Ceiling sheetrock is attached to ceiling joists, which are supposed to run evenly to each other so the sheetrock will have a flat, even surface to which to attach. If you rip out an old ceiling to replace it, and you find that the bare joists have bowed and fallen out of alignment over the years, you won't be able to add the new sheetrock until you even out the joists. You can do this by installing new joists alongside the old ones, with the new ones slightly lower and one another.
Instructions
1. Hammer lines of nails at the tops of the two walls that are parallel to the ceiling joists, nailing them every few feet along the top of the wall, three inches down from the top. Make the nails in a level line, using your level.
2. Use your 3-inch screws and screw gun to affix the new joists to the sides of the old joists, with the bottoms of the new joists even with the strings. Shoot the screws all along the top and bottom edges of the joists, about every two feet.
3. Measure across the ceiling, in a direction perpendicular to the joists, from the starting wall out to the final joist within eight feet of the starting wall. Record the measurement from the middle of the edge of the new joist.
4. Mark out the measurement on a piece of drywall. Cut the drywall sheet to size by scoring a line alongside your level, then bending the piece at the line unit until it snaps cleanly.
5. Hold the drywall to the ceiling, so the cut side is facing the wall and the manufactured edge is running along the middle of the new joist. Shoot drywall screws every six inches along every joist that's above the drywall.
6. Install the remaining sheets of drywall over the whole ceiling in the same fashion, in courses, hanging them end to end and then side by side. Position the sheets of drywall so the ends don't line up between courses. Cut the end pieces as needed.
7. Cover the seams of the drywall sheets with mesh drywall tape. Apply joint compound onto the seam, in a flat, smooth coats. Let it set six hours.
8. Repeat the process to add two additional coats of joint compound, making each layer wider than the previous one and keeping them all flat. Let the final layer set for eight hours. Sand it smooth and paint.
Tags: ceiling joists, even with, every feet, joint compound, sheets drywall, starting wall