How to Paint a Joint Compound

Joint compound used on seams in between pieces of drywall can be a challenge to paint. If the seams are not properly finished and prepared, it will result in noticeable rises or lumps in the wall surface. With a little patience and some preparation, painting over drywall joint compound is not too difficult at all. This simple step-by-step guide will show you everything you need to know in order to paint over joint compound in drywall seams. Let's get started.

Step 1 - Sand the Seams

Take a fine grit sandpaper and start sanding the seam area between the sheets of drywall. Sand the joint compound that has been used to cover the seams until the seams are flat and smooth. Use your hands to run over the seams after sanding to ensure there are no lumps or rises in the sanded surface. Try to sand the seams as smooth as possible.

Step 2 - Wipe Away Dust

Use an old towel or rag to wipe away the dust created by sanding the seams.

Step 3 - Fill Small Holes and Cracks

Use a drywall putty knife to apply small amounts of joint compound into any cracks or holes in the surface of the seams. When applying the compound, use as little as possible to reduce the amount of sanding that will need to be performed.

Step 4 - Allow Joint Compound to Dry

Allow the joint compound to completely dry before continuing. Depending on how much joint compound you had to apply to fill cracks and holes, you may be able to continue in a couple of hours or so. However, if you had to apply a large amount of compound to fill the holes or crevices, you may need to wait 24 hours or more.

Step 5 - Sand and Wipe Again

After the joint compound has dried, take a fine-grit sandpaper and sand the areas where you filled the holes or cracks. Again, try to sand the seams as smooth as possible.

Step 6 - Prepare to Paint

Spread out plastic sheeting or old newspapers along the base of the wall where you will do the painting. If you have properly prepared the seams, you really don't have to do anything special to paint them. Rather, you simply want to paint them at the same time you do the other surface areas of all the wall.

Step 7 - Apply Primer

Use a paint roller to apply a heavy coat of paint primer to the entire surface of the drywall you'll be painting. This will help the paint better adhere and bond to the drywall surface. It will also help to hide any imperfections in the seams where the joint compound was applied.

Step 8 - Roll On Paint

Use a paint roller and paint to roll on the paint as you normally would.