Many thanks to all of you for your replies. Appreciate that very
much. The tree is a fairly healthy size maple tree and the trunk is
approximately 15' from the slab. A trencher just might be the easiest
approach. Any thoughts on using an axe versus some sort of root saw
if a person doesn't want to bring great harm to the tree. It's fairly
mature and I hate to damage it too significantly but at the same time,
have property to protect.

Chris