I take care of many trees (cherries etc) with girdling roots that are choking and killing one side of the tree. Has anyone ever "bridge grafted from a girdling root to the trunk above the root? Help
Bob east end of Long Island NY

I haven't done any bridge grafting.
How do you know the girdling root isn't from a different tree? I have a western red cedar which has a cottonwood root crossing at the root crown of the cedar. I'd probably cut away the offending root and let the girdled tree recover on its own.

I agree with dubyadee. Probably rootstock. If it's killing the tree you could just cut the root.
John S
PDX OR