Leylandii conifers

[swampydrill]

I have these conifers around my front garden and they are about 10 ft tall, i notice some of the roots coming up on the lawn. I want to either re-tirf my front garden or block pathe it, can i dig the roots out of the lawn and put a steel plate along the length of the garden to act as a root barrier without actually killing the conifers. I should have put a root barrier in years ago, i know.

 

[BrynRovers]

Best thing you can do is to get rid of them altogether.
I just got rid of 10 of them at 40ft high at a cost of £1500.