It’s best to drywall the ceiling before you do the walls. This way, the top edges of the wall panels can butt up against the ceiling panels, supporting them along the edges. The long edges of ceiling panels run perpendicular to the joists or joist chords. In bedrooms and other small rooms, you’ll probably be able to cover the full length of the ceiling with 12-ft. panels. If the ceiling is more that 12 ft. long, stagger the end joints where the panels butt together, just as you do on floor and roof sheathing panels. Try not to have a drywall joint land on an electrical or heat outlet, because this makes it harder to tape and hide the seam.
Measuring and cutting drywall panels
If you watch professional drywall installers measure and cut panels, you’ll be impressed with the speed and accuracy of their work. Although you may not achieve speed right away, accuracy is possible from the start if you use some of the tips explained here. With accurate cuts, you’ll have a much easier time mudding and taping the panels.
MAKE STRAIGHT CUTS. Instead of cutting a panel to the exact dimensions you measure on a wall or ceiling, cut it ‘/4 in. short. This leaves a ‘/s-in. gap on both sides of the panel, allowing you to fit the piece without binding on neighboring walls or panels. Make a straight cut by scoring along the cut line; snap the cut open so the panel folds back on itself and slice through the resulting crease on the back. Mark and cut on the “good” side of the panel.
If you have a drywall T-square and need to make a square cut, guide the knife against the edge of the square (see the top left photo on p. 21s). Take care not to let the knife slip and cut the hand that’s holding the T-square. Just cut through the paper and slightly into
