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DIY Drywall Repair

drywall, Wall Coverings, walls March 28, 2007 Sonia


Here’s something that happens in remodeling projects all the time: You (or the electrician) installs a light fixture or receptacle in the wrong location. It’s easy enough to get him to move it, but having an electrician repair drywall is like getting a demolition laborer to cut dovetail joints—it ain’t gonna happen. So that leaves you with a light switch in the right place and a hole in the wrong one.

The good news is that with a little Dura-Bond 20 or other fast-setting, site-mixed compound (see sidebar pg. 24), you can make a seamless repair that you can complete in about half a day. The other good news is that this technique is also great for patching other holes: Like when “Sheeter Dave” gouges the wall hauling plywood through the house.

But these techniques aren’t just for the jobsite. They’re also terrific for making repairs in drywall—or plaster for that matter—from other damage, like a wall gouged during a furniture moving fiasco (moving furniture is always a fiasco!), your teenager’s wrestling match, or from breaking the age-old Mom-rule: no playing ball in the house! Soundproofing Products for the Home

The tricks laid out below are called the Bullet Patch and Batten Patch respectively. They minimize the size of the patch and don’t require you to peel drywall back to existing studs for fastening purposes.

The bullet patch (so-called, because you can do it pretty darn fast, or at least that’s what I’m told) is smart and easy. It works great for holes around the size of a two-gang light switch, but can be used for bigger or smaller repairs too. The batten patch (that’s what I call it due to the “batten backers” inserted behind the existing drywall) is often best suited to larger repairs and ceiling repairs. It offers more stability while the compound sets up, but requires a little more trowel trickery with taping and sanding.


Bullet Patch

The bullet patch is such an ingenious and time saving idea that whoever thought of it should be given some sort of Lifetime Achievement Award. My guess is that this is the kind of site-borne invention that clever carpenters, drywallers and painters devised individually until the word spread and it became part of many tradesmen’s bag of tricks.

The key to is to cut a blank of drywall bigger than the hole, then on the back of the blank, expose a “plug” of drywall just a bit smaller than the hole. You do this with a series of clever cuts and breaks. What’s great about this is that while you remove the oversized portion of the drywall, you leave the paper—which acts as tape when you mud it. It’s as seamless as seamless gets.

Clean Cut: The first step in the bullet patch process is to clean out and square the hole. This is done in the case shown here, where the repair is being made because of an errantly placed switch box. But, if the hole is made by a fist, hammer, or some other blunt force, then use a drywall saw to remove the broken or damaged drywall (or plaster and lath) to make it rectangular in shape.

Next, if there are any obstructions or finishes near the patch location (like a light switch cover), remove what you can. If the finish can’t be removed (like wallpaper or molding) protect it as necessary with blue painter’s tape.

dwrep1 DIY Drywall Repair

Measure and Cut the Repair Piece: Once the hole is squared out, measure it. Now, go to your new drywall and cut a piece that is 2 inches bigger than the hole’s measurement all the way around. For example: Say that the hole turns out to be 4 inches by 4 inches; cut a new piece of drywall 8 inches by 8 inches.

Now, flip the blank over so the front is face down on your work bench and the back is face up (the brown side of the drywall is the back). Use a tape measure to locate the center of the blank. Mark it. Note: It’s easiest to mark the drywall by cutting slits with your utility knife rather than marking with a pencil.

From the center point, map out the plug. Make the plug about 1/4 inch smaller than the hole’s dimensions all the way around. For example, if the hole is 4 inches by 4 inches, make the plug 3-3/4 inches by 3-3/4 inches. The easiest way to mark both edges of the plug is to hold the center point of the measurement—1-7/8 inches in this case—aligned with the center point lines on the drywall. Mark both edges of the tape and in two locations. Use a straight edge (a scrap of 1-by works fine) and connect the dots by cutting with your utility knife.

Cut and Break: With your lines mapped out on the back of the drywall in a grid pattern, cut them with a utility knife. Grasp the drywall firmly in both hands and break it along one line. Then—and this is the cool part of this process—carefully peel the gypsum (the white chalky material) away from the paper. Discard the gypsum and leave the paper flange. Do this all the way around the piece until you have exposed the center plug.

dwrep2 DIY Drywall Repair

Note: it is much easier to use a piece of drywall that is not from the factory edge of a piece of wallboard because of the way the paper folds over at that location—or because ends are usually banged-up, cracked, or have labels you have to deal with. Use a piece cut from somewhere inside the factory edge of the wallboard for better results.


Applying Mud

With all finished surfaces masked as necessary, apply a thin coat of mud (skim coat) to the wall before installing the bullet patch. Don’t wipe it down tight. You need enough mud on there so you can embed the back of the paper flanges into it.

dwrep3 DIY Drywall Repair

Next, put the patch on the wall and lightly press the paper into the wet compound with your fingertips (don’t press on the plug) this usually holds it in place. Now, put a little compound on the edge of your knife. I use a 6-inch knife for this job. The mud “lubricates” the knife edge and enables it to ride across the paper. Take the knife and press hard enough on the patch to squeeze the mud out from behind the paper. Be careful not to press too hard or you risk “oil-canning” or rippling the paper. A couple of passes ensures a tight bond.

Now, with the paper adhered from the back, wipe a feather-coat on the front of the paper. You only need a light coat. Smooth down all rough spots—but don’t expect perfection. A thin light coat that bonds the paper to the wallboard is the key here. A cool trick is to flare your knife. (See “Flare Up” sidebar).