Drywall an Existing Wall
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Drywall an Existing Wall
Dave's Don'ts
Drywalling is dusty work. To preserve domestic bliss, it's smart to protect your house and furnishings before you start. Tape plastic to within 1" of the wall.
It's handy to know how to use drywall when a wall has flubbed at its job of being flat, smooth, and paintable. It's also handy when you need to quickly and cheaply put a flat surface on a new stud wall. Drywalling is not something you'll do for entertainment, but it's an easy knack to learn, and a handy one to know.
Drywall is sold in sheets, 4' by 8', 9', or 10' and up. The 8' sheets are awkward enough; buy the larger sheets only if you are sure you can handle them. Drywall comes in three thicknesses:
- 3⁄8": Cheap, light, and fragile; it's suitable for covering a wall that's already in decent shape.
- 1⁄2": The standard drywall, used in most cases.
- 5⁄8": Premium stuff; quieter, heavier, and harder to handle.
Step 1: Getting Started
Building Smarts
Drywall nails are tricky to use and almost obsolete. Screws hold the drywall tighter to the studs but cause less damage to nearby walls. Buy screws that bite 3⁄4" into the studs—deeper is not better. Hide screws if you can: Place the bottom row under the baseboard. Screws around doors and windows can be hidden by the casing, the molding around an opening. The only trick with screws is to set them below the surface, but not deep enough to damage the panel. This is almost foolproof with a screw gun; it takes some practice with a variable-speed drill. Make sure to press the panel against the stud while screwing. Ideal screw locations are as follows:
- 12" apart on every ceiling joist
- 16" apart on every stud
- About 1⁄2" from panel edges
First, assess your situation. If you're drywalling a new wall, add nailers (hunks of wood to hold your nails or screws) at inside corners to support both sides of corner joints.
Find the studs. (Drill through the existing wall if you have to.) Mark the center of the studs on the floor.
If you are fastening over 1⁄2" or thicker plywood, rescrew the plywood to the studs using 2" construction or drywall screws.
Stripping Old Molding
To remove molding, pull off the top pieces, then the lower ones. Don't try to remove several pieces at once! If the molding doesn't budge, drive a few nails through the back with a nail punch, and then pry some more.
After the molding is off, remove any old wall material that's higher than the wall surface.
Electrical Considerations
Cut openings for electrical boxes in the new drywall, using either of these techniques:
Measure the position and cut the drywall using a jigsaw or a hand drywall saw. (It's helpful to make the hole a hair larger than the box.)
Hold the sheet against the wall and trace the box outline with a RotoZip tool.
The front of electrical boxes should be no more than 1⁄ 4" below the new wall surface. If any are deeper, slip in a box extender, making sure it does not touch wires.
Tip: Hand drywall saws are one of the cheaper beauties on the tool rack. They leave less mess than a jigsaw or a RotoZip.
