While hanging drywall takes a little muscle, getting the drywall ready for paint or wallpaper requires finesse. The goal here is simple: Make the joints between drywall panels disappear so that walls and ceilings are perfectly smooth.
Is It Hard to Finish Drywall?
The process isn’t complicated. It takes just a few tools—a small and a large drywall knife and a swivel-head pole sander—to finish drywall. Here, Paul Landry, of P.L. Drywall in Waltham, Massachusetts, shows us how to mud and tape drywall, using premixed joint compound (a.k.a. “drywall mud”) and drywall tape.
How to Finish Drywall Step-By-Step
1. Drywall Finishing Steps Overview
The tricky part is learning how to properly bed the tape and feather out the compound to an imperceptible edge. “First time out, you’ll probably get more ‘mud’ on the floor and on your clothes than you do on the wall,” says Landry, who finished the walls at This Old House‘s recent TV project in Manchester, Massachusetts.
Sanding is the other key skill. Joint compound is soft, so the challenge is to avoid removing so much that you risk fraying or tearing the paper tape. “Be patient,” Landry advises. “Even beginners can do a fine job if they take their time.”
2. Stir compound and prep surfaces
- Cut band on top of the bucket with a utility knife or tin snips and pry off lid.
- If there’s water on top of the compound, chuck a mixing paddle into a ½-inch drill. Mix at slow speed until water is blended and compound is smooth. If there’s no water, the compound is ready to use.
- Look for any screwheads poking above the drywall surface and drive them until slightly recessed.
- Tear away any loose or torn paper from drywall (especially at corners and cut edges) to prevent bits from ending up in the compound.
3. Cover joints and screwheads
- Using 5-inch knife, fill mud box halfway with compound.
- Load the edge of the knife blade with about 2 inches of compound.
- Starting in one corner of the room, force the compound into the joints between sheets. When they’re completely filled, hold the knife at a 25-degree angle to the surface and smooth out the compound in a single pass.
- Scrape excess compound off knife and into mud box.
- Fill screw holes with a swipe of a compound-loaded knife.
- When all the joints and screwheads on a wall or ceiling are filled, go to Step 4.
4. Apply paper tape
- Unroll 3 feet of tape from dispenser, but don’t tear it off.
- Center tape over seam and, using fingers, gently press into the fresh compound.
- Unroll and bed tape into rest of joint.
- At the end of the joint, place the knife edge perpendicular to the tape face and tear.
5. Smooth tape
- Starting halfway along the joint, hold the 5-inch knife against the tape at a 25-degree angle to the wall.
- Pull knife to one end of the joint in a single stroke, smoothing the tape and pressing it firmly into the compound.
- Scrape excess compound from the blade into mud box.
- Return to the starting point and repeat in the other direction. (This technique prevents tape from pulling off wall.)
- Repeat Steps 3, 4, and 5 on remaining walls or ceiling.
6. Tape Inside Corners
- Using a 5-inch knife, fill the seam and cover 2 inches on either side of the corner with compound.
- Cut a piece of tape the full length of the corner; crease it in half lengthwise. With knife, gently push into corner.
- Starting in the middle, draw the knife along the drywall, smoothing the tape on one side of the crease. Skew blade 45 degrees to squeeze out excess mud.
- Run knife in the same way on the opposite side of the crease. Finish by smoothing back to the starting point.
7. Cover outside corners
- Make sure the metal corner bead on outside corners is nailed or clinched every 10 inches. Straighten bends, if necessary, with corner clincher (see tools and materials above)
- Using the 5-inch knife, smear one side of bead with compound. Repeat on the other side.
- Holding the blade against drywall and bead at the same time, run the knife down the corner, smoothing the compound in a single stroke. Repeat on the other side.
- Let compound dry overnight.
8. Sand the first coat
- Check that compound is uniformly white, which indicates that it is dry. (Wet areas appear darker.)
- Sand inside corners with corner sanding block.
- Sand all other surfaces using a pole sander with medium-grit abrasive. Apply gentle, even pressure. Sand only enough to smooth rough areas; don’t sand down into paper tape.
- Feel for rough areas and sand as needed.
9. Apply second and third coats
- With the 10-inch knife, scoop up 2 inches of compound. Then scrape off 2 inches worth at each end of the blade.
- Apply compound to all joints and screwheads, then smooth it in a separate pass. Allow to dry overnight.
- The next day, sand with fine-grit drywall sandpaper.
- For third coat, load entire edge of 10-inch knife with compound and apply to joints and screwheads as before. Smooth to an imperceptible, feathered edge.
- Let dry overnight, then sand as before. Wipe all surfaces with a damp cloth to ready them for priming.