Installing drywall requires measuring a board to fit the installation location, scoring it with a utility knife, snapping along the score line and using drywall screws to attach it to the ceiling. Lengthwise joints have a factory-beveled edge, meaning there is a slight indentation in which you can embed paper drywall tape in joint compound to seal the joint. But the joints you make across the sheetrock's width -- in other words, the joints you create while installing boards in a row -- don’t have a beveled edge because you cut them to size. These joints, called butt joints, often form raised humps after you embed tape over them.
Hang the largest section of drywall you can, cutting it to size so that its end rests halfway over a ceiling joist. To attach the board, install drywall screws every 7 to 8 inches along every ceiling joist through the drywall to the joist, including the joist that is only half-covered. Leaving half the joist exposed provides a place to attach the edge of the next board in the series.
Butt the next board against the installed board as close as possible to form a tight seam, and use screws to attach it to the ceiling joists, including the joist you left exposed. Continue installing sheetrock until the row is complete, allowing each board in the series to end halfway over a ceiling joist.
Install the largest board you can to start the new row, but place it so that it ends on a different joist than any butt joints you made in the first row. This is called staggering the joints, meaning you install the boards on the ceiling so that the butt joints in adjacent rows don’t connect with one another to form a single, long butt joint.
Continue installing the boards in rows until the ceiling is complete.