How to Repair Sagging Drywall

Climb in the attic, taking a flashlight and tape measure with you. Carefully make your way across the attic to the area where the drywall has come loose from the joists. The easiest way to locate this area is to ask a helper to lightly tap on the ceiling where the sag is located. Pull the insulation out from between the joists. This will enable you to install braces between the joists.

Measure the distance between the two joists where the sagging drywall is located. The average distance will be 16 to 24 inches.

Cut the 8 foot long 2-by-4 board with the circular saw into 16 or 24-inch lengths. Take the sections of wood into the attic. Place the brace boards horizontally, 4-inch side down, between the vertical joists. Make sure the braces are located over the sagging area of drywall spaced approximately 6 inches apart. Tap the braces down with a hammer until the bottoms of the braces are even with the bottoms of the joists. Drive 3-inch nails through the side of the joists and into the ends of the brace boards.

Measure and cut the 8 foot long 1-by-3 inch board in half. Use a stud finder to locate the joists on both sides of the center portion of the sagging drywall. Mark the joist locations on the ceiling with a pencil. This step is performed inside the house, not in the attic.

Drive a 2-inch screw partway through both ends of the 3-inch side of one section of 1-by-3 inch board. The screws should be at least 1 inch from the ends of the board to keep the board from splitting.

Hold one end of the board up to one of the pencil marks on the ceiling. Ask a helper to hold the other end of the board. Drive the screw through the brace board, and into the ceiling joist. Move to the opposite end and hand the helper the drill. Ask the helper to slowly drive the screw on that end of the board into the ceiling joist. The second screw will draw the sagging drywall up so that you can insert screws through it into the braces in the attic.

Use the variable speed drill to drive 1-inch drywall screws through the drywall into the brace boards you installed in the attic. Space the screws 3 to 4 inches apart. Make sure that the screw heads are level with the surface of the drywall. Remove the brace board and cover the screw heads with drywall compound.