I have a 20ft x 22ft room with a cathedral ceiling that starts at 8ft at the wall and goes up 11ft on each side and had an 19in. flat spot in the center of the ceiling. I am ready to hang drywall but I don't know wether to run my drywall vertically (so I won't have any butt-joints) or run the horizontally (perpendicular to the studs) I've heard vertically from the construction contractors around my hometown, but I've read horizontally on most websites. Which one is preferred or is it really my choice.