For most species, the tree should have a single trunk. If removal of main branches is necessary, cut them back to the trunk to avoid leaving stubs. We don't always appreciate how far roots can extend. Understanding how and where roots grow will help you avoid damage from trenching and construction. The framework of major roots usually lies less than 8 to 12 inches below the surface.
Roots often grow outward to a diameter one to two times the height of the trees.