- 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.