Gypsum board (also called sheetrock or drywall) is a modern alternative to plaster when building walls and ceilings, and is much easier to install. The boards come in 8-by-4-foot sheets of varied thickness. You secure the boards with drywall screws along the joists, then ``tape'' the edges of the boards together with joint compound (a kind of plaster) and sand it smooth.
Instructions
1. Measure the ceiling starting the one end along a wall perpendicular to the joists. Find the joist that's closest to being 8 feet from the wall, without being further than that. Measure from the middle of the joist to the wall.
2. Use your razor knife to score and snap a piece of gypsum board at that length, running the blade alongside your t-square to keep it straight.
3. Set up two ladders, one by the starting wall, the other under the joists to which you measured. With an assistant, hold the gypsum board up to the ceiling, with the cut end facing the wall and the uncut end lining up with the middle of the joist.
4. Shoot drywall screws ever six inches or so along the edge of the board where it is under the joist. Do the same for the rest of the joists above the board. (You will be able to judge the positions of the joists behind the board based on where they come out from the side of it.) Make sure to completely sink the screw heads below the surface
5. Hang the rest of the boards in the same manner, positioning them end to end, in courses, always meeting at the joists. Stagger the positions of the board between courses, so there are no four-way intersections.
6. Press mesh drywalling tape over all the seams between the boards. Use your drywall knife to spread joint compound over the tape, making a smooth line about 4 inches wide. Also spread a little compound over the sunken screw holes. Let it dry for about 4 hours.
7. Sand the seams and screw holes by hand to smooth out the dried joint compound. Apply another layer of joint compound over the first along the seams, making the seams a little wider. Let it dry, sand it, and apply a third, very thin final coat. Sand it lightly and paint.
Tags: joint compound, compound over, drywall screws, gypsum board, joint compound over, middle joist, screw holes