How to Float Drywall

Each coat of joint compound levels the surface around a seam.

Once drywall has been hung and corner beads installed, it must be taped and mudded or floated to create a uniform finish. Each seam and screw hole must be filled with joint compound and sanded smooth. An initial coat, then tape and three additional coats of compound must be applied to achieve a smooth, level surface. Drywall professionals spend years learning the proper technique, but unless you are looking for a completely pristine finish, you can try it yourself and save a bundle of cash.

Things You'll Need

• Joint compound
• Electric drill
• Mixing paddle
• Measuring tape
• Drywall tape
• Hand trowel
• 6-inch drywall knife
• 8-inch drywall knife
• Hand sander or electric sander
• Level
• 10-inch drywall knife
• Bucket of water

Instructions

1. Fill a bucket with water. Fit an electric drill with a mixing paddle and mix the drywall thoroughly until it reaches a uniform texture.

2. Scoop some compound onto the hand trowel with the 6-inch knife. Hold the trowel with your non-dominant hand and use your dominant hand to apply a layer of compound to a seam. The layer should be slightly wider than the tape and not too thick.

3. Measure a strip of tape to match the first seam. Press the tape into the wall, beginning at the corner of the wall and ceiling or two walls, depending on which direction drywall was hung. Hold the length of tape steady with one hand and drag the drywall knife down the entire length. Exert enough pressure to press the tape into the wall, but not enough to press all the compound out of the sides of the tape. Continue along each seam, corner and screw hole. Cut a smaller piece of tape for each screw hole.

4. Apply a 1/4-inch layer of compound over the entire length of the seam. Press the rear edge of the hand trowel against the seam and pull it along the length to clean any excess compound from the area. Leave a layer of compound over the top of the tape and allow it to dry overnight.

5. Apply a second, thicker coat of compound to each seam, corner and screw hole with the 8-inch knife. Allow it to dry, then sand compound carefully. Smooth it out as much as possible, and check to make sure the wall is level across the seam.

6. Repeat the process with the 10-inch knife. This time, dip your knife in a bucket of water during the last pass to create the smoothest possible finish. You should only have to sand the compound lightly this time.

References

• "Drywall: Professional Techniques for Walls & Ceilings"; Myron R. Ferguson; 1996