Removing invasive bamboo

Well... the roots have got to go (obviously!) .... That's not easy as you know. However I have done a good job previously by cutting the bamboo down one stem at a time to about 3" (I can't visualise cms!) above the ground and painting a really strong herbicide such as 'Round-up' onto the cut stump. The 'Round-up' travels down the sap and kill s the root. I hope this helps. By the way you need 2 people - a cutter and a poison painter!!