- Q. What is the maximum joist spacing for ceiling drywall? Does it matter if the panels are oriented parallel or perpendicular to the joists?
A.The maximum joist spacing for
1/2- or 5/8-inch drywall is 24 inches on-center. Ceiling drywall should always be installed perpendicular to the joists, even when they are 16 inches on-center. Drywall is much stronger along the length of the panel because the paper facing provides the strength, and the paper grain runs lengthwise.