How to Install the Second Layer of Sheetrock on a Cracked Ceiling

Prepare the Ceiling

• 1

  Tighten the old ceiling to the joists by locating the ceiling joists with a stud finder and popping chalk lines over the centers of every joist. Insert drywall screws along the chalk lines, every 2 feet.

• 2

  Scrape away loose and crumbling bits of old drywall and joint compound from the cracks and seams with a putty knife.

• 3

  Countersink screws or nails that might have worked loose and now protrude from the ceiling.

Install the New Layer

• 4

  Position a new Sheetrock panel at one corner of the ceiling, perpendicular to the joists. Use a drywall hoist to lift and hold the panel. Drywall panels are 4 feet wide and come in various lengths. The edge of the panel should be located in the exact center of a ceiling joist. Use the chalk lines as guides.

• 5

  Secure the new panel to the ceiling joists by inserting drywall screws that are a minimum of 1 inch longer than the thickness of the ceiling. For example, if the old drywall and the new drywall panels are both 1/2 inch thick, that gives your ceiling a total thickness of 1 inch. In that case, you would use drywall screws that are at least 2 inches long.

• 6

  Insert the screws, with a drywall screwgun, every 8 inches along the seams and 1/2 inch from the edge of the drywall panel.

• 7

  Install the next Sheetrock panel, butting it tightly to the first. Because ceiling joists sit on 16-inch or 24-inch centers, the drywall panels should fit from joist to joist. When you reach the end of the ceiling, measure and cut a new panel to fit the space.

• 8

  Continue adding panels until the new layer is in place.

Tape and Finish the Ceiling

• 9

  Apply self-adhesive mesh drywall tape over the seams, but do not overlap the tape where the joints meet.

• 10

  Spread joint compound over the taped seams, using enough pressure to push the compound through the holes in the mesh tape. A 5-inch or 6-inch taping knife works well for this step.

• 11

  Smooth out the wet joint compound with a wider taping knife over the seams. A 10-inch to 12-inch knife is sufficient. Let the compound dry completely.

• 12

  Sand the dried seams in the ceiling with a drywall sander on an extension pole.

• 13

  Add at least two more joint compound applications the same way you applied the first.