No doubt there’s a knack to finishing drywall (wallboard) and for a large project, it’s one job that you might let a pro handle. However, hiring someone to do a standard 3-coat taping job for a small project at a reasonable cost can be difficult. Although each coat doesn’t take long to do, especially for a pro, it does mean three trips, setup, and cleanup time. Typically the worst thing that happens when a novice attempts to tape is that they must do a little more sanding to achieve good results.
After the drywall is installed, the joints between panels or between a drywall patch and the surrounding area must be concealed with taping or an all-purpose joint compound. However, if you spread this compound over a crack without reinforcing it, the dry compound will crack. The reinforcement is either a reinforcing paper tape or self-adhering fiberglass mesh tape.
Metal or plastic corner bead is nailed over any outside corners in the installation process. Although not shown here, apply three coats of the compound to each wall surface using the corner bead as one side of a screed and the wall surface on the other side of your blade as the other half of the screed.
Before You Begin: (We’re assuming that the new drywall is already in place.) Before taping, first, inspect the drywall carefully. Grab a 6-inch taping knife and either a drill driver or a hammer, depending on whether the drywall is fastened with screws or nails. Draw the knife across any fastener that is not clearly set below the surface. If you hear a metallic sound, drive in the fastener a little more but stop short of puncturing the paper. Check all joints to make sure nothing protrudes above the surface. If so, tap it with a hammer or trim it with a utility knife.
1. Prefill Joints
Load a mud pan half full with compound. Then use a flexible 5- or 6-inch joint finishing knife to apply about a 1/8-inch-thick strip of compound along the joint. On factory edges, there is a V-groove and a recessed area on each side of the joint. Scrape off any excess compound that extends beyond a 3-inch wide strip.
Tip: For large jobs, a hawk is better than a mud pan. A hawk is a thin flat metal or plastic platform with a handle on the underside. For small patch jobs, you can get away with using a tin bread pan.
2. Embed Reinforcing Tape
Embed a strip of paper reinforcing tape, centered on the joint. Draw a flexible joint knife at a nearly flat angle along the tape, lightly at first so you don’t drag the tape out of place, then firmly with the knife held at a 45-degree angle. Squeeze out the excess above, below, and to the sides of the tape. Then apply a thin coat on top to prevent wrinkling. Allow this to dry overnight or until the compound is uniformly white. Caution: Don’t press so hard that you squeeze out all of the compound or the paper won’t bond properly.
Tip: To cut the other end of the tape to length, press your knife firmly against the tape. Then tear off the tape using the knife blade as a cutting edge.
3. Apply Second Coat
Scrape off any lumps or bumps with a taping knife. Then apply compound to extend about 2 inches beyond the edges of the first coat. Lay it on one knife full at a time. Then work your way along the joint with the knife at a 45-degree angle to level the compound. Scrape your knife clean on the wiping blade of the mud pan as needed. Make your last pass one continuous motion from end to end. Allow this coat to dry thoroughly as before.
Tip: It takes practice to judge how hard to press- too firmly, and you scoop off compound nearly to the tape; too lightly and you leave ridges at the edge. The second is preferable to the first but will require sanding.
4. Apply Third Coat
Third verse, same as the first! After scraping off excess compound, you may need to lightly sand using a large, flat sanding block, but be careful to not sand the paper or it will get fuzzy. As before, lay on more compound with a 6-inch knife, scrape off the excess, and level it 2 inches beyond the edges of the previous coat, but using a 10-inch-wide flexible finishing knife. Allow the area to dry completely.
5. Prefill Inside Corner
The process of taping an inside corner is similar. Lay a 3-inch wide band of compound on both wall surfaces (or wall/ceiling surfaces) with a 4- to a 6-inch taping knife. Typically, you won’t have any recessed area at the edges of the panels unless they were installed vertically. Smooth the compound until it is roughly 1/8 inch thick.
6. Crease Tape
Cut a length of paper reinforcing tape and crease it between your fingers to make a 90-degree angle. The paper tape will naturally bend one way more easily than the other, so experiment first to see which way works best. Run your index finger down the center while pulling up on the edges with your thumb and middle finger, then crease as shown.
7. Apply Tape
Starting at the ceiling, lightly press the tape into the corner. Tear off the excess paper tape at or near the floor, using the blade of your taping knife as a cutting edge. As before, pass your knife over the tape on both surfaces lightly at first, and then firmly.
8. Embed Tape in Corner
Immediately apply a coat of compound over one side of the tape only. After that dries, scrape off any bumps and repeat the process for the second side. This two-step second coat takes an extra day to allow for drying time, but it is much easier than trying to do both sides at once because every time you level one side you tend to mess up the other.
9. Apply Additional Corner Coats
Apply the second coat using the same two-step approach. When the second coat is dry, scraped, and sanded (if needed), you can usually apply a third (very thin) coat in one step. The little bits of the excess compound that you may spill over onto the second surface can be sanded off later. If you get too frustrated, just go back to the two-step approach. The third coat usually dries quickly enough to allow two steps on the same day.
10. Spot Fastener Heads
After each taping coat, take time to cover the fasteners. Apply compound in one direction and scrape it off in another. On the second and third coats, the pros will cover typically three aligning fasteners in one pass. The finished result looks less spotty than if each fastener were done separately.
Unless you’ve managed to lay down a nice level second coat, you’ll probably need to sand after it and you must also sand after the final coat. Use a 3-inch by 9-inch sanding pad or a pole sander (a pad on the end of a long handle with a flexible joint so the pad stays flat on the surface). Sand lightly with 120-grit paper, being careful not to roughen the surface of the drywall’s paper covering.
Tip: Drywall dust gets everywhere. The best method to make sure it doesn’t get all over the house is to place a 24-inch exhaust fan in a window in the room where you are working. Open the door to the room and a nearby window outside the room.
Tip: Maintaining a positive airflow while you’re sanding and sweeping up keeps the dust contained and reduces your exposure as well. Do wear a disposable dust mask and a hat, and protect your eyes with goggles, especially when working overhead.