You can indeed use both andirons and a grate together. Authentic andirons had large shanks that stood several inches from the hearth floor, allowing wood to be piled on the shanks and combustion air to be drawn from below to fuel the fire. Because fireplace grates do a superior job of supporting partially burned logs, the andirons faded from use. They are predominantly made for appearance, rather than function now. A grate should be used as the primary mechanism for a wood fire.
Collin C. - NFI Master Hearth Professional
on November 18, 2013