Dunbar. I had a job not long ago in a state school, the drainage went under a large concrete area, had lots of trouble with roots, we finished recommending to cut down the only tree in the area, the govt were aghast “Shock, Horror” the maintenance manager finally agreed to plug up the line & we introduced “tordon” into the drg. About a month later the only tree in the area started to wilt uneplained & died. We have’nt replaced the drainage. however we hav’nt been back to to a choke.
Bob