Taken from [[https://www.portland.gov/ppd/trees-development/construction-and-tree-preservation/prescriptive-path|Portland tree code]]

Roots over 4 inches in diameter should not be cut.

root encroachment zone is one foot for every inch of diameter. 

See [[https://www.portland.gov/ppd/documents/tree-code-information-guide-calculating-encroachment-prescriptive-tree-protection/download|this]] handy pamphlet.


What is diameter of tree?