existing 5" - 6" roots are even going to grow that much more.

Thanks for any info.