How to Finish the Outside Walls of a Garage for a Workshop
- 1). Measure the length and width of the garage. For areas where a full drywall panel will not fit, measure the space from the edge of the ceiling to the middle of the farthest ceiling joist that the board will cover.
- 2). Cut the number of drywall boards needed to cover the ceiling. Measure and mark the cut line, then hold a level or T-square against the cut line. Run a utility knife along the straight edge to score the drywall. Stand the drywall up and snap it along the score line.
- 3). Measure the location on any boards which will be placed over a light or any other electrical fixtures. Cut a hole to fit the fixture in the drywall with a jigsaw.
- 4). Lift the first panel of drywall into a corner of the ceiling (with the help of an assistant) and drive five evenly-spaced screws into the joists across the width of the drywall. Keep the screws at least 1/2 inch away from the edges of the boards and drive the heads slightly below the surface. Continue installing drywall until the ceiling is completed.
- 5). Measure the height and width of the walls and cut drywall to fit the walls as you did for the ceiling boards in Step 2 (but use the wall studs instead of the ceiling joists). Measure and cut boards to fit around doors and windows as needed.
- 6). Measure the location on any boards which will be placed over a light switch or any other electrical fixtures. Cut a hole to fit the fixture in the drywall with a jigsaw.
- 7). Place the first drywall panel against the studs in one corner, pushing it up against the ceiling (again with the help of an assistant). Drive five evenly-spaced screws into the studs down the length of the drywall. Keep the screws at least 1/2 inch away from the edges of the boards and drive the heads slightly below the surface. Continue installing drywall until the walls have been covered.
- 8). Inspect the walls and ceiling and tighten any screwheads that are sticking out of the drywall.
- 9). Fill the gaps between the drywall boards by pressing joint compound into the gaps with a 5-inch putty knife. After the gaps have been completely filled, hold the blade of the knife at a 25-degree angle and scrape away any excess joint compound.
- 10
Run paper tape over the first joint and press it into the joint compound. Hold the putty knife at a 25-degree angle and run it over the tape in both directions to press it into the compound, removing any excess joint compound with the putty knife. Repeat this step until all joints have been taped. - 11
Tape the corners where the walls and ceiling meet, repeating the process from Step 10. Allow the compound to dry overnight. - 12
Sand the joint surfaces with a sanding block until the surfaces are smooth and uniform. - 13
Cover all joints and screwheads with compound, this time using a 10-inch putty knife, smoothing out the compound with the putty knife after you apply the compound. Allow it to dry overnight. - 14
Sand the surface smooth. Add a third layer of compound to the joints and screwheads with the 10-inch putty knife as you did in Step 13. Allow it to dry overnight. - 15
Sand the surfaces smooth, then wipe them down with a damp sponge to remove any dust or grit. - 16
Paint the wall with a coat of primer and allow it to dry. - 17
Paint the walls with two coats of the paint color of your choice.