Home Improvement : It’s a Breeze to Patch Drywall the Modern Way

There are lots of different ways to patch a large hole in a gypsum-board wall or ceiling. All of them work, but some are overly complicated, relying on all sorts of arcane tricks.

Here’s my favorite, based on the two major innovations in drywall installation over the last 40 years: drywall screws and fiberglass mesh drywall tape. Although the sketch shows the technique being used to repair a ceiling, it works just as well on walls.

To start, reshape the hole in the drywall to a neat, rectangular shape. The easy way to do this is to draw the rectangular shape right on the drywall with a pencil. Drill quarter-inch starting holes at each of the four corners, then saw along the lines with a keyhole saw. Drywall saws very easily.

Remove the rectangular cutout and set it aside. You’ll use it in a minute as a pattern for your patch. For now, you need to make a plywood backer to support that patch. Cut this from a scrap of half-inch or thicker plywood. Make it about two inches longer than your rectangular hole and about two or three inches narrower.

Next, fit your variable-speed drill with a Phillips screwdriver bit. Slip a Phillips drywall screw onto the bit. If it’s a sloppy fit, you might put a drop of white glue on the driver bit so the screw won’t fall off. Set your loaded drill where you can reach it.

Now, slip the plywood backer into the hole. Since it’s narrower than the hole, you’ll be able to hold it in position with one hand while you grab your drill and drive the screw through the existing drywall into the plywood backer. Drive a few more screws into the backer board to secure it well.

Now turn to the old piece of drywall you cut away earlier. Place this, good side up, on a sheet of drywall, also good side up. Draw around the old scrap, transferring its shape onto the new drywall, outlining the perimeter of your patch. Cut the patch out--just inside the lines you have drawn--and you are ready to install it.

Place the patch in the hole in the existing drywall, press it against the plywood backer and secure it with several screws driven through the patch into the backer.

That’s it. The patch is installed. Now all you have to do is finish it off.

To do this, apply a strip of fiberglass mesh drywall tape over each seam around the patch. This tape is self-adhesive. Just cut each piece about four inches longer than the patch and press it in place, centered over the seam.

Next, take a four-inch putty knife and a container of premixed drywall compound. Trowel a thin layer of compound over the taped seams, feathering it out smoothly, and let dry.

When this first coat of compound has set up, trowel on a second, feathering it out smoothly about four inches past the edges of the repair. Let this coat dry and repeat, feathering the compound even wider. Ideally you’ll want to use a wide, 10-inch knife for this purpose.

If you’re really good with your knife, you may be able to smooth the compound out so neatly that it won’t need sanding.

Most of us, however, will want to go over the repair with 120 paper wrapped around a sanding block. You can check the smoothness of the repair by shining a light at a low-skimming angle over the work. Any unevenness will show up.

Trowel on more compound, let dry and sand again as necessary, then paint and the fix is complete.

HOW TO PATCH DRYWALL

Drywall, screws, mesh tape have modernized the art of patching.