How to Apply a Smooth Coat to Drywall

Applying smooth coat, or skim coating, is the final step in your preparation before priming and painting your walls and ceiling. It requires a careful eye, but with a little practice you can give surfaces that professional look.

Difficulty: Challenging

Instructions

Things You'll Need:

• Drywall Compound
• Drywall Trowel And Knives
• Sanding Blocks

Finish Coat on Walls

1. Sand all joints smooth.

2. Check joints for uneven spots (depressions, humps, ridges and waves). Hold the edge of a mud knife across a joint and try to rock the knife back and forth. If you get a rocking motion, you'll need to feather the joint out farther.

3. Feather the joint out if necessary. ("Feathering" refers to the process of spreading the drywall compound out to a wider and wider, ever-thinning edge. It's a trick used to keep the eye from noticing the slightly higher center of the joint.)

4. Sand the joint if one side is too high, or feather more drywall compound (a.k.a. "mud") on any low spots.

5. Let dry and check again, repeating steps until smooth.

Finish Coat on Ceiling

6. Sand all joints smooth.

7. Apply a thin layer of mud over entire ceiling. Use a 12-inch-wide trowel and, with even pressure, smooth mud over ceiling.

8. Go back over area with trowel until smooth. You'll remove most of the mud, leaving only a very thin layer.

9. Allow this coat to dry.

10. Sand the entire ceiling to remove any rough spots.

11. Turn a light on and step back at an angle and look for any uneven areas on the ceiling.

12. Sand the area or apply more mud if you have uneven areas.

Tips & Warnings

• If your mud is too thick to spread evenly, you can thin it with water. Do not make mud so runny that it doesn't stay on your knife, and remember: thin mud is weak mud.
• Applying a smooth coat of mud to the ceiling is a very challenging job. It may require several coats.
• Wear safety glasses and dust mask when sanding joints. The dust can be harmful to eyes and lungs.

[funkmarsh]

on 6/17/2009 I know when you board a ceiling you go 90 degrees to the joices. Im doing patching for this renovation company and I was patching a ceiling, less than half of the ceiling and I didnt board parallel to joices because It worked out to be less board and less joints. This jerk was ripping a strip of me for it. Is he right to do that? After all this is patching (almost 4 sheets, less than half of the ceiling) Also whoever boarded the ceiling originally boarded this way aswell

[jophy]

on 1/7/2009 always! always! prime sheetrock and mud, mud repairs,...primer is cheap,....

[jcjrcrew]

on 10/11/2008 I was repairing a large area of my ceiling. I mudded and sanded 3 times and felt it looked smooth. When I applied 2 coats of paint I can see the entire patch. I didn't use primer. I persume that was a mistake but now do I sand over the painted repair or what? Would appreciate your help. Thanks

on 8/28/2006 I would never recommend dry sanding a Sheetrock repair. The dust just gets everywhere! Been there, done that.

I usually plan on mudding over a patch 3 times to get the right finish. When the mud is completely dry, I cut up an old T-shirt and with a bucket of water handy, I feather out the final finish.

on 8/8/2006 I do a lot of repair work, and homeowners like that I do not create dust. With a little practice; use a large car cleaning sponge to wet sand your work. Depending on the smoothness of the sponge and mudding, you can feather your work nicely. Move in a circular motion with a lite touch. Using a bright light at a sharp angle to the wall will show you the area in need of work. Use a bit of watered-down mud on large indentations. Then sponge those areas again when dry. It takes a bit longer to do it the wet sponge way, but with no dust everyone likes that.