I recently added an entryway that has 20 inch footings. The drywallers left a 1/2 inch gap between the footings and the drywall. I assumed the would drywall all the way down to the top of the footings but they didn't. Is there a reason you can't or shouldn't do this? If so what can I fill the gap with because I can't use wood trim in these spots. Is there a special material needed?